Gastroprotective effect of swallow root (Decalepis hamiltonii) extract: Possible involvement of H⁺-K⁺-ATPase inhibition and antioxidative mechanism

The present study reports the antiulcer potentials of aqueous extract of swallow root (Decalepis hamiltonii Wight & Arn, SRAE) belonging to the family Asclepiadaceae. Swim stress-induced ulcers with an ulcer index (UI) of 6.0 ± 0.01 was protected up to 43% and 72% at 100 and 200 mg/kg b.w. of SRAE, respectively, similar to protection offered by ranitidine (79%) at 30 mg/kg b.w. Depletion in antioxidant enzymes and increased Thiobarbituric Acid Reactive Substances (TBARS) were observed in ulcer-induced rats while SRAE fed rats showed normal levels. SRAE also normalized ∼3.1 and 2.4 folds of increased H⁺-K⁺-ATPase and gastric mucin, respectively, in ulcerous animals, similar to the levels found in healthy controls. SRAE also possessed reducing power, free radical scavenging ability with an IC₅₀ of 0.17 μg/mL gallic acid equivalent (GAE), comparable to that of BHA (IC₅₀-0.08 μg/mL). DNA protection up to 80% at 0.2 μg was also observed. Toxicity studies indicated no lethal effects in rats fed up to 5 g/kg b.w. Antioxidant, proton pump inhibition as well as boosting of gastric mucin effects of SRAE have been implicated to be responsible for antiulcer property of SRAE.