Neuroprotective effect of Thuja orientalis in haloperidol induced animal model of Parkinsons Disease

Introduction: Neuro-inflammation, increased microglial activation & interaction and oxidative stress are the new targets for Parkinson management. Protective effect of NSAIDs and anti-oxidants has been demonstrated in many animal studies with inconclusive epidemiological reports. Thuja orientalis (TOFE) a common shrub found widely in India has shown neuro-protective effect against 6-OHDA induced toxicity on SH-SY cells. Aim & Objective: To assess and compare neuro-protective effect of TOFE with Ibuprofen and vitamin E in haloperidol induced rat models of Parkinson. Methodology: 6 adult male Sprague Dawley rats each in 4 groups were given Thuja orientalis (500mg/kg) / Ibuprofen (100mg/kg) and Vitamin E (35mg/kg) orally followed 1 hour latter by haloperidol. (2mg/kg.IP) for 7 days. Motor activity and rigidity were assessed with actophotometer and common bar test. Catatonia scoring was also done. One way ANOVA and Kruscal-Wallis tests followed by Dunn’s multiple comparison test were used for statistical significance of <0.05. Results: Significant reduction in motor activity was observed in all on 7 th day. Mild protection by thuja orientalis against motor rigidity was noted with p-value of 0.032 and against catatonia with 2.5 scoring. Conclusion: Neuroprotective effect shown in-vitro experiments by anti-oxidants and anti-inflammatory drugs did not show any significant effects in our in vivo animals study against clinical features as seen in Parkinson’s disease. This inconclusive neuroprotective effect of standards & thuja observed signifies that all preclinical data from in vitro studies cannot be effectively extrapolated to in vivo animal & human studies due to many variations. Further probe in this aspect is suggested.