Evaluation of Antidiabetic Activity of Aqueous Extract of Leaves from <i>Phragmanthera capitata</i> (Sprengel) S. Balle (Laurenthaceae) in <i>Wistar</i> Albino Rats

Abstract

Diabetes mellitus is a public health problem affecting about 8.4% of people in the world and knows an alarming progression in sub-Saharan Africa and in Cameroon precisely. The current therapeutic strategies have prohibitive prices, are unavailable and have harmful side-effects. So, this work aimed at contributing to the valorization of medicinal flora and `knowledge of traditional healers in Foumban, West-Cameroon, in the treatment of diabetes. An ethnopharmacological survey was conducted by consulting traditional healers of the District of Foumban. At the end of this investigation, Phragmanthera capitata, which was found to be the most active plant following preliminary tests, was selected for antidiabetic studies on three groups of rats: normal glycaemia, temporary hyperglycemia and diabetic. The first two groups were treated per os, with aqueous extract of leaves from P. capitata, with the doses of D2 (4 mL/kg) obtained from the traditional healers, D1 (half of D2), D3 (double of D2) and by glibenclamide (2.5 mg/kg). The rats of the last group were treated twice per day, with the same doses of extract and glibenclamide for 13 days and were sacrificed on the 14th day. Their blood was collected by cardiac puncture for the determination of biochemical and hematological parameters. Phytochemical screening was performed using standard methods. The administration of aqueous extract of P. capitata led to a hypoglycaemia effect in normal rats, a reduction of glycaemia in the temporary hyperglycaemia and diabetic rats. In addition, an improvement of lipid assessment, renal and hepatic parameters related to the installation of diabetes, as well as an immune-modulator effect of the extract were noted in diabetic rats treated for 13 days. Phytochemical screening indicated that the extract contains saponins, tannins, flavonoids, steroids and terpens. This work along with findings justifies the traditional use of this plant in the treatment of diabetes mellitus.

In Vivo Antidiabetic Activity and Mechanism of Action of Three Cameroonian Medicinal Plant Extracts

“…This drop of blood was deposited on the active zone of a strip followed by automatic reading of the glycaemia 5 seconds later. The result was expressed in mg/dL of blood [4].…”

“…Two groups made up of 3 lots of 3 rats each were constituted in addition to the three control groups (Healthy, negative and positive controls). Rats were force-fed with a 60% glucose solution at 4 g/kg body weight dose, using a gastroesophageal tube [4]. Aqueous extracts (37.5 mg/kg body weight) were used in the first group while methanol extracts (37.5 mg/kg body weight) were used in the second group.…”

“…Seventy-two hours after injection of alloxan, the establishment of diabetes mellitus was verified in rats by measuring blood glucose level. Animals with blood glucose level greater than 333 mg/L were in permanent hyperglycaemia [4] and were selected for the study.…”

“…Medicinal plants that have the advantage of being available, with little or no toxicity, could be a good source for such substances. Feudjo et al conducted an ethnobotanical survey in three villages (Njisse, Njimbam I and Njimbam II) of the Foumban district after what he found that among the most represented species used alone in the treatment of diabetes, are Catharenthus roseus, Eucalyptus globulus, and Persea americana [4] with decoction being the mode of preparation used by the healers. Al-Shaqha et al observed the antidiabetic effect of ethanolic extract from C. roseus on diabetic wistar rats and greatly advocate its candidature for the design of a novel herbal drug to cure deadly diabetes [5].…”

The Influence of Solvent, Host, and Phenological Stage on the Yield, Chemical Composition, and Antidiabetic and Antioxidant Properties of Phragmanthera capitata (Sprengel) S. Balle

“…In a previous research work in our laboratory, we demonstrated that the administration of Phragmanthera capitata aqueous extract to diabetic rats significantly decreased hyperglycaemia at the dose used by the herbal medicine doctors. It showed hypolipidemic and immunomodulatory effects as well [ 12 ]. Furthermore, the water extract from P. capitata showed no toxic reactions, no change in behavior, and no mortality at a dose of 3000 mg/kg and 5000 mg/kg in mice and Wistar rats [ 7 , 13 ], while acetone, methanol, ethanol, and water extracts showed not toxic (lethal concentration > 1 mg/mL) in Brine shrimp hatchability assay.…”