METHODS: Sprague-Dawley female rats (12 weeks old) were divided randomly into five groups (n = 6): healthy; nontreated OA; OA + diclofenac (5 mg/kg); OA + extract (200 mg/kg); and OA + extract (400 mg/kg). Two weeks after bilaterally ovariectomy, OA was induced by intra-articular injection of monosodium iodoacetate into the right knee joints. After 28 days of treatment, the rats were evaluated for knee OA via physical (radiological and histological observations), biochemical, enzyme-linked immunosorbent assay, and gene expression analysis, for inflammation and cartilage degradation biomarkers.
RESULTS: The osteoarthritic rats treated with the extract, and diclofenac showed significant reduction of cartilage erosion (via radiological, macroscopic, and histological images) compared with untreated osteoarthritic rats. The elevated serum interleukin-1β, prostaglandin E2, and C-telopeptide type II collagen levels in osteoarthritic rats were significantly reduced by F deltoidea leaf extract comparable to diclofenac. The extract significantly down-regulated the interleukin-1β, prostaglandin E2 receptor, and matrix metalloproteinase-1 mRNA expressions in the osteoarthritic cartilages, similar to diclofenac.
CONCLUSIONS: F deltoidea leaf extract mitigated postmenopausal osteoarthritic joint destruction by inhibiting inflammation and cartilage degradation enzymes, at an effective extract dose equivalent to about 60 mg/kg for humans. The main bioactive compounds are probably the antioxidative flavonoids vitexin and isovitexin.
METHODS: Eight cyclists exercised at three submaximal intensities before completing a TTE100% at sea-level (SEA) and at 1657 m of altitude (ALT), with pre-exercise consumption of 1000 mg of POMx or a placebo (PLAC) in a randomized, double-blind, crossover design. Data were analysed using a three way (treatment x altitude x intensity) or two-way (treatment x altitude) repeated measures ANOVA with a Fisher's LSD post-hoc analysis. Significance was set at p ≤ 0.05. The effect size of significant interactions was calculated using Cohen's d.
RESULTS: TTE100% performance was reduced in ALT but was not influenced by POMx (p > 0.05). Plasma NO3- were 10.3 μmol greater with POMx vs. PLAC (95% CI, 0.8, 19.7,F1,7 = 7.83, p 0.05). Submaximal VO2 values were not affected by POMx (p ≥ 0.05).
CONCLUSIONS: The restoration of SEA VO2 values at ALT is likely driven by the high polyphenol content of POMx, which is proposed to improve nitric oxide bioavailability. Despite an increase in VO2, no change in exercise performance occurred and therefore this study does not support the use of POMx as an ergogenic supplement.
METHODS: Geraniin (95% purity) was extracted and purified from rambutan rind. Two groups of male Sprague-Dawley rats were fed with 60% high-fat diet and standard rat chow, respectively, for 12 weeks. High-fat diet-treated rats were then administered geraniin at different doses. Body weight, blood pressure and blood glucose readings were measured. At the end of treatment, blood was collected for analysis of glycated haemoglobin A1c (HbA1c), insulin, advanced glycation end-product (AGE) levels, renin, aldosterone and electrolytes.
RESULTS: Within the first week of treatment, even the lowest dose of geraniin caused a significant reduction in blood pressure, which was comparable to control diet-treated rats. There were no changes in serum electrolytes, renin or aldosterone. Similarly, there was a significant reduction in serum insulin, insulin resistance and AGE levels at the lowest dose. However, there was no significant decrease in fasting blood glucose or HbA1c. The effects of decreasing insulin, insulin resistance and AGEs were observed only at the lower doses, unlike the results observed for blood pressure reduction.
CONCLUSION: Geraniin at lower doses improved blood pressure and other metabolic parameters. Secondary metabolites of geraniin, associated with antihypertensive activity, are relatively different to those involved in inhibiting AGE formation and increasing insulin sensitivity. The secondary metabolites of geraniin may be individually responsible for the bioactivities demonstrated.