Evaluation of antimicrobial activity and phytochemical composition of some fractions of methanol stem bark extract of Diospyros mespiliformis

The aim of this study was to determine the active phytochemical(s) most probably responsible for microbial inhibitions, following a bioassay guided protocol. Column chromatographic fractions (AG) obtained from n-Butanol partitioned portion of stem bark extract of Diospyros mespiliformis were analyzed for phytochemical composition. These were subjected to antimicrobial activity tests on clinical isolates of Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans. Phytochemical screening conducted on the column fraction E revealed the presence of tannins, free anthraquinones, cardiac glycosides, saponins, terpenoids, and flavonoids. The anti-microbial test results from fractions A, B, F and G, obtained showed no inhibition against most of the micro-organisms tested, while fractions C, D and E showed significant (P<0.05) activities with diameters of inhibition zone of inhibition ranging from 15.00±1.00 mm to 13.00±6.67 mm against Streptococcus pyogenes at all the concentrations tested (50, 12.5, 6.25 mg/ml equivalent to 3, 1.5 and 0.75 mg/disc). The column fraction E showed the highest inhibition zones with broader concentration dependent pattern with MIC at 12.5 mg/ml. The findings from this study showed the presence of bio-active components against Streptococcus pyogenes with relative higher potency in fraction E. Based on this findings, it can be surmised that Fraction E with significant dose-dependent activity is expected to revealed a potent broad-spectrum antimicrobial agent and thus recommended for further purification stages towards compound(s) isolation of a novel antimicrobial agent.Keywords: Antimicrobial, Diospyros mespiliformis, Phytochemical, Potency, Stem Bar

The Protective Effect of Aqueous Extract of the Calyx of Hibiscus sabdariffa Roselle on the Kidneys of Salt-Loaded Rats

The biochemical and histopathological effects of aqueous extract of Hisbiscus, sabdariffa (Roselle) calyx were investigated in salt-loaded albino rats. Salt-loading resulted in an increase (15.0 ± 2.45%) in body weight, while the administration of the extract caused a decrease in body weight (13.2 ± 2.3%, 14.41 ± 0.55%). Salt-loading resulted in signficantly higher serum Na+, HCO-3, creatinine and urea levels and significantly lower (P < 0.05) serum K+ levels. Treatment with the plant extract caused significantly lower (P < 0.05) serum levels of Na+, HCO-3, creatinine and urea, while serum K+ was significantly increased (

Toxicity Studies and Effects of Momordica balsamina (Balsam Apple) Aqueous Extract on Serum Electrolytes and Plasma Trace Elements

Graded doses of M. balsamina aqueous leaf extract were administered orally and intraperitoneally (i.p) to separate groups of rats to determine the acute toxicities. The effects of the prolonged (3 weeks) oral administration of M. balsamina aqueous extract on serum electrolytes and plasma trace elements were also tested. No toxic clinical signs were observed in the animals given the extract orally. Sixteen grams per kilogram body weight (16 g/kg) was the maximum amount that was physically administered. The i.p LD50 with confidence interval of 95% was estimated to be 3750 mg/kg. Clinical signs observed before mortality included weakness, sleepiness and depression, dilation of the pupils, urination and death within 24 hours. The extract did not produce any statistically significant change in serum electrolytes (Na+, K+, HCO3+ and Cl- ) after prolonged oral administration. However, the effects of M. balsamina extract on plasma Zn and Mn were significantly increased (p0.01). It was, therefore, concluded that Momordica balsamina at low dosages is safe (not toxic). Keywords: Acute toxicity, M. balsamina, electrolytes, trace elementsSahel Journal of Veterinary Sciences Vol. 5 (1) 2006 pp. 13-1

Balsamin, a novel ribosome-inactivating protein from the seeds of Balsam apple Momordica balsamina

Plant seeds, a rich source of proteins, are considered important for their application as functional ingredients in a food system. A novel ribosome-inactivating protein (RIP), balsamin was purified from the seeds of Balsam apple, Momordica balsamina. Balsamin was purified by ion exchange chromatography on CM Sepharose and gel filtration on superdex-75. It has a molecular weight of 28 kDa as shown by SDS-PAGE analysis. Balsamin inhibits protein synthesis in a rabbit reticulocyte lysate-based cell free translation assay with an IC50 of 90.6 ng ml&minus;1. It has RNA N-glycosidase activity and releases a 400-base long fragment termed the Endo fragment from 28S rRNA in the same manner as does saporin-6 from Saponaria officinalis. The N-terminal sequence analysis of the first 12 amino acids of balsamin revealed that it shares 83% similarity with type I RIP &alpha;-MMC from Momordica charantia and 50% similarity with &beta;-MMC (from Momordica charantia), bryodin I (from Bryonia dioica) and luffin a (from Luffa cylindrica). Balsamin was further characterized by mass spectrometry. CD spectroscopic studies indicate that secondary structure of balsamin contains helix (23.5%), &beta;-strand (24.6%), turn (20%) and random coil (31.9%). Thus RIPs activity expressed in vegetables like Momordica sp. advocates its usage in diet