Papers by Keyword: Nitrosamine Formation Inhibiting

Abstract: Chroogomphis rutillus extracts were prepared with solvent of petroleum ether, acetic ester, methanol and water. The effects of four different extract on nitrite scavenging (NS) and nitrosamine formation inhibiting (NFI) were evaluated in vitro systems. Results showed that all the extract showed NS and NFI potentials with a dose-dependent manner. With regard to NS activity, at 50μg/mL, the scavenging rates of ethyl acetate and methanol extracts were 96.65% and 93.48%, respectively. While, those of petroleum ether and water extract were only 86.96% and 26.09%, respectively. With regard to NFI activity, at 200μg/mL, both petroleum ether and ethyl acetate extracts showed excellent inhibition abilities of 94.46% and 91.33%, respectively, much higher than those of methanol and water extract (78.57% and 4.06%, respectively) (P<0.05). Chroogomphis rutillus especially ethyl acetate extract may have a preventive effect against carcinogenesis induced by nitrosamines.

Abstract: 50% (V/V) ethanol extract from laoying tea (Litsea coreana Level.) was fractionated by liquid-liquid partition using ethyl acetate, n-butanol and water, respectively. The activities of nitrite scavenging (NS) and nitrosamine formation inhibiting (NFI) of three different fractions have been investigated in vitro systems. In the above assays, all the fractions showed NS and NFI potentials to varying degrees. With regard to NS activity, fractions were effective in the order: ethyl acetate > n-butanol > water fraction. EC₅₀ values for inhibiting ability on nitrosamine formation for ethyl acetate, n-butanol and water fraction were 0.170, 0.554 and 0.725 mg/mL, respectively. Total flavonoids could be the major NS and NFI components and were in the order: ethyl acetate > n-butanol > water fraction. Based on EC₅₀ values, laoying tea especially ethyl acetate-soluble fraction may have a preventive effect against carcinogenesis induced by nitrosamines.