ISOLATION AND CHARACTERIZATION OF CHEMICAL CONSTITUENTS FROM Chrysophyllum albidum G. DON-HOLL. STEM-BARK EXTRACTS AND THEIR ANTIOXIDANT AND ANTIBACTERIAL PROPERTIES

Background: The plant, Chrysophyllum albidum is indigenous to Nigeria and its stem-bark has found relevance in folkloric medicine for infections and oxidative stress linked diseases medicaments. The study targets to isolate the chemical constituents accountable for the antioxidant and antibacterial actions of the plant stem-bark to substantiate some of its ethnomedicinal uses. Materials and Methods: Stem-bark extract of Chrysophyllum albidum was obtained from 80 % ethanol was partitioned in sequence with ethyl acetate (EtOAc) and n-butanol. The solvent fractions and isolated compounds were verified for antioxidant chattels utilizing 2-2-diphenyl-1-picrylhydrazyl. Antibacterial actions were also assessed by agency of agar-diffusion and broth micro dilution methods. EtOAc fraction was on many occasions chromatographed on silica and Sephadex LH-20 column to afford four compounds and their chemical structures were proven with the employment of NMR (1D and 2D) and MS. Results: Chromatographic fractionation of EtOAc fraction with the premier antioxidant and antimicrobial activities afforded stigmasterol (1), epicatechin (2), epigallocatechin (3) and procyanidin B5 (4). Procyanidin B5 isolated for the first time from Chrysophyllum genus proven the supreme antioxidant activity with IC50 values of 8.8 µM and 11.20 µM in DPPH and nitric oxide assays respectively and equally established the ultmost inhibitory activity against Escherichia coli (MIC 156.25 μg/mL), Staphylococcus aureus (MIC 156.25 μg/mL), Pseudomonas aeruginosa (MIC 625 μg/mL) and Bacillus subtilis (MIC 156.25 μg/mL). Conclusion: The antibacterial and antioxidant activities of epicatechin, epigallocatechin and procyanidin B5 isolated from Chrysophyllum albidum stem-bark substantiate the folkloric use

Effect of NPK Fertilizer on Chemical Composition of Pumpkin (Cucurbita pepo Linn.) Seeds

An investigation of the proximate composition and antioxidant profile of pumpkin seeds obtained from different levels of NPK 15 : 15 : 15 compound fertilizer application at the Obafemi Awolowo University, Ile-Ife, Nigeria was carried out. Pumpkin seeds were grown in 2010 for two cropping seasons (May to August and August to November), and the following fertilizer rates were applied: 0, 50, 100, 150, 200, and 250 kg/ha. Standard analytical methods were used to determine protein, crude fibre, ash, fat, carbohydrate, antioxidant activities, phenol, flavonoid, proanthocyanidin, and anthocyanin. The highest concentrations of the proximate and antioxidants analysed were found from the seeds of control and those treated with lower NPK rates. The mean protein, ash, crude fibre, and carbohydrate values of pumpkin seeds at zero to 100 kg NPK/ha were 27%, 1.56%, 0.56%, and 11.7% respectively. At these same levels of fertilizer, pumpkin seed oil yield was 59%. Antioxidant activities ranged from 89.9 to 90.4% while total phenol was 47 mg/100 g. Except for carbohydrate, the % concentration of nutrients and antioxidants in pumpkin seeds was significantly (P=0.05) depressed with fertilizer rates above 100 g/ha

Anti-hyperglycaemic and anti-oxidant activities of five Nigerian antidiabetic plants

Leaves of Olax subscorpioidea, Hoslundia opposita, Cleistopholis patens, Plumbago zeylanica and Dioscoreophyllum cumminsii that are used as anti-diabetics were evaluated for hyperglycaemic-lowering and antioxidant activities to justify their Nigerian ethnomedicinal usage. Leaf methanolic extracts (100, 200 and 400 mg/kg, p.o.) were assayed in normal, glucose- and alloxan-induced diabetic rats, while 1,1,-diphenyl-2-picrylhydrazyl, total antioxidant capacity, ferric reducing antioxidant power and hydroxyl radical scavenging tests were used for their antioxidant activity. Effects of n-hexane, dichloromethane, ethylacetate and aqueous partition fractions of the three most active anti-hyperglycaemic extracts were also tested in glucose-loaded rats. In normoglycaemic rats, all extracts generally lacked activity, while with glucose-loaded rats, only O. subscorpioidea (200mg/kg) and C. patens (400 mg/kg) at 1 h and O. subscorpioidea (200, 400 mg/kg) and C. patens (400 mg/kg) at 2-4 hours gave lowered (p < 0.05) blood glucose levels than glibenclamide (5 mg/kg), while activity of H. opposita and P. zeylanica (200 mg/kg) were only comparable to glibenclamide. When daily fed for fourteen days to alloxan-induced diabetic rats, all extracts, at their most active doses, gave significantly higher activity than glibenclamide. Olax subscorpioidea leaf extract had the highest hyperglycaemic-lowering and least antioxidant activities. Highest antioxidant activity of H. opposita may suggest some contribution of antioxidant property to its hyperglycaemic-lowering activity. The glucose-lowering and insulinotropic constituents of O. subscorpioidea, H. opposita and C. patens should be concentrated in their aqueous, aqueous and dichloromethane fractions, respectively. Anti-hyperglycaemic ethnomedicinal use of these plants was justified and H. opposita has additional antioxidant property. Keywords: Antioxidant activity; Diabetes mellitus; Nigerian anti-diabetic plants