Ebiamadon Andi Brisibe

Controlling bruchid pests of stored cowpea seeds with dried leaves of Artemisia annua and two other common botanicals

Insecticidal activities of dried Artemisia annu a L. leaves were evaluated against bruchid ( Callosobruchus maculatus F.) pests in comparison with those of Azadirachta indica, Ocimum gratissimum and a conventional grain storage insecticide, Actellic® 2% dust. Each treatment was added to a mixture of 250 g cowpea seeds and 25 adult bruchids and laid out in a completely randomized design with four replicates. Irrespective of the concentration tested, all three plant materials significantly (P < 0.05) increased mortality rate of adult insects earlier than the control. Higher concentrations of the botanical pesticides equally resulted in an increased reduction in the number of surviving bruchids and reduction to seed damage through a lower number of eggs laid and weevil perforation index (WPI) after 90 days. Comparatively, A. annua was more effective than the other plant materials at all levels evaluated though it was not as effective as Actellic 2% dust. Moreover, differences amongst the efficiency rates and interactions between A. annua and A. indica in three treatment combinations produced a significant (P < 0.05) effect on two of the parameters evaluated. Taken together, all plant materials evaluated here were seen to have significant insecticidal properties and could therefore, be used as environmentally friendly products for controlling bruchid pests during storage of cowpeas with no adverse effects on eventual mammalian consumers as observed during an animal feeding trial in this study. Key words: Actellic 2% dust, botanical pesticides, Callosobruchus maculatus, Vigna unguiculata, weevil perforation index.

A Safety Assessment of the Antimalarial Herb Artemisia annua During Pregnancy in Wistar Rats

Artemisia annua is a Chinese antimalarial herb that has been used for more than 2000 years. The maternal and foetal safety of the ethanolic leaf extract of therapeutically active Artemisia annua (EAA), with previously determined artemisinin yield of 1.098% was evaluated in Wistar rats. Twenty pregnant rats, divided into four study groups of saline treated (control), and test groups administered orally with 100, 200 and 300 mg/kg body weights of EAA, respectively, from gestation days (GD) 8 to 19. Following overnight fast, animals were sacrificed on GD 20, and maternal blood was collected to evaluate biochemical and haematological markers. Foetuses were carefully removed, weighed, and observed for any possible malformation. Biochemical and haematological studies revealed that EAA did not result in maternal hepatotoxicity, haematotoxicity, and hyperlipidemia. While litter size significantly decreased (p < 0.05) at 100 mg/kg EAA, maternal estrogen levels decreased in all the EAA‐treated groups. Non‐viable (21%) and malformed (31%) foetuses were observed at the 300 mg/kg dose of EAA, which implies that although consumption of the leaf extract may not predispose users to hepatotoxicity, haematotoxicity, and hyperlipidemia, it should be taken with caution during pregnancy due to possible risk of embryotoxicity at concentrations higher than the therapeutic dose. Copyright

Biochemical and haematological evaluation of repeated dose exposure of male Wistar rats to an ethanolic extract of Artemisia annua.

Artemisia annua is widely used for the treatment of malaria and other disorders. In a previous study, the artemisinin concentration in the dry leaves of A. annua grown under humid tropical conditions was determined to be 1.098% using reversed phase high performance liquid chromatography. In the current study, biochemical and haematological evaluations of ethanolic leaf extracts derived from such plants (EAA) were carried out in 20 male Wistar rats. Rats were divided into four study groups of saline‐treated (control) and test groups exposed orally to graded doses of EAA for 28 days. The results showed that the liver function and haematological indices, and testosterone levels were not adversely affected. High density lipoprotein ‐cholesterol was reduced at 100 mg/kg of EAA, atherogenic index as well as low density lipoprotein ‐cholesterol was raised, and glucose concentration was reduced significantly at the 100 and 200 mg/kg of EAA (p < 0.05). In addition to serving as a possible antidiabetic agent, EAA may not predispose users to hepatotoxicity, haematotoxicity and testicular toxicity. However, due to the possible risk of atherosclerosis, we advise that the plant extract should be taken with caution in people with atherosclerotic condition. Copyright

Production of Artemisinin In Planta and in Microbial Systems Need Not Be Mutually Exclusive

Artemisia annua L. is an innocuous medicinal plant that is suddenly found at the forefront of global efforts aimed at the eradication of malaria. The plant is also seen as an effective treatment against several other infectious diseases and human cancer cell lines, and this has been correlated with its richness in several bioactive compounds including artemisinin, other sesquiterpenes, and antioxidants. Undoubtedly, this is a development that has drastically increased artemisinin demand worldwide. Up until now, A. annua L. remains the only commercial source for the supply of this vital antimalarial drug to the international market. Recent advances in biotechnology, however, such as have been demonstrated in the production of isoprenoid precursors of artemisinin in yeast, and bacteria are feasible complementary strategies that would help reduce artemisinin cost in the future. The key genes encoding for enzymes regulating the biosynthesis of artemisinin in planta are fully understood to enable metabolic engineering of the pathway, and results from pilot genetic engineering studies in microbial strains thus far are very inspiring. This current treatise, therefore, explores the status of artemisinin and other plant metabolites for use in both human and animal healthcare and highlights the implications of in planta production of artemisinin in comparison with that from synthetic biology. Overall, these two methods need not be mutually exclusive and can be made complementary to each other depending on the location of production. Aside from artemisinin, required for saving the lives of countless patients in malaria-stricken societies, the plant also contains several other secondary metabolites with enormous benefits in the promotion of human and animal health. Consequently, keeping in planta production of artemisinin would play a pivotal role in providing artemisinin for ACTs as well as maintaining profit margins to local and regional economies in countries where malaria is endemic, especially in Africa where A. annua has been cultivated for the past 10 years.

Protective capacity of Artemisia annua as a potent antioxidant remedy against free radical damage.

OBJECTIVE To evaluate the antioxidant capacity of four leaf-derived solvent extracts of Artemisia annua (A. annua), a medicinal plant widely touted for its vast phyto-therapeutic potential. METHODS A. annua leaves were extracted with four solvents (absolute ethanol, absolute methanol, 70% ethanol and 70% methanol), and extracts obtained studied by five complementary in vitro antioxidant test systems using ascorbic acid (vitamin C) and rutin as standard references. RESULTS The extracts remarkably inhibited lipid peroxidation (79.81%-86.70%), and erythrocyte haemolysis (40.02%-49.91%). Their IC50 values for hydroxyl, nitric oxide and hydrogen peroxide radical scavenging activities ranged from 2.39-3.81 mg/mL (superior to the standards), 107.24-144.49 µg/mL and 28.53-53.20 µg/mL, respectively. 70% alcohol extracts generally showed better antioxidant activity than absolute alcohol extracts. CONCLUSIONS The results indicate that A. annua leaf extracts have potent antioxidant activities that would have beneficial effect on human health, and aqueous organic solvents are superior to the absolute counterparts in yielding extracts with better antioxidant potential.

Comparative assessment of annual wormwood and local accessions of bitter leaf for antioxidant composition and activity

Aim: To evaluate ethanol extracts of two anti-malarial herbs from Asteraceae family, annual wormwood (Artemisia annua L.) and bitter leaf (Vernonia amygdalina Del.), for antioxidant composition and activity. Methods: Aerial leaves from both herbs were sampled at flowering stage, extracted with 95% ethanol and resulting crude extracts evaluated for antioxidant composition and activity using selected assay systems. Results: Extract yield from annual wormwood doubled the mean yield from four bitter leaf accessions studied, while its total phenol content (5.19 mg Gallic Acid Equivalents/ 1 g dry weight) was nearly ten folds (p