Lancemaside A, a major triterpene saponin of Codonopsis lanceolata enhances regulation of nitric oxide synthesis via eNOS activation.

BACKGROUND: Many studies on the effect of saponin-rich Codonopsis lanceolata as a bioactive source for improving physical health have been performed. C. lanceolata contains triterpenoid saponins, including lancemasides. These saponins are known to be particularly involved in the regulation of blood pressure or hypertension. This study investigated whether lancemaside A (LA), a major triterpenoid saponin from C. lanceolata, regulates nitric oxide (NO) production via the activation of endothelial NO synthase (eNOS) in human umbilical vein endothelial cells. METHODS: Upon separation with petroleum ether, ethyl acetate, and n-butanol, LA was found to be abundant in the n-butanol-soluble portion. For further purification of LA, HPLC was performed to collect fraction, and LA was identified using analysis of LC/MSMS and 13C-NMR values. In in vitro, the effects of LA on NO release mechanism in HUVECs were investigated by Griess assay, quantitative real-time reverse-transcription PCR, and Western blotting. RESULTS: Our results showed that NO production was efficiently improved by treatment with LA in a dose-dependent manner. In addition, the LA treatment resulted in extensive recovery of the NO production suppressed by the eNOS inhibitor, L-NAME, compared with that in the control group. Additionally, the level of eNOS mRNA was increased by this treatment in a dose-dependent manner. These results suggested that LA is an inducer of NO synthesis via eNOS mRNA expression. Also, the study indicated that LA is involved in activating the PI3K/Akt/eNOS signaling pathway. CONCLUSION: These results suggested that LA is an inducer of NO synthesis via eNOS mRNA expression. Also, the study indicated that LA is involved in activating the PI3K/Akt/eNOS signaling pathway. These findings suggest the value of using LA as a component of functional foods and natural pharmaceuticals.

Antibacterial characteristics of Curcuma xanthorrhiza extract on Streptococcus mutans biofilm.

This study evaluated the antibacterial effects of a natural Curcuma xanthorrhiza extract (Xan) on a Streptococcus mutans biofilm by examining the bactericidal activity, inhibition of acidogenesis and morphological alteration. Xan was obtained from the roots of a medicinal plant in Indonesia, which has shown selective antibacterial effects on planktonic S. mutans. S. mutans biofilms were formed on slide glass over a 72 h period and treated with the following compounds for 5, 30, and 60 min: saline, 1% DMSO, 2 mg/ml chlorhexidine (CHX), and 0.1 mg/ml Xan. The Xan group exposed for 5 and 30 min showed significantly fewer colony forming units (CFU, 57.6 and 97.3%, respectively) than those exposed to 1% DMSO, the negative control group (P<0.05). These CFU were similar in number to those slides exposed to CHX, the positive control group. Xan showed similar bactericidal effect to that of CHX but the dose of Xan was one twentieth that of CHX. In addition, the biofilms treated with Xan and CHX maintained a neutral pH for 4 h, which indicates that Xan and CHX inhibit acid production. Scanning electron microscopy showed morphological changes in the cell wall and membrane of the Xan-treated biofilms; an uneven surface and a deformation in contour. Overall, natural Xan has strong bactericidal activity, inhibitory effects on acidogenesis, and alters the microstructure of S. mutans biofilm. In conclusion, Xan has potential in anti-S. mutans therapy for the prevention of dental caries.