Neuroprotective effect of Tinospora cordifolia ethanol extract on 6-hydroxy dopamine induced Parkinsonism

Objective:

The present study investigates the neuroprotective activity of ethanol extract of Tinospora cordifolia aerial parts against 6-hydroxy dopamine (6-OHDA) lesion rat model of Parkinson''s disease (PD).

Materials and Methods:

T. cordifolia ethanol extract (TCEE) was standardized with high performance thin layer chromatography using berberine. Experimental PD was induced by intracerebral injection of 6-OHDA (8 μg). Animals were divided into five groups: sham operated, negative control, positive control (levodopa 6 mg/kg) and two experimental groups (n = 6/group). Experimental groups received 200 and 400 mg/kg of TCEE once daily for 30 days by oral gavage. Biochemical parameters including dopamine level, oxidative stress, complex I activity and brain iron asymmetry ratio and locomotor activity including skeletal muscle co-ordination and degree of catatonia were assessed.

Results:

TCEE exhibited significant neuroprotection by increasing the dopamine levels (1.96 ± 0.20 and 2.45 ± 0.40 ng/mg of protein) and complex I activity (77.14 ± 0.89 and 78.50 ± 0.96 nmol/min/mg of protein) at 200 and 400 mg/kg respectively when compared with negative control group. Iron asymmetry ratio was also significantly attenuated by TCEE at 200 (1.57 ± 0.18) and 400 mg/kg (1.11 ± 0.15) when compared with negative control group. Neuroprotection by TCEE was further supported by reduced oxidative stress and restored locomotor activity in treatment groups.

Conclusion:

Results show that TCEE possess significant neuroprotection in 6-OHDA induced PD by protecting dopaminergic neurons and reducing the iron accumulation.KEY WORDS: Complex I activity, dopamine, iron asymmetry, levodopa, neurodegeneration