Deciphering the interactions of scopoletin and scopolin from Catunaregam nilotica roots against Naja nigricollis phospholipase A2 enzyme.

Catuneragam nilotica has been used in ethnomedicine to treat snakebite, inflammation, and diarrhea among others. The aim of this research is to isolate, and characterize potential potential phospholipase A2 (PLA2) inhibitors from the roots of C. nilotica. The plant material was collected, authenticated, and sequentially extracted using solvents of increasing polarity starting from n-hexane, ethyl acetate, and methanol. The extracts as reported in our previous work, were screened in vitro for their inhibitory activity against PLA2 enzyme from N. nigricollis venom using acidimetric assay. In line with the bio-activity guided isolation, methanol extract (being the most active) was subjected to chromatographic separation using silica gel and sephadex LH-20 which resulted in the isolation and characterization of scopoletin, and scopolin; the compounds were able to inhibit the hydrolytic actions of PLA2 enzyme with percentage inhibition ranging from 67.82 to 100.00 % and 65.76-93.15 %, respectively while the standard Antisnake Venom (ASV) had 74.96-85.04 % after 10 min incubation at 37 °C. The molecular docking of the compounds against PLA2 enzyme was performed using Auto Dock Vina while ADME-Tox analysis was evaluated using swissADME and ProTox-II online servers; The findings indicated that both compounds were able to bind to the active site of PLA2 enzyme with high affinity (-6.5 to -6.2 kcal/mol) and they exhibited favorable drug-likeness and pharmacokinetic properties, and according to toxicity predictions, scopolin was found to be non-toxic (LD50 of 5000 mg/kg) while scopoletin has a slight chance of being toxic (LD50 of 3800 mg/kg). In conclusion, the findings of the research revealed that the roots of C. nilotica contains phytoconstituents with anti-PLA2 enzyme activity and thus, validates the ethnomedicinal claim of the use of the plant as herbal therapy against N. nigricollis envenomation.

Nutritional composition of the seeds of wild melon (Citrullus ecirrhosus).

The proximate, minerals and amino acids contents of wild melon (Citrullus ecirrhosus) seeds were determined. The results for proximate analysis (% DW) showed a composition of 3.73 +/- 0.25 moisture, 2.12 +/- 0.08 ash 26.36 +/- 0.10 crude protein, 50.67 +/- 10.76 crude lipid, 2.17 +/- 0.29 crude fibre, 18.69 +/- 0.82 available carbohydrate and energy value of 601.7 +/- 8.75 kcal/100 g. The seeds amino acids profile revealed that for adults but leucine, lysine and threonine are below the requirement value for children. The overall result implies that seed of the wild melon possessed the potential to be used as a source of nutrition.

Phytochemical and toxicological studies of aqueous leaves extracts of Erythrophleum africanum.

The leaves of Erythrophleum africanum is known in the arid land of tropical Africa to posses toxicological properties. Phytochemical, acute and sub-acute evaluation of the possible toxicity risk of E. africanum aqueous leaves extracts were investigated in this study. Phytochemical constituents detected in the leaves extracts were saponins (1.16% w/v), cardiac glycosides, tannins (0.17 true tannins and 0.23% w/v pseudotannins), flavonoid glycosides, free flavonoids and alkaloids (4.34% w/v). The Lethal Dose (LD50) of the aqueous leaves extracts was greater than 3000 mg kg(-1) per os (orally) in albino rats. Sub-acute administration of the extract for 28 days resulted in significant (p<0.05) changes in some renal and liver indices at 3000 and 2000-3000 mg kg(-1) body weight, respectively. Histopathological lesions of the kidney and liver in form of moderate and marked infiltration with necrosis and perivascular lymphocytic cuff were observed. The observed lesions could be due to roles played by liver and kidneys in metabolism of xenobiotics and their elimination from the body. These investigations thus seem to indicate the toxic effects of the aqueous leaves extracts of E. africanum at 2000-3000 mg kg(-1). These could be attributed to the combined toxicity of the phytochemical constituents such as tannins, saponins, glycosides and alkaloids.