Essential oils for the treatment of dust mites

House mites, including D. pteronyssinus and D. farina, are common causes of allergic diseases, such as asthma, atopic dermatitis, eczema, conjunctivitis and perennial rhinitis in susceptible patients. Conventional acaricides, such as benzyl benzoate, bifenthrin, chlorpyrifos are effective chemicals in treating mites. However, they are usually with high drug resistance and high adverse effects on environment, human health, and non-target organisms. Recently, essential oils from different plants were found to be safe and effective alternatives for killing different types of mites. The present review summarized the essential oils from different plants. The crude essential oils from Melissa officinalis, S.lavandulifolia oil, cade oil, P. cattleianum, Patchouli oil, Horseradish oil, C. cassia, P. cablin, Manuka oil, Clove Bud oil, and the pure essential oils, such as eugenol, caryophyllene, and camphor might be good candidates for the dust mites. Further studies on biological mechanisms of the acaricidal effects of these active essential oils, and the structure-activity relationships are needed to make the functions of these drugs more clear.

Exploring Additive, Synergistic or Antagonistic Effects of Natural Plant Extracts on In Vitro Beef Feedlot-Type Rumen Microbial Fermentation Conditions

Six Essential oils (EO) (tea tree oil—TeTr, oregano oil—Ore, clove bud oil—Clo, thyme oil—Thy, rosemary oil—Ros, and sage oil—Sag) in Experiment 1; and different combinations of selected oils in Experiment 2, were evaluate at four doses in an in vitro microbial fermentation system using ruminal fluid from beef cattle fed a 10:90 straw: Concentrate diet. In Experiment 1, TeTr, Ore, Clo and Thy improved rumen fermentation profile in a direction consistent with better feed utilization. In Experiment 2, TeTr mixed with Thy, Ore, Thy + Ore or Clo at 200 and 400 mg/L increased the molar proportion of propionate and decreased that of acetate, and the acetate to propionate ratio. However, the size of the effect was similar to that obtained with TeTr alone, suggesting that effects were not additive. When Thy, Ore or Thy + Ore where mixed with Clo, most effects on rumen fermentation profile disappeared, suggesting an antagonistic interaction of Clo with Thy and Ore. Results do not support the hypothesis of additivity among the EO tested, and antagonistic effects of Clo mixed with Thy or Ore were demonstrated at least in a low pH, beef-type fermentation conditions.

Comparing two high-intensity ultrasound processes to produce clove bud oil-in-water emulsions

The aim of this work was to compare two high-intensity ultrasound (HIUS) emulsification processes: high power short time (HPST) and low power long time (LPLT), giving the same specific energy of 10 kJ/g. Clove bud oil-in-water emulsions were obtained from the different HIUS processes. The emulsions were characterized with respect to droplet size distribution, rheological behavior, microestructure, color parameters, kinetic stability and volatile compounds profile by gas chromatography–mass spectrometry (GC-MS).

Essential Oil Emulsions as Postharvest Sanitizers To Mitigate Salmonella Cross-Contamination on Peppers

ABSTRACT Alternative postharvest sanitizers to chlorine are of increasing interest for many organic growers and consumers. An emulsion of clove bud oil (CBO; 0.2 and 0.5%) or thyme oil (0.2 and 0.5%) was evaluated as a sanitizer for produce washing against a five-serovar cocktail of Salmonella on snacking peppers and compared for antimicrobial efficacy with sodium hypochlorite (200 ppm). To further evaluate these compounds, the sanitation efficacy of an emulsion was examined after the addition of 1% organic load (OL). Emulsion treatments at 0.2 and 0.5% thyme oil and 0.5% CBO were the least effected by OL and effectively reduced cross-contamination of Salmonella on clean peppers, in many cases to below the limit of detection (1 CFU/10 g; P < 0.05). Chlorine and 0.2% CBO were rendered ineffective by the addition of OL in preventing cross-contamination and performed similarly to the water control. For surface-inoculated peppers, none of the evaluated treatments performed better than a water-only wash. The antimicrobial efficacy of the essential oil emulsions in the presence of OL indicates these emulsions may be suitable replacements for chlorine in postharvest produce wash systems.