Antimicrobial properties of kacangma (Leonurus sibiricus): The effect of extraction and heat treatment

H.P. Chua and A. Aminah

Abstract
Kacangma (Leonurus sibiricus) is a popular traditional herb that has been consumed for decades by the people of Sarawak as a herbal medicine and culinary ingredient. Several studies conducted worldwide have found that Leonurus species has high antimicrobial activities. Evaluation of antimicrobial effectiveness of kacangma extract was carried out using disc diffusion test and direct inhibition test. Results showed that both the water and ethanolic extracts reacted differently in inhibiting microorganisms growth. Ethanolic extracts at concentrations of 50 and 100 mg/ml inhibited Staphylococcus aureus. Water extracts at concentrations of 10, 25, 50 and 100 mg/ml inhibited Aspergillus niger, while concentrations of 25, 50 and 100 mg/ml inhibited Saccharomyces cerevisae and a concentration of 100 mg/ml inhibited S. aureus. Effect of temperature treatments on antimicrobial activity of kacangma extract was studied using direct inhibition test by exposing the extracts to temperatures of 50, 100 and 121 °C. When the temperature of the heat treatments increased, the extract inhibitory effect on microorganisms growth also increased. Heat treatment at a high temperature of 121 °C did not reduce the inhibitory effect but instead increased it.

Full text (299 KB)