International Journal of Innovation Sciences and Discoveries Available online at Vol. 1, No, 01, pp.015-017, November,2012 Research Article HYPOGLYCAEMIC INVESTIGATIONS OF MISTLETOE (LORANTHUS MICRANTHUS) LEAF EXTRACTS ON DIABETIC RATS 1Eze-Steven, P. E., 2Njoku, O. U., 3Udedi, S., and 4Ogeneh, B. 1Dept. of Biochemistry, Faculty of Natural Sciences, Caritas University, Amorji-Nike, Enugu State, Nigeria 2Dept. of Biochemistry, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria 3Dept. of Applied Biochemistry, Faculty of Applied Natural Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria 4Dept. of Medical Microbiology, Col ege of Medicine, University of Nigeria, Enugu Campus, Nigeria ABSTRACT
This study investigated the hypoglycaemic activities of water extract of mistletoe leaf in the management of diabetes mellitus. Male Wistar rats were used for this study and they were housed to acclimatize in five different cages according to their groups. Each group contained four animals. Diabetes was induced in rats in all but groups 4 and 5 following the intravenous injection of alloxan monohydrate (90mg/kg) dissolved in normal saline through rat tail vein. Group 1 diabetic rats were treated with 600mg/kg body weight concentration of crude methanol extract of L. micranthus leaves orally. Group 2 diabetic rats were treated with 600mg/kg body weight concentration of crude water extract of L. micranthus leaves orally. Group 3 diabetic rats were treated with 250mg/kg body weight concentration of glibenclamide orally. Group 4 diabetic rats were not treated and served as positive control. Rats in Group 5, which were non-diabetic, received normal saline and served as negative control. The experiments were repeated using different Wistar rats for groups 1, 2, and 4 for the second, third, and fourth weeks. The results of this study showed that both the methanol and aqueous extracts of L. micranthus leaves significantly (P<0.05) reduced mean fasting blood sugar concentrations in normal rats. In diabetic rats, both extracts caused a significant (P<0.05) reduction in serum glucose levels. Key Words: Hyperglycaemia, mistletoe, Loranthus micranthus, diabetes mellitus, histopathology, glucose, alloxan. Copy Right, IJISD, 2012.World Research Publications. All rights reserved. INTRODUCTION
shrubs from different genera including the American mistletoe
(Phoradendron leucarpum), the European mistletoe (Viscum
Diabetes mellitus is a metabolic disorder characterized by
album), and the African mistletoe (Loranthus micranthus),
hyperglycaemia with lipoprotein abnormalities (Scoppola et
which is the European equivalent of Viscum album and the
al., 2001). It is one of the main threats to the human health in
American equivalent of Phoradendron. Loranthus micranthus
the 21st century (Zimmet, 2000). Diabetes mellitus is of two
belongs to the family of African bushy plants called
types: Type 1 diabetes mellitus or insulin dependent diabetes
Loranthaceae (Anderson and Phillipson, 1982 and Newall et
mellitus (IDDM) and Type 2 diabetes mellitus or non-insulin
dependent diabetes mellitus (NIDDM). This study focused on
the use of traditional plant remedies in the management of
MATERIALS AND METHODS
blood glucose during diabetes mellitus using animal models.
As we reported earlier, Loranthus micranthus leaf extracts
indicated antilipidaemic properties (Eze-Steven and Njoku,
Male Wistar albino rats of about 8 to 11 weeks old and weight
2010), so we investigated the hypoglycaemic properties of the
range of 100 to 200g were used for this study. The rats,
aqueous and methanol extracts of African mistletoe (Loranthus
obtained from the animal houses of both the Faculty of
micranthus). Traditional plant remedies have been in use
Biological Sciences and Veterinary Medicine of the University
for centuries in the treatment of diabetes, but only a few have
of Nigeria, Nsukka, Nigeria (UNN), were kept under standard
been scientifically evaluated (Akhtar and Ali, 1984). In
conditions for 7 days with water and food ad libitum for
Nigeria, local herbal practitioners claim that extracts from
acclimatization before the experiments commenced.
mistletoe leaf is effective in the management of high blood
glucose levels that is associated with diabetes mellitus
Animal Stock
(Osadebe et al., 2004). Mistletoe is a semi-parasitic woody
perennial plant commonly found growing on oaks and other
Fifty-six male Wistar rats were used for this study. They were
deciduous trees. Its semi-parasitic nature is because the plant
acclimatized and housed in separate cages according to their
synthesizes its own chlorophyll but depends on the host for its
groups. Diabetes was induced in rats by the intravenous
supply of water and minerals. (Duke, 1985). The plant relates
injection of alloxan monohydrate (90mg/kg) through the rat’s
to several different species of perennial, evergreen, parasitic
tail vein. Diabetic condition in the rats was observed with an
increase in the rat’s blood glucose concentration and other
*Corresponding author: pejansej@yahoo.co.uk
clinical features including loss of weight, increased frequency
016 International Journal of Innovation Sciences and Discoveries, Vol. 1, No, 01, pp. 015-017, November,2012
Following the induction of diabetes, the rats were divided into
blood sample. The colour intensity was read instantly from the
five groups of four animals each (n = 4).
Group 1 was diabetic rats treated with 600mg/kg methanol Statistical Analysis
extract (ME) of Loranthus micranthus orally.
Group 2 was diabetic rats treated with 600mg/kg of the
The results of the experiment were presented as meanSEM
aqueous (distilled water) extract orally and was called the AE.
and were subjected to One Way Analysis of Variance
Group 3 was diabetic rats treated with 250mg/kg of
(ANOVA). The differences between the means were tested
glibenclamide orally. Diabetic untreated rats named the
using post Hoc L.SD at P0.05 significance level.
Group 4. And Group 5 included non-diabetic rats given
The methanol and aqueous extracts significantly (P<0.05)
The experiments were repeated with different animals for
reduced the fasting blood sugar in normal wistar rats. The
groups 1, 2, and 3 for the second, third, and fourth weeks.
reduction in fasting blood sugar caused by the methanol extract
was higher within the first 6 h post-administration compared to
PLANT MATERIAL
that of the aqueous extract. The effect of the aqueous extract
increased gradually within the first 2 h post-administration.
The experiment was carried out in two parts with the same
Both extracts did not significantly (P>0.05) affect the fasting
plant material. One part was carried out using methanol extract
blood sugar in normal rats after 18 h post-administration.
while the other was carried out using aqueous (distilled water)
extract. Preparation of the Methanol and Aqueous Extracts The procedure for the preparation of the methanol extract was as we earlier reported (Eze-Steven and Njoku, 2010). The second part of the dried leaves were also pulverised into coarse form and used for the preparation of the aqueous extract. Determination of the Concentration of Various Extracts To determine this, known weights of both extracts were
determined separately. The weight of dry crucible was also
Fig. 1: Effect of extracts on fasting blood sugar concentration of
determined. Later, known weights of both extract were put into
normal rats
the dry crucible, respectively, and their weight determined
before heating. The crucible with its content was heated and after the heating, the crucible was weighed with its heated content and the weight recorded. The concentrations of both extracts were then calculated from the various weights. Acute Toxicity Test (LD50) The median lethal doses (LD50) of the methanol extract and aqueous extract were determined in mice using the oral route of administration (Lorke, 1983). Both extracts did not cause death in mice at dose concentrations above 2900mg/kg. Consequently, the methanol extract and aqueous extract of mistletoe (Loranthus micranthus) are considered non toxic (Lorke, 1983) at such concentration.
Determination of Plasma Glucose concentration Fig. 2: Effect of extracts on blood glucose level of diabetic rats
ONE-TOUCH blood glucose monitoring meter and test strips
The methanol and aqueous extracts significantly (P<0.05)
reduced the blood glucose level of alloxan-induced diabetic
California, USA) were used for this assay. The principle of the
rats within the four weeks of treatment. The extracts caused
reaction is based on the glucose oxidase reaction. The blood
highest reduction in serum glucose level after the second week
glucose estimation involves the reaction between glucose in
of treatment. The magnitude of effect caused by the methanol
the blood and oxygen in the presence of glucose oxidase,
extract was significantly (P<0.05) higher than that of the
which is immobilised in the test strip, to yield gluconic acid
and hydrogen peroxide. The hydrogen peroxide subsequently
oxidizes the dye in a reaction mediated by peroxidase to
DISCUSSION AND CONCLUSION
produce a blue-coloured product. The intensity of the colour
produced is proportional to the glucose concentration in the
The results of this research work show a gradual reduction in the serum glucose concentrations in both fasting and non-
017 International Journal of Innovation Sciences and Discoveries, Vol. 1, No, 01, pp. 015-017, November,2012
fasting states in the diabetic and non-diabetic rats. The crude
Duke, J. A. 1985. CRC Handbook of Medicinal Herbs. Boca
extracts gradually reduced the serum fasting glucose
concentrations in the non-diabetic rats. In the diabetic states,
Eze-Steven, P. E. and Njoku, O. U. 2010. Antilipidaemic
both extracts also indicated an antihyperglycaemic activity.
studies of mistletoe (Loranthus micranthus) leaf extracts
This shows that the methanol extract and aqueous extract of
on diabetic rats. Int J Curr Research. 8: 048-055.
Loranthus micranthus have antihyperglycaemic properties
Hoglund, P. 1999. Initiation of autoimmune diabetes by
with the methanol extract having a greater effect than the
developmentally regulated penetration of islet cell
aqueous extract. This result confirms that the methanol extract
antigens in the pancreatic lymph nodes. J Exp Med. 189:
shows antilipidaemic properties as we reported earlier but
might have some destructive effect on the hepatocytes of
Lorke, D. 1983. A new approach to practical toxicity testing.
treated rats. This could be a result of destructive effect of the
Archives of Toxicology. 54: 275-287.
alcohol on the hepatocytes of treated rats. It further indicates
Newall, C. A., Anderson, L. A. and Phillipson, J. D. 1996.
that the methanol extract has a less destructive effect on the
Herbal medicines: a guide for health-care professionals.
kidneys than it has on the liver. The liver is a vital organ
involved in the detoxification and deamination reactions in the
Osadebe, J. O., Okide, G. B. and Akabogu, I. C. 2004. Study
body. The kidneys are involved in the excretion of metabolites,
on anti-diabetic activities of crude methanolic extracts of
mostly inactive, from the body. Thus, during the process of
Loranthus micranthus (Linn.) sourced from five different
host trees. J Ethnopharmacol. 95: 133-138.
compounds in the methanol extract destroyed the hepatocytes
Ross and Wilson. (2001). Anatomy and Physiology in Health
of the organ of detoxification more than those of the kidney
and illness. Churchill Livingstone Pub., UK. pp. 234.
Scoppola, A., Montecchi, F. R., Mezinger, G. and Lala, A.
2001. Urinary mevalonate excretion rate in type 2
REFERENCES
diabetes: role of mevalonate control. Artheroscl. 1556:
Akhtar M. S. and Ali M. R. 1984. Study of antidiabetic effect
Zimmet, P., Alberti, K. G. M. M., and Shaw, J. 2001. Global
of a compound medicinal plant prescription in normal and
and societal implications of the diabetes epidemic. Nature.
diabetic rabbits. J Pakistan Med Assoc. 34: 239-244.
Anderson, L. A. and Phillipson, J. D. 1982. Mistletoe – the
magic herb. PharmJ. 229: 437 – 439.
Brownlee, M. (2001). Biochemistry and Molecular cell
biology of diabetic complications. Nature. 414: 281-320.
The Official Regulation of the Design Contest Burn Night Experiences within ADfel 2008 Organizer: S.C. BLUE IDEA PROMOTIONS S.R.L., Romanian legal entity , having the registered office in Bucharest, 11 Sold. Tina M. Petre Street, block L39, entrance B, 5th floor, ap. 65, sector 3, registered at the Trade Register under number J40/19144/2006, Fiscal Code RO19233120, legally r
The item below was posted on journalreview.org on May 1, 2007, attached to the article by Vaccarino et al., but discussing article by Jha et al and Trivedi et al. that appeared with the Vaccarino article in the August 28, 2005 issue of the New England Journal of Medicine. In light of the closing of the journalreview.org site, it is reproduced here. A correction regarding the statements concer