Malaria remains an overwhelming infectious disease with significant health challenges in African and other endemic countries globally. Resistance to antimalarial drugs has become one of the most momentous challenges to human health, and thus has necessitated the hunt for new and effective drugs. Consequently, few decades have witnessed a surfeit of research geared to validate the effectiveness of commonly used traditionally medicines against malaria fever. The present review work focuses on documenting natural products from African whose activity has been reported in vivo or in vitro against malaria parasite. Literature was collected using electronic search of published articles (Google Scholar, PubMed, Medline, Sciencedirect, and Science domain) that report on antiplasmodial activity of natural products from differernts Africa region. A total of 652 plant taxa from 146 families, 134 isolated antimalarial compounds from 39 plants species, 2 herbal formulations and 4 insect/products were found to be reported in literature from 1996 to 2015. Plants species from family Asteraceae (11.04%), Fababceae (8.128%), Euphorbiaceae (5.52%), Rubiaceas (5.52%), and Apocyanaceae (5.214%), have received more scientific validation than others. African natural products possess remarkable healing properties as revealed in the various citations as promising antimalarial agents. Some of these natural products from Africa demonstrate high, promising or low activities against Plasmodium parasite. This study also shows that natural products from Africa have a huge amount of novel antimalarial compounds that could serve as a leads for the development of new and effective antiplasmodial drugs. However, in a view of bridging the gap in knowledge, clinical validation of these natural products are of paramount importance.

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Background Diabetes mellitus (DM) is a metabolic disorder that affects the body's ability to produce or use insulin. This study evaluated the hypoglycaemic activity of biosynthesized copper oxide nanoparticles (CuO‐NPs) in alloxan‐induced diabetic Wister rats. Methods CuO‐NPs were synthesized via the green route and characterized using different analytical tools. Diabetes was induced intraperitoneally using 90 mg/kg body weight of alloxan monohydrate in albino rats. Thirty (30) rats were randomly divided into 5 groups of 6 rats each and orally treated for 21 days. Groups I and II were treated with 300 mg/kg bwt Cereus hildmannianus extract and CuO‐NPs, respectively. Groups III and IV received 5 mg/kg bwt of Glibenclamide and 2 mL of normal saline, respectively, while Group V was left untreated as the diabetic control. Blood glucose (BG) levels and body weight changes were monitored at 3‐ and 7‐day intervals, respectively, throughout 21‐day treatment period. Lipid profiles, enzyme assays and histopathological studies of the liver were also carried out. Results Spheroidal tenorite phase of CuO‐NPs with a crystallite size of 62.57 nm, surface area (20.64 m2/g) and a UV‐maximum absorption at 214.27 nm was formed. The diabetic rats treated with 300 mg/kg bwt CuO‐NPs had the highest BG lowering ability (from 482.75 ± 27.70 to 124.50 ± 2.50 mg/dL). A significant difference (p < 0.05) in weight gain and serum enzymes was also observed in the CuO‐NPs treated group compared with other groups. The CuO‐NPs‐treated group had a significant increase (p < 0.05) in HDL‐cholesterol and a decrease in total cholesterol, triglycerides, LDL‐cholesterol and VLDL‐cholesterol compared with other groups. Conclusion The green synthesized CuO‐NPs nanoparticles significantly reduced (p < 0.05) blood glucose levels in rats and other associated indices and could serve as drug lead in the treatment of diabetes.

Calotropis procera is an evergreen perennial shrub, which is found mainly in the arid regions and produces copious latex when cut. It has been reported to possess medicinal properties but equally pose deleterious effect in animals. In a bid to exploit its pharmacological properties, it was necessary to ascertain its level of safety. A toxicological evaluation of the aqueous extract of fresh leaves of the plant was therefore conducted in the more sensitive female rabbits of the same weight range. Low levels of phytochemicals (alkaloids, saponins, tannins, cardiac glycosides and flavonoids) were found, while elemental analyses showed traces of iron, lead, sodium, and potassium in concentrations of 0.23, 0.03, 0.82 and 9.5 mg/g, respectively. Acute toxicity study was conducted with oral administration of 200, 400, 800 and 1600 mg/kg of the extract once to groups I, II, III and IV, respectively with a 24 h observation period. Clinical signs such as mouth chewing, photophobia, bradycardia, coughing, vomiting and convulsion amongst others were noticed. Four rabbits died within 24 h and LD 50 was estimated (940 mg/kg). 80, 40 and 20 mg/kg of the extract were administered daily to groups I, II, and III, respectively, during sub-acute toxicity study for 14 days. Grossly, catarrhal enteritis and mesenteric congestion of the small intestines, congestion of the lungs, hepatization and paleness of the liver, congestion and pallor of the kidney cortex, and congestion of the meninges were noticed. Histopathological examination of the tissues revealed mild pulmonary oedema and peribronchial lymphocytic infiltration of the lungs, hepatization of the liver, disruption of cardiac architecture, generalised cell necrosis and erosion of the villi of the small intestine. All the rabbits that survived gained weight, which is indicative of some nutrient value in the extract. It was concluded that the extract had dose-dependent deleterious effects on the tissues as higher dose groups were more affected. Hence, it is evident that sub-chronic toxicity studies would reveal greater lesions to better ascertain extent of damage.