Synergistic activity between Triphala and selected antibiotics against drug resistant clinical isolates.

BACKGROUND: Triphala is an indigenous medical product used for a variety of diseases. This study was conducted to determine the effect of Triphala on antibiotic properties of gentamicin and oxacillin against multi-drug resistant organisms. METHODS: The checkerboard method was used to determine the synergy of Triphala with gentamicin and oxacillin against multi-drug resistant (MDR) Gram negative bacilli and methicillin-resistant Staphylococcus aureus (MRSA) using 2,3,5-triphenyltetrazolium chloride (TTC) assay. Fractional inhibitory concentration (FIC) index was calculated. RESULTS: When tested alone, the minimum inhibitory concentration (MIC) values of gentamicin for Gram negative isolates ranged from 8 to > 64 µg/ml. The MIC values of gentamicin for the Gram negative isolates ranged from 1 to 32 µg/ml when tested with Triphala. The FIC index was < 1 indicating a synergistic interaction in 10 of the 11 isolates and it was 1 indicating an additive effect in one isolate. The MIC values of oxacillin for MRSA isolates ranged from 4 to > 16 µg/ml with all MICs being equal to or higher than the resistance cut-off level. The MIC level with the addition of Triphala ranged from 0.25 to 4 µg/ml. FIC index was < 1 for all tested isolates indicating a synergistic interaction. CONCLUSIONS: Triphala has synergistic activity with gentamicin against the selected MDR Gram negative bacilli and with oxacillin against MRSA isolates warranting further studies on the possibility of clinical use.

Methanol Extract of Holarrhena antidysenterica Inhibits the Growth of Human Oral Squamous Cell Carcinoma Cells and Osteoclastogenesis of Bone Marrow Macrophages.

Oral squamous cell carcinoma (OSCC) frequently invades mandibular bone, and outcomes for treatment with surgical resection are typically poor, ultimately resulting in death. Holarrhena antidysenterica L. (Apocynaceae), distributed throughout Sri Lanka and India, has been used as a folk remedy to treat various diseases. Treatment with methanol extract of H. antidysenterica bark (HABE) inhibited cell viability and BrdU incorporation and induced apoptotic cell death in Ca9-22 gingival and HSC-3 tongue SCC cells. Flow cytometric analysis indicated that HABE treatment preferentially induces apoptotic cell death via increasing the sub-G1 peak in Ca9-22 cells and cell cycle arrest at the G1 phase in HSC-3 cells. HABE treatment in the presence of zVAD-fmk, a pan-caspase inhibitor, rescued cell viabilities in both OSCC cell lines. The ratio of Bax to Bcl-2 increased with reductions in the Bcl-2 protein expression, and the activation of caspase 3 and subsequent cleavage of PARP was detected in HABE-treated Ca9-22 and HSC-3 cells. Furthermore, HABE treatment at noncytotoxic concentrations inhibited osteoclast formation in RANKL-stimulated bone marrow macrophages. Taken together, HABE possesses the inhibitory activity on the growth of OSCC cells and antiosteoclastogenic activity. Therefore, HABE may be a promising alternative and complementary agent for preventing and treating OSCC.

Antimicrobial potential of two traditional herbometallic drugs against certain pathogenic microbial species.

BACKGROUND: Mineral based preparations are widely used for centuries as antimicrobial agents. However, the efficacy and the mode of action of mineral based preparations are uncertain due to the insufficient antimicrobial studies. Arogyawardhana Vati (AV) and Manikya Rasa (MR) are such two Rasashastra herbo-minerallic drugs commonly in India and other countries in South Asia. Despite of their well known traditional use of skin diseases, reported antimicrobial and mineralogical studies are limited. Therefore, in this study antimicrobial activities of the drugs and their organic, inorganic fractions were evaluated against Pseudomonas aeruginosa, Escherischia coli, Staphylococcus aureus, Methecilline Resistance Staphylococcus aureus - MRSA and Candida albicans. METHODS: Antimicrobial activity of the drugs, their inorganic residues and organic extracts were determined using four assay techniques viz agar well diffusion, modified well diffusion, Miles and Misra viable cell counting and broth turbidity measurements. Mineralogical constituents of the drugs were determined using X-ray diffraction, while total cation constituents and water soluble cation constituents were determined using inductively coupled plasma-mass spectrometer and the atomic absorption spectrophotometer respectively. Thermogravimetric analysis was used to determine the weight percentages of organic and inorganic fraction of the drugs. Particle sizes of the drugs were determined using the particle size analyzer. RESULTS: AV and MR drugs showed antibacterial activity against both gram positive and gram negative bacterial species when analyzed separately. Inorganic residues of the drugs and organic extracts showed activity at least against two or more bacterial species tested. All tested components were inactive against C. albicans. Common mineral constituents of drugs are cinnabar, biotite and Fe-rich phases. Drugs were rich in essential elements such as Na, K, Ca, Mg and Fe and toxic elements such as Zn, Cu and As. However, the water soluble concentrations of the toxic elements were below the detection limits. Both drugs have significantly higher percentages of organic constituents and volatile minerals and particle sizes of drugs are in the nanometer range. CONCLUSIONS: AV and MR Rasashastra preparations could provide alternatives to synthetic antibiotics against human bacterial infections. Improved solubility and reduced particle sizes are influential physicochemical properties used to enhance the antimicrobial efficacy of the drugs. Therefore, traditional knowledge on the use of antimicrobial mineral sources could provide a novel path for the producing of effective antimicrobial drugs. However, further chemical and toxicological studies are urgently needed for a greater understanding of their toxicity to humans.

Phyllosticta musarum Infection-Induced Defences Suppress Anthracnose Disease Caused by Colletotrichum musae in Banana Fruits cv 'Embul'.

Anthracnose development by Colletotrichum musae was observed to be significantly less in the fruits of the banana cultivar 'Embul' (Mysore, AAB) infected with Phyllosticta musarum than in fruits without such infections. Anthracnose disease originates from quiescent C. musae infections in the immature fruit. P. musarum incites minute, scattered spots, referred to as freckles, in the superficial tissues of immature banana peel which do not expand during maturation or ripening. P. musarum does not appear to have a direct suppressive effect on C. musae as conidia of C. musae germinate on both freckled and non-freckled fruit forming quiescent infections. Our investigations have shown that P. musarum infection induced several defence responses in fruit including the accumulation of five phytoalexins, upregulation of chitinase and ß-1,3-glucanase, phenylalanine ammonia lyase (PAL) activity and cell wall lignification. (1)H and (13)C NMR spectral data of one purified phytoalexin compared closely with 4'-hydroxyanigorufone. Some of the P. musarum-induced defences that retained during ripening, restrict C. musae development at the ripe stage. This paper examines the potential of P. musarum-induced defences, in the control of anthracnose, the most destructive postharvest disease in banana.

Antimicrobial activity of some Sri Lankan Rubiaceae and Meliaceae.

Ninety solvent extracts (n-hexane, dichloromethane and methanol) obtained from the leaves, bark and stem of 13 Sri Lankan Rubiaceae and two Sri Lankan Meliaceae plants have been screened for antibacterial and antifungal activities. Morinda tinctoria, Mussaenda frondosa, Psychotria gardneri and Psychotria stenophylla displayed the widest spectrum of antibacterial activity.