Acute and sub-chronic oral toxicity studies on the methanol leaf extract of Gnetum africanum Welw in wistar rats.

Abstract

Aim: Acute and subchronic toxicity studies were performed on Gnetum africanum Welw leaves using well-established guidelines and methods. In spite of its use as a herbal remedy, there is a dearth of data on toxicity studies of the plant extract. Method: Gnetum africanum leaves were identified by a plant taxonomist, air-dried, pulverized, and extracted with 80% methanol for 48 hours in July 2015. The extract was concentrated in-vacuo and stored as Gnetum africanum extract (GAE) at 4°C. Thirty-five male albino rats randomly divided into seven groups (n = 5) were used for acute toxicity test, which was done in August 2015. Rats in groups 1-6 were given GAE at 500, 1,000, 2,000, 3,000, 4,000 and 5,000 mg/kg, respectively, while group 7 rats received 10 ml/ kg distilled water. Feed and water were provided and they were observed for signs of toxicity for 48 hours. A 90-day subchronic toxicity study was conducted using 56 rats of four groups (n = 14) in December 2015-March, 2016. Group 1 received feed without GAE, while groups 2-4 were given feed with GAE at 10, 20 and 40 mg/kg respectively. Four rats from each group were bled on days 30, 60, and 90 for clinical biochemistry and sacrificed for histopathological examination. Result: The median lethal dose (LD 50 ) was greater than 5,000 mg/kg while no-observed-adverse-effect-level was 40 mg/kg. Serum marker enzymes and creatinine were not increased in rats given extract in feed, while there were no histopathological lesions in the organs studied. Conclusions: The extract is safe at both the acute and subchronic levels. ARTICLE HISTORY

Fabrication, in vitro and ex vivo evaluation of proliposomes and liposomal derived gel for enhanced solubility and permeability of diacerein

“…Various parameters of the clinical findings are illustrated in Table 5 . The renal, liver function tests and various biochemical parameters showed slight variation as compared to the control group and the overall results were found in line with the already reported literature [ 28 ]. No mortality rate was observed during the study, there was neither significant nor gross histopathological lesion in the heart, lung, liver, kidney and intestine tissues of Wistar rats ( Fig 7 ).…”

Assessment of the total aqueous stem bark extract of Sacoglottis gabonensis (Baille) Urban on the anatomo-histology of Wistar rat liver, kidneys and heart

“…This result suggests that this extract, administered orally to rats for 90 days, does not have a toxic effect on the heart. The effects of ETASg on the histology of heart of the rats tested in our study were similar to the results of studies by Udeh et al (2018). These authors showed that the histological test of the heart of the rats tested with the methanolic extract of the leaves of Gnetum africanum Welw (Gnetaceae) at the doses of 10, 20 and 40 mg/kg b. w. has normal heart tissue after 90 days of experimentation.…”

Bioactivity-guided fractionation of a methanol leaf extract from Gnetum africanum with potential anti-diabetic activity: (-)-Epicatechin as the active principle

“…Studies on Gnetum africanum showed that the crude extract caused significant reductions in blood glucose levels of diabetic rats [10] and reversed alloxan-induced destruction of the pancreatic islet cells [11,31]. Its safety has also been established in Wistar rats following acute and sub-chronic studies (12). Like other flavanols, (-)-epicatechin are known to prevents oxidation and covalentmodifications caused by free radicals in proteins,improve the plasma insulin and antioxidant levels in diabetic rats and alsosignificantly decreased the levels of blood glucose, HbA1c [29,30].…”

“…It is relevant in ethnomedicine in Nigeria for the treatment of diabetes, piles, high blood pressure, sore throats and enlarged spleen [8,9]. Recent studies have established antidiabetic and antidyslipidaemic as well as protective effects of G. africanum on rat pancreatic islets [10][11][12]. However, no active principle has hitherto been isolated from the plant with these bioactivities.…”

“…In this study, Gnetum africanum leaf extract, a safe [12] and readily available anti-diabetic plant used in folkloric medicine, was subjected to antidiabetic activity-guided fractionation on alloxan-induced diabetic Wistar rats. Antidiabetic activity of the crude methanol extract has been scientifically validated [10], however, no active compound has been hitherto, identified to possess such activity.…”