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

Anti-allergic and anti-inflammatory compounds from Aglaia andamanica leaves

The leaves from Aglaia andamanica were determined for their anti-allergic and anti-inflammatory effects using RBL- 2H3 and RAW264.7 cells, respectively. Among the isolated compounds, 24-epi-piscidinol A (5) exhibited the highest antiallergic activity against -hexosaminidase release with an IC50 value of 19.8 M, followed by (-)-yangambin (3, IC50 = 33.8 M), pyramidaglain A (8, IC50 = 37.1 M), pachypodol (2, IC50 = 38.3 M) and pyramidaglain B (9, IC50 = 44.8 M), respectively; whereas other compounds possessed moderate to mild effects (IC50 = 67.5->100 M). For anti-inflammatory activity, 24-epi-piscidinol A (5) possessed potent activity with an IC50 value of 24.0 M, followed by pyramidaglain B (9, IC50 = 25.6 M), pachypodol (2, IC50 = 34.5 M) and (-)-yangambin (3, IC50 = 37.4 M), respectively; whereas other compounds exhibited moderate to mild activities (IC50 = 54.2->100 M). These active compounds could be developed as anti-allergic and anti-inflammatory agents in the future

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

สารที่มีฤทธิ์ต้านเอนไซม์ HIV-1 protease ของต้นแสมสาร

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HIV-1 protease inhibitory substances from the rhizomes of Boesenbergia pandurata Holtt.

Four flavonoids (pinostrobin, pinocembrin, cardamonin and alpinetin) isolated from the ethanol extract of Boesenbergia pandurata Holtt. (yellow rhizome) were tested for their activities against HIV-1 protease (HIV-PR). The result showed that cardamonin exhibited an appreciable anti-HIV-1 PR activity with an IC50 value of 31 μg/ml

Synthesis and evaluation of coumarin derivatives on antioxidative, tyrosinase inhibitory activities, melanogenesis, and in silico investigations

Abstract New coumarin derivatives were designed using a 2-(2-oxo-2H-chromen-4-yl)acetic acid scaffold conjugated with amino acid esters or tyramine. The anti-tyrosinase and anti-lipid peroxidation activities of the synthesized compounds were investigated. Coumarin derivatives 7,9, 11–13, 15–18 showed strong anti-lipid peroxidation activity. Compound 13 exhibited uncompetitive tyrosinase inhibitory activity with an IC50 value of 68.86 µM. Compound 14 (% activity = 123.41) showed stronger tyrosinase activating activity than 8-methoxypsolaren (8-MOP, % activity = 109.46). In silico studies revealed different poses between the inhibitors and activators near the tyrosinase catalytic site. Compounds 13 (25–50 μM) and 14 (25–100 μM) did not show cytotoxicity against B16F10 cells. In contrast to the tyrosinase inhibition assay, compound 13 (50 μM) suppressed melanogenesis in B16F10 cells with two times higher potency than KA (100 μM). Compound 14 at 100 μM showed melanogenesis enhancement in B16F10 cells in a dose-dependent manner, however, inferior to the 8-MOP. Based on the findings, compound 13 and 14 offer potential for development as skin-lightening agents and vitiligo therapy agents, respectively

Synthesis of 2‐(2‐oxo‐2 H ‐chromen‐4‐yl)acetamides as potent acetylcholinesterase inhibitors and molecular insights into binding interactions

Sixteen novel coumarin-based compounds are reported as potent acetylcholinesterase (AChE) inhibitors. The most active compound in this series, 5a (IC50 0.04 ± 0.01 µM), noncompetitively inhibited AChE with a higher potency than tacrine and galantamine. Compounds 5d, 5j, and 5 m showed a moderate antilipid peroxidation activity. The compounds showed cytotoxicity in the same range as the standard drugs in HEK-293 cells. Molecular docking demonstrated that 5a acted as a dual binding site inhibitor. The coumarin moiety occupied the peripheral anionic site and showed π-π interaction with Trp278. The tertiary amino group displayed significant cation-π interaction with Phe329. The aromatic group showed π-π interaction with Trp83 at the catalytic anionic site. The long chain of methylene lay along the gorge interacting with Phe330 via hydrophobic interaction. Molecular docking was applied to postulate the selectivity toward AChE of 5a in comparison with donepezil and tacrine. Structural insights into the selectivity of the coumarin derivatives toward huAChE were explored by molecular docking and 3D QSAR and molecular dynamics simulation for 20 ns. ADMET analysis suggested that the 2-(2-oxo-2H-chromen-4-yl)acetamides showed a good pharmacokinetic profile and no hepatotoxicity. These coumarin derivatives showed high potential for further development as anti-Alzheimer agents. © 2019 Deutsche Pharmazeutische Gesellschaf