Screening for Anticandidal and Antibiofilm Activity of Some Herbs in Thailand

Purpose: To evaluate the anticandidal activity of the ethanol extracts of 12 herbs from Thailand.Methods: The herbs studied were Alpinia galanga, Curcuma longa,  Curcuma zedoaria, Mentha cordifolia, Ocimum africanum, Ocimum basilicum, Ocimum sanctum, Piper betle, Piper chaba, Piper nigrum, Piper sarmentosum and Zingiber officinale. Various Candida spp. were examined for minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) using microdilution method; time-kill assay was also used to assess the plants. Antibiofilm activity was investigated using a 3-[4, 5- dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium-bromide (MTT assay). Gas chromatography mass spectrometry (GC-MS) analysis, thin layer chromatography (TLC) fingerprinting and TLC-bioautography were used to determine the active anticandidal compounds.Results: All tested herbs, except extracts of P. nigrum and Limiaceae family, showed varying zones of inhibition against Candida albicans ATCC 90028. P. betle revealed the strongest anticandidal activity against all tested strains with MIC ranging from 1.56 to 3.13 mg/ml, and MFC from 3.13 to 8.33 mg/ml. Killing activity depended on time and concentrations of the extract. The concentration of P. betle extract required to inhibit . 90 % biofilm formation of C. albicans ATCC 90028 was 3.13 } 0.15 mg/ml, while that to remove . 90 % biofilm growth was 12.50 } 0.69 mg/ml. The result of GC-MS analysis showed the major compound of P. betle extract responsible for anticandidal activity as 4-chromanol.Conclusion: P. betle extract contains 4-chromanol which is a good potential anticandidal agent for the treatment of oral infectious diseases caused by certain Candida spp.Keywords: Piper betle, 4-Chromanol, Anticandida, Biofilm, Candidiasis, Herb

In vitro Antimicrobial and Antibiofilm Activity of Artocarpus Lakoocha (Moraceae) Extract against Some Oral Pathogens

Purpose: To evaluate the antimicrobial and antibiofilm activity of A. lakoocha extract against oral pathogens by an in vitro method.Methods: The dried powder of the aqueous extract of A. lakoocha was purchased from a Thai traditional drug store. Representative strains of oral pathogens (Streptococcus mutans ATCC 25175, Streptococcus sobrinus ATCC 33478, Enterococcus faecalis ATCC 19433, Lactobacillus fermentum ATCC 14931, Lactobacillus salivarius ATCC 11741, Aggregatibacter actinomycetemcomitans ATCC 33384, Porphyromonas gingivalis ATCC 33277, Prevotella intermedia ATCC 25611, Prevotella nigrescens ATCC 25261, Fusobacterium nucleatum ATCC 25586 and Tanerella forsythia ATCC 43037) were tested for minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) using a microdilution technique, as well as by a time kill assay. Antibiofilm activity was investigated by a 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium-bromide (MTT) assay.Results: All tested strains were susceptible to A. lakoocha extract with variable degrees of antimicrobial inhibition. The extract was effective against both Gram-negative bacteria (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis) and Gram-positive bacteria (Streptococcus mutans, Streptococcus sobrinus), with MIC ranging from 0.10 – 0.39 mg/ml and MBC from 0.10 – 3.12 mg/ml. Killing activity depended on time and concentrations of the extract. The extract acted as a potent antibiofilm agent with dual actions, preventing biofilm formation and also eradicating the existing biofilm.Conclusion: A. lakoocha extract possesses compounds with good antimicrobial properties that may be used for oral infectious diseases caused by certain oral pathogens associated with dental caries and/or periodontal diseases. For the application, A. lakoocha extract may be incorporated in mouthwash or toothpaste.Keywords: Artocarpus lakoocha, Antimicrobial, Biofilm, Dental caries, Periodontal diseases, Time-kill assa