Avaliação da atividade antidiarreica e antimicrobiana do p-cimeno em modelos experimentais.

Abstract

p-Cymene (p-isopropyltoluene) is an aromatic organic compound of the monoterpene class and is considered the precursor of carvacrol. The objective of the present study was to evaluate the antidiarrheal activity of p-cymene, effects on gastrointestinal motility and possible related mechanisms of action, as well as antimicrobial activity in experimental models. In the castor oil-induced diarrhea model, p-cymene at doses of 100 mg / kg and 200 mg / kg showed antidiarrheal activity, with 85% inhibition (p <0.01) and 100% (p <0.001), respectively, when compared to the negative control. In the gastric emptying model, p-cymene (50, 100 and 200 mg / kg) reduced gastric emptying by 89% (p <0.01), 84% (p <0.001) and 79% (p <0.001), respectively, when compared to the negative control group. In the intestinal transit model, all doses evaluated (25 mg / kg, 50 mg / kg, 100 mg / kg and 200 mg / kg) reduced intestinal motility compared to the negative control, with percentages of inhibition 49% (p < 0.001), 47% (p <0.001), 42% (p <0.001) and 29% (p <0.001), respectively. In the antimotility mechanisms, pcymene reversed the percentage of intestinal transit when blocked with L-NAME, glibenclamide, propranol and yohimbine, in 85% (p <0,001), 89% (p <0,001), 84%(p <0,001) e 92% (p <0,001), respectively. For enteropooling results, pcymene reduced intestinal fluid weight by 42% (p <0.001) when compared to the negative control group. In the evaluation of the antibacterial and antifungal activity of p-cymene (1024 µg/mL - 16 µg/mL), it was observed in the minimum inhibitory concentration (MIC) model that p-cymene showed growth inhibition up to 32 µg/mL and concentration minimum fungicide (CFM) and minimum bactericidal (CBM) inhibition was up to 64 µg/mL. Thus, p-cymene has antidiarrheal activity, and this activity is related to the antimotility and antisecretory effect. The antimotility effect is related to the participation of the nitrégica, adrenergic and KATP pathways of this terpene. In addition, p-cymene has antimicrobial activity related to the antifungal and antibacterial effect of this compound.