Antimicrobial effect of lemongrass oil against oral malodour micro-organisms and the pilot study of safety and efficacy of lemongrass mouthrinse on oral malodour.

AIMS: Lemongrass oil (LG) has been reported as being effective against bacteria embedded within the biofilm. The aims of this study were to investigate antimicrobial activity against common odourigenic micro-organisms, the safety and efficacy of LG mouthrinse on oral malodour in healthy volunteers. METHODS AND RESULTS: Antimicrobial activity of LG mouthrinse was examined against common odourigenic micro-organisms using broth microdilution assay and the disc diffusion method. A randomised double-blind clinical study was performed in 20 healthy volunteers. Volatile sulphur compounds (VSCs) level was measured using a Halimeter on day 0 and day 8 in each volunteer. The results showed that LG mouthrinse was effective against Aggregatibacter actinomycetemcomitans ATCC43718 and Porphyromonas gingivalis W50 but less effective against Streptococcus mutans ATCC 25175. In addition, the mouthrinse significantly reduced VSCs on day 8. CONCLUSIONS: LG mouthrinse was able to reduce oral malodour and appeared to be safe. The overall satisfaction of the mouthrinse was acceptable. However, the spiciness and taste of the mouthrinse need to be improved. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated that the LG mouthrinse significantly reduced oral malodour. This mouthrinse would be another alternative mouthrinse choice for prevention of malodour, plaque and gingivitis.

Ethnoveterinary study for antidermatophytic activity of Piper betle, Alpinia galanga and Allium ascalonicum extracts in vitro.

Crude ethanolic extracts of Piper betle leaves (Piperaceae), Alpinia galanga rhizomes (Zingiberaceae) and Allium ascalonicum bulbs (Liliaceae) were tested against selected zoonotic dermatophytes (Microsporum canis, Microsporum gypseum and Trichophyton mentagrophyte) and the yeast-like Candida albicans. A broth dilution method was employed to determine the inhibitory effect of the extracts and compared to those of ketoconazole and griseofulvin. All extracts suppressed the growth of the fungi in a concentration-dependent manner. Among the extracts tested, P. betle exhibited more effective antifungal properties with average IC(50) values ranging from 110.44 to 119.00 microg/ml. Subsequently, 10% Piper betle (Pb) cream was formulated, subjected to physical and microbial limit test and evaluated for antifungal effect. The disc diffusion assay revealed comparable zones of inhibition between discs of Pb cream containing 80 microg P. betle extract and 80 microg ketoconazole against tested fungi at 96 h after incubation. Thereafter, the inhibitory effect of Pb cream markedly decreased and completely lost effectiveness by day 7. In summary, the results supported the traditional wisdom of herbal remedy use and suggested a potential value-addition to agricultural products. It was suggested that the Pb cream has potential therapeutic value for treatment of dermatophytosis. However, clinical testing as well as improving the Pb cream formulation with greater efficacy and duration of action would be of interest and awaits further investigation.

In vitro antiparasitic activity of extracts of Cardiospermum halicacabum against third-stage larvae of Strongyloides stercoralis.

Extracts of Cardiospermum halicacabum, medicinal plant, were tested in vitro for their effectiveness against third-stage larvae of Strongyloidesstercoralis. Third-stage larvae of S. stercoralis were isolated from cultures of dog's feces using agar plate culture method. The larvae (1,000 larvae/ml), suspended in phosphate buffer saline solution, pH 7.4, were exposed to aqueous and alcohol extracts (2,000 microg/ml) of C. halicacabum at 37 degrees C with 5% CO2. Ivermectin (250 microg/ml) and piperazine (2,000 microg/ml) were also used as the reference drugs. The survival of Strongyloides larvae based on its motility was determined daily for 7 days. Strongyloides larvae were viable after contact with ivermectin, piperazine and C. halicacabum (aqueous and alcohol) solutions, but most of them were immobilized, after exposure to aqueous and alcohol extracts of C. halicacabum within 72 and 48 h, respectively, while ivermectin took from 72 to 144 h, and piperazine more than 7 days, to achieve the same rate of nonmotility. Clearly, the viability of S. stercoralis larvae was significantly reduced when exposed to extracts of C. halicacabum. Further study is needed on the antiparasitic activity of aqueous and alcohol extracts of C. halicacabum against S. stercoralis.

In vitro antifilarial activity of extracts of the medicinal plant Cardiospermum halicacabum against Brugia pahangi.

The in vitro effects of ethanol and aqueous extracts of the medicinal plant Cardiospermum halicacabum on adult worms and microfilariae of Brugia pahangi were investigated. With or without the plant extracts in culture medium, the motility of adult worms, microfilariae and microfilarial release from female worms were monitored daily. After 7 days of culture, viability or tissue damage of adult worms was assessed using the MTT assay. At > 500 microg ml-1, the aqueous extract significantly reduced motility of adult females after 24 h of exposure and adult males after 3 days. The aqueous extract, at > 500 microg ml-1, also significantly reduced microfilarial release from female worms, starting on day 2. The reduction in the motility of adult worms and the pattern of microfilarial release from female worms were concentration and time dependent. The MTT assay results revealed that adult worms cultured in the presence of aqueous extracts at > 500 microg ml-1 were damaged. However, the aqueous extract did not affect the motility of microfilariae with the exception of those in higher concentration extracts. Higher concentrations of ethanol extracts (2 mg ml-1) inhibited both the motility of adult worms and the release of microfilariae from females. Little effect of ethanol extracts was detected by the MTT assay, as only slight damage was caused to worms exposed only to the highest concentration (2 mg ml-1). However, ethanol extract at 500 microg ml-1 rapidly reduced the motility of microfilariae on day 2. The present study revealed that an aqueous extract of C. halicacabum has mild but definite direct macrofilaricidal action on B. pahangi.

X-ray microanalysis of chlorine and phosphorus content in biguanide-treated Acanthamoeba castellanii.

Energy dispersive analysis of X-rays (EDAX) was used to study the effects of chlorhexidine diacetate (CHA) and polyhexamethylene biguanide (PHMB) on Acanthamoeba castellanii. A high variation of elements occurred in untreated individual cells and only two elements, Cl (a biocide marker) and P, were investigated. X-ray dot mapping of untreated trophozoites and cysts revealed that Cl in cells was uniformly distributed throughout the cytoplasm, whereas P was less dense in the vacuoles. X-ray dots of Cl in biocide-treated trophozoites and cysts appeared denser and evenly distributed within the cells as the biguanide concentration increased. Quantitative analysis of either CHA or PHMB within the cells using Cl as an elemental marker was unsatisfactory because of the high Cl levels in untreated cells. The apparent increases of P in some experiments with treated cells might be associated with reduced permeability, protein coagulation or aggregation of phospholipids.