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

Abstract

The aim of the present work is to study and compare antidiabetic activity of extracts from Catharentus roseus, Persea americana, and Eucalyptus globulus as well as their mechanism of action. The aqueous and methanolic plant extracts were respectively prepared by decoction and maceration. The phytochemical screening was done by standard methods. The extracts were subsequently tested in vivo on Wistar albino rats (Rattus norvegicus) with temporary hyperglycemia. The methanolic extract of P. americana leaves showing the best activity was selected for the antidiabetic test at doses 37.5, 75 and 150 mg/kg. For that purpose, permanent diabetes mellitus was induced in rats fasted overnight by intraperitoneal injection of alloxan (150 mg/kg). Hematological and biochemical parameters were evaluated from the cardiac puncture’s blood. The antidiabetic mechanism of action of the 6 extracts was performed by evaluating their inhibitory activity on alpha glucosidase, beta glucosidase and glucoamylase.
 Phytochemical analysis of aqueous and methanolic extracts revealed that all extracts contain phenols, anthraquinones and tannins. On the other hand, no extract contains sterols. All extracts showed hypoglycemic activities. The antidiabetic tests showed that the methanolic extract of P. americana caused a decrease in blood sugar level in all the treated rats with the dose of 150 mg / kg of body weight being the most effective, without any adverse side effect in the animals. All the tested extracts showed an inhibitory activity against alpha glucosidase and glucoamylase enzymes and have no inhibitory activity on beta glucosidase.
 The results of the present study demonstrate the antidiabetic properties of the tested plants through inhibitory effect on alpha glucosidase and glucoamylase enzymes with P. americana being the most active.

Formulation of category-2 hypoglycemic Improved Traditional Medicines from selected Cameroonian medicinal plants: <i>Mangifera indica, Persea americana</i> and <i>Ageratum conyzoides</i>

“…Similarly, for P. americana (Njateng et al, 2018) in an in vitro study showed that methanol extract from leaves of P. Americana Mill strongly inhibits alpha-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase and showed almost no effect against beta-glucosidase. Also, Chimi et al (2019) carried out an in vivo study where it was shown that the methanol and aqueous extracts of the leaves of P. Americana have high antidiabetic activities with 150 mg/Kg as the best dosage. These above results probably justify why these plants species are used in folk medicine for the treatment of diabetes, and suggest validity of the formulated antidiabetic drugs presented herein.…”

Histological Features of Different Organs Before and After Treatment of Diabetes by Using Avocado Extract in Rats

“…Flavonoids, which are well-known to be potent antioxidants and may help protect organs against toxicity or oxidative stress caused by substances like alloxan, have been shown to be an active component in many herbal medications [21,22]. The plant extract's apparent hypoglycaemic activity may have been influenced by saponins, which have been found to exhibit hypoglycaemic activity [23]. This activity may be caused by the suppression of liver glycogenesis or glycolysis.…”

Ethnomedicinal Knowledge of Plants Used in Nonconventional Medicine in the Management of Diabetes Mellitus in Kinshasa (Democratic Republic of the Congo)

“…Ngwaka Tb [48] In vivo rat: 37.5-150 mg/kg [49] Chromolaena corymbosa (Aubl.) R. M. King and H. Rob.…”