Suppressive effects of nitric oxide production and inducible nitric oxide synthase (iNOS) gene expression by Calystegia soldanella methanol extract on lipopolysaccharide-activated RAW 264.7 cells

Abstract

Since nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) has been found to be involved in various pathophysiological processes, including inflammation and carcinogenesis, the modulators of NO synthesis or expression have been considered as potential anti-inflammatory and cancer chemopreventive agents. In this study, to procure the iNOS inhibitors from natural products, we evaluated 57 methanol extracts of natural products including Korean indigenous plants for the inhibition of NO formation on lipopolysaccharide (LPS)-activated mouse macrophage-like RAW 264.7 cells. As a result, several extracts including those from Actinodaphne lancifolia, Calystegia soldanella, Caryratia japonica, Citrus dachibana, Dystaenia takeshimana, Erysimum aurantiacum, Hovenia undulata, Stewartia koreana and Viburnum awabuki showed potent inhibitory activities of NO production (>70% inhibition at the test concentration of 40 microg/ml). In particular, the extract of Calystegia soldanella showed a potential inhibition of NO production in a dose-dependent manner (IC50=4.3 microg/ml). Subsequent study also exhibited that the extract of Calystegia soldanella significantly suppressed iNOS protein and gene expression in a dose-dependent manner. These results suggest that Calystegia soldanella might be a new potential candidate for developing an iNOS inhibitor from natural products and also could be warranted for further elucidation of active principles for the development of new anti-inflammatory and/or cancer chemopreventive agents.

Resveratrol derivatives as promising chemopreventive agents with improved potency and selectivity

“…Nitrite in cultured media, a stable end product of NO, was estimated by the addition of Griess reagent and the absorbance was measured at 540 nm. A standard curve was created by using known concentrations of sodium nitrite to convert the absorbance to the concentration of nitrite in cultured media [84]. …”

Cancer Chemopreventive and Anticancer Evaluation of Extracts and Fractions from Marine Macro- and Microorganisms Collected from Twilight Zone Waters around Guam[1]

“…A standard curve was created by using known concentrations of sodium nitrite [46]. The positive control in this assay was Na-L monomethyl arginine (L-NMMA); IC 50 = 19.7 μM.…”

Crude extract and solvent fractions of Calystegia soldanella induce G1 and S phase arrest of the cell cycle in HepG2 cells

“…Another species, C. japonica , which has been used as a traditional medicine to treat urination problems, fever, or diarrhea in Chinese and oriental herb medicine (33,34). Moreover, C. soldanella has been shown to exhibit a number of biological activities, including anti-inflammatory, antiviral, antifungal, anticancer, and analgesic properties, and more specifically, inhibition of protein tyrosine phosphate 1B (PTP1B) (35–42). Methanol extracts of C. soldanella decreased NO production, iNOS protein, and mRNA expression in LPS-activated Raw 264.7 cells (35).…”

“…Moreover, C. soldanella has been shown to exhibit a number of biological activities, including anti-inflammatory, antiviral, antifungal, anticancer, and analgesic properties, and more specifically, inhibition of protein tyrosine phosphate 1B (PTP1B) (35–42). Methanol extracts of C. soldanella decreased NO production, iNOS protein, and mRNA expression in LPS-activated Raw 264.7 cells (35). Water extracts of C. soldanella induced anti-inflammatory and analgesic effects in mice (36).…”