ABSTRACT
Diarrhea
is the condition of having at least three loose or liquid bowel movements each
day. It can result in dehydration due to fluid loss. Morinda lucida belongs to the family Rubiaceae. M.
lucida extracts have been reported to have antioxidant and reducing activities
and anti-microbial activity. This medicinal plant has
also been reported to be effective in treatment or management of diarrhea. This
study shows the effect of aqueous leaf extract of morinda lucida (dry and fresh
extracts) on the liver status of lactose induced osmotic diarrhea of
albino wistar rats using the liver function test such as; serum albumin
analysis, serum total protein and serum bilirubin. In this study the effectiveness of morinda lucida is tested for in albino
rats induced with osmotic diarrhea using 25% lactose enriched diet. The animals were treated thereafter
with both dry and fresh extracts of Morinda
lucida and also a standard drug, loperamide. Findings reveal
that there was a significant change in albumin level, the total protein and
bilirubin comparing the control (normal) with the lactose induced rats, level.
Although on administration of the extracts, there level of albumin, total
protein and bilirubin were not restored to the valves in the control. The study
shows that the aqueous extract of the leaf of morinda lucida is not as
effective as claimed in the management of the liver status of lactose induced osmotic
diarrhea in albino wistar rats, although the dry extract showed some degree of
effectiveness than the fresh extract.
TABLE
OF CONTENTS
CHAPTER ONE
1.0 INTRODUCTION AND LITERATURE REVIEW
1.1 INTRODUCTION
1.1.1 SECRETORY DIARRHEA
1.1.2 OSMOTIC DIARRHEA
1.1.3 EXUDATIVE DIARRHEA
1.1.4 INFLAMMATORY DIARRHEA
1.1.5 DYSENTERY
1.1.6 INFECTIOUS DIARRHEA
1.1.7 MALABSORPTION
1.1.8 OTHER CAUSES,
1.2 PREVENTION
1.3 MANAGEMENT
1.3 LITERATURE REVIEW
1.3.1 DESCRIPTION OF MORINDA LUCIDA
1.3.2 TAXONOMY
OF MORINDA LUCIDA
1.3.3 OTHER
NAMES FOR MORINDA LUCIDA
1.3.4 HABITAT
OF MORINDA LUCIDA
1.3.5 TOXICITY
OF M.LUCIDA
1.4 LACTOSE
INTOLERANCE
1.4.1 SYMPTOMS
1.4.2 DIAGNOSIS
1.4.3 HYDROGEN BREATH TEST
1.4.4 BLOOD TEST
1.4.5 INTESTINAL BIOPSY
1.4.6 MANAGEMENT
1.5 THE LIVER
1.5.1 ANATOMY
1.5.2 CELL TYPES
1.5.3 BLOOD FLOW
1.5.4 PHYSIOLOGY
1.5.5 SYNTHESIS:
1.5.6 BREAKDOWN
1.5.6 OTHER FUNCTIONS
1.5.2 DISEASES OF THE LIVER
1.5.3 LIVER FUNCTION TESTS
1.5.3.1 ALBUMIN
1.5.3.2 TOTAL
BILIRUBIN
1.5.3.3 SERUM TOTAL
PROTEIN
1.6 AIM AND OBJECTIVE OF RESEARCH
1.7 AIM
1.8 OBJECTIVE
CHAPTER
TWO
2.0 MATERIALS
AND METHODS
2.1 APPARATUS
2.2 REAGENT
2.3 EXPERIMENTS
2.4 PREPARATION OF PLANT EXTRACTS USING
STANDARD METHOD (WILLIAMS ET AL., 1996)
2.5 COLLECTION
OF ANIMALS
2.6 EXPERIMENTAL
DESIGN
2.7 MODE
OF SACRIFICE
2.8 TREATMENT OF LACTOSE INDUCED RATS
2.9 ASSAY
METHODS
2.9.1 Determination of liver
bilirubin by Evelyn Malloy method(Magos,1960).
Principle:
2.9.2 Estimation of liver Albumin
by Bromocresol Purple Method (Lasky et al., 1985)
2.9.3 ESTIMATION OF LIVER TOTAL
PROTEIN BY BIURET METHOD (OKUTUCU ET AL., 2007).
CHAPTER
THREE
3.0 RESULTS
3.1 OBSERVATIONS
3.2 FINAL RESULTS OF ALBUMIN, BILIRUBIN AND
TOTAL PROTEIN AS MEAN + S.E.M
CHAPTER
FOUR
4.0 DISCUSSION
AND CONCLUSION
REFERENCES
APPENDIX I: ABSORBANCE FOR ALBUMIN FOR VARIOUS GROPUS
APPENDIX
II: CONCENTRATION OF ALBUMIN FOR EACH
RAT (g/l)
APPENDIX
III: CONCENTRATION OF ALBUMIN FOR
VARIOUS GROUPS AS IN MEAN AND S.E.M (g/l)
APPENDIX
IV: ABSORBANCE FOR BILIRUBIN OF VARIOUS
GROUPS (g/l)
APPENDIX
V: CONCENTRATION OF BILIRUBIN FOR EACH
RAT (mg/dl)
APPENDIX
VI: CONCENTRATION OF BILIRUBIN FOR
VARIOUS AS IN MEAN AND S.E.M (IN mg/dl)
APPENDIX
VII: STANDARD CURVE FOR TOTAL PROTEIN
APPENDIX
VIII: ABSORBANCE FOR TOTAL PROTEIN OF
VARIOUS GROUPS
APPENDIX
IX: CONCENTRATION OF TOTAL PROTEIN FOR
EACH RAT (mg/ml)
APPENDIX
X: CONCENTRATION OF TOTAL PROTEIN OF
VARIOUS GROUP AS IN MEAN AND S.E.M (mg/ml)
APPENDIX
XI: WEIGHT OF RATS BEFORE SACRIFICE (IN
GRAM)
APPENDIX
XII: ANOVA FOR ALBUMIN
APPENDIX
XIII: ANOVA FOR BILIRUBIN
APPENDIX
XIV: ANOVA FOR TOTAL PROTEIN
CHAPTER
ONE
1.0 INTRODUCTION AND LITERATURE REVIEW
1.1 INTRODUCTION
Diarrhea or diarrhoea (from the Ancient Greek from dia
"through" and rheo "flow") is the condition of having at least
three loose or liquid bowel movements each day. It often lasts for a few days
and can result in dehydration due to fluid loss. Signs of dehydration often
begin with loss of the normal stretchiness of the skin and changes in
personality. This can progress to decreased urination, loss of skin color, a
fast heart rate, and a decrease in responsiveness as it becomes more severe. Loose
but non watery stools in babies who are breast fed, however, may be normal
(WHO, 2014).The most common cause is an infection of the intestines due to a
virus, bacteria, parasite, or a condition known as gastroenteritis. These
infections are often acquired from food or water that has been contaminated by
stool, or directly from another person who is infected. It may be divided into
three types: short duration watery diarrhea, short duration bloody diarrhea,
and if it lasts for more than two weeks persistent diarrhea. The short duration
watery diarrhea may be due to an infection by cholera. If blood is present it
is also known as dysentery (WHO, 2014). A number of non-infectious causes may
also result in diarrhea including: hyperthyroidism, lactose intolerance, inflammatory
bowel disease, a number of medications, and irritable bowel syndrome among
other (Doyle et al., 2013). In most cases stool cultures are not required to
confirm the exact cause (Dupont, 2014).Prevention of infectious diarrhea is by
improved sanitation, clean drinking water, and hand washing. Breastfeeding for
at least six months is also recommended as is vaccination against rotavirus. Oral
rehydration solution (ORS), which is clean water with modest amounts of salts
and sugar, along with zinc tablets are the treatments of choice (WHO, 2014).
This treatment has been estimated to have saved 50 million children in the past
25 years (WHO, 2014). When people have diarrhea it is recommended that they
continue to eat healthy food and babies continue to be breastfeed. If commercial
ORS are not available, homemade solutions may be used (Sarah et al., 2012). In
those with severe dehydration, intravenous fluids maybe required. Most cases;
however, can be managed well with fluids by mouth. Antibiotics, while rarely used, may be recommended
in a few cases such as those who have bloody diarrhea and a high fever, those
with severe diarrhea following travelling, and those who grow specific bacteria
or parasites in their stool (Dupont, 2014). Loperamide may help decrease the
number of bowel movement but is not recommended in those with severe disease. About
1.7 to 5 billion cases of diarrhea occur per year (Doyle, 2013). It is most
common in developing countries, where young children get diarrhea on average
three times a year (WHO, 2014). Worldwide, as of 2012, it is the second most
common cause of deaths in children younger than five (0.76 million or 11%)
(CDC, 2014). Frequent episodes of diarrhea are also a common cause of
malnutrition and the most common cause in those younger than five years of age
(WHO, 2014). Other long term problems that can result include poor physical and
intellectual development (CDC, 2014).Diarrhea is defined by the World Health
Organization as having three or more loose or liquid stools per day, or as
having more stools than is normal for that person. (WHO)Acute diarrhea is
defined as an abnormally frequent discharge of semi solid or fluid fecal matter
from the bowel, lasting less than 14days, by World Gastroenterology
Organization (WGO, 2011).
1.1.1 SECRETORY
DIARRHEA
Secretory diarrhea means that there is an increase in the active secretion,
or there is an inhibition of absorption. There is little to no structural
damage. The most common cause of this type of diarrhea is a cholera toxin that
stimulates the secretion of anions, especially chloride ions. Therefore, to
maintain a charge balance in the lumen, sodium is carried with it, along with
water. In this type of diarrhea intestinal fluid secretion is isotonic with
plasma even during fasting. It continues even when there is no oral food
intake.
1.1.2 OSMOTIC DIARRHEA
Osmotic diarrhea occurs when too much water is drawn into the bowels.
If a person drinks solutions with excessive sugar or excessive salt, these can
draw water from the body into the bowel and cause osmotic diarrhea (WHO, 2005).
Osmotic diarrhea can also be the result of mal digestion (e.g., pancreatic
disease or Coeliac disease), in which the nutrients are left in the lumen to
pull in water. Orit can be caused by osmotic laxatives (which work to alleviate
constipation by drawing water into the bowels). In healthy individuals, too
much magnesium or vitamin C or undigested lactose can produce osmotic diarrhea
and distention of the bowel. A person who has lactose intolerance can have
difficulty absorbing lactose after an extraordinarily high intake of dairy products.
In persons who have fructose mal absorption, excess fructose intake can also
cause diarrhea. High-fructose foods that also have high glucose content are
more absorbable and less likely to cause diarrhea. Sugar alcohols such as
sorbitol (often found in sugar-free foods) are difficult for the body to absorb
and, in large amounts, may lead to osmotic diarrhea. In most of these cases,
osmotic diarrhea stops when offending agent (e.g. milk, sorbitol) is stopped.
1.1.3 EXUDATIVE DIARRHEA
Exudative diarrhea occurs with the presence of blood and pus in the
stool. This occurs with inflammatory bowel diseases, such as Crohn's disease or
ulcerative colitis, and other severe infections such as E. coli or other forms
of food poisoning.
1.1.4 INFLAMMATORY DIARRHEA
Inflammatory diarrhea occurs when there is damage to the mucosal
lining or brush border, which leads to a passive loss of protein-rich fluids
and a decreased ability to absorb these lost fluids. Features of all three of
the other types of diarrhea can be found in this type of diarrhea. It can be
caused by bacterial infections, viral infections, parasitic infections, or
autoimmune problems such as inflammatory bowel diseases. It can also be caused
by tuberculosis, colon cancer, and enteritis.
1.1.5 DYSENTERY
If there is blood visible in the stools, it is also known as dysentery.
The blood is trace of an invasion of bowel tissue. Dysentery is a symptom of,
among others, Shigella, Entamoebahistolytica, and Salmonella.
1.1.6 INFECTIOUS DIARRHEA
There are many causes of infectious diarrhea, which include viruses,
bacteria and parasites (Navaneethan et al., 2008). Norovirus is the most common
cause of viral diarrhea in adults, (Patel et al., 2009). But rotavirus is the
most common cause in children under five years old (Greenberg et al., 2009).
Adenovirus types 40 and 41, (Uhoo et al., 1990) and astroviruses cause a
significant number of infections.
1.1.7 MALABSORPTION
Mal-absorption is the inability to absorb food fully, mostly from disorders
in the small bowel, but also due to mal-digestion from diseases of the
pancreas.
1.1.8 OTHER CAUSES,
Diarrhea can be caused by chronic ethanol ingestion (Kasper et
al., 2005). Ischemic bowel disease usually affects older people and can be due
to blocked arteries. Microscopic colitis is a type of inflammatory bowel
disease where changes are only seen on histological examination of colonic biopsies.
Bile salt mal-absorption (primary bile acid diarrhea) is where excessive bile
acids in the colon produce a secretory diarrhea. Hormone-secreting tumors: some
hormones (e.g. serotonin) can cause diarrhea if excreted in excess (usually
from a tumor). Chronic mild diarrhea in infants and toddlers may occur with no
obvious cause and with no other ill effects; this condition is called toddler's
diarrhea.
1.2 PREVENTION
A rotavirus vaccine decreases the rates of diarrhea in a population
(WHO). New vaccines against rotavirus, Shigella, ETEC, and cholera are under
development, as well as other causes of infectious diarrhea. Probiotics
decrease the risk of diarrhea in those taking antibiotics (Hempel et al.,
2012). In institutions and in communities, interventions that promote hand
washing lead to significant reductions in the incidence of diarrhea (Ejemot et
al., 2008).
1.3 MANAGEMENT
In many cases of diarrhea, replacing lost fluid and salts is the only
treatment needed. This is usually by mouth – oral rehydration therapy – or, in
severe cases, intravenously (WHO). Diet restrictions such as the BRAT diet are
no longer recommended (King et al., 2003). Research does not support the
limiting of milk to children as doing so has no effect on duration of diarrhea.
To the contrary, WHO recommends that children with diarrhea continue to eat as
sufficient nutrients are usually still absorbed to support continued growth and
weight gain and that continuing to eat speeds also recovery of normal
intestinal functioning. CDC recommends that children and adults with cholera
also continue to eat (CDC, 2010).Medications such as loperamide (Imodium) and
bismuth subsalicylate may be beneficial; however they may be contraindicated in
certain situations (Schiller, 2007).
1.3 LITERATURE REVIEW
In the world, mostly in the rural areas of the
developing countries, people depend on local medicinal plant as remedy for
their diseases and illness probably either because of the absence of modernized
functional health facilities or because of ancestral and traditional beliefs.
Plants produce a diverse range of bioactive molecules, making them rich sources
of different types of medicines (Nair et al., 2005).
In
different parts of Nigeria, different varieties of plants are used in the
treatment of different types of diseases. Roots, barks or leaves of Newbolbea
leavis are used in the treatment of dysentery, syphilis, ear ache, ringworm
and scrotal elephantiasis (Azoro, 2002.) Morinda lucida known as Oruwo
in the South-Western part of Nigeria is a medium sized tree with a crooked hole
and rather short twisted branches. It belongs to the family Rubiaceae.
It has a rough bark, grey in colour, flaking off in irregular patches. Its
leaves are about 7 to 15 cm long by 3.5 to 7.5 cm broad, and flowers are white
with a narrow glabrous corolla-tube about 2.5 cm. Stem bark, roots and leaves
infusion is used as an anti-malarial, anti-diabetic, jaundice and dysentery
treatment (Burkill, 1997), and it is used in anti-malarial activity (Tona et
al., 1999; Agomo et al., 1992; Asuzu and Chineme, 1990; Koumaglo et al., 1992),
anti-Salmonella typhi activity (Akinyemi et al., 2005), effect on
contractility of isolated uterine smooth muscle of pregnant and non-pregnant
mice (Elias et al., 2007), toxicity and mutagenic studies (Sowemimo et al.,
2007; Akinboro and Bakare, 2007; Raji et al., 2005), and it has anti-diabetic
property (Olajide et al., 1999). M. lucida extracts have been reported
to have antioxidant and reducing activities (Ogunlana et al., 2008), and
anti-microbial activity (Ogundare and Onifade, 2009; Adomi, 2006, 2008).
Several
drugs including some antibiotics are no longer active against targeted
organisms. It has been reported that the effective life span of these
therapeutics agents are limited (Cowan, 1999). Therefore, we experience
antibiotic resistant organisms, and ineffective malarial drugs. More so,
majority of the orthodox drugs are both expensive and display dangerous side
effects in the users. Hence, discovering and identifying new safe drugs without
severe side effects has become an important goal of research in biomedical
science. It is in this context that the aqueous and ethanolic extracts of stem
bark, leaves and roots of M. lucida were screened for possible
anti-typhoid effect in vitro in comparison with known standard
antimicrobial or anti-typhoid agents.
1.3.1 DESCRIPTION OF MORINDA LUCIDA
Morinda lucida occurs from Senegal to
Sudan and Southwards to Angola and Zambia, sometimes planted around villages in
Nigeria. It grows in grassland, exposed hillsides, thickets, forest, often on
termite mounds, sometimes in areas, which are regularly flooded, from sea level
up to 1300m altitude. Evergreen small to medium-sized tree, up to 9-18m or 25m
tall in coastal areas of Ivory Coast, with bole and branches often crooked or
gnarled or straight, sometime short, 20-30cm in diameter. Bark is smooth to
roughly scaly, grey to brown colour often with distinct purple layers. Leaves
are opposite, simple and entire. Inflorescence is a staked cup-shaped gland.
Flowers are bisexual and the fruits are drupe several arranged together into an
almost globuse succulent syncarp. Morinda
lucida comprises about 80 species and occurs throughout the tropics. In
Africa, 5 species are found. The comparatively small flowering and fruiting
heads on long slender peduncles are distinct characteristics of Morinda lucida. Many species
including those from Africa are important medicinal plants, widely applied
against various kinds of fevers and infections.
1.3.2 TAXONOMY OF MORINDA LUCIDA
Kingdom
|
Plantae
|
Phylum
|
Tracheophyta
|
Subphylum
|
Euphyllophytina
|
Class
|
Spermatopsida
|
Subclass
|
Asteridae
|
Super-order
|
Gentiananes
|
Order
|
Gentianales
|
Family
|
Rubiaceae
|
Subfamily
|
Rubioideae
|
Tribe
|
Morindeae
|
Genus
|
Morinda
|
Species
|
Lucida
|
(sambamurty,
2005).
1.3.3 OTHER NAMES FOR MORINDA LUCIDA
Sangogo(cote d’
ivoire)
Kno kroma(Ghana)
Atak ake(togo)
Egbogo(esan,
Nigeria)
Oruwo (Yoruba,
Nigeria)
Eze ogu or njisi
(Igbo, Nigeria) (adeneye and agbaje, 2008).
1.3.4 HABITAT OF MORINDA LUCIDA
Morinda
lucida is a mesophytic plant that can be found in tropical regions, coastal
zone or coastal savannah and also in northern savannah.
1.3.5 TOXICITY OF M.LUCIDA
Toxicity
test is done on animals to assess the potential adverse effect of chemical
compounds or plant extracts on administration to humans. In research done by
ashafa and olumu, 2001, it was shown that the ethanolic extract of morinda
lucida was not toxic to the liver, kidney or heart and the hematological
parameters were not affected by administration to study animal.
1.4 LACTOSE INTOLERANCE
Lactose
intolerance is the inability of adults individual to digest lactose, a sugar
found in milk and dairy product. Lactose intolerance individual has a low level
of lactase, an enzyme that break down lactose into glucose and galactose in
their digestive system.
Lactase deficiency has a number of causes and is classified as one
of three types:Primary lactase deficiency is genetic, only affects adults, and
is caused by the absence of a lactase persistence allele (Heyman, 2006 and
Enattah et al., 2002). It is the most common cause of lactose intolerance, as a
majority of the world's population lacks these alleles (Swallow,
2003).Secondary, acquired, or transient lactase deficiency is caused by an
injury to the small intestine, usually during infancy, from acute
gastroenteritis, diarrhea, chemotherapy, intestinal parasites, or other
environmental causes (Lawson et al., 2002 and Swagerty et al., 2002).Congenital
lactase deficiency is a very rare, autosomal recessive genetic disorder that
prevents lactase expression from birth (Heyman, 2006). It is particularly common
in Finland (Behrendt et al., 2009). People with congenital lactase deficiency
cannot digest lactose from birth, so cannot digest breast milk. Lactose
intolerance is not an allergy, because it is not an immune response, but rather
a problem with digestion caused by lactase deficiency. Milk allergy is a
separate condition, with distinct symptoms that occur when the presence of milk
proteins trigger an immune reaction.
1.4.1 SYMPTOMS
The principal symptom of lactose intolerance is an adverse reaction
to products containing lactose (primarily milk), including abdominal bloating
and cramps, flatulence, diarrhea, nausea, borborygmi and vomiting (particularly
in adolescents). These appear one-half to two hours after consumption (NDDIC,
2011). The severity of symptoms typically increases with the amount of lactose
consumed; most lactose-intolerant people can tolerate a certain level of lactose
in their diets without ill effects (Savaiano et al., 1987 and Madry et al.,
2011).
1.4.2 DIAGNOSIS
To assess lactose intolerance, intestinal function is challenged
by ingesting more dairy products than can be readily digested. Clinical
symptoms typically appear within30 minutes, but may take up to two hours,
depending on other foods and activities (Bowen, 2006). Substantial variability
in response (symptoms of nausea, cramping, bloating, diarrhea, and flatulence)
is to be expected, as the extent and severity of lactose intolerance varies
among individuals. Lactose intolerance is distinct from milk allergy, an immune
response to cow's milk proteins. They may be distinguished in diagnosis by
giving lactose-free milk, producing no symptoms in the case of lactose
intolerance, but the same reaction as to normal milk in the presence of a milk
allergy. A person can have both conditions. If positive confirmation is
necessary, four tests are available (Olivier et al., 2012).
1.4.3 HYDROGEN BREATH TEST
In a hydrogen breath test, the most accurate lactose intolerance
test, after an overnight fast, 25 g of lactose (in a solution with water) are
swallowed. If the lactose cannot be digested, enteric bacteria metabolize it
and produce hydrogen, which, along with methane, if produced, can be detected
on the patient's breath by a clinical gas chromatograph or compact solid-state
detector. The test takes about 2.5 hours to complete. If the hydrogen levels in
the patient's breath are high, they may have lactose intolerance. This test is
not usually done on babies and very young children, because it can cause severe
diarrhea.
1.4.4 BLOOD TEST
In conjunction, measuring blood glucose level every 10 to
15minutes after ingestion will show a "flat curve" in individuals with
lactose mal absorption, while the lactase persistent will have a significant
"top", with a typical elevation of 50% to100%, within one to two
hours. However, due to the need for frequent blood sampling, this approach has
been largely replaced by breath testing. After an overnight fast, blood is
drawn and then 50 g of lactose (in aqueous solution) are swallowed. Blood is
then drawn again at the 30-minute, 1-hour, 2-hour, and 3-hourmarks. If the
lactose cannot be digested, blood glucose levels will rise by less than 20
mg/dl. Stool acidity test can be used to diagnose lactose intolerance in infants,
for whom other forms of testing are risky or impractical (NDDIC, 2006). The
infant is given lactose to drink. If the individual is tolerant, the lactose is
digested and absorbed in the small intestine; otherwise, it is not digested and
absorbed, and it reaches the colon. The bacteria in the colon, mixed with the
lactose, cause acidity in stools. Stools passed after the ingestion of the
lactose are tested for level of acidity. If the stools are acidic, the infant
is intolerant to lactose (Jay et al., 2011). Stool pH in lactose intolerance is
less than 5.5.
1.4.5 INTESTINAL BIOPSY
An intestinal biopsy can confirm lactase deficiency following discovery
of elevated hydrogen in the hydrogen breath test (Hargrove et al., 1993).
Modern techniques have enabled a bedside test, identifying presence of lactase
enzyme on upper gastrointestinal endoscopy instruments (Kuokkanen et al.,
2006). However, for research applications such as mRNA measurements, a specialist
laboratory is required.
1.4.6 MANAGEMENT
Lactose intolerance is not considered a condition that requires
treatment in societies where the diet contains relatively little dairy produce.
However, those living among societies that are largely lactose-tolerant may
find lactose intolerance troublesome. Although no way to reinstate lactase
production had been found as of 2013, some individuals have reported their
intolerance varies over time, depending on health status and pregnancy (Roy et
al., 2006). About 44% of lactose-intolerant women regain the ability to digest
lactose during pregnancy. This might be caused by slow intestinal transit and
intestinal flora changes during pregnancy. Lactose intolerance can also be managed
by ingesting live yogurt cultures containing lactobacilli that are able to
digest the lactose in other dairy products. This may explain why many South
Asians, though genetically lactose intolerant, are able to consume large quantities
of milk without many symptoms of lactose intolerance. Consuming live yogurt
cultures is very common in the South Asian population. Lactose intolerance is
not usually an absolute condition: The reduction in lactase production, and the
amount of lactose that can therefore be tolerated, varies from person to person.
Since lactose intolerance poses no further threat to a person's health, the
condition is managed by minimizing the occurrence and severity of symptoms.
Berdanier and Hargrove recognized four general principles in dealing with lactose
intolerance—avoidance of dietary lactose, substitution to maintain nutrient
intake, regulation of calcium intake and use of enzyme substitute (Hargrove et
al., 1993).
Avoiding lactose-containing products
Since each individual's tolerance to lactose varies, according to
the U.S. National Institutes of Health (NIH),"Dietary control of lactose
intolerance depends on people learning through trial and error how much lactose
they can handle." (NDDIC) Label reading is essential, as commercial terminology
varies according to language and region (Hargrove et al., 1993).Lactose is
present in two large food categories—conventional dairy products, and as a food
additive (casein, caseinate, whey), which may contain traces of lactose.
1.5 THE LIVER
The liver is a vital organ of the digestive system present
invertebrates and some other animals. It has a wide range of functions, including
detoxification, protein synthesis, and production of biochemical substances necessary
for digestion. The liver is necessary for survival; there is currently no way
to compensate for the absence of liver function in the long term, although new liver
dialysis techniques can be used in the short term. This gland plays a major
role in metabolism and has a number of functions in the body, including
glycogen storage, decomposition of red blood cells, plasma protein synthesis,
hormone production, and detoxification. It lies below the diaphragm in the
abdominal-pelvic region of the abdomen. It produces bile, an alkaline compound
which aids in digestion via the emulsification of lipids. The liver's highly
specialized tissues regulate a wide variety of high-volume biochemical
reactions, including the synthesis and breakdown of small and complex
molecules, many of which are necessary for normal vital functions (Maton et
al., 1993). Estimates regarding the organ's total number of functions vary, but
textbooks generally cite it at around 500 or so (Zakim et al.,
2002).Terminology related to the liver often starts in hepar- or hepat-from the
Greek word for liver, hēpar ( root hepat).
1.5.1 ANATOMY
The liver is a reddish brown organ with four lobes of unequal size
and shape. A human liver normally weighs 1.44–1.66 kg(3.2–3.7 lb), (Cotran et
al., 2001) and is a soft, pinkish-brown, triangular organ. It is both the
largest internal organ (the skin being the largest organ overall) and the
largest gland in the human body. It is located in the right upper quadrant of
the abdominal cavity, resting just below the diaphragm. The liver lies to the
right of the stomach and overlies the gall bladder. It is connected to two
large blood vessels, one called the hepatic artery and one called the portal vein.
The hepatic artery carries blood from the aorta, whereas the portal vein
carries blood containing digested nutrients from the entire gastrointestinal
tract and also from the spleen and pancreas. These blood vessels subdivide into
capillaries, which then lead to a lobule. Each lobule is made up of millions of
hepatic cells which are the basic metabolic cells. Lobules are the functional
units of the liver.
1.5.2 CELL TYPES
Two major types of cells populate the liver lobes; parenchymaland
non-parenchymal cells. 80% of the liver volume is occupied by parenchymal cells
commonly referred to as hepatocytes. Non-parenchymal cells constitute 40% of
the total number of liver cells but only 6.5% of its volume. Sinusoidal hepatic
endothelial cells, Kupffer cells and hepatic stellate cells are some of the
non-parenchymal cells that line the liver sinusoid (Kmie, 2001).
1.5.3 BLOOD FLOW
The liver gets a dual blood supply from the hepatic portal vein and
hepatic arteries. Supplying approximately 75% of the liver's blood supply, the
hepatic portal vein carries venous blood drained from the spleen,
gastrointestinal tract, and its associated organs. The hepatic arteries supply
arterial blood to the liver, accounting for the remainder of its blood flow.
Oxygen is provided from both sources; approximately half of the liver's oxygen
demand is met by the hepatic portal vein, and half is met by the hepatic
arteries (Shneider et al., 2008).Blood flows through the liver sinusoids and
empties into the central vein of each lobule. The central veins coalesce into hepatic
veins, which leave the liver.
1.5.4 PHYSIOLOGY
The various functions of the liver are carried out by the liver cells
or hepatocytes. Currently, there is no artificial organ or device capable of
emulating all the functions of the liver. Some functions can be emulated by
liver dialysis, an experimental treatment for liver failure. The liver is
thought to be responsible for up to 500 separate functions, usually in
combination with other systems and organs.
1.5.5 SYNTHESIS:
Proteins produced and secreted by the livera large part of amino
acid synthesis. The liver performs several roles in carbohydrate metabolism:
Gluconeogenesis (the synthesis of glucose from certain amino
acids, lactate or glycerol)
Glycogenolysis (the breakdown of glycogen into glucose)
Glycogenesis (the formation of glycogen from glucose) (muscle
tissues can also do this)
The liver is responsible for the mainstay of protein metabolism, synthesis
as well as degradation. The liver also performs several roles in lipid
metabolism: Cholesterol synthesis Lipogenesis, the production of triglycerides
(fats).A bulk of the lipoprotein is synthesized in the liver. The liver
produces coagulation factors I (fibrinogen), II(prothrombin), V, VII, IX, X and
XI, as well as protein C, protein S and antithrombin. In the first trimester
fetus, the liver is the main site of red blood cell production. By the 32nd
week of gestation, the bone marrow has almost completely taken over that task. The
liver produces and excretes bile (a yellowish liquid) required for emulsifying
fats and help the absorption of vitamin K from the diet. Some of the bile
drains directly into the duodenum, and some is stored in the gallbladder. The
liver also produces insulin-like growth factor 1 (IGF-1),a polypeptide protein
hormone that plays an important role in childhood growth and continues to have
anabolic effects in adults. The liver is a major site of thrombopoietin
production. Thrombopoietin is a glycoprotein hormone that regulates the production
of platelets by the bone marrow.
1.5.6 BREAKDOWN
The liver breaks down insulin and other hormones. The liver breaks
down or modifies toxic substances (e.g. methylation) and most medicinal
products in a process called drug metabolism. This sometimes results in
toxication, when the metabolite is more toxic than its precursor. Preferably,
the toxins are conjugated to avail excretion in bile or urine. The liver
converts ammonia to urea (urea cycle).
1.5.6 OTHER FUNCTIONS
The liver stores a multitude of substances, including glucose (in the
form of glycogen), vitamin A (1–2 years' supply), vitamin D(1–4 months'
supply), vitamin B12 (1–3 years' supply), vitamin K, iron, and copper. The
liver is responsible for immunological effects—the mononuclear phagocyte system
(MPS) of the liver contains many immunologically active cells, acting as a
'sieve' for antigens carried to it via the portal system. The liver produces
albumin, the major osmolar component of blood serum. The liver synthesizes
angiotensinogen, a hormone that is responsible for raising the blood pressure
when activated by renin, an enzyme that is released when the kidney senses low
blood pressure. The liver also functions as a blood reservoir, being an expandable
organ. Large quantities of blood can be stored in its blood vessels, its normal
blood volume in the hepatic veins and that in the hepatic sinuses is about
450ml. During cardiac failure with peripheral congestion, the liver expands,
and 0.5 to 1 liter of extra blood is occasionally stored in the hepatic veins
and sinuses, due to high pressure in right atrium which causes back pressure in
the liver.
1.5.2 DISEASES OF THE LIVER
The liver supports almost every organ in the body and is vital for
survival. Because of its strategic location and multi dimensional functions,
the liver is also prone to many diseases (NDDIC, 2010).The most common include:
Infections such as hepatitis A, B,C, D, E, alcohol damage, fatty liver,
cirrhosis, cancer , drug damage (particularly by acetaminophen (paracetamol)
and cancer drugs).Many diseases of the liver are accompanied by jaundice caused
by increased levels of bilirubin in the
system. The bilirubin results from the breakup of the hemoglobin of dead red
blood cells; normally, the liver removes bilirubin from the blood and excretes it
through bile. There are also many pediatric liver diseases including biliary atresia,
alpha-1 antitrypsin deficiency, alagille syndrome, progressive familial intra hepatic
cholestasis, and Langerhans cell histiocytosis, to name but a few. Diseases
that interfere with liver function will lead to derangement of these processes.
However, the liver has a great capacity to regenerate and has a large reserve
capacity. In most cases, the liver only produces symptoms after extensive
damage. Liver diseases may be diagnosed by liver function tests, for example,
by production of acute phase proteins.
1.5.3 LIVER FUNCTION TESTS
Liver function tests (LFTs or LFs) are groups of blood tests that give
information about the state of a patient's liver (Lee, 2009). These tests
include prothrombin time (PT/INR), aPTT, albumin, bilirubin (direct and
indirect), and others. Liver transaminases (AST or SGOT and ALT or SGPT) are
useful biomarkers of liver injury in a patient with some degree of intact liver
function (Johnston, 1999). Most liver diseases cause only mild symptoms initially,
but these diseases must be detected early. Hepatic (liver) involvement in some
diseases can be of crucial importance. This testing is performed on a patient's
blood sample. Some tests are associated with functionality (e.g., albumin),
some with cellular integrity (e.g., transaminase), and some with conditions linked
to the biliary tract (gamma-glutamyl transferase and alkaline phosphatase).
Several biochemical tests are useful in the evaluation and management of
patients with hepatic dysfunction. These tests can be used to detect the
presence of liver disease, distinguish among different types of liver
disorders, gauge the extent of known liver damage, and follow the response to treatment.
Some or all of these measurements are also carried out (usually about twice a
year for routine cases) on those individuals taking certain medications, such
as anticonvulsants, to ensure the medications are not damaging the person's
liver.
1.5.3.1 ALBUMIN
Albumin is a protein made specifically by the liver, and can be measured
cheaply and easily. It is the main constituent of total protein (the remaining
from globulins). Albumin levels are decreased in chronic liver disease, such as
cirrhosis. It is also decreased in nephrotic syndrome, where it is lost through
theurine. The consequence of low albumin can be edema since the intravascular oncotic pressure becomes lower
than the extravascular space. An alternative to albumin measurement is prealbumin,
which is better at detecting acute changes (half-lifeof albumin and prealbumin
is about 2 weeks and about 2 days, respectively).
1.5.3.2 TOTAL BILIRUBIN
Measurement of total bilirubin includes both unconjugated and conjugated
bilirubin. Unconjugated bilirubin is a breakdown product of heme (a part of
hemoglobin in red blood cells). It is very hydrophobic and is mainly
transported bound to albumin circulating in the blood. Addition of
high-concentration hydrophobic drugs (certain antibiotics, diuretics) and high
free fatty acids can cause elevated unconjugated bilirubin. Heme can also come
from myoglobin, found mostly in muscle, cytochromes, found mostly in
mitochondria, catalase, peroxidase, and nitric oxide synthase. The liver is
responsible for clearing the blood of unconjugated bilirubin, and about 30% of
it is taken up by a normal liver on each pass of the blood through the liver by
the following mechanism: bilirubin is taken up into hepatocytes, 'conjugated' (modified
to make it water-soluble) by UDP-glucuronyl-transferase, and secreted into the
bile by CMOAT (MRP2), which is excreted into the intestine. In the intestine, conjugated
bilirubin may be metabolized by colonic bacteria, eliminated, or reabsorbed. Metabolism
of bilirubin into urobilinogen followed by reabsorption of urobilinogen
accounts for the yellow color of urine, as urine contains a downstream product of
urobilinogen. Further metabolism of urobilinogen into stercobilin while in the
bowels accounts for the brown color of stool. Thus, having white or
clay-colored stool is an indicator for a blockage in bilirubin processing and
thus potential liver dysfunction or cholestasis .Increased total bilirubin
(TBIL) causes jaundice, and can indicate a number of problems:
1. Prehepatic: Increased bilirubin production can be due to a number
of causes, including hemolytic anemias and internal hemorrhage.
2. Hepatic: Problems with the liver are reflected as deficiencies in
bilirubin metabolism (e.g., reduced hepatocyte uptake, impaired conjugation of
bilirubin, and reduced hepatocyte secretion of bilirubin). Some examples would
be cirrhosis and viral hepatitis.
3. Posthepatic: Obstruction of the bile ducts is reflected as deficiencies
in bilirubin excretion. (Obstruction can be located either within the liver or
in the bile duct).
DIRECT BILIRUBIN
The diagnosis is narrowed down further by evaluating the levels of
direct bilirubin. If direct (conjugated) bilirubin is normal, then the problem
is an excess of unconjugated bilirubin (indirect bilirubin), and the location
of the problem is upstream of bilirubin conjugation in the liver. Hemolysis, or
internal hemorrhage can be suspected. If direct bilirubin is elevated, then the
liver is conjugating bilirubin normally, but is not able to excrete it. Bile
duct obstruction by gallstones, hepatitis, cirrhosis or cancer should be suspected.
1.5.3.3 SERUM TOTAL PROTEIN
Serum total protein, also known as total protein, is a biochemical
test for measuring the total amount of protein in serum. Protein in the plasma
is made up of albumin and globulin. The globulin in turn is made up of α1, α2,
β, and γ globulins. These fractions can be quantitated using protein
electrophoresis, but the total protein test is a faster and cheaper test that
estimates the total of all fractions together. The traditional method for measuring
total protein uses the biuret reagent, but other chemical methods such as
Kjeldahl method, dye-binding and refractometry are now available. The
measurement is usually performed on automated analysers along with other
laboratory tests.
1.6 AIM AND OBJECTIVE OF RESEARCH
Extracts
of morinda lucida have been used over the years for the treatment of several
diseases and ailment including malaria, diabetes and typhoid fever.
1.7 AIM
This
study is aimed at investigating biochemically the effect of the aqueous leaves
extracts of morinda lucida on the liver of lactose induced wister albino female
rat with a view to justifying the use of the plant in forklore medicine.
1.8 OBJECTIVE
1. To
assess the effect of aqueous extracts of morinda lucida on the total protein,
bilirubin and albumin
2. To
assess the capability of the liver in the presence of the aqueous extracts of
morinda lucida
3. To
assess the detoxifying function of liver on treatment with the aqueous extract
of morinda lucida.
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