Ocimum gratissimum (scent leaf) extract protects diabetics from heart, testicular damage

DIABETES is an age long, serious metabolic disorder with complications that results in significant morbidity and mortality. Chronic hyperglycemia (high blood glucose) during diabetes has been shown to cause glycation of body protein, which in turn leads to secondary complications that affect the eyes, kidneys, nerves and arteries. These complications may be delayed, lessened or prevented by maintaining blood glucose levels close to normal.


Several studies have indicated that cardiovascular disease is the major cause of mortality and morbidity in modern societies, among the numerous complications of diabetes. Long standing diabetes has been documented to cause structural and functional cardiac impairment, which was found to lead to ischemic heart disease, cardiomyopathy and congestive heart failure.

Previous studies have also shown that diabetics have significantly reduced testicular weights and tubule diameters. The changes in seminiferous tubules ranged from premature sloughing of epithelium to total cessation of spermatogenesis.

But recent studies suggest that a combination of bitter leaf (Vernonia amygdalina) and scent leaf (Ocimum gratissimum) extracts could not only reduce the blood glucose level, but protects the heart and testes against impairment and complete destruction due to diabetes.

A study by researchers at the University of Calabar published in February 2012 edition of The Internet Journal of Tropical Medicine concluded, "we therefore conclude that extracts of Vernonia amygdalina and Ocimum gratissimum apart from their hypoglycemic actions could protect the heart against impairment and complete destruction due to diabetes."

The study is titled: "Cardioprotective Potential Of Vernonia Amygdalina And Ocimum Gratissimum Against Streptozotocin (Stz) – Induced Diabetes In Wistar Rats."

Another study published in Health Inequalities Hub concluded, "we therefore conclude that the use of the extracts of these plants should be used in combination as they exert a better improvement to combat the adverse effects of diabetes on the testes of male rats."

The study is titled: "Ethanolic Extracts of Vernonia Amygdalina And Ocimum Gratissimum Enhance Testicular Improvement In Diabetic Wistar Rats."

Diabetes mellitus is characterised by disordered metabolism and abnormally high blood sugar resulting from insufficient levels of insulin. It is a disease of the developed world that is gradually creeping into developing countries, especially in Africa where westernised diets are imbibed.

Vernonia amygdalina and Ocimum gratissimum are among the traditionally used herbal plants to treat different ailments. Vernonia amygdalina has been found useful in the ethno therapy of asthma, schistosomiasis, malaria, measles, diarrhoea, tuberculosis, abdominal pain and fever.

Ocimum gratissimum is commonly used in cooking due to its minty aromatic flavour. Traditionally, Ocimum gratissimum has been used for the treatment of headache, diarrhoea, wart worms and kidney infections. The leaves of the African varieties of Ocimum gratissimum are said to contain thymol oil, which has been found to be highly antiseptic and also used to prevent mosquito bite. Vernonia amygdalina and Ocimum gratissimum have been found to have anti-diabetic properties.

According to the University of Calabar study, 40 Wistar rats of an average weight of 140g were used for this study and were randomly divided into five groups of eight rats each. Groups A and B served as the normal and diabetic controls respectively and were given placebo treatment. Groups C, D and E were the experimental groups administered with 200mg/kg body weight of the extracts by gastric intubations for 28 days.

Groups C and D received extracts of Vernonia amygdalina and Ocimum gratissimum respectively. Group E received a combination of both extracts. Fasting blood glucose (FBG) level was checked on a weekly basis.

Results showed a significant lowering of FBG level of animals in the treated groups, while the diabetic control group recorded a significant increase in FBG. The normal control group had FBG level within the normal range. Histological examination revealed a normal cytoarchitecture in the group A animals.

The diabetic control group B animals showed degeneration of myocytes, loss of nuclei, loss of cross striation of the cardiac muscles and an increase in myofibre diameter. These conditions were greatly reversed in the treated groups that received the extracts. It can, therefore, be concluded that Vernonia amygdalina and Ocimum gratissimum may be effective and safe in the proper management of cardiomyopathy, one of the numerous complications of diabetes mellitus.

According to the study published in Health Inequalities Hub, to study the effects of ethanolic extracts of Vernonia amygdalina and Ocimum gratissimum on the testes of diabetic rats, forty male rats were used. Group A consisted of eight rats, which served as non- diabetic control. The remaining rats were injected intraperitoneally with streptozotocin to induce diabetes.

The rats confirmed diabetic were randomly divided into four experimental groups (B, C, D and E) made up of eight rats each. Group B served as the diabetic control and were given normal saline. Groups C, D and E received 200mg/kg body weights of Vernonia amygdalina (VA), Ocimum gratissimum (OC) and a combination of VA and OC respectively. This investigation lasted for 28 days.

Results revealed normal testicular architecture in the normal control. Diabetic control exhibited alteration of germinal epithelium, distortion of seminiferous tubules as well as vacuolation of seminiferous tubules. The effects of the extracts on diabetic rats' testes showed improvements compared to the diabetic control group.

These improvements were more pronounced in the group D rats, which received OC than in group C treated with VA. A more appreciable testicular improvement was observed in group E treated with combination of the extracts of VA and OC.

Meanwhile, diabetes cardiomyopathy is well known to develop in human in the absence of coronary or hypertensive diseases. Endothelial dysfunction, endomyocardial fibrosis- a direct toxic effect of hyperglycemia on cardiomyocytes and autonomic neuropathy, play an important role in the mechanism of diabetic cardiomyopathy development.

These cardiovascular complications compromise cardiac performance ultimately resulting in cardiac failure, seen in cardiovascular complication individuals with diabetic cardiomyopathy.

The University of Calabar researchers wrote: "The STZ diabetic induced rats are reminiscent of a model of uncontrolled hyperglycemia due to the direct pancreatic beta cell destruction and resulting insulin deficiency. The death of some rats in the course of the experiment may be as a result of acidosis. Earlier studies have shown that STZ and product of its reduction, establishes a redox cycle with formation of superoxides radicals resulting in the formation of highly reactive hydroxyl radical within the pancreas, bringing about acidosis and subsequent death.

"Lowering of the FBG level in the experimental groups is consistent with earlier reports on the hypoglycemic and antihyperglycemic actions of the extracts. The chemical base, tannin, present in both plants might have played a vital role in the action of the extracts, since it has been reported to suppress oxidation. The myocardial salvaging effect of OC was more potent than those treated with VA. This is in accordance with other results obtained using herbs.

"How OG carries out this action is not known, but it might be due to the volatile oils it contains. The polyherbal therapy, however, produced a more impressive result. The mechanism through which this is done is not well known, it may be likely due to the presence of phytochemicals in the plants that led to synergism of actions rather than been antagonistic to each other. It may also be as a result of augmentation of endogenous antioxidants and suppression of oxidative stress by the various constituents of the plants acting together to give a better effect.

"The study of cardiomyopathies in small animals will contribute to the understanding of cardiac pathophysiology and an evaluation of experimental treatment strategy."

Culled fro TheGuardian