In this study, we report the effects of a non-antioxidant flavonoid flavone on vascular reactivity in Wistar-Kyoto (WKY) rat isolated aortae. Whether flavone directly modulates vascular reactivity in spontaneously hypertensive rat (SHR) and streptozotocin-induced diabetic-WKY rat isolated aortae was also determined. Thoracic aortic rings were mounted in organ chambers and exposed to various drug treatments in the presence of flavone (10 microM) or its vehicle (DMSO), which served as control. Pretreatment with flavone enhanced relaxant effects to endothelium-dependent vasodilator acetylcholine (ACh) and attenuated contractile effects to alpha(1)-receptor agonist phenylephrine (PE) in WKY aortae compared to those observed in control aortic rings. Flavone had no effect on relaxations to ACh in WKY aortae incubated with either L-NAME or methylene blue, but enhanced relaxations to ACh in WKY aortae incubated with indomethacin or partially depolarized with KCl. Relaxations to ACh are totally abolished in both control or flavone pretreated endothelium-denuded WKY aortae. Flavone attenuated the inhibition by beta-NADH of ACh-induced relaxation in WKY aortae, but it had no significant effect on the transient contractions induced by beta-NADH nor the pyrogallol-induced abolishment of ACh-induced relaxation in WKY aortae. Flavone enhanced endothelium-independent relaxation to sodium nitroprusside (SNP) in both endothelium-intact and -denuded WKY aortae. Flavone enhanced relaxation to ACh and SNP as well as attenuated contractile effects to PE in SHR and diabetic aortae, a finding similar to that observed in normal WKY aortae. From these results, we conclude that flavone modulates vascular reactivity in normal as well as hypertensive and diabetic aortae. These effects of flavone results probably through enhanced bioactivity of nitric oxide released from the endothelium.
Osteoarthritis (OA) is a joint disease characterized by degeneration of cartilage, intra-articular inflammation, remodeling of subchondral bone and joint pain. The present study was designed to assess the therapeutic effects and the possible underlying mechanism of action of Manjarix, a herbal combination composed of ginger and turmeric powder extracts, on chemically induced osteoarthritis in rats. An OA model was generated by intra-articular injection of 50 μL (40 mg mL-1) of monosodium iodoacetate (MIA) into the right knee joint of rats. After one week of osteoarthritis induction, a comparison of the anti-inflammatory efficacy of indomethacin at an oral dose of 2 mg kg-1 daily for 4 successive weeks versus five decremental dose levels of Manjarix (1000, 500, 250, 125, and 62.5 mg kg-1) was performed. Serum inflammatory cytokines, interleukin 6, interleukin 8, and tumor necrosis factor alpha; C-telopeptide of type II collagen (CTX-II) and hyaluronic acid (HA) were measured, along with weekly assessment of the knee joint swelling. Pain-like behavior was assessed and knee radiographic and histological examination were performed to understand the extent of pain due to cartilage degradation. Manjarix significantly reduced the knee joint swelling, decreased the serum levels of IL6, TNF-α, CTX-II and HA, and reduced the pathological injury in joints, with no evidence of osteo-reactivity in the radiographic examination. Manjarix also significantly prevented MIA-induced pain behavior. These results demonstrate that Manjarix exhibits chondroprotective effects and can inhibit the OA pain induced by MIA, and thus it can be used as a potential therapeutic product for OA.
CONTEXT: Bauhinia purpurea L. (Fabaceae) is a native plant species of many Asian countries, including Malaysia and India. In India, the root, stem, bark, and leaf of B. purpurea are used to treat various ailments, including ulcers and stomach cancer.
OBJECTIVE: In an attempt to establish its pharmacological potential, we studied the antiulcer activity of lipid-soluble extract of B. purpurea obtained via extraction of air-dried leaves using chloroform.
MATERIALS AND METHODS: The rats were administered the chloroform extract (dose range of 100-1000 mg/kg) orally after 24 h fasting. They were subjected to the absolute ethanol- and indomethacin-induced gastric ulcer, and pyloric ligation assays after 30 min. The acute toxicity study was conducted using a single oral dose of 5000 mg/kg extract and the rats were observed for the period of 14 days. omeprazole (30 mg/kg) was used as the standard control.
RESULTS: At 5000 mg/kg, the extract produced no sign of toxicity in rats. The extract exhibited significant (p < 0.05) dose-dependent antiulcer activity for the ethanol-induced model. The extract also significantly (p < 0.05) increased the gastric wall mucus production and pH of gastric content, while significantly (p < 0.05) reducing the total volume and total acidity of the gastric content in the pylorus ligation assay.
DISCUSSION AND CONCLUSION: The extract possesses antiulcer, antisecretory and cytoprotective activities, which could be attributed to its flavonoid and tannin content. These findings provide new information regarding the potential of lipid-soluble compounds of B. purpurea for the prevention and treatment of gastric ulcers.