NO Production Inhibitory Activity Research Articles

Design and synthesis of urea and thiourea derivatives and their inhibitory activities on lipopolysaccharide-induced NO production

Series of ureas and thioureas were designed and synthesized, and their inhibitory activities of NO production in lipopolysaccharide-activated macrophages were evaluated. We found several essential moieties in the structure of the prepared compounds for the activity. Thiourea derivatives revealed higher inhibitory activity than the corresponding urea derivatives. Among these compounds, 7e having carboxymethyl group at N3 position of thiourea was the most potent in the inhibition of NO production. They inhibited NO production through the suppression of iNOS protein and mRNA expression.

Correlation between Flavonoid Content and the NO Production Inhibitory Activity of Peel Extracts from Various Citrus Fruits

We investigated the correlation between the flavonoid content and NO production inhibitory activity of fruit peel extracts using 20 citrus plants. The contents of seven flavonoids (naringin, naringenin, hesperidin, hesperetin, rutin, nobiletin, and tangeretin) were determined by HPLC analysis. Each citrus peel extract varied in flavonoid content, but the contents of nobiletin and tangeretin, which were contained in all 20 fruit peels, showed a positive and significant correlation with each other (r=0.879, p<0.0005 for immature fruit peels; r=0.858, p<0.0005 for mature fruit peels). All citrus peel extracts dose-dependently inhibited LPS-induced NO production in RAW 264.7 cells. This inhibitory effect was significantly and positively correlated with the content of nobiletin and tangeretin. Nobiletin showed a more potent NO production inhibitory activity (IC50=26.5 microM) compared to tangeretin (IC50=136.6 microM). This result supports the premise that nobiletin-rich citrus may provide protection against disease resulting from excessive NO production.

Inhibitory activity of Chinese herbal medicines toward histamine release from mast cells and nitric oxide production by macrophage-like cell line, RAW 264.7

One hundred and six species of traditional Chinese herbs were collected from the northeast of China, extracted with 60% ethanol, and tested for activity inhibiting histamine release and nitric oxide (NO) production. We found that 18 of the 106 species showed strong histamine-release inhibitory activity (inhibition >80%, 100 μg/ml), of which Bidens parviflora Willd. was recognized to present the strongest activity (inhibition 97.8%, 100 μg/ml). Seven species exhibited strong NO-production inhibitory activity (inhibition >50%, 100 μg/ml) with Pholidota chinensis Lindl. as the most active one (inhibition 86.2%, 100 μg/ml).

Anti-inflammatory and related pharmacological activities of cultured mycelia and fruiting bodies of Cordyceps militaris

This study aimed to elucidate pharmacological activities of Cordyceps militaris. The 70% ethanolic extracts of cultured mycelia (CME) and fruiting bodies (FBE) of Cordyceps militaris were prepared. CME was able to directly scavenge the stable free radical diphenyl-2-picrylhydrazyl (DPPH), indicating its antioxidant activity. Both CME and FBE showed topical anti-inflammatory activity in the croton oil-induced ear edema in mice. CME was found to contain acute anti-inflammatory activity, which was evaluated using the carrageenin-induced edema, and also strong antinociceptive activity in writhing test. CME and FBE contain potent inhibitory activity on the chick embryo chorioallantoic membrane (CAM) angiogenesis in a dose-dependent manner. Cordycepin, a metabolite of Cordyceps militaris, appeared to be at least partly responsible for its anti-inflammatory and anti-angiogenic activities. CME concentration-dependently inhibited the NO production and iNOS expression upon stimulation by lipoposaccharide in RAW 264.7, a murine macrophage cell line. In brief, we demontrate that Cordyceps militaris possesses anti-inflammatory and antinociceptive activites, and related antioxidant, anti-angiogenic, and NO production-inhibitory activities.