Comparative study on anti-oxidant and anti-inflammatory activities of Caesalpinia crista and Centella asiatica leaf extracts

BACKGROUND: Amyloidosis, oxidative stress and inflammation have been strongly implicated in neurodegenerative disorders like Alzheimer's disease. Traditionally, Caesalpinia crista and Centella asiatica leaf extracts are used to treat brain related diseases in India. C. crista is used as a mental relaxant drink as well as to treat inflammatory diseases, whereas C. asiatica is reported to be used to enhance memory and to treat dementia. OBJECTIVE: The present study is aimed to understand the anti-oxidant and anti-inflammatory potential of C. asiatica and C. crista leaf extracts. MATERIALS AND METHODS: Phenolic acid composition of the aqueous extracts of C. crista and C. asiatica were separated on a reverse phase C18 column (4.6 x 250 mm) using HPLC system. Antioxidant properties of the leaf extracts were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and the reducing potential assay. The anti-inflammatory activities of aqueous extracts of C. crista and C. asiatica were studied using 5-lipoxygenase assay. Polymorphonuclear leukocytes (PMNLs) were isolated from blood by Ficoll-Histopaque density gradient followed by hypotonic lysis of erythrocytes. RESULTS: Gallic, protocatechuic, gentisic, chlorogenic, caffeic, p-coumaric and ferulic acids were the phenolic acids identified in C. crista and C. asiatica leaf aqueous extracts. However, gallic acid and ferulic acid contents were much higher in C. crista compared to C. asiatica. Leaf extracts of C. asiatica and C. crista exhibited antioxidant properties and inhibited 5-lipoxygenase (anti-inflammatory) in a dose dependent manner. However, leaf extracts of C. crista had better antioxidant and anti-inflammatory activity compared to that of C. asiatica. The better activity of C. crista is attributed to high gallic acid and ferulic acid compared to C. asiatica. CONCLUSIONS: Thus, the leaf extract of C. crista can be a potential therapeutic role for Alzheimer's disease.