An assessment of in vitro antibacterial, anti-biofilm, anti-diabetic and antioxidant activities of bioactive compounds from Muntingia calabura Linn. leaves extracts

Abstract

Muntingia calabura Linn. is one of the medical plants that has been used to treat various types of illnesses. Thus, the aim of this experiment is to observe bioactive compounds from Muntingia calabura Linn. leaves extracts in different solvents such as boiled distilled water, 95% ethanol and 75% acetone. The results showed that bioactive activities of these leaves extracts were found from saponins, tannins, flavonoids, alkaloids, and steroids. For antibacterial result, the leaves were extracted with 95% ethanol (1:20) had the highest ability in inhibiting Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Enterococcus faecalis DMST 4736 by agar well diffusion assay. The inhibition zones were 7.17±0.41 -17.83±0.41 mm. Broth micro-dilution as MICs and MBCs revealed the MIC values as 12.50-50.00 mg/mL and the MBC values as 50.00-100.00 mg/mL, respectively. Moreover, crude extracts in different solvents also displayed inhibitory effects (>65%) on the biofilm formation. Particularly, the 95% ethanolic extract (1MIC) had the highest inhibition of the biofilm formation in S. aureus ATCC 25923, P. aeruginosa ATCC 27853 and S. typhimurium ATCC 13311 as 90.030.28%, 88.050.24% and 86.250.25%, respectively. Based on antioxidant activities, the IC50 values of Muntingia calabura Linn. leaves extracts with 95% ethanol ranged between 106.600.30 -293.970.10 g/mL by DPPH assay. The total phenolics and flavonoids contents showed the highest as 258.950.64 mg GAE/g DW and 86.440.38 mg RE/g DW. In addition, it exhibited the most effective anti-diabetic activity in amylase inhibition (IC50) as 98.670.15 g/mL. The benefits of these results suggest that M. calabura Linn. leaves extracts can be used as a source of bioactive compounds in potential therapeutic agent for the bacterial infections as well as treatment of diabetes.