Evaluation of Additive or Synergistic Effect of Piper nigram and Ocimum sanctum Extracts for their Antidepressant Activity

Abstract

Depression is a state of excessive sensitivity to criticism, fear of rejections, lack of self-interest, loss of pleasure. In the traditional systems of medicine, many plants and formulations have been used to treat depression for thousands of years. In recent times, research on the plants increased globally and so many plants provide the evidence to cure diseases. Ocimum sanctum, popularly known as Tulsi is one of the sacred herbs for Hindus in the Indian subcontinent. It has a versatile role in traditional medicine. The fruits of Piper nigrum are used to make black pepper. This hotly pungent spice is one of the earliest known and most widely used spices in the world today. Wide range of animal tests for antidepressant agents are commonly used. The Forced swim test and Tail suspension test in mice were mostly used. Hence in the present study Forced swim test was used as animal model of depression. In present study immobility time in Forced swim test was significantly decreased by a combination of Piper nigrum fruit extract and Ocimum sanctum extract treated groups compared to control group. The combination of extracts (50 mg/kg each) activity was comparable to standard drug Fluoxetine. Treatment with extracts does not modify the locomotor activity of mice, which indicates that they exert antidepressant effects without modifying significantly locomotor activity. Therefore, the present study confirms the combination of alcoholic extract of Piper nigrum (AEPN) fruit and aqueous extract of Ocimum sanctum (AEOS) possessing additive/synergistic antidepressant activity.