Protective effects of five allium derived organosulfur compounds against mutation and oxidation.

In this study, we examined the ability of five allium-derived organosulfur compounds to protect cells against mutation and oxidation. The compounds tested were 1-propylmercaptan (PM), dimethyl disulfide (DMDS), diallyl disulfide (DADS), propyl disulfide (PDS), and 2,5-dimethylthiophene (DMT). Our results showed that when used at concentrations of 100-400 µmol/l, the five compounds inhibited the mutagenicity of 4-nitroquinoline-N-oxide, a direct mutagen, and benzo[a]pyrene, an indirect mutagen, toward Salmonella typhimurium TA 98 and TA 100. Furthermore, at these concentrations, all five of the compounds protected HepG2 cells against tert-butyl hydroperoxide-induced oxidative cytotoxicity. The compounds likely enhanced cell viability by suppressing the formation of reactive oxygen species and the depletion of glutathione depletion in cells. DMT and PM inhibited mutation and oxidation to a greater extent than DMDS, DADS, and PDS. These results demonstrate for the first time that DMT and PM can contribute to the antimutagenic and the antioxidative property of Allium vegetables.

Effects of lactic acid bacteria isolated from fermented mustard on lowering cholesterol.

OBJECTIVE: To evaluate the ability of lactic acid bacteria (LAB) strains isolated from fermented mustard to lower the cholesterol in vitro. METHODS: The ability of 50 LAB strains isolated from fermented mustard on lowering cholesterol in vitro was determined by modified o-phtshalaldehyde method. The LAB isolates were analyzed for their resistance to acid and bile salt. Strains with lowering cholesterol activity, were determined adherence to Caco-2 cells. RESULTS: Strain B0007, B0006 and B0022 assimilated more cholesterol than BCRC10474 and BCRC 17010. The isolated strains showed tolerance to pH 3.0 for 3 h despite variations in the degree of viability and bile-tolerant strains, with more than 10(8) CFU/mL after incubation for 24 h at 1% oxigall in MRS. In addition, strain B0007 and B0022 identified as Lactobacillus plantarum with 16S rDNA sequences were able to adhere to the Caco-2 cell lines. CONCLUSIONS: These strains B0007 and B0022 may be potential functional sources for cholesterol-lowering activities as well as adhering to Caco-2 cell lines.

Inhibitory effects of water extract from longan twigs on mutation and nitric oxide production.

This study examines the inhibitory effects of water extract from longan twigs (WLTs) on mutation and nitric oxide (NO) production. The results show that WLT inhibited the mutagenicity of 2-aminoanthracene (2-AA), an indirect mutagen, and 4-nitroquinoline-N-oxide (4-NQO), a direct mutagen toward Salmonella typhimurium TA 98 and TA 100. In addition, WLT in the range 0-0.6 mg/ml showed radical scavenging, reducing activities and chelating activity, as well as decreased lipid oxidative damage. Meanwhile, WLT also inhibited tyrosinase activity and NO generation in lipopolysaccharide (LPS) stimulated macrophages. High performance liquid chromatography analysis suggests that the major phenolic constituents in WLT are epicatechin, ellagic acid and gallic acid. These bioactive components may contribute to the protective effects of WLT. Our data suggests that WLT can be applied to antimutation, anti-inflammation and antityrosinase.