Antiglycation and Hypolipidemic Effects of Polyphenols from Zingiber officinale Roscoe (Zingiberaceae) in Streptozotocin-Induced Diabetic Rats

Purpose: To evaluate the antiglycation and hypolipidemic potential of polyphenols from Zingiber officinale in streptozotocin-induced diabetic rats.Methods: Diabetes was induced in male Wistar rats by single intraperitoneal injection of 50 mg/kg body weight (bw) of streptozotocin. This was followed by oral administration of 500 mg/kg each of free and bound polyphenol extracts of Z. officinale to the rats daily for 42 days. Distilled water and glibenclamide (5 mg/kg) were used as normal and positive controls, respectively.Results: Significant increases (p < 0.05) in blood glucose level (369.26 mg/dL), serum advanced glycation end-products (AGEs) (6.80 μg/mL), lipid profile and atherogenic indices, with decrease in high density lipoprotein cholesterol (HDL-C) (15.55 mg/dL) were observed in diabetic rats compared to control. Free polyphenol extracts of Z. officinale significantly reduced (p < 0.05) blood glucose (147.96 mg/dL), serum AGEs (1.98 μg/mL), lipid profile and atherogenic indices while it significantly increased HDL-C (23.28 mg/dL). However, bound polyphenol extract did not cause any significant change in the lipid profile of the diabetic rats except for LDL-C.Conclusion: This study indicates that free and bound polyphenols from Z. officinale can ameliorate diabetes as well as its complications, and its effect is comparable to that of the standard drug, glibenclamide.Keywords: Zingiber officinale, Diabetes, Lipid profile, Atherogenic index, Polyphenol, Glycation, Streptozotoci

Antimicrobial Activity of the Solvent Fractions from Bulbine Natalensis Tuber

Bulbine natalensis Baker has been acclaimed to be used as an antimicrobial agent in the folklore medicine of South Africa without scientific evidence to substantiate or refute this claim. In view of this, the in vitro antimicrobial activity of solvent fractions (ethanol, ethyl acetate, n-butanol and water) from Bulbine natalensis Tuber against 4 Gram positive and 12 Gram negative bacteria as well as 3 fungal species were investigated using agar dilution. The ethanolic extract, n-butanol and ethyl acetate fractions inhibited 75, 87.5 and 100% respectively of the bacterial species in this study. The ethanolic, n-butanol and ethyl acetate fractions produced growth inhibition at MIC range of 1-10, 3-10 as well as 1 and 5 mg/ml respectively whereas the water fraction did not inhibit the growth of any of the bacterial species. Again, it was only the ethyl acetate fraction that inhibited the growth of Shigelli flexneri, Staphyloccus aureus and Escherichia coli. The ethanolic, ethyl acetate and n-butanolic fractions dose dependently inhibited the growth of Aspergillus niger and A. flavus whereas the water fraction produced 100% growth inhibition of the Aspergillus species at all the doses investigated. In contrast, no growth inhibition was produced on Candida albicans. The growth inhibition produced by the solvent fractions of B. natalensis Tuber in this study thus justifies the acclaimed use of the plant as an antimicrobial agent. The ethyl acetate fraction was the most potent

Toxicological evaluation of the aqueous extract of Felicia muricata Thunb. leaves in Wistar rats

The effect of the aqueous extract of Felicia muricata leaves at 50, 100 and 200 mg/kg body weight in Wistar rats was evaluated for 14 days. The extract caused significant increase in white blood cell (WBC)while it decreased the large unstained cells (LUC). The red blood cell (RBC), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), neurophils,eosinophils and gamma-glutamyl transferase (GGT) compared favourably with the control. There was no significant difference in haemoglobin (Hb) and alanine aminotransferase (ALT) at both 50 and 100 mg/kg, but at 200 mg/kg, there was slight reduction in both parameters. The extract caused progressive significant increase in platelets concentration. The lymphocytes level was significantly higher at 50 and 100 mg/kg. The extract at all doses did not significantly alter the levels of Na, K, Cl, inorganic phosphorus, urea, creatinine, total bilirubin, globulin, total protein, total cholesterol, high densitylipoprotein-cholesterol (HDCL-C) and low density lipoprotein-cholesterol (LDL-C). The liver- and kidneybody weight ratios were not altered by all the doses except an increase in kidney-body weight ratio by the 200 mg/kg body weight of the extract. The concentration of triacylglycerol was increased by the 50 and 100 mg/kg body weight, while that of alkaline phophatase did not follow any regular pattern. There was reduction in the concentration of aspartate aminotransferase (ALT) from 50 to 200 mg/kg body weight. The alterations on some hematological and liver function parameters were an indication that theextract possessed selective toxicity

Morphological characters and ascorbic acid content of an elite genotype of Corchorus olitorius : the influence of moisture stress

Moisture stress can be deleterious to physicochemical properties of crop species to a varying degree. The influence of moisture stress on the ascorbic acid content in the leaf and morphological characters of an elite genotype of Corchorus olitorius were tested in a glasshouse experiment. The experiment was arranged in a completely randomized design replicated four times. The results of the study showed that a distinct moisture-stress threshold, described as heavy moisture stress, existed for the genotype and ascorbic acid accumulation in the leaves decreased by up to 88.7% because of moisture stress. A comparison of the control with heavy moisture stress showed a decline of 57.1% and 68.4% for plant height and number of leaves, respectively. A degree of resilience of C. olitorius to moisture stress was observed with increasing plant age, but with a significant trade-off in the nutritional quality of the genotype at harvest

Effects of aqueous extract from the leaves of Chrysocoma ciliata L. on some biochemical parameters of Wistar rats

The effect of oral administration of aqueous extract of Chrysocoma ciliata leaves at 50, 100, 200 and 400 mg/kg body weight for 14 days on some biochemical parameters of male rats was investigated. Theextract did not have any significant effect (p > 0.05) on the serum concentrations of sodium, potassium, chloride, urea, calcium, albumin, magnesium, inorganic phosphorus, uric acid, globulin and total protein as well as the red blood cell (RBC), hemoglobin (Hb), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC) and red cell distribution width (RCW). While the WBC was reduced at 50 and 100 mg/kg body weight, the 200 and 400 mg/kg body weight increased the blood parameter. The 50, 100 and 200 decreased the MCV. The doses increased the levels of large unstained cells (LUC), neutrophils, eosinophils, serum alkaline phosphatase, gamma glutamyl transferase, alanine and aspartate aminotransaminases whereas the lymphocytes, basophils, serum total and conjugated bilirubin were decreased in the animals. Theplatelet levels fluctuated throughout the experimental period. The level of the monocyte was only increased at 100 mg/kg body weight of the extract. The 50, 100 and 200 mg/kg body weight of the extract decreased the serum cholesterol concentration in the animals, whereas the 400 mg/kg body weight increased the lipid parameter. Similarly, the 50, 100 and 200 mg/kg body weight also decreased the serum triacylglycerol of the animals. The HDL-C, LDL-C and atherogenic index compared favourably with the control. While there was no significant change at all the doses investigated in the kidney and heart-body weight ratios, the extract at 50 and 400 mg/kg body weight increased the liverbody weight ratio. In contrast, the 50, 100 and 200 mg/kg body weight decreased the testes-body weight ratio. The parameter and dose specific effect of the extract on the biochemical parameters suggest selective toxicity