Siderophore-producing rhizobacteria reduce heavy metal-induced oxidative stress in Panax ginseng Meyer.

BACKGROUND: Panax ginseng is one of the most important medicinal plants and is usually harvested after 5 to 6 years of cultivation in Korea. Heavy metal (HM) exposure is a type of abiotic stress that can induce oxidative stress and decrease the quality of the ginseng crop. Siderophore-producing rhizobacteria (SPR) may be capable of bioremediating HM contamination. METHODS: Several isolates from ginseng rhizosphere were evaluated by in vitro screening of their plant growth-promoting traits and HM resistance. Subsequently, in planta (pot tests) and in vitro (medium tests) were designed to investigate the SPR ability to reduce oxidative stress and enhance HM resistance in P. ginseng inoculated with the SPR candidate. RESULTS: In vitro tests revealed that the siderophore-producing Mesorhizobium panacihumi DCY119T had higher HM resistance than the other tested isolates and was selected as the SPR candidate. In the planta experiments, 2-year-old ginseng seedlings exposed to 25 mL (500 mM) Fe solution had lower biomass and higher reactive oxygen species level than control seedlings. In contrast, seedlings treated with 108 CFU/mL DCY119T for 10 minutes had higher biomass and higher levels of antioxidant genes and nonenzymatic antioxidant chemicals than untreated seedlings. When Fe concentration in the medium was increased, DCY119T can produce siderophores and scavenge reactive oxygen species to reduce Fe toxicity in addition to providing indole-3-acetic acid to promote seedling growth, thereby conferring inoculated ginseng with HM resistance. CONCLUSIONS: It was confirmed that SPR DCY119T can potentially be used for bioremediation of HM contamination.

Lactobacillus fermentum KP-3-fermented ginseng ameliorates alcohol-induced liver disease in C57BL/6N mice through the AMPK and MAPK pathways.

Panax ginseng was fermented using Lactobacillus fermentum KP-3, and the levels of the minor ginsenosides were measured. Then, the effect of fermented ginseng on alcohol-induced liver injury was investigated. C57BL/6N mice were randomly assigned to 4 groups: pair fed (PF), alcohol fed (AF), alcohol with non-fermented ginseng (AF + NFG) and alcohol with fermented ginseng (AF + FG) groups. After treatment for 8 weeks, fermented ginseng intervention significantly reduced the levels of serum ALT, AST, LPS, TG and TC compared with the AF group. The western-blotting results showed that fermented ginseng activated the adenosine-monophosphate-activated protein kinase (AMPK) pathway to inhibit de novo lipogenesis in the liver and inhibited phosphorylation of p38 through the mitogen-activated protein kinase (MAPK) pathway to alleviate hepatic inflammation, and these effects were superior than those of non-fermented ginseng. Furthermore, fermented ginseng reduced alcohol-induced liver oxidative damage by upregulating the levels of antioxidant enzymes. These findings suggested that the L. fermentum KP-3-fermented ginseng product may be used as a potential dietary nutraceutical for alleviating alcoholic liver injury.

Protective effects of enhanced minor ginsenosides in Lactobacillus fermentum KP-3-fermented ginseng in mice fed a high fat diet.

Lactobacillus fermentum KP-3 was isolated from Korean pickle and used to ferment ginseng. The changes in the minor ginsenosides in the fermented ginseng were analyzed and the material was evaluated in high fat diet-fed mice. Total ginsenosides increased from 0.746 mg g-1 to 0.939 mg g-1 after fermentation, and the levels of minor ginsenosides (Rg2, Rg3, Rh1, Rh2, F2, and Ro) increased from 0.186 mg g-1 to 0.704 mg g-1. In an animal study, the serum TC and LDL levels in the HFD group were significantly higher than those of the control group. Compared with the HFD group, the probiotic-fermented ginseng significantly decreased the serum TC and LDL levels. In addition, the serum and liver ALT and AST levels were dramatically increased in the HFD group, but these increases were significantly inhibited by treatment with the probiotic-fermented ginseng. Furthermore, fermented ginseng reduced high fat diet-induced liver lipid accumulation. Overall, fermentation with L. fermentum KP-3 enhanced minor ginsenosides in ginseng and this probiotic-fermented ginseng ameliorated hyperlipidemia and liver injury induced by a high fat diet.