Pharmacological Evaluation of Central Nervous System Effects of Ethanol Leaf Extract of Olax Subscorpioidea in Experimental Animals.

BACKGROUND

Olax subscorpioidea Oliv. (Olacaceae) is a medicinal plant used in folk medicine in the management of pain, mental illness, and convulsion. We evaluated neurosedative and anticonvulsant properties of the ethanol leaf extract of O. subscorpioidea (ELEOS).

METHODS

Effects of ELEOS (3.125, 6.25, 12.5, 25 mg/kg) on novelty-induced behaviors were determined using open field test. Anxiolytic effect of ELEOS (3.125, 6.25, 12.5, 25 mg/kg) was assessed using hole-board and elevated-plus maze paradigms. The effect of O. subscorpioidea on pentobarbitone sleeping time was also investigated. Anticonvulsant property of ELEOS (12.5-50 mg/kg) was evaluated using pentylenetetrazole, picrotoxin and strychnine-induced convulsions assays. The extract was administered once intraperitoneally.

RESULTS

The LD50 of ELEOS was 300 mg/kg. ELEOS (3.125, 6.25, 12.5, 25 mg/kg) significantly reduced rearing (99.8±2.8, 76.2±2.9, 37.4±1.2, 5.8±0.8) and grooming (48.0±3.6, 33.8±2.9, 25.4±1.6, 7.6±0.8) as compared with controls (185.8±5.1; 63.8±4.3). Treatment with ELEOS (3.125, 6.25, 12.5, 25 mg/kg) significantly reduced head-dipping on hole-board (10.6±1.9, 8.8±1.2, 7.2±0.9, 6.0±1.1) as compared with control (27.8±1.5). However, there was no anxiolytic effect on EPM. ELEOS (12.5, 25, 50 mg/kg) significantly prolonged pentobarbitone-induced sleeping time (43.0±1.4, 51.0±1.2, 61.0±1.8) as compared with control (31.0±0.7). At 50 mg/kg, ELEOS significantly prolonged onset of seizure (2.72±2.07) and latency to death (9.20±1.24) as compared with controls (0.54±0.02; 2.00±0.44) in pentylenetetrazole-induced convulsions with no effect on picrotoxin and strychnine-induced convulsions.

CONCLUSION

The ELEOS is sedative and has mild anticonvulsant activity and this study supports pharmacological basis for its use in the management of mental illness and convulsion.