Study Design

All animals were acclimatized for six days prior to enrollment in the study and were examined for clinical signs. They were reported to be free from physiological and clinical abnormalities during this period.

We selected 28 healthy rats from an acclimatized colony of 32 and randomized them based on their body weight into four groups of seven animals as follows: control animals (CL-group), CUS-induced animals (CUS-group), AshwaSR treated CUS-induced animals (AshwaSR-group), and escitalopram treated CUS-induced animals (ESC-group). Individual animal body weights were recorded on the day of dosing and dose volume was calculated based on the body weight of each rat.

A full dose of Ashwagandha for humans would be between 1000 and 1500 milligrams per day of extract. By translating the human dose to the rat dose, we arrived at the 100 mg dose of AshwaSR (containing NLT 5% withanolides). Animals in the CL-group and CUS-group were administered 0.5% CMC-Na orally. The AshwaSR pellets were filled into mini-capsules by using capsule filling equipment and orally administered to the animals. AshwaSR was encapsulated in Torpac’s size 9 gelatin capsules and administered orally using TORPAC9el dosing syringe. Torpac’s capsules of size 9 provide a convenient method for orally dosing laboratory rats. Such dosing is similar to hard gelatin capsules in clinical setting.²⁸ Animals in the ESC-group received escitalopram orally at a dose of 20mg/kg/body weight. All animals were dosed with either vehicle, test item, or reference standard once daily until day 35. All animals except those in the CL-group underwent various predefined paradigms of chronic unpredictable stress as shown in Table 1.

Experimental Schedule for the Chronic Unpredictable Stress Procedure

Abbreviations: MWM, Morris water test; OFT, open field test; EPM, elevated plus maze test; FST, forced swim test.

All the animals were evaluated for the following parameters: