Effects of the Hydroalcoholic Extract of Passiflora edulis on Anxiety Induced by Sub-acute Immobilization Stress

Aims: This study was carried out to assess the anxiolytic effects of the hydroalcoholic extract of P. edulis.

Place and Duration of Study: Animal Physiology Laboratory of the Higher Teachers’ Training College, Animal Physiology Laboratory of the Faculty of Sciences , University of Yaoundé I, from November 2017 to August 2018.

Methodology: Anxiety was induced to mice by the sub-acute immobilization stress. After 11 days treatment, behavioural parameters were assessed using Elevated Plus Maze (EPM) and Open Field (OF), then biochemical parameters (MDA, GSH, SOD, catalase, GABA, GABA-T and 5-HT) were estimated.

Results: The results show that treatment with P. edulis at doses 100 and 200 mg/kg significantly increased open arms entries and time, while reducing closed arms entries and time in the EPM test. Lines crossed as well as passages through the centre and the centre time were significantly increased in the OF test. It is suggested that P. edulis would protect against anxiety and this effect probably linked to its ability to fight oxidative stress and counteract hyperexcitability by potentiating the GABA action. The more effective dose, 100 mg/kg significantly (P<0.01) increased to 4.44 ± 0.24 µmol/g the activity of GSH. In mice treated with dose 100 mg/kg, the extract induced a significant decrease of three oxidative stress markers including MDA, catalase and SOD to 0.22 ± 0.01 µmol/g, 1.05± 0.15 mmol H2O2/min/g; and 19.46±0.00 unit/min/mg respectively when compared to the negative control. Animals treated with P. edulis 100 mg/kg presented a significant increase level (P<0.001) of GABA and 5-HT up to 4.62 ± 0.28 and µg/g and 31.47 ± 1.58 ng/ml respectively. GABA-T activity was also impacted by the treatment with P. edulis, since the value of GABA-T activity of 1.27 ± 0.10 in the negative control significantly (P<0.001) decreased to 0.37± 0.00 in the group treated with dose 100 mg/kg.

Conclusion: The beneficial effects of this extract observed in this study justify the empirical use of P. edulis in the treatment of head ache and insomnia.