Sesquiterpene fractions of Artemisia plants as potent inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 expression.

OBJECTIVES: Artemisia species are important medicinal plants throughout the world. Some species are traditionally used for their anti-inflammatory effect. The present study was designed to isolate sesquiterpene fractions from several Artemisia species and evaluate their anti-inflammatory activities on key mediators and signaling molecules involved in regulation of inflammation. MATERIALS AND METHODS: Sesquiterpene fractions were prepared from several Artemisia species using the Herz-Högenauer technique. Lipopolysaccharide (LPS)-stimulated J774A.1 macrophages were exposed to isolated fractions. Their possible cytotoxic effect was examined using MTT assay. In addition, nitric oxide (NO) release was measured using Griess method and prostaglandin E2 (PGE2) level was determined by enzyme-linked immunosorbent assay (ELISA). Moreover, protein expression of pro-inflammatory enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were investigated using Western blot analysis. RESULTS: Nitric oxide level produced by LPS-primed macrophages was significantly decreased with all prepared fractions in a dose-dependent manner. Saturated sesquiterpene lactones-rich species (Artemisia kopetdaghensis, Artemisia santolina, Artemisia sieberi) showed the highest suppressive activity on NO and PGE2 production via suppression of iNOS and COX-2 expression. Fractions bearing unusual (Artemisia fragrans and Artemisia absinthium) and unsaturated sesquiterpene lactones (Artemisia ciniformis) possess less modulatory effect on PGE2 production and COX-2 expression. CONCLUSION: It can be concluded that some of the medicinally beneficial effects attributed to Artemisia plants may be associated with the inhibition of pro-inflammatory signaling pathways. However, these effects could be dependent on the type of their sesquiterpene content. These findings also introduce new Artemis species cultivated in Iran as a useful anti-inflammatory agents.

A study to investigate the biological activity of proteoglycan mixture extract from Convolvulus arvensis.

BACKGROUND: Convolvulus arvensis L. (Convolvulaceae), bindweeds, is inhabitant to Iran and its proteoglycan mixture (PGM) has been reported to possess different biological activities. In the present study, we aimed to investigate different properties of PGM including anti-tumor, anti-angiogenesis and immunostimulatory activities. METHODS: PGM was prepared from the roots of C. arvensis. Various cancer cell lines were treated with PGM and the cytotoxicity was assessed after 24 h of incubation using MTT assay. In addition, J774A.1 macrophages were stimulated with LPS (1 µg/mL) and then with PGM. Then, production of nitric oxide (NO) as a marker of inflammation was measured using Griess reagent. Moreover, PGM was subjected to cultivated Leishmania major promastigotes and leishmanicidal activity was determined using MTT assay. More importantly, human umbilical vein endothelial cells (HUVEC) cultured on matrigel basement matrix and tube formation after treatment with PGM was considered microscopically for the determination of angiogenesis. RESULTS: Obtained results revealed that PGM significantly inhibited the formation of vascular-like tubes by HUVECs without any effect on their viability. Furthermore, PGM significantly exhibited leishmanicidal activity by the mechanism of suppressing L. major promastigotes developmental growth in vitro. However, PGM was shown to have no effect on the growth of cancer cells and production of NO by LPS-stimulated macrophages. CONCLUSIONS: The present study provides some new evidence on remarkable leishmanicidal and anti-angiogenic activities of PGM. These findings also afford the scientific basis for the use of C. arvensis as a candidate medicinal plant for further thoroughly phytochemical investigations toward discovering leishmanicidal and anti-angiogenic compounds.

Rose Bengal suppresses gastric cancer cell proliferation via apoptosis and inhibits nitric oxide formation in macrophages.

Rose Bengal (RB) has been used as a safe agent in clinical diagnosis. In addition, it is used as a photodynamic sensitizer for removing microorganisms and cancer cells. Recently, its preferential toxicity after direct exposure to cancer cells was proven. The present study focuses on anti-cancer and anti-inflammatory activities of RB. The toxicity of RB against AGS gastric cancer and NIH 3T3 fibroblast cell lines was studied using an MTT assay. Patterns of any cell death among the AGS cells were defined using Annexin-V and PI staining. In addition, the effect of RB on nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production induced by lipopolysaccha-ride in J774A.1 macrophages was determined. Modulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 expressions in the macrophages was also evaluated by Western blots. The results showed that AGS cells exhibited significant concentration-dependent decreases in growth in response to RB; these cells showed a greater growth inhibition than did non-malignant 3T3 cells, suggesting that anti-growth activity of RB could be cell-specific. Moreover, AGS cells exposed to RB exhibited a significant increase in apoptosis; only at high RB doses did the cells display significant levels of necrosis. While RB also caused a modest decrease in the growth of J774A.1 macrophages, the cells displayed remarkable decreases in NO production and iNOS expression without significant concurrent modulation in PGE(2) production or COX-2 expression. The data from this study appears to suggest that RB differentially impacts on transformed cell lines, preferentially suppresses growth of a gastric cancer cell line through induction of apoptosis, and induces changes in cells that could reflect potential anti-inflammatory effects that might be induced in situ.