Pyroligneous acid from Mimosa tenuiflora and Eucalyptus urograndis as an antimicrobial in dairy goats.

AIMS: To evaluate the applicability of the Mimosa tenuiflora and Eucalyptus urograndis pyroligneous acids (PAs) as alternative antiseptics in dairy goats. METHODS AND RESULTS: Cytotoxicity was evaluated in vitro using bacteria, as well as in vivo using goats, and the influence of PAs on the physicochemical parameters of fresh milk were examined. The cytotoxicity of PAs was evaluated in terms of morphology, cell viability and metabolic activity of goat tegumentary cells. The PA of M. tenuiflora had results similar to those of 2% iodine. For the in vitro tests, strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were used with the well technique, demonstrating inhibition halos greater than 9 mm. In the in vivo test, 15 animals were used per phase of the experiment, and the plate counting technique showed that there was antiseptic action of both extracts, with emphasis on the M. tenuiflora PA. Physicochemical analysis of the milk showed that neither PAs interfered with its physical-chemical parameters. CONCLUSIONS: The PA of M. tenuiflora presented potential as an alternative antiseptic in dairy goats. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates the use of PA as an antimicrobial agent in animals.

Evaluation of the Effectiveness of Crotoxin as an Antiseptic against Candida spp. Biofilms.

The growing number of oral infections caused by the Candida species are becoming harder to treat as the commonly used antibiotics become less effective. This drawback has led to the search for alternative strategies of treatment, which include the use of antifungal molecules derived from natural products. Herein, crotoxin (CTX), the main toxin of Crotalus durissus terrificus venom, was challenged against Candida tropicalis (CBS94) and Candida dubliniensis (CBS7987) strains by in vitro antimicrobial susceptibility tests. Minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and inhibition of biofilm formation were evaluated after CTX treatment. In addition, CTX-induced cytotoxicity in HaCaT cells was assessed by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) colorimetric assay. Native CTX showed a higher antimicrobial activity (MIC = 47 µg/mL) when compared to CTX-containing mouthwash (MIC = 750 µg/mL) and nystatin (MIC = 375 µg/mL). Candida spp biofilm formation was more sensitive to both CTX and CTX-containing mouthwash (IC100 = 12 µg/mL) when compared to nystatin (IC100 > 47 µg/mL). Moreover, significant membrane permeabilization at concentrations of 1.5 and 47 µg/mL was observed. Native CTX was less cytotoxic to HaCaT cells than CTX-containing mouthwash or nystatin between 24 and 48 h. These preliminary findings highlight the potential use of CTX in the treatment of oral candidiasis caused by resistant strains.

American Civil War plant medicines inhibit growth, biofilm formation, and quorum sensing by multidrug-resistant bacteria.

A shortage of conventional medicine during the American Civil War (1861-1865) spurred Confederate physicians to use preparations of native plants as medicines. In 1863, botanist Francis Porcher compiled a book of medicinal plants native to the southern United States, including plants used in Native American traditional medicine. In this study, we consulted Porcher's book and collected samples from three species that were indicated for the formulation of antiseptics: Liriodendron tulipifera, Aralia spinosa, and Quercus alba. Extracts of these species were tested for the ability to inhibit growth in three species of multidrug-resistant pathogenic bacteria associated with wound infections: Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter baumannii. Extracts were also tested for biofilm and quorum sensing inhibition against S. aureus. Q. alba extracts inhibited growth in all three species of bacteria (IC50 64, 32, and 32 µg/mL, respectively), and inhibited biofilm formation (IC50 1 µg/mL) in S. aureus. L. tulipifera extracts inhibited biofilm formation (IC50 32 µg/mL) in S. aureus. A. spinosa extracts inhibited biofilm formation (IC50 2 µg/mL) and quorum sensing (IC50 8 µg/mL) in S. aureus. These results support that this selection of plants exhibited some antiseptic properties in the prevention and management of wound infections during the conflict.

Eco-friendly rapid removal of triclosan from seawater using biomass of a microalgal species: Kinetic and equilibrium studies.

Triclosan is an important emerging pollutant. It has become ubiquitous due to its incomplete elimination in municipal wastewater treatment plants causing serious environmental problems. Biomass from microorganisms as sorbent of pollutants can be an eco-friendly alternative for triclosan removal. In this work, the elimination of triclosan using biomass (dead and living) of the marine microalga Phaeodactylum tricornutum was characterized in cultures exposed to light and in a complex solution (seawater). Maximum removal capacity, isotherms, kinetics, FTIR characterization, pH effect and reuse were evaluated and discussed. Photodegradation of triclosan was also evaluated. Both biomasses showed similar effectiveness; around 100% of pollutant was eliminated when its concentration was 1 mg L-1 in only 3 h using a biomass concentration of 0.4 g L-1. A pseudo-second order model guided the biosorption process. Considering the photodegradation as a first-order process, the whole process (photodegradation + biosorption) was suitably modelled with pseudo-third order and Elovich kinetics. Biosorption increased with the decrease in pH. Temkin isotherm showed the best fit for the experimental data. Both biomasses showed good reuse after five cycles, losing only 7% in efficiency. P. tricornutum biomass is an attractive eco-material for triclosan elimination with low-cost and easy handling than other sorbents.

Hydroperoxides derived from marine sources: origin and biological activities.

Hydroperoxides are a small and interesting group of biologically active natural marine compounds. All these metabolites contain a group (R-O-O-H). In this mini-review, studies of more than 80 hydroperoxides isolated from bacteria, fungi, algae, and marine invertebrates are described. Hydroperoxides from the red, brown, and green algae exhibit high antineoplastic, anti-inflammatory, and antiprotozoal activity with a confidence of 73 to 94%. Hydroperoxides produced by soft corals showed antineoplastic and antiprotozoal activity with confidence from 81 to 92%. Metabolites derived from sea sponges, mollusks, and other invertebrates showed antineoplastic and antiprotozoal (Plasmodium) activity with confidence from 80 to 90%.

Thymol nanoemulsion exhibits potential antibacterial activity against bacterial pustule disease and growth promotory effect on soybean.

An antibacterial and plant growth promoting nanoemulsion was formulated using thymol, an essential oil component of plant and Quillaja saponin, a glycoside surfactant of Quillaja tree. The emulsion was prepared by a sonication method. Fifty minutes of sonication delivered a long term stable thymol nanoemulsion which was characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), cryogenic-field emission scanning electron microscopy (Cryo-FESEM) and fourier transform infra-red (FTIR) spectroscopy. Creaming index, pH and dilution stability were also studied for deliberation of its practical applications. The nanoemulsion (0.01-0.06%, v/v) showed substantial in vitro growth inhibition of Xanthomonas axonopodis pv. glycine of soybean (6.7-0.0 log CFU/ml). In pot experiments, seed treatment and foliar application of the nanoemulsion (0.03-0.06%, v/v) significantly lowered the disease severity (DS) (33.3-3.3%) and increased percent efficacy of disease control (PEDC) (54.9-95.4%) of bacterial pustule in soybean caused by X. axonopodis pv. glycine. Subsequently, significant enhancements of plant growth were also recorded in plants treated with thymol nanoemulsion. This is the first report of a thymol based nanoemulsion obtained using Quillaja saponin as a surfactant. Our study claims that nano scale thymol could be a potential antimicrobial and plant growth promoting agent for agriculture.

Preservation of large yellow croaker (Pseudosciaena crocea) by Coagulin L1208, a novel bacteriocin produced by Bacillus coagulans L1208.

Large yellow croaker (Pseudosciaena crocea) is a cultivated fish of great economic importance and abundant nutritional value. However, due to its high protein and water contents, it is susceptible to decomposition, leading to considerable economic loss and adverse effects on consumer health. Here, we assessed the function of the bacterial strain Bacillus coagulans L1208 (Bcoa) in preserving large yellow croaker during storage at 4°C and found that Bcoa elongates the shelf-life significantly. Further investigations showed that Bcoa prolongs the storage time mainly by suppressing the growth of spoilage bacteria. Moreover, a novel bacteriocin, designated as Coagulin L1208 and produced by Bcoa, was purified and identified by N-terminal sequencing. Finally, the activity of Coagulin L1208 for suppressing spoilage bacteria during the preservation of large yellow croaker was assessed. Our results reveal the mechanism by which Bcoa aids the preservation of large yellow croaker and identify Coagulin L1208 as a potential novel antiseptic.

Brote de Serratia marcescens producido por clorhexidina acuosa al 2% contaminada / Serratia marcescens outbreak due to contaminated 2% aqueous chlorhexidine

Introducción y objetivo: Describimos un brote de infección por Serratia marcescens (S. marcescens) y la investigación epidemiológica que asoció el brote al uso de clorhexidina acuosa al 2% como antiséptico. Método: A finales del mes de noviembre del 2014 detectamos un aumento en la incidencia de infecciones por S. marcescens en pacientes atendidos en Urgencias, por lo que nos planteamos la posibilidad de estar ante un brote e iniciamos una investigación epidemiológica. Resultado: Se aisló S. marcescens en 23 muestras de 16 pacientes y en todos los frascos nuevos de 2 lotes de clorhexidina acuosa al 2%. Se ordenó retirar el desinfectante y se alertó a la Agencia Española del Medicamento (COS 2/2014). El estudio epidemiológico demostró que los aislamientos de las muestras clínicas y las recuperadas de la clorhexidina pertenecían al mismo clon. Una vez retirados los lotes contaminados, no se produjeron más casos. Conclusión: La sospecha del brote y la investigación epidemiológica fueron fundamentales para controlar la incidencia (AU)

Introduction and objective: An outbreak of Serratia marcescens infections outbreak is described, as well as the epidemiological study that linked the outbreak to the use of 2% aqueous chlorhexidine antiseptic. Method: In late November 2014 an increasing incidence of S. marcescens isolates was detected in patients treated in the emergency department. It was considered a possible outbreak, and an epidemiological investigation was started. Result: S. marcescens was isolated in 23 samples from 16 patients and in all new bottles of two lots of 2% aqueous chlorhexidine. The contaminated disinfectant was withdrawn, and the Spanish Drugs Agency was alerted (COS 2/2014). The epidemiological study showed that strains isolated from clinical samples and from chlorhexidine belonged to the same clone. No further isolates were obtained once the disinfectant was withdrawn. Conclusion: The suspicion of an outbreak and the epidemiological study were essential to control the incidence (AU)

Antioxidant, anti-inflammatory and anti-septic potential of phenolic acids and flavonoid fractions isolated from Lolium multiflorum.

CONTEXT: Interest has recently renewed in using Lolium multiflorum Lam. (Poaceae) (called Italian ryegrass; IRG) silage as an antioxidant and anti-inflammatory diet. OBJECTIVE: This study investigated the antioxidant, anti-inflammatory and anti-septic potential of IRG silage and identified the primary components in IRG active fractions. MATERIALS AND METHODS: Total 16 fractions were separated from the chloroform-soluble extract of IRG aerial part using Sephadex LH-20 column before HPLC analysis. Antioxidant and anti-inflammatory activities of the fractions at doses of 0-100 µg/mL were investigated using various cell-free and cell-mediated assay systems. To explore anti-septic effect of IRG fractions, female ICR and BALB/c mice orally received 40 mg/kg of phenolic acid and flavonoid-rich active fractions F7 and F8 every other day for 10 days, respectively, followed by LPS challenge. RESULTS: The active fractions showed greater antioxidant and anti-inflammatory potential compared with other fractions. IC50 values of F7 and F8 to reduce LPS-stimulated NO and TNF-α production were around 15 and 30 µg/mL, respectively. Comparison of retention times with authentic compounds through HPLC analysis revealed the presence of caffeic acid, ferulic acid, myricetin and kaempferol in the fractions as primary components. These fractions inhibited LPS-stimulated MAPK and NF-κB activation. Supplementation with F7 or F8 improved the survival rates of mice to 70 and 60%, respectively, in LPS-injected mice and reduced near completely serum TNF-α and IL-6 levels. DISCUSSION AND CONCLUSION: This study highlights antioxidant, anti-inflammatory and anti-septic activities of IRG active fractions, eventually suggesting their usefulness in preventing oxidative damage and inflammatory disorders.

Inhibitory Effect of Three Diketopiperazines from Marine-Derived Bacteria on HMGB1-Induced Septic Responses in Vitro and in Vivo.

The nucleosomal protein high-mobility group box-1 (HMGB1), which has recently been established as a late mediator of lethal systemic inflammation, has a relatively wide therapeutic window for pharmacological interventions. Compounds produced by marine-derived microbes have been widely investigated for their potential use as bioactive natural products. Cyclic dipeptides, which are also known as diketopiperazines, are molecules that are frequently found in marine-derived microorganisms. While their pharmacological potential has been well established, their biological activities against septic responses have not yet been reported. Here, three diketopiperazines (1-3) isolated from two strains of marine-derived bacteria were investigated for their potential activities against HMGB1-mediated septic responses. The data showed that 1-3 effectively inhibited the lipopolysaccharide (LPS)-induced release of HMGB1 and suppressed the HMGB1-mediated septic responses, including hyperpermeability, leukocyte adhesion and migration, and cell adhesion molecule expression. In addition, 1-3 inhibited the HMGB1-mediated production of tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text] and interleukin (IL)-6 and the activation of nuclear factor-[Formula: see text]B (NF-[Formula: see text]B) and extracellular signal-regulated kinase (ERK) 1 and ERK2. Collectively, these results indicated that 1-3 might act as potential therapeutic agents for various severe vascular inflammatory diseases through the inhibition of the HMGB1 signaling pathway.

The dynamics and mechanism of the antimicrobial activity of tea tree oil against bacteria and fungi.

Tea tree oil (TTO) is a yellow liquid extracted from Melaleuca alternifolia. Although the antimicrobial activity of TTO has been known for a long time, its specific antimicrobial effects and mechanism underlying these remain poorly characterized. The present study investigated the chemical composition of TTO and the dynamics and mechanism of its antimicrobial activities in two bacterial and two fungal strains. Gas chromatography-mass spectrometry analysis identified alkenes and alcohols as the main constituents of TTO. Terpinen-4-ol was the most abundant individual component, accounting for approximately 23 % of the TTO. Poisoned food technique assessment showed that the minimum inhibitory concentrations of TTO for bacterial strains (Escherichia coli and Staphylococcus aureus) and fungal strains (Candida albicans and Aspergillus niger) were 1.08 and 2.17 mg/mL, respectively. Antimicrobial dynamic curves showed that with increasing concentrations of TTO, the rate of cell killing and the duration of growth lag phase increased correspondingly. These data indicated that TTO produced concentration and time-dependent antimicrobial effects. The minimum bactericidal and fungicidal concentrations of TTO were 2.17, 4.34, and 4.34 against E. coli, S. aureus, and C. albicans, respectively. However, A. niger conidia were not completely eradicated, even after 3 days in the presence of 17.34 mg/mL TTO. Transmission electron microscopy images indicated that TTO penetrated the cell wall and cytoplasmic membrane of all the tested bacterial and fungal strains. TTO may also penetrate fungal organelle membrane. These findings indicated that TTO maybe exerts its antimicrobial effects by compromising the cell membrane, resulting in loss of the cytoplasm and organelle damage, which ultimate leads to cell death.

Development of novel magnetic solid phase extraction materials based on Fe3O4/SiO2/poly(acrylamide-N,N'-methylene bisacrylamide)-Pluronic L64 composite microspheres and their application to the enrichment of natamycin.

Novel magnetic adsorbents based on Fe3O4/SiO2/poly(acrylamide-N,N'-methylene bisacrylamide) magnetic microspheres modified with non-ionic triblock copolymer surfactant were successfully prepared as a magnetic solid phase extraction adsorbent for the determination of trace natamycin in jam samples. The adsorbent was characterized by scanning electron microscopy, transmission electron microscopy, Fourier transformed infrared spectroscopy, vibrating sample magnetometer, and X-ray diffractometer analysis, confirming that Pluronic L64 was effectively functionalized on the magnetic materials. Various experimental parameters affecting the extraction capacity were investigated including adsorbent amount, extraction time, desorption time, sample pH, and ionic strength. For recovery evaluations, the jam samples were spiked at two concentration levels of 100 and 200µgkg(-1) of natamycin and the recovery values were in the range of 78.8-93.4%. The relative standard deviations (RSD) for the recoveries were less than 3.5%. The novel magnetic solid phase extraction method provided several advantages, such as simplicity, low environmental impact, convenient extraction procedure, and short analysis time when used for natamycin analysis.

Synthesis of core-shell SiO2@MgO with flower like morphology for removal of crystal violet in water.

In this study, we report a facile and effective route to synthesize core-shell SiO2@MgO with flower like morphology, which the shell is assembled by magnesium oxide nanosheets. The SiO2@MgO composite (SMC) was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDX), X-ray fluorescence (XRF) and N2 adsorption-desorption techniques. The sample showed excellent performance for the removal of crystal violet due to its high specific surface area and porous structures. Adsorption data fitted better with Langmuir isotherm and the maximum adsorption capacity was 2244.85 mg g(-1). The kinetic data was better described by pseudo-second order model and thermodynamic studies showed that adsorption process was spontaneous and endothermic. The adsorbent also showed very good reproducibility and reusability for the successive five cycles, indicating a promising potential material for environmental remediation.

Anti-septic activity of α-cubebenoate isolated from Schisandra chinensis.

Sepsis is a life-threatening, infectious, systemic inflammatory disease. In this study, we investigated the therapeutic effect of α-cubebenoate, a novel compound isolated from Schisandra chinensis against polymicrobial sepsis in a cecal ligation and puncture (CLP) experimental model. Administration of α-cubebenoate strongly enhanced survival in the CLP model. α-cubebenoate administration also markedly blocked CLP-induced lung inflammation and increased bactericidal activity by enhancing phagocytic activity and hydrogen peroxide generation in mouse bone marrow-derived macrophages and neutrophils. Expression of two important inflammatory cytokines, IL-1ß and IL-6, was strongly increased in the CLP model, and this was dramatically blocked by α-cubebenoate. Lymphocyte apoptosis and caspase-3 activation, which are associated with immune paralysis during sepsis, were markedly attenuated by α-cubebenoate. Taken together, our findings indicate that α-cubebenoate, a natural compound isolated from Schisandra chinensis, is a powerful potential anti-septic agent.

[Microbicides for preventing sexually transmitted infections: Current status and strategies for preclinical evaluation of new candidates]. / Microbicidas para la prevención de infecciones de transmisión sexual: estado actual y estrategias para la evaluación preclínica de nuevos candidatos.

Microbicides are a new tool, still under investigation, which could help prevent infection by the human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). Increasing evidence shows that the complexity of sexual transmission of viral pathogens requires the identification of compounds able to block the early events during the cycle of viral infection. In this manuscript we provide a comprehensive review of the different microbicide strategies that have been studied or are currently being considered for STI prevention, particularly emphasizing those having the potential to block HIV infection. The manuscript also reviews the complex process that is required to conduct future clinical studies in humans and concludes with a brief discussion of the strategies that could be part of the immediate future in microbicide research.

Alcohol extract of Schinu sterebinthifolius raddi (anacardiaceae) as a local antimicrobial agent in severe autogenously fecal peritonitis in rats.

PURPOSE: To develop an alcoholic extract of the inner bark of the Schinus terebinthifolius raddi and to test its impact on autogenously fecal peritonitis in Wistar rats. METHODS: The inner bark of the Schinus terebinthifolius raddi was kept for seven days in 70% ethanol alcohol. The total elimination of the solvent was performed in a rotary evaporator under reduced pressure at 55-60°C. Four milliliter of this extract was injected, after 24 h, into the abdominal cavity of six out of eight survival rats that underwent autogenously fecal peritonitis with five milliliter of 10% filtered fecal suspension. They were clinically followed up for 45 days when they were euthanized. The necropsy findings (inventory) of the abdominal and thorax cavities were inspected and the main findings were recorded and photographed. The investigation was approved by the Ethics Committee. RESULTS: Two out of six survival rats that were critically ill after 24 h died within the 12 h after the extract injection into the abdominal cavity. Four rats that were also critically ill recovered and gradually became healthy, eating well, regaining weight and moving normally in the cage. At 45 days post severe peritonitis the necropsy findings revealed few signs of residual infection on the abdominal and thorax cavities. There were no bowel adhesions. CONCLUSION: The impact of alcoholic extract of the inner bark of the Schinus terebinthifolius raddi was considered very positive and promising as natural local antiseptic against very severe peritonitis in Wistar rats.

Alcohol extract of Schinu sterebinthifolius raddi (anacardiaceae) as a local antimicrobial agent in severe autogenously fecal peritonitis in rats

PURPOSE: To develop an alcoholic extract of the inner bark of the Schinus terebinthifolius raddi and to test its impact on autogenously fecal peritonitis in Wistar rats. METHODS: The inner bark of the Schinus terebinthifolius raddi was kept for seven days in 70% ethanol alcohol. The total elimination of the solvent was performed in a rotary evaporator under reduced pressure at 55-60°C. Four milliliter of this extract was injected, after 24 h, into the abdominal cavity of six out of eight survival rats that underwent autogenously fecal peritonitis with five milliliter of 10% filtered fecal suspension. They were clinically followed up for 45 days when they were euthanized. The necropsy findings (inventory) of the abdominal and thorax cavities were inspected and the main findings were recorded and photographed. The investigation was approved by the Ethics Committee. RESULTS: Two out of six survival rats that were critically ill after 24 h died within the 12 h after the extract injection into the abdominal cavity. Four rats that were also critically ill recovered and gradually became healthy, eating well, regaining weight and moving normally in the cage. At 45 days post severe peritonitis the necropsy findings revealed few signs of residual infection on the abdominal and thorax cavities. There were no bowel adhesions. CONCLUSION: The impact of alcoholic extract of the inner bark of the Schinus terebinthifolius raddi was considered very positive and promising as natural local antiseptic against very severe peritonitis in Wistar rats. .

Microbicidas para la prevención de infecciones de transmisión sexual: estado actual y estrategias para la evaluación preclínica de nuevos candidatos. / [Microbicides for preventing sexually transmitted infections: Current status and strategies for preclinical evaluation of new candidates].

Microbicides are a new tool, still under investigation, which could help prevent infection by the human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). Increasing evidence shows that the complexity of sexual transmission of viral pathogens requires the identification of compounds able to block the early events during the cycle of viral infection. In this manuscript we provide a comprehensive review of the different microbicide strategies that have been studied or are currently being considered for STI prevention, particularly emphasizing those having the potential to block HIV infection. The manuscript also reviews the complex process that is required to conduct future clinical studies in humans and concludes with a brief discussion of the strategies that could be part of the immediate future in microbicide research.

Diaryltriazine non-nucleoside reverse transcriptase inhibitors are potent candidates for pre-exposure prophylaxis in the prevention of sexual HIV transmission.

OBJECTIVES: Pre-exposure prophylaxis and topical microbicides are important strategies in the prevention of sexual HIV transmission, especially since partial protection has been shown in proof-of-concept studies. In search of new candidate drugs with an improved toxicity profile and with activity against common non-nucleoside reverse transcriptase inhibitor (NNRTI)-resistant HIV, we have synthesized and investigated a library of 60 new diaryltriazine analogues. METHODS: From this library, 15 compounds were evaluated in depth using a broad armamentarium of in vitro assays that are part of a preclinical testing algorithm for microbicide development. Antiviral activity was assessed in a cell line, and in primary human cells, against both subtype B and subtype C HIV-1 and against viruses resistant to therapeutic NNRTIs and the candidate NNRTI microbicide dapivirine. Toxicity towards primary blood-derived cells, cell lines originating from the female reproductive tract and female genital microflora was also studied. RESULTS AND CONCLUSIONS: We identified several compounds with highly potent antiviral activity and toxicity profiles that are superior to that of dapivirine. In particular, compound UAMC01398 is an interesting new candidate that warrants further investigation because of its superior toxicity profile and potent activity against dapivirine-resistant viruses.

Search for a potent microbicidal spermicide from the isolates of Shorea robusta resin.

BACKGROUND: An alarming increase in global population is the root cause of poverty, malnutrition, sexually transmitted infections (STIs) and many other social problems. Microbicidal spermicides possessing dual function of contraception and STI protection can effectively combat this problem, and their development is of utmost importance at present. STUDY DESIGN: A major metabolite isolated from Shorea robusta resin was spectroscopically characterized as asiatic acid. Spermicidal efficacy of the isolate was evaluated in vitro by a modified Sander-Cramer test. The mode of spermicidal action was assessed by (a) double fluoroprobe staining, (b) hypoosmotic swelling test and (c) scanning electron microscopy. Antimicrobial efficacy was assessed by disc diffusion and broth dilution methods using human isolates of bacteria (Escherichia coli ATCC 25938 and Pseudomonas aeruginosa 71) and fungus (Candida tropicalis). RESULTS: The minimum effective concentration of asiatic acid that induced instantaneous immobilization of rat spermatozoa in vitro was 125 mcg/mL. The mechanism of action involved disruption of sperm plasma membrane. The microbicidal efficacy was found to be moderate for vaginal pathogens, with no effect on normal vaginal flora. CONCLUSION: Asiatic acid possesses appreciable spermicidal and microbicidal potential and may be explored as an effective microbicidal spermicide.