Screening of Antistress and Anxiolytic Activities of Piper longum Fruits Extract

The aim of the study was to investigate adaptogenic and anxiolytic activities of methanol extract of Piper longum fruits at different dose levels (100, 250 and 500 mg/kg) using different experimental animal models. In the present research work antistress activity was assessed by swimming endurance and immobilization stress models, and anxiolytic activity were assessed by elevated plus maze behavior of mice, light dark exploration test in mice and open field apparatus test in rats. In swimming endurance test, the mean time of swimming performance and swimming stress induced biochemical parameters such as serum cortisol, the weights of adrenal glands, ascorbic acid and cortisol levels were recorded in the adrenal gland. There was dose dependent significant increase in swimming performance time observed in mice pretreated with graded doses of the test extracts. Animals pretreated with test extracts at different dose levels showed significant and dose dependent fall in all the biochemical parameters, as compared to the stress control animals. Treatment with standard and test extracts significantly reversed the stress induced altered hematological parameters, biochemical parameters, organs weight, GSH and LPO levels and neurotransmitters such as dopamine, nor adrenaline and serotonin levels in rat brain In immobilization stress. The test extracts demonstrated the significant increase in time spent and number of entries into open arm in elevated plus maze apparatus test and also increase in time spent and number of entries into lit box was observed in light box exploration test and reduction in time spent and number crossing into the dark compartment observed in animals pretreated with test extract. Pretreatment with test extracts demonstrated dose dependent significant increase in ambulation, rearing and self-grooming and significant decrease in fecal dropping in case of open field test.