Herbal Formula IM-B Possesses Antioxidant Activities and Reduces Expression of Proinflammatory Cytokines in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages.

Abstract

IM-B is a herbal formula comprising extracts derived from four medicinal herbs previously reported to exhibit antioxidant and anti-inflammatory properties. In this study, the bioactive compounds of IM-B extract, as well as its antioxidant and anti-inflammatory properties, were explored. Chemical compounds in IM-B extract were identified through phytochemical analysis using LC-ESI-QTOF-MS/MS. Fifteen compounds comprising naringenin 5-methyl ether, alpinetin, pinocembrin, 2',4',6'-trihydroxydihydrochalcone, demethoxycurcumin, curcumin, alpinetin methyl ether, caffeic acid, myrcene, bisdemethoxycurcumin, geraniol, pinostrobin, pinostrobin chalcone, cannabidiol, and astaxanthin were analyzed. Based on the total phenolic (106.20 ± 3.11 mg GAE/g extract) and flavonoid (94.65 ± 2.65 mg QE/g extract) contents of the IM-B extract, we consider it a good source of these secondary metabolites. Its antioxidant activities were 4.03 ± 0.63 μg/mL, 9.11 ± 0.57 μg/mL, and 126.84 ± 0.30 mg FeSO₄/g extract based on 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays, respectively. Analyses of the association of IM-B extract with nitric oxide (NO), prostaglandin E2, and cytokines (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]) revealed that IM-B extract significantly inhibits the LPS-stimulated proinflammatory responses in RAW 264.7 macrophage cells. These findings support the potential effectiveness of IM-B as an herbal supplement in health promotion.