Inhibition of soluble epoxide hydrolase by extracts derived from inflammation-treating Chinese medicinal herbs.

Soluble epoxide hydrolase (sEH) has been proved to be a key enzyme involved in inflammation progression, and inhibition of sEH is therefore very helpful or crucial for the treatment of inflammation-related diseases. In order to uncover new clues suggesting the presence of phytochemical-based sEH inhibitors, and to rationalize the utility of the inflammation-treating Chinese medicinal herbs, the ethanol extracts derived from 46 medicinal herbs, traditionally used for the treatment of inflammation-associated diseases in China, were tested for sEH-inhibition activity using a recently developed sensitive fluorescence-based assay. Screened at 10 microg/mL, four extracts showed substantial inhibitions of sEH (inhibition rates >50%). The ethanol extract of Sophora flavescens root (Fabaceae) possessed the strongest inhibitory activity against sEH (IC(50): 2.07 microg/mL). These preliminary findings highlighted the presence of sEH inhibitor(s) in the plant kingdom, and the possibility that the inflammation-treating herbal medicines could be an untapped reservoir for sEH-inhibition agents.

Anti-adhesive effect of an acidic polysaccharide from Aloe vera L. var. chinensis (Haw.) Berger on the binding of Helicobacter pylori to the MKN-45 cell line.

OBJECTIVES: The emergence of antibiotic-resistant Helicobacter pylori strains has necessitated a search for alternative therapies for the treatment of this infection. The aim of this study was to evaluate whether or not polysaccharide fractions from Aloe vera are effective in inhibiting the adherence of H. pylori in vitro. METHODS: Polysaccharide fractions were extracted from A. vera and subjected to carbohydrate analysis. The adhesive effect was determined by co-incubation of H. pylori and cells with polysaccharides followed by fluorescein isothiocyanate labelling and Gram staining in vitro. Inhibition of H. pylori growth and cellular viability was tested by agar diffusion and MTT assay. KEY FINDINGS: APS-F2 contained significant amounts of galacturonic acid, galactose and arabinose. APS-F1 was galacturonic acid-free and consisted of mannose, glucose and galactose. APS-F2 (0.1, 0.5 and 1.0 mg/ml) reduced the count of H. pylori attached to MKN45 cells to 88, 76 and 64%, respectively. APS-F1 did not show the same effect. Neither polysaccharide revealed an inhibitory effect on the growth of H. pylori or cell viability. In addition, APS-F2 was shown to have a potent anti-adhesive effect against Escherichia coli. CONCLUSIONS: The results show that the acidic polysaccharide from A. vera has a potent anti-adhesive effect against H. pylori in vitro. However, there have yet to be any in-vivo studies to demonstrate the clinical relevance of this finding.