Suppressive effects of wild bitter gourd (Momordica charantia Linn. var. abbreviata ser.) fruit extracts on inflammatory responses in RAW 264.7 macrophages

Aim of the study: Bitter gourd (Momordica charantia) is used to treat various diseases including inflammation. A wild species of bitter gourd, Momordica charantia Linn. var. abbreviata ser. (WBG), is considered to be more potent in disease prevention than is bitter gourd; however, little is known about the biological and physiological characteristics of WBG. Materials and methods: The present study investigated the anti-inflammatory effect of WBG on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Results: Among the hot water, 95% ethanol, and ethyl acetate extracts of WBG, the ethanol extract showed the greatest reduction of LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production and inducible nitric oxide synthase (iNOS) and pro-interleukin-1β expression. LPS-induced cyclooxygenase-2 expression was not affected by WBG extracts. Compared with WBG, extracts from bitter gourd showed a lesser inhibition of LPS-induced events. Electrophoretic mobility shift assay further showed that both the hot water and the ethanol extracts of WBG inhibited NF-κB activation. Although information is lacking on the bioactive components of WBG, the phenolic compound contents of each extract significantly paralleled its anti-inflammatory ability (r = 0.74, 0.88 and 0.65 for NO, PGE2 and iNOS expression, respectively, P < 0.05). Conclusions: These results suggest that WBG is beneficial for reducing LPS-induced inflammatory responses by modulating NF-κB activation.