An extensive pharmacological evaluation of novel anti-nociceptive and IL-6 targeted anti-inflammatory guaiane-type sesquiterpenoids from Cinnamomum migao H. W. Li through in-depth in-vitro, ADMET, and molecular docking studies

Abstract

Guaiane-type sesquiterpenoids are most prevalent in the genus Cinnamomum. Hence this study investigates the structures, anti-nociceptive and IL-6 targeted anti-inflammatory potential of three novels C-14 guaiane-type sesquiterpenoids and two new monoterpenoids, isolated from Cinnamomum migao. The structures were precisely confirmed and characterized through the modern chromatographic and spectroscopic techniques of HRESIMS, ¹D NMR, ²D NMR, experimental circular dichroism (ECD), and calculated (ECD). Novel sesquiterpenoids 1 and 2 exhibited significant anti-inflammatory activities against the NO production and pro-inflammatory cytokines. Their IC₅₀ values were determined as 9.52 and 13.42 μΜ against IL-6 mRNA, respectively. Similarly, subcutaneous injection of n-BuT and EA extracts showed a dose-dependent suppression of formalin-induced tonic biting/licking responses during the tonic antinociceptive phase. Furthermore, absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis of guaiane-type sesquiterpenoids 1 and 2 displayed that both compounds have a high level of GIT absorption, with a high zone of safety for cardiac and hepatotoxicity and no inhibition of cytochromes. In addition, molecular docking and simulation studies strengthen the anti-inflammatory potential of sesquiterpene 2 which showed a good binding affinity with IL-6 protein. Overall the inclusive results showed that the extracts and newly isolated guaiane-type sesquiterpenoids from C. migao will provide new evidence for the traditional use of this species to treat inflammation and nociception.

Keywords: ADMET; Anti-inflammatory activity; Anti-nociceptive effect; Cinnamomum migao H. W. Li; Guaiane-sesquiterpenoids; Molecular dynamic simulations.