Antibacterial activity of the ethanol extracts of plant based preparations described in Thai Pharmaceutical Textbook namely: Tri-Khan-Tha-Wart, Tri-Ke-Son-Phet, Tri-Phit-Tha-Chak, Tri-Ka-Tuk, Tri-Pha-La, Tri-Kan-La-Phit, Tri-Chin-Tha-La-Ma-Ka, Tri-San, Tri-Sa-Mo, and Tri-Ke-Son-Mat were evaluated on 20 isolates of Gram-positive and Gram-negative pathogens. Qualitative phytochemical analysis and cytotoxic effect on Vero cells of the extracts were additionally performed.
The extract of Tri-Chin-Tha-La-Ma-Ka possessed the highest and most significant antibacterial activity with minimum inhibitory concentration (MIC) values of <16 渭g/mL against methicillin resistant Staphylococcus aureus (MRSA), a biofilm-producing Staphylococcus epidermidis, acne lesion isolated coagulase-positive and coagulase-negative staphylococci isolates. Our preliminary phytochemical test revealed that triterpenoids and phenolics were common components found in all tested preparations. Most of the tested remedies had IC50 > 50 渭g/mL on Vero cells, whereas Tri-Chin-Tha-La-Ma-Ka, Tri-Ka-Tuk, and Tri-Kan-La-Phit had IC50 value of 0.9, 48.8, and 28.9 渭g/mL, respectively.
These findings suggest that Tri-Chin-Tha-La-Ma-Ka could be further studied as a promising antibacterial agent. Investigations on other biological activities related to its traditional applications, appropriate biomarkers, and treatment mechanisms of the preparation are required.