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 ear‐induced edema. CIE exerted antidiarrheal activity with an effective dose 50 (ED50) of 2.0 mg/kg p.o. in the castor oil‐induced diarrhea model and inhibited intestinal fluid accumulation. Three models demonstrated the 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, and inhibiting fluid accumulation. The opioidergic system participates in the antinociceptive effects of CIE.