Background:Caesalpinia bonduc (L.) Roxb are traditionally used in Indonesia to treat various diseases, but still limited study about different part of this plant. Objective: The aim of this study was to screen the phytochemicals, to evaluate the total flavonoid and total phenolic contents as well as antioxidant activity of ethanol extract of root, stem, leaves, and seed kernel of C. bonduc. Methods: Each part of plant were extracted by reflux using 70% ethanol as the solvent for 2 h and repeated 3 times. Total flavonoid content was determined by aluminium chloride colorimetric assay on 415 nm. Total phenolic content was determined with Folin-Ciocalteu 1:4 on 765 nm using microplate reader. Antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenger methods. Results: Phytochemical screening showed that all of samples positively contain flavonoid and saponin. Total flavonoid content was the highest in leaf and the lowest in root whereas total phenols content was highest in leaf and the lowest in seed kernel. The crude extracts displayed DPPH free radical scavenging activity with highest value in leaf extract followed by root, stem, and seed kernel. Conclusion: The 70% ethanol leaf extract of C. bonduc showed the highest yield, total flavonoid content and total phenolic content among other parts investigated. Moreover, leaf extract has highest DPPH free radical scavenging activity (79.802 µg/ml) which could be related to its higher phenolic content.

The part of the plant were collected and cleaned, dried at room temperature, and then powdered and stored in an air tight glass container. 50 g of each plant part was extracted by maceration with 500 mL of 70% ethanol ABSTRACTBackground: Some phenolic compounds are potential source for arginase inhibitor that can be used in management of disease associated with endothelial dysfunction. Objective: The aim of this study was to investigate the inhibitory effect on arginase and to determine total phenolic content of extracts from different parts of Melastoma malabathricum L. Methods: Each part were extracted with 70% ethanol by maceration. The extracts were mixed with bovine liver arginase and L-arginine as a substrate. The inhibitory effect of extracts were determined in vitro, by measuring its absorbance on 430 nm. Total phenolic content were determined with Folin-Ciocalteu 25% on 750 nm. Results: The 70% ethanol extract of M. malabathricum leaves at 100 µg/mL was found to have highest inhibition (81.26 ± 5.27 %) followed by flower 73.39 ± 9.39%, fruit 67.63 ± 7.61 and stem 61.61 ± 4.56%. The IC 50 value of the most active extract was 62.43 µg/mL while the IC 50 value of N-hidroksi-nor-L-arginin (nor-NOHA) acetate, an arginase inhibitor was found to be 3.91 µg/mL. Total phenolic content of 70% ethanolic extracts of M. malabathricum leaves, flower, fruit and stem was 15.9, 20.7, 6.44, and 6.29%. Conclusion: The 70% ethanol extract of M. malabathricum leaves exhibited the highest inhibition on arginase but highest total phenolic content was from flower part. Pearson correlation test showed no correlation p>0.05 between arginase inhibition and total phenolic content of the samples.