Catasetum integerrimum Hook. (Orchidaceae) pseudobulbs ethanol extract induces antidiarrheal and antinociceptive actions.

This work assessed the antioxidant, antimicrobial, genotoxic, acute toxicity, antidiarrheal, antinociceptive, and anti-inflammatory effects of an ethanolic extract from the Catasetum integerrimum pseudobulbs (CIE). The antidiarrheal activity of CIE (1-100 mg/kg p.o.) was assessed with castor oil-related tests. The anti-inflammatory activity was estimated using the 12-O-Tetradecanoylphorbol-13-acetate (TPA) ear-induced edema. CIE exerted antidiarrheal activity (ED50 = 2.0 mg/kg p.o.) in the castor oil-induced diarrhea model and inhibited the intestinal fluid accumulation. Three models demonstrated antinociceptive effects of CIE, with the acetic acid-induced writhing test demonstrating the highest activity (ED50 = 35 mg/kg p.o.). Naloxone reversed the antinociceptive effects of CIE in the hot plate test. The antidiarrheal mechanism of CIE relies on inhibiting secretory-induced diarrhea through the alpha-1 adrenergic system, decreasing pro-inflammatory mediators such as COX-2, avoiding the apoptosis of colon cells, and inhibiting fluid accumulation. The opioidergic system participates in the antinociceptive effects of CIE.