1.Antimicrobial activity of green tea extract against isolates of methicillin-resistant Staphylococcus aureus and multi-drug resistant Pseudomonas aeruginosa
Radji Maksum ; Agustama Adi Rafael ; Elya Berna ; Tjampakasari Riana Conny
Asian Pacific Journal of Tropical Biomedicine 2013;(8):663-667
Objective: To evaluate antibacterial activity of the Indonesian water soluble green tea extract,Camellia sinensis, against clinical isolates of methicillin-resistant Staphylococcus aureus (S. aureus) (MRSA) and multi-drug resistant Pseudomonas aeruginosa (MDR-P. aeruginosa).
Methods:Antimicrobial activity of green tea extract was determined by the disc diffusion method and the minimum inhibitory concentration (MIC) was determined by the twofold serial broth dilutions method. The tested bacteria using in this study were the standard strains and multi-drug resistant clinical isolates of S. aureus and P. aeruginosa, obtained from Laboratory of Clinical Microbiology, Faculty of Medicine, University of Indonesia.
Results:The results showed that the inhibition zone diameter of green tea extracts for S. aureus ATCC 25923 and MRSA were (18.970±0.287) mm, and (19.130±0.250) mm respectively. While the inhibition zone diameter for P. aeruginosa ATCC 27853 and MDR-P. aeruginosa were (17.550±0.393) mm and (17.670±0.398) mm respectively. The MIC of green tea extracts against S. aureus ATCC 25923 and MRSA were 400 μg/mL and 400 μg/mL, respectively, whereas the MIC for P. aeruginosa ATCC 27853 and MDR-P. aeruginosa were 800 μg/mL, and 800 μg/mL, respectively.
Conclusions: Camellia sinensis leaves extract could be useful in combating emerging drug-resistance caused by MRSA and P. aeruginosa.
2. A new angiotensin-converting enzyme inhibitor from Peperomia pellucida (L.) Kunth
Islamudin AHMAD ; Neneng AMBARWATI ; Berna ELYA ; Arry YANUAR ; Abdul MUŃIM ; Hanita OMAR ; Kamarza MULIA ; Osamu NEGISHI ; Abdul MUŃIM
Asian Pacific Journal of Tropical Biomedicine 2019;9(6):257-262
Objective: To isolate, identify, and evaluate a new angiotensin-converting enzyme inhibitor from Peperomia pellucida (L.) Kunth herbs. Methods: A dried sample of Peperomia pellucida herb was successively macerated with n-hexane and ethyl acetate. The ethyl acetate extract solution was evaporated to obtain the crude extract. Vacuum liquid column chromatography and thin layer chromatography were performed to obtain two pure compounds. Then, both compounds were elucidated and identified using the spectroscopic method. Angiotensin-converting enzyme inhibitory activity studies of both compounds were determined using angiotensin-converting enzyme kit WST-1 with spectrophotometer microplate reader 96-well at 450 nm wavelength. Results: Two bioactive compounds were successfully isolated from Peperomia pellucida herb, including a new compound of 2,3,5-trimethoxy-9-(12,14,15-trimethoxybenzyl)-1H-indene and pellucidin A. Both compounds demonstrated angiotensin-converting enzyme inhibitory activity, with IC