M. Ofosuhene

The antidiabetic and antioxidant effects of the herbal preparation ADD-199 were investigated in STZ-induced diabetic C(3)H mice and results were compared with two allopathic hypoglycaemic drugs, glibenclamide and metformin. Plasma glucose, insulin and lipids as well as liver glycogen, lipids and lipid peroxidation were measured following treatment for 8 weeks. The results indicated that plasma insulin levels in normal controls at termination were about 76 micromol/L compared to trace levels in untreated diabetic mice. Glibenclamide and ADD-199 increased insulin levels in diabetic mice up to 70% of levels in untreated non-diabetic mice whilst metformin had no effect. Basal plasma glucose levels in diabetic controls (18.8 mM) were reduced to 14.0 mM by 100 mg/kg ADD-199 in <2 weeks compared to 4 and 6 weeks for glibenclamide and metformin, respectively. This hypoglycaemic effect of ADD-199 appeared to be associated with the alkaloidal content of the extract. Treatment with ADD-199 ...

Indigofera arrecta, an anti diabetic plant was investigated in ddY mice to determine its acute and subchronic effects, and whether it modulated hepatic cytochrome P450 (CYP) isozymes and glutathione (GSH). No mortality was observed in the acute (up to 10 g I. arrecta/kg body wt, p.o.) and subchronic (2 g I. arrecta/kg body wt, p.o. daily for 30 days) studies. The extract did not alter haematological indices, serum and tissue lipids and glutathione but lowered serum bile acids. The latter phenomenon is under further investigation. Neither the duration of pentobarbital (PB) and zoxazolamine (ZA) effects in vivo, nor CYP-dependent 7-ethoxyresorufin-O-deethylase (EROD), 7-pentoxyresorufin-O-depentylase (PROD) and p-nitrophenol hydroxylase (PNPH) activities in vitro were altered by I. arrecta. The extract was thus devoid of overt acute and subchronic toxic effects, and did not affect CYPs and GSH whose modulation may cause interactions of components in a multiple drug therapy.

The subchronic toxicity of the aqueous antidiabetic herbal extract ADD-199, prepared from Maytenus senegalensis, Annona senegalensis, Kigelia africana and Lanneawelwitschii, and administered at a daily dose of 100 or 500 mg/kg body weight over 30 days, was investigated in male Wistar albino rats. Certain haematological, urine and plasma biochemical parameters, and modulation of some hepatic cytochrome P450 (CYP) isozymes were measured as indices of organ specific toxicity or potential for drug interactions. ADD-199 did not affect plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and albumin or creatinine kinase (CK) levels. It also did not affect plasma creatinine and urea levels. Furthermore, ADD-199 neither affected PCV nor blood Hb, RBC, reticulocytes, platelets, lymphocytes and granulocyte levels. It, however, caused significant dose-dependent reductions in WBC counts at day 15 with varying degrees of recovery by day 30. It also reduced the rate of body weight increases after week 3. However, no changes were observed in organ weights at termination. ADD-199 did not significantly affect zoxazolamine-induced paralysis and pentobarbital-induced sleeping times as well as certain CYP isozyme activities in rats. These findings suggest that ADD-199 had no overt organ specific toxicity and did not demonstrate a potential for drug interactions via CYP-mediated metabolism in the rat on subchronic administration.

A 3-month double-blind and placebo-controlled, phase IIa clinical trial was conducted in Ghana to investigate the safety, tolerance and aflatoxin-sorption efficacy of dietary NovaSil (NS). Volunteers (507 subjects) were clinically screened to evaluate their general health, pregnancy status and blood AFB(1)-albumin adduct levels. Of these subjects, 177 were randomly assigned to three groups: high-dose (HD), low-dose (LD) and placebo-control (PL) groups receiving 3.0, 1.5 and 0 g NS day(-1) in capsules. Trained study-monitors supervised NS capsule administration to participants and recorded side-effects daily. Physical examinations were performed monthly. Blood and urine samples were collected for laboratory analysis. Approximately 92% of the participants (162 of 177) completed the study and compliance rate was over 97%. Overall, 99.5% of person x time reported no side-effects throughout the study. Mild to moderate health events ( approximately 0.5% of person x time) were recorded in some participants. Symptoms included nausea, diarrhea, heartburn and dizziness. These side-effects were statistically similar among all three groups. No significant differences were shown in hematology, liver and kidney function or electrolytes in the three groups. These findings demonstrate that NS clay is apparently safe and practical for the protection of humans against aflatoxins in populations at high risk for aflatoxicosis.