An in vivo study of the pharmacological activities of a methanolic acetate fraction of Pistia stratiotes L.: An ethno-medicinal plant used in Bangladesh

Background The present study covered an assessment of methanolic acetate fractions of Pistia stratiotes, commonly known as water lettuce, for analgesic, anti‐inflammatory, and CNS depressant activities. Methods The methanol acetate fractions were extracted from Pistia stratiotes and administered to the experimental animals as 200 and 400 mg/kg doses to determine the effect on acetic acid‐induced writhing and formalin‐induced licking and biting, for the assessment of analgesic activity. The anti‐inflammatory assay was done using the carrageenan‐induced hind paw edema method, while assessment of CNS depressant activity was done using the open field and hole cross tests. The effects were compared to standard reference drugs. Results At both doses (200 and 400 mg/kg body weight), the methanolic acetate extract of P. stratiotes showed significant analgesic action (P