In silico molecular docking analysis of Equisetum diffusum D. Don phytocompounds against potent inflammatory markers and validating its role through in vitro and in vivo anti-inflammatory assays.

Abstract Equisetum diffusum D. Don (Fam. Equisetaceae ), commonly known as ‘Himalayan horsetail’, is an important medicinal pteridophyte species having various ethnobotanical properties; and traditionally been used in the treatment of back pain, bone fracture, bone dislocation, and arthritis by various tribal communities of India. Although the pharmacological uses are known, no study related to its ethnobotanical validation in experimental animal models has been reported till date. The goal of the present study was to validate the anti-inflammatory properties of the whole plant methanolic-extract (EDME) using in silico, in vitro , and in vivo strategies. The GC-MS analysis of EDME detected the presence of 47 phyto-compounds, out of which Stigmasta-3,5-dien-7-one and 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl showed good inhibition of cyclooxygenase-2 (Cox-2) and IL-6 respectively compared to standard NSAIDs, in docking analysis. In vitro anti-inflammatory studies indicated that EDME inhibits 48.2 ± 3.74% of protein denaturation at a concentration of 1000 µg/ml compared to standard diclofenac sodium (57.6 ± 3.70% at 100 µg/ml concentration). The similar concentration (1000 µg/ml) of extract inhibits heat-induced (33.6 ± 2.55%) and hypotonicity-induced (58.1 ± 3.39%) erythrocyte membrane lyses respectively, compared to indomethacin standard (45.6 ± 2.36% and 67.2 ± 1.45% respectively at 200 µg/ml concentration). The in vivo anti-inflammatory study of EDME showed 52.26% and 73.36% reduction in paw-edema in both low and high dose protective groups respectively, when compared to the carrageenan control-group. Our findings established the anti-inflammatory roles of the whole plant methanolic extract of Equisetum diffusum on strong ground which may encourage drug-development for the treatment of inflammation-related complications.