GC-MS and LC-TOF-MS profiles, toxicity, and macrophage-dependent in vitro anti-osteoporosis activity of Prunus africana (Hook f.) Kalkman Bark.

Osteoporosis affects millions of people worldwide. As such, this study assessed the macrophage-dependent in vitro anti-osteoporosis, phytochemical profile and hepatotoxicity effects in zebrafish larvae of the stem bark extracts of P. africana. Mouse bone marrow macrophages (BMM) cells were plated in 96-well plates and treated with P. africana methanolic bark extracts at concentrations of 0, 6.25, 12.5, 25, and 50 µg/ml for 24 h. The osteoclast tartrate-resistant acid phosphatase (TRAP) activity and cell viability were measured. Lipopolysaccharides (LPS) induced Nitrite (NO) and interleukin-6 (IL-6) production inhibitory effects of P. africana bark extracts (Methanolic, 150 µg/ml) and ß-sitosterol (100 µM) were conducted using RAW 264.7 cells. Additionally, inhibition of IL-1ß secretion and TRAP activity were determined for chlorogenic acid, catechin, naringenin and ß-sitosterol. For toxicity study, zebrafish larvae were exposed to different concentrations of 25, 50, 100, and 200 µg/ml P. africana methanolic, ethanolic and water bark extracts. Dimethyl sulfoxide (0.05%) was used as a negative control and tamoxifen (5 µM) and dexamethasone (40 µM or 80 µM) were positive controls. The methanolic P. africana extracts significantly inhibited (p < 0.001) TRAP activity at all concentrations and at 12.5 and 25 µg/ml, the extract exhibited significant (p < 0.05) BMM cell viability. NO production was significantly inhibited (all p < 0.0001) by the sample. IL-6 secretion was significantly inhibited by P. africana methanolic extract (p < 0.0001) and ß-sitosterol (p < 0.0001) and further, chlorogenic acid and naringenin remarkably inhibited IL-1ß production. The P. africana methanolic extract significantly inhibited RANKL-induced TRAP activity. The phytochemical study of P. africana stem bark revealed a number of chemical compounds with anti-osteoporosis activity. There was no observed hepatocyte apoptosis in the liver of zebrafish larvae. In conclusion, the stem bark of P. africana is non-toxic to the liver and its inhibition of TRAP activity makes it an important source for future anti-osteoporosis drug development.

Hypoglycemic Activity of Aqueous Root Bark Extract Zanthoxylum chalybeum in Alloxan-Induced Diabetic Rats.

BACKGROUND: Medicinal plants offer cheaper and safer treatment options to current diabetic drugs. The present study evaluated the effect of aqueous root bark extract of Zanthoxylum chalybeum on oral glucose tolerance and pancreas histopathology in alloxanized rats. METHOD: Diabetes was induced in rats by administration of alloxan monohydrate. Root extract of Z. chalybeum was administered to rats at 200 and 400 mg/kg BW daily for 28 days. Blood glucose was measured by glucometer and pancreatic histopathology evaluated microscopically. RESULTS: Initial increase was observed in blood glucose of the rats after oral administration of glucose from time zero. Two hours after treatment with Z. chalybeum, a significant reduction in blood glucose was observed within treatment groups (p < 0.05) compared to 0.5 hr and 1 hr. There was no significant difference between treatment group receiving 400mg/Kg BW extract and the normal groups (p = 0.27), implying that the former group recovered and were able to regulate their blood sugar, possibly via uptake of glucose into cells. The reversal in pancreatic histopathology further supports the protective effect of Z. chalybeum extract towards diabetic damage. CONCLUSION: Extract of Z. chalybeum is effective in controlling blood glucose in diabetes and protecting pancreatic tissues from diabetic damage.