Cholesterol-lowering activity of Lactobacillus plantarum HLX37 in vitro and in vivo

Lactobacillus plantarum HLX37 is a new lactic acid bacteria strain isolated from the naturally fermented yogurt prepared by local dairy farmer in Nanping City( Fujian,China).In this paper,the tolerance capacity of HLX37 to acid or bile salt stresses and its cholesterol- lowering activity both in vitro and in vivo were investigated. The result of in vitro study showed that HLX37 could survive after 4 h of incubation in MRS medium at p H3.0 or 3.0 g / L of bile salt,with the survival rates being 59.1% ± 4.8% and 48.2% ± 4.9%,respectively. HLX37 could reduce the cholesterol content by 37.33% ± 2.55% and 44.72% ± 2.74% after 24 h and 48 h of incubations in MRS medium supplemented with cholesterol and bile salt.The in vivo experiment demonstrated that intragastric administration of HLX37- fermented yogurt for consecutive 65 days could significantly decrease the serum level of total cholesterol in hypercholesterolaemic rats( p < 0.05),while the heat- inactivated HLX37- fermented yogurt did not possess the ability. This indicated that only the active HLX37 strain had the capacity to lower serum cholesterol in hypercholesterolemic rats.In conclusion,HLX37 exhibited a good cholesterol- lowering activity both in vitro and in vivo,it may have great potentiality to be applied in the production of functional fermented foods.