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This study evaluated the anti-hyperglycemic potential of Stemonocoleus micranthus Harms. (Fabaceae) stem bark. Three models used in this study were: normoglycemic animal model, oral glucose tolerance test (OGTT) and alloxan-induced hyperglycemic model for acute and prolonged administration. Five (5) groups of rats (n=5) were used for all models; group 1 served as the control (received 2 ml/kg of distilled water; p.o.), groups 2, 3, and 4 received S. micranthus extract (SME) 100, 200, and 400 mg/kg, respectively, while group 5 received glibenclamide (GLI 0.2 mg/kg) as a reference drug. In the normoglycemic study, the % reduction in blood glucose concentration (BGC) was 22.24, 29.97, 30.03 and 37.28% for SME (100, 200 and 400 mg/kg) and GLI, respectively. In the OGTT study, suppression in BGC was statistically significant (p

Geophagy is the consumption of earth materials across several cultures in many continents. For various reasons, consumption of kaolin is common among pregnant women in Nigeria. This earth material is known to contain heavy metals. This study was carried out to determine the effect of kaolin consumption on some heavy metal levels in pregnant women attending antenatal clinic in a Teaching Hospital in the south east Nigeria. A total of eighty pregnant women recruited for this study were grouped as follows; Group 1, (30 geophagic pregnant women within the first trimester). Group 2 (30 geophagic pregnant women within the second trimester) and Group 3 (20 non-geophagic pregnant women that served as control) Subjects in Groups 1 and 2 were subdivided into three based on the quantity of kaolin consumed per week, Group A (100 g/week), group B (150 g/week) and group C (200 g/week). Preliminary analysis of the heavy metal contents of kaolin was carried out. After two weeks of kaolin consumption, the serum levels of lead, arsenic, cadmium and mercury of the subjects were determined. The mean concentrations of lead (0.347 ± 0.12), arsenic (0.354 ± 0.15), cadmium (0.209 ± 0.11) and mercury (0.029 ± 0.02) in the kaolin exceeded the maximum permissible concentrations in food. The concentration of lead increased significantly (p < 0.05) in the first and second trimester pregnant women on 150 and 200 g of kaolin per week. There was a significant (p < 0.05) increase in the concentration of arsenic and cadmium in the second trimester women who consumed 200 g of kaolin per week. These results indicate that unregulated consumption of kaolin in pregnancy increases the serum level of the heavy metals and may be a risk factor for lead toxicity with its attendant complications in the infants.

In Nigerian ethnomedicine, Stemonocoleus micranthus Harms (Fabaceae) is used in the management of heart related diseases. This study investigated the effect of sub-chronic administration of methanol-dichloromethane stem bark extract of S. micranthus (SME) on lipid profile and histology of liver and kidney of rats. Adult albino rats of both sexes were randomly divided into four groups (n=5) and received daily administration of SME (100, 200, and 400 mg/kg) and 2 ml/kg distilled water (control) respectively for 28 days per oral. Biochemical tests were performed pre-treatment and subsequently fortnightly as the treatment commenced. The results showed that the extract increased the serum high density lipoprotein cholesterol concentration while low density lipoprotein cholesterol, total cholesterol, triacylglycerol, and very low density lipoprotein cholesterol concentrations were reduced compared with the baseline values. However, the histopathological examination of the liver and kidney of the rats that received extract and solvent revealed normal portal area with bile ducts and hepatic artery as well as normal glomerulus and renal tubules without observable changes suggesting zero tendency of causing toxic effects. The preliminary phytochemical analysis showed that SME contained alkaloids, glycosides, flavonoids, reducing sugars, terpenoids, saponins, proteins and, fats oils. SME exhibited an oral LD50 >5 g/kg in mice. These findings suggest that the stem bark extract of S. micranthus contains constituents that possess hypolipidemic activity in rats.

Preparation, distribution, advertisement, and usage of phythomedicinal products in Nigeria are weakly regulated raising genuine concern for public safety. In this study, twelve highly patronised commercial herbal products (S1- S12) claimed to be beneficial in the management of either diabetes mellitus, diarrhoea, or hypertension were procured from herbal vendors in Nigeria and evaluated against their claims of efficacy and safety using established whole animal and in vitro models. S1, S2, and S3 were tested for anti-hyperglycaemic activity in normoglycemic and diabetic rats and only S1 and S2 showed some reductions in blood glucose at some time points but S3 produced no reduction in blood sugar at all the time points. Three samples, S4, S5, and S6 significantly (P ≤ 0.05) inhibited the frequency of diarrhoea drops in rats at a dose of 250 mg/kg and caused minimal (P>0.05) reduction in intestinal transit of a charcoal meal in mice. Infusion of aqueous extract of samples (S7-S12) up to 1mg/kg, showed that only the mean arterial blood pressure of cannulated cat was reduced by S7 and S8 but samples S9, S10, S11, and S12 did not cause any reduction in the arterial blood pressure. At a dose of 1 mg/kg, S7 and S8 caused a BP reduction of 150 and 76.92% relative to the reduction produced by ACh (1 μg/kg). The safety of these samples was assessed by determining the acute toxicity of these preparations and checking the nature of contaminating organisms and the levels of such contamination (bio-load). Acute toxicity studies in mice showed that at doses above 5000 mg/kg, per os, all the herbal samples did not cause death or produced signs of acute intoxication in mice. The samples were found to be contaminated with a variety of microorganisms, although their bio-loads were largely within pharmacopoeia specification. S7 is the most heavily contaminated; S3, S4, and S12 are contaminated with Gram negative organisms that may be potentially pathogenic. The outcome of this preliminary investigations demonstrates the need for stricter regulation and registration of commercial herbal products. Post-marketing surveillance, pharmacovigilance, and random screening of herbal products should be entrenched in the regulatory framework to quickly dictate any possible adverse effect and ensure consistency in the quality of distributed herbal medicines.

Medicinal plants have been the basis of treatment of various diseases in African traditional medicine as well as other forms of treatment from diverse cultures of the world. About 80% of the world’s population still depends solely on traditional or herbal medicine for treatment of diseases, mostly in Africa and other developing nations. Most of the potent medicinal plants have relatively no toxic or adverse effects when used by humans, while some are very toxic to both humans and animals with the potential of damaging certain organs in the body. This calls for caution in the use of medicinal plants of which the use is presently on the increase due to easy availability, affordability, accessibility, and promising efficacy comparable to the often high cost and adverse effects of standard synthetic drug agents. This chapter highlights some safe medicinal plants with good toxicological profile in laboratory animals and/or cell culture experiment that are qualified for clinical trials in humans. Several medicinal plants were evaluated for their good toxicological profile using online research. After much screening, only those medicinal plants without serious toxic effects in animals and cell culture experiments were chosen and precisely discussed.