Isoflavanquinones from Abrus precatorius roots with their antiproliferative and anti-inflammatory effects.

Phytochemical studies on the root of Abrus precatorius Linn. (Fabaceae), leads towards the identification of four undescribed (abruquinones M, N, O, and P), and seven known abruquinones, (abruquinones A, E, B, F, I, D, and G). Spectroscopic analyses (1D, and 2D NMR, HRESI-MS) were used in elucidating structures of the all compounds. Evaluation of anticancer activities of the isolated isoflavanquinones revealed that abruquinones M, and N showed cytotoxicity against oral CAL-27 (IC50 values 6.48 and 5.26 µM, respectively), and colon (Caco-2) cell lines (IC50 values 15.79 and 10.33 µM, respectively). Abruquinone M also inhibited the growth of lung cancer cells (NCI-H460) with IC50 of 31.33 µM. The isolated isoflavanquiones also showed potent anti-inflammatory potential through phagocyte oxidative burst and pro-inflammatory cytokine TNF-α inhibition in vitro. These findings suggest isoflavanquinones from A. precatorius roots as candidates for further research in cancer treatment.

Antioxidant activity of the simulated gastro-intestinal digestion hydrolysate of two edible Nigerian marine molluscs: Tympanatonus fuscatus var radula (L.) and Pachymelania aurita (M.).

The multifunctional nature of antioxidant peptides makes them more attractive candidates as dietary ingredients in health maintenance. Therefore, food protein-derived antioxidant peptides are continuously investigated. This study investigated the in vitro antioxidant properties of hydrolysate and ultrafiltered peptide fractions of Pachymelania aurita and Tympanatonus fuscatus var radula-two commonly consumed marine molluscs known as periwinkles in southern Nigeria. Simulated gastrointestinal digestion (SGID) of soluble proteins of T. fuscatus and P. aurita was carried out using pepsin, trypsin and chymotrypsin, and the SGID hydrolysates were fractionated using a 3 kDa membrane filter. The hydrolysates and their fractions were investigated for anti-lipid peroxidation, hydroxyl radical scavenging activity (HRSA), ferric reducing antioxidant property (FRAP) and metal chelation activity, and they demonstrated clear antioxidant properties in all the assay models used. Low molecular weight fractions of the hydrolysates demonstrated more potent antioxidant activity than higher molecular weight fractions. This is profound in the metal chelation assay, where low molecular weight peptide fractions, T ≤ 3 kDa and P ≤ 3 kDa (IC50 values of 8.10 ± 0.011 and 5.56 ± 0.50 µg/ml respectively) had activity that is similar to that of EDTA (11.84 ± 0.89 µg/ml). Similar activity effects were observed in other assays where there was about 3-fold higher activity in low molecular weight fractions. These results demonstrate the presence of antioxidant peptide(s) in the protein hydrolysates of the periwinkles.

Modulation of Blood Coagulation and Hematological Parameters by Crassocephalum crepidioides Leaf Methanol Extract and Fractions in STZ-Induced Diabetes in the Rat.

Diabetes affects the homeostasis of the circulatory system. Crassocephalum crepidioides Benth S. Moore (Asteraceae) is an edible plant locally used in the treatment of wounds, stomach ulcer, and skin-related conditions in Africa and some other parts of the world. This study investigated the effects of C. crepidioides leaf methanol extract and fractions on blood coagulation profile of diabetic Wistar rats. The effect of 100 mg/kg body weight of the methanol extract and partitioned fractions of C. crepidioides on blood coagulation profile of STZ-induced diabetic rats were initially evaluated, while graded concentrations (50-200 mg/kg body weight) of the aqueous and hexane fractions were further tested in diabetic rats against standard drugs aspirin (anticoagulant) and metformin (antidiabetic). Rats were allocated into groups (n = 6) and administration was done orally, once daily for 2 weeks. The methanol extract and fractions of C. crepidioides at concentrations of 50, 100, and 200 mg/kg significantly prolonged the bleeding (58-200%), clotting (65-133%), prothrombin (176-441%), and activated partial thromboplastin (209-518%) times in diabetic rats compared to the control rats (LD50 ≥ 5000 mg/kg). Highest prolongation effects were recorded in the diabetic group treated with 100 mg/kg body weight of the hexane fraction. Plasma calcium concentration and platelet counts of C. crepidioides treated diabetic rats were significantly (P < 0.05) reduced compared to diabetic control rats, while the red blood cells (RBC), hemoglobin concentration, and packed cell volume (PCV) were significantly increased. This study showed that C. crepidioides possess anticoagulant and antianemic activities. The leaves can thus be a potential source of novel anticoagulant and nutraceutical for management of the thrombotic disorder in diabetes and other diseased states.

Broadening Participation in the Sciences within and from Africa: Purpose, Challenges, and Prospects.

Many of Africa's challenges have scientific solutions, but there are fewer individuals engaged in scientific activity per capita on this continent than on any other. Only a handful of African scientists use their skills to capacity or are leaders in their disciplines. Underrepresentation of Africans in scientific practice, discourse, and decision making reduces the richness of intellectual contributions toward hard problems worldwide. This essay outlines challenges faced by teacher-scholars from sub-Saharan Africa as we build scientific expertise. Access to tertiary-level science is difficult and uneven across Africa, and the quality of training available varies from top-range to inadequate. Access to science higher education needs to increase, particularly for female students, first-generation literates, and rural populations. We make suggestions for collaborative initiatives involving stakeholders outside Africa and/or outside academia that could extend educational opportunities available to African students and increase the chance that Africa-based expertise is globally available.