Anti-inflammatory effects of triterpenes and steroid compounds isolated from the stem bark of Hiptage benghalensis

Research Highlights
• Isolation of seven triterpenes and a steroid derivative from the stem bark of Hiptage benghalensis.
• Compounds 1, 2, and 5–8 suppress inflammation by modulating iNOS and COX-2 expressions.
• Compounds 1, 2, 7, and 8 exhibit anti-inflammatory activity through the suppression of NF-κB.

In this study, we investigated the anti-inflammatory effects of triterpenes and steroid derivative isolated from the stem bark of Hiptage benghalensis in LPS-stimulated RAW 264.7 macrophages. In the extraction and isolation section, the chloroform-soluble fraction of the stem bark of H. benghalensis led to the isolation of seven triterpenes and a steroid derivative. These compounds were characterized as alnus-5(10)-en-3β-yl acetate (1), oleanan-3-one (2), 3β-acetoxy-9β-bauer-7-en-6-one (3), lupeol (4), (24R)-24-propylcholesterol (5), alnus-5(10)-en-3β-ol (6), 3β-acetoxy-20-hydroxylupane (7), and betulonic acid (8) by spectroscopic methods. In vitro anti-inflammatory activity, compounds 1, 2, 5, 6, 7, and 8 significantly inhibited the productions of NO and PGE2, and protein expressions of iNOS and COX-2 in LPS-stimulated RAW 264.7 macrophages. Compounds 1, 2, 7, and 8 also significantly increased the protein expression of IκBα, and decreased the protein expression of p-p65 and transcriptional activity of NF-κB in LPS-stimulated RAW 264.7 macrophages. Taken together, the present study clearly demonstrates that compounds isolated from the stem bark of H. benghalensis exhibit anti-inflammatory activity through the suppression of NF-κB in LPS-stimulated RAW 264.7 macrophages.