Indigenous Myanmar medicinal plants and comparison of their in vitro antioxidant, antiglycation, and antimicrobial activities

Objective: The purpose of this study was to evaluate the potential biological activities of 23 ethanolic extracts from 19 traditional medicinal plants from Myanmar. Methods: Antioxidant activity was determined using DPPH, nitric oxide and superoxide free radical scavenging assays. Antiglycation activity was studied with nonenzymatic protein glycation assay. Total phenolic content was measured compared with the gallic acid standard curve. The antimicrobial activity was evaluated against six clinically important bacteria by agar well-diffusion method. Results: Among the studied plant extracts, AGE228 (Syzygium cumini (L.) Skeels. seed) was the promising medicinal plant for oxidative stress-related disease as it showed high antioxidant activities with the percent inhibition of 75.80 +/- 1.02 and 98.45 +/- 1.12 for DPPH and NO radical scavenging assays. The extract AGE223 (Tamarindus indica Linn. bark) also showed the high antioxidant activity for SO radical scavenging assay with the percent inhibition of 89.35 +/- 5.72. These two extracts contained the highest phenolic content with 233.85 +/- 0.04 and 214.47 +/- 0.01 mgGAE/g of extract, respectively. AGE221 (Terminalia chebula Retz. branch) was the best AGE inhibitor with the percent inhibition of 79.06 +/- 1.90. Most of the selected extracts showed antimicrobial activity. Among them, the antimicrobial activity of AGE232 (Phyllanthus distichus Muell. fruit) was comparable to the standard antibiotic, Chloramphenicol. Conclusion: The results confirmed that the ethanolic extracts of traditionally used medicinal plants could be effective not only for decreasing the oxidative stress and glycation end-products formation in glycation related diseases but also for treating the infectious diseases.