EVALUATION OF ANTIOXIDANT POTENTIAL OF Humboldtia vahliana WIGHT IN NEUROPHARMACOLOGICAL SCREENING ON MICE

Objective: This present study was carried out to investigate in vitro and in vivo antioxidant potential of bark extracts of Humboldtia vahliana Wight in neuropharmacological screening on mice.

Materials and Methods: Different concentrations (1.25 – 20 µg/mL) of benzene, chloroform, ethanol and aqueous extracts of Humboldtia vahliana (HV) were used for various in vitro antioxidant assay methods such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), Hydroxyl radical scavenging assay, Metal chelating assay, Reducing power assay and Super oxide radical Scavenging assay. Ascorbic acid (AA) was used as the standard. The effect of two doses (200-400mg/kg) of ethanol and aqueous extract of HV on antioxidant enzyme levels of GSH and MDA was estimated when the animals were subjected into various neuropharmacological screening methods such as sedative and hypnotic activity which was evaluated by using phenobarbitone sodium induced sleep latency and sleep time, while maximum electric shock. Open field test for anxiolytic activity and forced swim test for antidepressant activity. The extract which had highly significant effect was subjected to High performance thin layer chromatography (HPTLC) study.

Results: In vitro antioxidant results revealed that there was an increased scavenging effects with increase in concentration of extracts range from 1.25– 20 µg/mL. The percentage inhibition increased with less IC50 values was in all extracts. The maximum scavenging effect was found with EEHV in all assay methods. Therefore the extract was considered as potent antioxidant than the rest. Treatment with Ethanol extract of Humboldtia vahliana (EEHV) and aqueous extract of Humboldtia vahliana (AEHV) significantly reduced the levels of Malondialdehyde (MDA) and increased the levels of glutathione (GSH) in animals which were undergone neuropharmacological screening. HPTLC fingerprint revealed that the presence of six peaks at 254 and 366 nm respectively.

Conclusion: The present study concluded that because of its chemical constituents the extracts restored the antioxidant enzyme and protected against various stimuli given for neuropharmacological study.