In vivo determination of analgesic and anti-inflammatory activities of isolated compounds from Cleome amblyocarpa and molecular modelling for the top active investigated compounds

Abstract

Cleome amblyocarpa Barr. and Murb. from the family Cleomaceae is used in folk medicine as it has analgesic, anti-inflammatory, antibacterial and antioxidant activities. In this study, ten compounds from the whole plant of C. amblyocarpa, a wild plant that grows in the Sinai Peninsula of Egypt, were isolated. Six compounds, β-sitosterol 3-O-β-D-glucoside 2, calycopterin 5, rhamnocitrin 6, 17α-hydroxycabraleahy-droxylactone 7, cleogynol 8, and β-sitosterol 10 were first isolated from this species. In addition, four previously reported compounds, kaempferol-3, 7-dirhamnoside 1, 15α-acetoxycleomblynol A 3, and 11-α-acetylbrachy-carpone-22(23)-ene 4, as well as cleocarpanol 9, were isolated and identified. Isolated compounds were evaluated to determine their analgesic properties utilizing a hot-plate test method, and their anti-inflammatory effects utilizing rat paw edema. In a hot-plate test, compounds 3, 4, 7, 8, and 9 showed significant pain inhibition in latency time as compared to the normal group. Compounds 3–9 exhibited a significant inhibition of carrageenan-induced inflammation. According to the results of this work, compounds 3 and 4 (Dammarane triterpenoid) have the strongest analgesic/anti-inflammatory activity as compared to the other tested compounds. These results give support to the medicinal benefits of the plant as an analgesic along with an anti-inflammatory agent in traditional therapy. Molecular modelling studies of the isolated compounds 3 and 4 assessed the molecular affinity and binding interaction patterns for these compounds towards COX-2 as compared to specific COX-2 inhibitors and in relation to COX-1 isozyme. Compound 3 revealed extended accommodation across COX-2's hydrophobic sub-pockets and preferential thermodynamic stability across molecular dynamics simulations.