Preliminary Observations on the Efficacy of Antidiabetic Plant, Tithonia Diversifolia (Hemsl.) A Gray (Tree Marigold) on Alloxan-Induced Diabetic Wistar Rats

Aim and Objectives: The world-threatening increases of types 1 and 2 diabetes mellitus and their pressure on insulin and other drugs led to the continued search for non-conventional drugs as remedy particularly in countries with reduced economic growth. Therefore, the traditional use of Tithonia diversifolia leaves as an antidiabetic medicinal plant was investigated for its documentation into a data bank for further technological development and enhancement of its antidiabetic capacities to meet the challenges of diabetes mellitus on animal and human population. Design and Methods: Eighteen (18) adult Wistar rats of both sexes, were placed at random into four groups and treated as follows: Group 1: Non-diabetic rats (ND) dosed orally with normal saline at 2 ml/kg.bd.wt. (n=3) served as normal control; Group 2: Diabetic rats that were left untreated (DU) (n=4) served as negative control; Group 3: Diabetic rats orally administered with crude ethanolic extracts of Anogeissus leicarpus stem bark as standard, (DEEAlSB) at a dose of 1,000 mg/kg.bd.wt. daily, (n=6), served as positive control; Group 4: Diabetic rats orally administered with crude ethanolic extracts of Tithonia diversifolia leaves (DEETdL) at a dose of 1,000 mg/kg.bd.wt. daily, (n=5). Administrations commenced immediately hyperglycaemia occurred in the alloxan-induced diabetic rats and when hyperglycaemia subsided in the diabetic rats, administrations were withdrawn. Random blood glucose (RBG) values were monitored post withdrawal of administrations. Google search, National Institute of Health, Research Direct, Research Gate and Library search for peer review articles, were utilized for the study. Results: Alkaloids, glycosides, phenolic compounds, tannins, steroids, carbohydrates, flavonoids, and terpenoids phytochemicals/phytconstituents are presented in the ethanolic extracts of T. diversifolia leaves, while saponins and anthraquinones are absent. Of these ten phytochemicals, only atraquinones were absent in the standard, crude ethanolic extracts of Anogeissus leiocarpus stem bark, applied in the current study. RBG values in normal control, ND (group 1) ranged between 92 and 129 mg/dl during the study; diabetic untreated rats, negative control. DU (group 2) and diabetic rats, orally administered the test sample, crude ethanolic extracts of T. diversifolia leaves, DEETdL, (group 4) developed an overwhelming hyperglycaemia one day post induction of diabetes, except one rat in the latter group 4, which developed hyperglycaemia three days post induction of diabetes. Group 3 diabetic rats assigned for treatment with the standard, crude ethanolic extracts of A. leiocarpus stem bark, DEEAlSB developed hyperglycaemia eight days post induction of diabetes, a delay that was ascribed to an observed enlarged body mass index (BMI), although one rat was overwhelmingly hypoglycaemic. Diabetic untreated rats died from an overwhelming hyperglycaemia, by day 4 post induction of diabetes. Oral administration of the standard, as from eight days post induction, revealed its effectiveness and efficacy in treating diabetes mellitus as from four days and completely effective on seven, nine and eleven days post treatment of diabetes, which led to the withdrawal of standard on eleven days post administration. The diabetic rats administered the test sample, crude ethanolic extracts of T. diversifolia leaves, one day post induction of diabetes, responded very slowly, displaying some levels of effectiveness five, six twelve, fourteen and sixteen days post treatment with reversals in between, which led to its withdrawal eighteen days post administration. Conclusion: Post withdrawal of administration of standard revealed maintenance of normoglycaemia for sixteen days; while with the test sample, ethanolic extracts of T. diversifolia leaves, moderate hyperglycaemia existed for sixteen days post withdrawal, suggestive of continuous daily usage of T. diversifolia leaves as an antidiabetic remedy.