Isolation, invitro, invivo anti-inflammatory, analgesic and antioxidant potential of Habenaria plantegania Lindl

Abstract

Habenaira plantaginea belong to orchid family which is native to Asia. Members of this family are commonly famous for the cure of pain and inflammation. To date, no research was found on isolation of compounds from this plant for the treatment of inflammation and analgesia nor has been published to our knowledge. The purpose of this study was to evaluate an analgesic, anti-inflammatory and anti-oxidant activity of the isolated compound from the most potent chloroform sub-fraction and the isolated compounds form the habenaria plantaginea. Anti-inflammatory analgesic and antioxidant potential of the various chloroform sub-fractions and isolated compounds from the most potent sub-fraction (HP-1 & HP-1) were screened for their in vitro enzymatic assays. Furthermore, prior to in-vivo investigation, the isolated compounds were subjected for their toxicity study. The potent compound was then examined for acetic acid-induced writhing, hot plate test, carrageenan-induced inflammation assays. Further various phlogistic agents were used for the evaluation of mechanism. In the COX-2 inhibitory assay the chloroform sub fraction Cf-4 demonstrated excellent activity as compared to the other sub-fraction with 92.15% inhibition. The COX-2 enzyme make prostaglandins which are directly involved in inflammation. Likewise against 5-LOX the Cf-4 was the most potent sub-fraction with IC₅₀ 3.77 µg/mL. The 5-LOX catalyzes the biosynthesis of leukotrienes which is a group of lipid mediators of inflammation derived from arachidonic acid. Free radicals can induce inflammation through cellular damage while chronic inflammation generates a large number of free radicals, whose eventually lead to inflammation. In antioxidant assays the Cf-4 fraction was displayed excellent results against ABTS, DPPH and H₂O₂ free radical with 88.88, 77.44, and 65.52% inhibition at highest concentration. Likewise, the compound HP-1 demonstrated 88.81, 89.34 and 80.43% inhibition while compound HP-2 displayed 84.34, 91.52 and 82.34% inhibition against ABTS, DPPH and H₂O₂ free radical which were comparable to the standard drug ascorbic acid respectively. This study's findings validate the use of this species as traditional use.

Keywords: 5-LOX; Acetic acid; COX-2; Carrageenan; Hot plate; Isolation.