Garlic as an insect repellent

Mosquito repellent fabric: Development and characterization of peppermint and garlic mixture finish on knitted fabric to examine mosquito repellency

Mosquito-repellent textiles are a part of protective textiles which help in protection from the species that are prone to cause diseases like malaria and dengue fever. This study explored the possibility of natural extract (alcoholic) from peppermint leaves, stems, and garlic cloves to use as a mosquito-repellent finish material on knit fabric. Accordingly, different concentration (5%, 15%, 25%, and 35%) of PGE (Peppermint Garlic Extract) solution was prepared and applied to the developed fabric using an exhaust dyeing process to assess the mosquito (Aedes Aegypti L.) repellency performance. Following WHO (World Health Organization) standard (cone bioassay) and a self-modified cage technique from literature survey, mosquito protection and repellency tests have been performed for characterization. The findings revealed that the PGE-treated fabric samples C (25% PGE) and D (35% PGE) had the highest mosquito mortality (50.00% and 76.67%, respectively) and repellency (78.6% and 85.6%, respectively) rates. Moreover, this study evaluated the prepared PGE formulations' shelf-life performance and colorfastness properties of PGE-treated fabrics, including the impact of washing cycles on the treated fabrics. There was no fungal growth, and the fabric showed excellent colorfastness properties. However, the efficacy of treated fabrics decreased with an increasing number of washes.

Monitoring of Hydrogen Emission from Bacteria in Food, Animals and in the Blood of Humans Suffering from Lyme Disease by A Specific Hydrogen Sensor

A novel straightforward analytical technique was developed to monitor the emission of hydrogen from anaerobic bacteria cultured in sealed headspace vials using a specific hydrogen sensor. The results were compared with headspace gas chromatography carried out in parallel. This technique was also applied to investigate the efficacy of chemical antibiotics and of natural compounds with antimicrobial properties. Antibiotics added to the sample cultures are apparently effective if the emission of hydrogen is suppressed, or if not, are either ineffective or the related bacteria are even resistant. The sensor approach was applied to prove bacterial contamination in food, animals, medical specimens and in ticks infected by Borrelia bacteria and their transfer to humans, thus causing Lyme disease. It is a unique advantage that the progress of an antibiotic therapy can be examined until the emission of hydrogen is finished. The described technique cannot identify the related bacteria but enables bacterial contamination by hydrogen emitting anaerobes to be recognized. The samples are incubated with the proper culture broth in closed septum vials which remain closed during the whole process. The personnel in the lab never come into contact with pathogens and thus safety regulations are guaranteed.

Repellent and acaricidal activity of essential oils and their components against Rhipicephalus ticks in cattle

Ticks, particularly the Rhipicephalus which are the most prevalent and invasive affect 80 % of the cattle population worldwide. Through transmission of pathogens, tick worry and physical damage to the hides, ticks cause economic loss of billions of dollars each year with 1 billion US dollars loss per annum reported only in Latin-America. These losses can be minimized only by successful management of Rhipicephalus ticks. Various strategies like chemical control, vaccination and biological control are aimed at control of Rhipicephalus ticks. There are some serious limitations associated with them like tick resistance, drug toxicity, antigenic variations etc. In contrast to these issues related with chemical tick control, the botanicals particularly the essential oils obtained from aromatic plants of medicinal importance are eco-friendly and non-toxic to most host. In recent years, essential oils-based control of cattle ticks has gained considerable attraction of scientists all over the world as depicted from this review. A comprehensive effort has been made to critically analyze the role of essential oils in controlling Rhipicephalus ticks with particular emphasis on the mode of action of bioactive compounds both as repellents and acaricides. Furthermore, we have pointed out the most important challenges which need to be addressed for development and commercialization of an essential oil based anti-tick product.

Hepatotoxicity of Herbal Supplements Mediated by Modulation of Cytochrome P450

Herbal supplements are a significant source of drug-drug interactions (DDIs), herb-drug interactions, and hepatotoxicity. Cytochrome P450 (CYP450) enzymes metabolize a large number of FDA-approved pharmaceuticals and herbal supplements. This metabolism of pharmaceuticals and supplements can be augmented by concomitant use of either pharmaceuticals or supplements. The xenobiotic receptors constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) can respond to xenobiotics by increasing the expression of a large number of genes that are involved in the metabolism of xenobiotics, including CYP450s. Conversely, but not exclusively, many xenobiotics can inhibit the activity of CYP450s. Induction of the expression or inhibition of the activity of CYP450s can result in DDIs and toxicity. Currently, the United States (US) Food and Drug Administration does not require the investigation of the interactions of herbal supplements and CYP450s. This review provides a summary of herbal supplements that inhibit CYP450s, induce the expression of CYP450s, and/or whose toxicity is mediated by CYP450s.

Repelling properties of some plant materials on the tick Ixodes ricinus L

The repellent effects on nymphal stages of Ixodes ricinus L. of some plant materials have been studied in the laboratory. The plant material consisted of an ethanolic extract from Achillea millefolium L., and volatile oils of birch and/or pine tar, citronella, cloves, eucalyptus, geranium, lavender, lily of the valley and peppermint. The most pronounced effects were observed for the oils of citronella, cloves and lily of the valley. They possessed repelling activities of the same magnitude as the reference repellent DEET (N,N-diethyl-m-toluamide). Some major constituents of these oils, e.g. citronellol and geraniol (oil of citronella and lily of the valley) and eugenol (oil of cloves) showed pronounced repelling effects. This was also the case for phenethyl alcohol, a minor component in the oil from lily of the valley.

Repellent efficacy of four commercial DEET lotions against Amblyomma hebraeum (Acari: Ixodidae), the principal vector of Rickettsia africae in southern Africa

African tick bite fever, caused by Rickettsia africae, is an emerging zoonotic infection in rural sub-Saharan Africa and the French West Indies. We tested the repellent efficacy of four commercial diethyl-3-methylbenzamide (DEET) lotions against Amblyomma hebraeum Koch, the principal vector of R. africae in southern Africa, by using a human bioassay in which repellent-treated fingers were presented to questing tick nymphs hourly for 4h. Three lotions with 19.5, 31.6 and 80% DEET concentrations, respectively, had a repellent efficacy of > or =90% at 1h post-application, of > or =77% at 2h post-application and of <70% during the rest of the experiment. By contrast, a lotion with 2% DEET plus 1% citronella oil provided only a 59% repellency at 1h post-application, with a drop to <22% during the following hours. Hourly negative control trials repelled <5% of tick attacks. Our results suggest that commercial repellents containing > or =19.5% DEET provide a significant but short-lasting protection against questing A. hebraeum ticks.

The efficacy of herbal medicine - an overview

Herbal medicine has become a popular form of healthcare. Even though several differences exist between herbal and conventional pharmacological treatments, herbal medicine can be tested for efficacy using conventional trial methodology. Several specific herbal extracts have been demonstrated to be efficacious for specific conditions. Even though the public is often misled to believe that all natural treatments are inherently safe, herbal medicines do carry risks. Ultimately, we need to know which herbal remedies do more harm than good for which condition. Because of the current popularity of herbal medicine, research in this area should be intensified.

A double-blinded, placebo-controlled trial of garlic as a mosquito repellant: a preliminary study

The hypothesis that the ingestion of garlic provides protection against bloodsucking pests such as mosquitoes was investigated using a randomized, double-blinded, placebo-controlled crossover study. Subjects were asked to consume either garlic (one visit) or a placebo (the other visit). They were then exposed to laboratory-reared Aedes aegypti (Linnaeus) (Diptera: Culicidae). The numbers of mosquitoes that did not feed on the subjects, the number of mosquito bites, the weights of the mosquitoes after feeding and the amounts of blood ingested were determined. The data did not provide evidence of significant systemic mosquito repellence. A limitation of the study is that more prolonged ingestion of garlic may be needed to accomplish repellence.

Five decades of tick-man interaction in Denmark--an analysis

The tick Ixodes ricinus (L.) is a known vector of several zoonotic diseases such as Tick Borne Encephalitis (TBE), Lyme borreliosis and ehrlichiosis. The interaction between humans and ticks are at the very core of our understanding of the epidemiology of tick borne zoonoses, but only few experimental studies have been performed. Hence our understanding of the epidemiology of tick-borne disease has to rest on the assumption that the potential tick activity, which is reflected in tick samples from the vegetation or samples from animals, corresponds with tick-human interaction. Observations which may reflect the long term tick-human contact are available in Denmark. These observations are records of requests for information on I. ricinus forwarded to the Danish Pest Infestation Laboratory (DPIL). This article was based on the assumption that the request could be seen as a measure of tick-human interaction reflecting the tick densities in relative terms. The perceived tick densities given by the number of requests on I. ricinus divided by the total number of requests to DPIL was fairly stable from 1965 to 1985, while it doubled during the late 1980's reaching a higher level in the beginning of the 1990's. The perceived density was well explained by the variation in temperature, solar radiation (monthly measurement) and deer abundance (yearly assessments). The measure of deviation, i.e. the ratio between observed requests + 1 and modelled requests + 1, for the individual years varied between 0.91 and 1.20, with considerable within-year variation. A gradual change in periodicity of the residual might suggest gradually changing tick population dynamics. In conclusion, the perceived tick densities appear to be consistent with the current knowledge of tick ecology and tick-transmitted diseases.

A prospective cross-over field trial shows protection of lemon eucalyptus extract against tick bites

Ixodes ricinus can transmit several microorganisms, out of which Borrelia burgdorferi and tick-borne encephalitis (TBE) virus are the most important pathogens in humans. A lemon eucalyptus extract (Citriodiol) has been shown to be a natural repellent against mosquitoes, stable flies, and midges. We have investigated whether the use of the extract would reduce the number of attached I. ricinus ticks in humans. A volunteer sample of 111 individuals was recruited among healthy, outdoor active adults living in two highly I. ricinus-infested areas. They were randomly divided into two groups: one group applied the Citriodiol spray daily for 2 wk to the lower extremities, whereas the other group was instructed not to use any type of repellent on any part of the body. After 2 wk, the scheme was reversed. All volunteers filled in a daily diary, giving information about outdoor activities and the number of observed, attached, or not yet attached ticks, including the anatomical location of the ticks found. Forty-two attached ticks were reported during the weeks when the Citriodiol spray was used, and 112 were reported when it was not. The median number of reported attached ticks per person decreased from 1.5 (range, 0-9) to 0.5 (range, 0-2; P < 0.05) during the weeks when the repellent was used. The number of reported attached ticks noted below the waist was 13/42 (31%) during the period when the spray was used and 73/112 (65%) when no spray was used (P < 0.001). No evident redistribution of attached ticks from protected areas to unprotected areas was seen. Citriodiol may become a useful means in reducing the number of tick bites and thereby tick-borne infections, although additional studies are warranted.

African tick bite fever in travelers to rural sub-Equatorial Africa

To estimate the incidence of, identify risk factors for, and describe the clinical presentation of travel-associated African tick bite fever (ATBF), a rapidly emerging disease in travel medicine, we prospectively studied a cohort of 940 travelers to rural sub-Equatorial Africa. Diagnosis was based on suicide polymerase chain reaction and the detection of specific antibodies to Rickettia africae in serum samples by multiple-antigen microimmunofluorescence assay, Western blotting, and cross-adsorption assays. Thirty-eight travelers, 4.0% of the cohort and 26.6% of those reporting flulike symptoms, had ATBF diagnosed. More than 80% of the patients had fever, headache, and/or myalgia, whereas specific clinical features such as inoculation eschars, lymphadenitis, cutaneous rash, and aphthous stomatitis were seen in < or = 50% of patients. Game hunting, travel to southern Africa, and travel during November through April were found to be independent risk factors. Our study suggests that ATBF is not uncommon in travelers to rural sub-Saharan Africa and that many cases have a nonspecific presentation.

Risk of acquiring tick bites in south-eastern Sweden

The incidence and the temporal pattern of tick bites were studied in a population frequently out-of-doors in a tick-endemic area in south-eastern Sweden between May 2000 and March 2001. The participants, who were well aware of tick-borne diseases, inspected their skin daily from May until September and completed a diary sheet, registering visited geographical places, time out-of-doors, observed tick bites, etc. The participants were also given questionnaires in both the initial and final stages of the study, asking questions about their earlier history of tick bites, previous tick-borne diseases and out-of-doors activities. The incidence was 0.04 [95% confidence interval (95% CI) 0.02-0.061 tick-bitten participants/10 h spent out-of-doors. In total, the participants registered 1767 tick bites, i.e. an incidence of 0.14 (95% CI 0.10-0.18) tick bites/10 h out-of-doors. Within 6 months after the registration period, 8/235 (3%) had been treated for physician-diagnosed Lyme borreliosis. In conclusion, this study found a 4% risk of being tick-bitten per 10 h spent out-of-doors. The risk of contracting Lyme borreliosis was 1/221 tick bites (0.5%, 95% CI 0.44-0.56). Thus, the results indicate a low risk of acquiring Lyme borreliosis when using daily tick checks and we underline the opinion of not recommending routine prophylactic treatment for observed tick bites.

Repellent efficacy of DEET and KBR 3023 against Amblyomma hebraeum (Acari: Ixodidae)

The bont tick, Amblyomma hebraeum Koch, is the principal vector of Rickettsia africae, the agent of African tick bite fever, in southern Africa. In contrast to most other hard ticks, members of the genus Amblyomma exhibit a characteristic attack host-seeking behavior. The efficacy of topically applied 20% lotions of DEET (diethyl-3-methylbenzamide), the currently considered reference repellent substance, and KBR 3023, a recently developed piperidine compound, was evaluated against laboratory-reared A. hebraeum nymphs on treated fingers. Both substances repelled >85% of nymph attacks at 0 and 1 h postapplication. At 2, 3, and 4 h, the repellent efficacies of DEET were 84%, 68% and 71%, whereas those of KBR 3023 were 56, 55, and 54%. The observed differences between the two test substances were statistically significant only at 2 h postapplication. This first study of topical repellents against A. hebraeum suggests that 20% lotions of DEET and KBR 3023 are effective for 2 and 1 h, respectively, but that the repellent efficacies decrease thereafter.

Nutraceuticals: vitamins and other nutrients in coronary heart disease

Nutraceuticals and specifically vitamins, oils and herbs are increasingly being taken by patients. Some supplements may improve cardiovascular outcome, most are unproved, and some could potentially cause harm. Marine lipid supplementation needs to be considered in all patients who have manifest coronary heart disease. For most supplements more data are needed before confident recommendations can be made.