Evaluation of the Antispasmodic and Antisecretory Activities of the 80% Methanol Extracts of Verbena officinalis L: Evidence From In Vivo Antidiarrheal Study

Verbena officinalis L. has a folkloric repute for the management of digestive disorders, including diarrhea. However, the safety and efficacy of the plant material has not been scientifically validated yet. This study was, therefore, aimed to evaluate the overall antidiarrheal activity of the 80% methanol extracts of V officinalis in mice. The antidiarrheal activity of the 80% methanol extracts of the roots (R-80ME) and the leaves (L-80ME) of V officinalis was tested in castor oil–induced diarrhea in mice. R-80ME was further evaluated using charcoal meal and entero-pooling. In each test, group I and group II (controls) received 10 mL/kg distilled water and standard drug (5 mg/kg loperamide), respectively, whereas groups III, IV, and V (test groups) received 100, 200, and 400 mg/kg of the 80ME, respectively. The R-80ME at 200 mg/kg (P < .01) and 400 mg/kg (P < .001) significantly delayed the onset of diarrhea compared with negative control. Both R-80ME and L-80ME at 200 and 400 mg/kg significantly decreased the frequency of wet fecal outputs (P < .01). Generally, 70.24% inhibition of the number of wet fecal output was recorded at R-80ME 400 mg/kg. Results from the charcoal meal test revealed that the R-80ME at 200 (P < .01) and 400 mg/kg (P < .001) produced a significant antimotility effect. In entero-pooling test, the R-80ME, at 200 and 400 mg/kg doses (P < .01), showed a significant decline in both the volume and weight of intestinal contents. The maximum in vivo antidiarrheal index was determined to be 95.25 at dose of 400 mg/kg R-80ME. This study demonstrated that the 80ME, mainly the root extract, produced promising antidiarrheal activity and hence provides a scientific support for acclaimed traditional use of the plant material for treatment of diarrheal diseases.