Antinociceptive, Free Radical–Scavenging, and Cytotoxic Activities of Acanthus hirsutus Boiss

Abstract

In vivo antinociceptive and in vitro radical scavenging and cytotoxic activities of Acanthus hirsutus Boiss. aqueous extract were investigated to give a new insight into plant usage in traditional medicine. The extract showed significant antinociceptive activity in acetic acid-induced writhing test in mice after oral application and did not change the hind-leg retraction period in the hot-plate test for any dose applied. In addition, the extract showed radical-scavenging activity against 2,2-diphenyl-1-picryl-hydrazyl, nitric oxide, and superoxide radicals similar to those of standard compounds 3-t-butyl-4-hydroxyanisole, ascorbic acid (vitamin C), and quercetin. The gallic acid equivalent total phenolic content of the plant was found to be 65.4 mg/g dry extract. Cytotoxic activity of the aqueous extract was tested against 3 different cancer cell lines-Hep-2 (human larynx epidermoid carcinoma), RD (human rhabdomyosarcoma), and L20B (transgenic murine L cells)-and 1 noncancerous cell line (VERO) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Through the phytochemical studies, the following compounds were isolated: 3 lignan glucosides [(-)-syringaresinol-di-O-β-glucopyranoside, (-)-medioresinol-di-O-β-D-glucopyranoside, (-)-pinoresinol-4'-O-β-glucopyranoside], 2 benzoxazinoids [2-hydroxy-1,4-benzoxazin-3(4H)-one, (2R)-2-O-β-glucopyranosyl-1,4-benzoxazin-3(4H)-one], 4 phenylethanoid glycosides (acteoside, leucosceptoside A, martynoside, hattushoside), and 2 phenylpropanoid glucosides (sinapyl aldehyde-4-O-β-glucopyranoside, sinapyl alcohol-4-O-β-glucopyranoside). Cytotoxic and radical-scavenging activities of the isolated compounds were also determined. 2-hydroxy-1,4-benzoxazin-3(4H)-one and acteoside were the most active compounds in both experiments.