Protective effect of Phlogacanthus thyrsiflorus Nees against experimentally induced gastric mucosal lesions in rats: Experimental evidence from biochemical and histological analysis

Abstract

Phlogacanthus thyrsiflorus Nees (Acanthaceae) is traditionally used in the North East Himalayan region to treat stomach issues, including gastritis. This study aimed to investigate the gastroprotective effect of 70% aqueous ethanol extract of Phlogacanthus thyrsiflorus flowers (PTE), standardized by HPTLC and LC-MS/MS, and to establish its possible mechanisms. The gastroprotective effect of PTE, at doses of 200 and 400 mg/kg body weight, was evaluated using both physical (pylorus ligation, PL; cold restraint stress, CRS) and chemical (ethanol, EtOH) ulcerogens-induced gastric ulcers in Wistar rats. Animals were randomly divided into control, ulcer control, positive control and PTE-treated groups, with PTE administered orally twice daily for 5 days. The protective effect of PTE was assessed through various gastric ulcer parameters, including gastric pH, gastric wall mucus, non-protein sulfhydryls (NP-SH) content, microvascular permeability, endogenous antioxidant markers, and gastric histopathology. HPTLC and LC-MS/MS confirmed the presence of gallic acid, naringenin, β-sitosterol and ascorbic acid in PTE. The active components of PTE showed significant dose-dependent inhibition of ulcer index, with reductions of 28.59-50.03% in PL, 27.69-53.23% in EtOH and 31.14-57.53% in CRS models (P< 0.01). Additionally, PTE at 400 mg/kg significantly increased gastric pH by 23.41%, mucus content by 33.69%, and NP-SH levels by 37.24%. PTE also demonstrated significant antioxidant potential and histopathological studies confirmed its protective effect. The study suggests that the anti-ulcer effect of PTE may be attributed to its ability to preserve adhered gastric mucus, exhibit antisecretory effects, and scavenge free radicals.