Antimicrobial activities of malaysian stingless bees propolis on klebsiella pneumoniae

Propolis is a resinous material that was collected by honeybees from various plants. Previous study had shown that propolis possess few important properties such as antimicrobial, antifungal, antiviral, anti-inflammatory and antioxidant. Thus, the aim of this study is to examine the antimicrobial properties of the Malaysian stingless bees propolis, MIC range and the correlation between the total phenolic compounds with the strength of the antimicrobial action. Stingless bees used in this study were H itama and G. thoracic. From each bee species, samples were taken from the sealant and the pot of the bee hives. For this study, the microorganism used was Klebsiella pneumoniae ATC 13 883. In order to examine the antimicrobial properties, agar well diffusion method with concentration range from 32 mg/mL to 128 mg/mL was used. Meanwhile, microwell plate method was used to examine the MIC range of the propolis sample. Then, the total phenolic compound was investigated by using Folin-ciocalteu reagent and comparison with the standard curve of gallic acid. Study revealed that for concentration 128 mg/mL, the diameter inhibition of zone range from 14.44 ± 1.40 mm to 17.33 ± 3.20 mm while for concentration 64 mg/mL, the diameter of inhibition zone range from 11.67 ± 1.80 mm to 16.44 ± 1.67 mm. Meanwhile, for the concentration of 32 mg/mL, the diameter inhibition of zone range from 0.00 mm to 14.00 ± 2.06 mm. On the other hand, HIS and HIP sample had shown the lowest MIC range of 8 mg/mL to 16 mg/mL while GTP sample with 16 mg/mL to 32 mg/mL. GTS sample exhibited the highest MIC range with 32 mg/mL to 64 mg/mL. In addition, both sealant samples had shown the highest total phenolic compounds (HIS, 0.1128 GAE mg/mL and GTS, 0.1067 GAE mg/mL) as compared to the pot samples (HIP, 0.1053 GAE mg/mL and GTP, 0.1010 GAE mg/mL). As the conclusion, all samples from Malaysian stingless bees propolis possess the antimicrobial activity and it is correlated with the total phenolic compounds that contained in each sample. Further study is highly recommended to be done in order to identify specific chemical compositions of the propolis.