Neuroprotective and antidepressant effects effect of Sesamum indicum leaf essential oil in Unpredictable chronic mild stress model of depression: Behavioral and biochemical evidences

Abstract

Background:  Sesamum indicum Linn. (Pedaliaceae) is an oilseed plant with neuroprotective, antioxidant, anticonvulsant, anticancer, and wound-healing activities, primarily attributed to its lignans, phenolic acids, unsaturated fatty acids, and tocopherols.

Objective:

The present study evaluated the antidepressant potential of Sesamum indicum leaf essential oil and its underlying mechanisms using in vitro assays and a UCMS-induced rat model of depression.

Materials and Methods: GC-MS analysis was performed to identify and quantify volatile constituents of SIEO. Antidepressant activity was initially assessed by evaluating inhibition of total MAO and MAO-A. Thirty-six Wistar rats were assigned to six groups (n = 6); group I received control (p.o, unstressed control), group II- UCMS (stressed animals), group III received Fluoxetine (10 mg/kg, p.o.), and groups IV, V, and VI received SIEO-treated groups (200, 300, and 400 mg/kg, p.o). The sucrose preference consumption and tail suspension tests were used to evaluate the behavioural activity in addition to the biochemical parameters (lipoperoxidation, reduced glutathione, superoxide dismutase, catalase activity, and nitrite).

Results: GC–MS identified 69 volatile compounds in Sesamum indicum essential oil, with 1,3-dioxolane, 2-methyl-2-(1-methylethyl) as the major constituent. SIEO preferentially inhibited MAO-A (IC₅₀: 400 µg/mL) over MAO-T (IC₅₀: 371.43 µg/mL) and significantly alleviated UCMS-induced depressive-like behaviors and oxidative stress in rats.

Conclusion: The study revealed that both the SIEO relieved depression-like states through the mitigation of oxidative stress with a reduction in glutathione levels, superoxide dismutase and

catalase activities and brain Monoamine Oxidase-A (MAO-A) levels.