Antiulcer and laxative potential of polysaccharides from the ripe seed pulp of Delonix regia: A preliminary study

Ulcers are a major global health problem, affecting nearly 10-15% of the population. Peptic ulcers, particularly gastric and duodenal ulcers, may progress to severe complications, including malignancy, if left untreated. Polysaccharides derived from natural sources are increasingly recognized for their gastroprotective and laxative effects. This study investigated the antiulcer and laxative activities of polysaccharides extracted from the ripe seed pulp of Delonix regia (DRSP) using experimental animal models. DRSP was extracted via ethanol precipitation and characterized using phytochemical screening, ATR-FTIR, TGA, and XRD analyses. Antioxidant activity was determined using free radical scavenging assays. Acute oral toxicity was assessed according to OECD Guideline 423. Antiulcer activity was evaluated in ethanol- and ibuprofen-induced rat models by measuring the gastric content, acidity, ulcer index, and histopathology. Laxative activity was studied in a loperamide-induced constipation model and validated using a charcoal meal gastrointestinal transit test. DRSP was confirmed to be a neutral, swallowable polysaccharide exhibiting characteristic functional groups and a semi-crystalline structure. It exhibited notable antioxidant activity (IC₅₀: 639.47 μg/mL) and was safe at 2000 mg/kg in acute toxicity studies. In ulcer models, DRSP (300-600 mg/kg) significantly reduced gastric volume, free acidity, ulcer score, and ulcer index, while increasing gastric pH, protection percentage, and mucosal healing. In constipated animals, DRSP improved laxation by enhancing moist fecal weight and gastrointestinal transit ratio, with efficacy comparable to that of bisacodyl. These findings demonstrate that DRSP possesses dual antiulcer and laxative effects, likely mediated through antioxidant and cytoprotective mechanisms, supporting its potential as a natural therapeutic agent.