Methanol extract of Caralluma dalzielli N.E. Br (Asclepiadaceae) possesses antidepressant activity in mice

Abstract

Caralluma dalzielli N.E. Br (Asclepidiaceae) is reportedly used in the management of depression by traditional practitioners in Northwestern Nigeria. However, there is paucity of data in the literature on the antidepressant potential of the plant scientifically. The aim of the work was to provide scientific rationale for the use of the plant Caralluma dalzielli in the management of depressive illnesses locally. Preliminary phytochemical screening was conducted using thin layer chromatography (TLC), acute toxicity study (LD₅₀) using OECD guideline 425 and beam walking assay (BWA) was used to assess effect of the extract on motor coordination deficit. Antidepressant activity of methanol extract of Caralluma dalzielli (125-500 mg/kg) was evaluated using tail suspension test (TST) and forced swim test (FST). The effect of extract on locomotor activity and cognitive behaviour was assessed using open field test (OFT) and novel object recognition test (NORT) respectively. Preliminary phytochemical tests revealed the presence of carbohydrates, saponins, tannins and flavonoids. The LD50 was found to be ≤2000 mg/kg. The extract at all doses tested significantly (p<0.05) and dose dependently decreased the duration of immobility in the TST and FST. Additionally, the extract significantly (p<0.001) increased climbing activity of mice in the FST. There was significant decrease in number of lines crossed from the OFT at the dose of 125 mg/kg. However, the extract neither increase nor decrease the discrimination index of mice in the NORT. The methanol extract of Caralluma dalzielli possesses significant antidepressant activity with no motor coordination deficit.

Keywords: Caralluma dalzielli; Tail suspension test; Forced swim test; Open field test