| Ixodes is the second largest vector of pathogenic microorganism after mosquitoes.For a long time,tick and tick borne diseases have restricted the development of animal husbandry in China.The production performance of affected animals has been damaged to varying degrees and caused huge economic losses.The use of insecticides to deal with ticks may lead to drug resistance of Ixodes,animal residues and environmental pollution.Repellents have the advantages of small dosage,small side effects and no drug resistance of Ixodes.However,conventional repellents have a short duration of efficacy.In this study,allicin was used as the active ingredient to develop a longterm,low-cost and easy-to-use tick repellent,in order to provide new technology and new products for protecting human and livestock from tick bite.1.In order to develope a long-acting tick repllent,Garlic oil was used as raw material,anhydrous ethanol as solvent α-Pyrrolidone and polyethylene glycol-400(PEG-400)were used as stabilizers and tackifiers,OP-10 was used as emulsifiers,and polyvinylpyrrolidone(pvp-k30),ethyl cellulose(EC)and maltodextrin were selected as sustained-release components to carry out a variety of solvent system combinations.Six repellent formulations with 10%allicin content were designed,The content of the final formula was determined.Results:the content of polyvinylpyrrolidone was 5%～20%α-The formula of pyrrolidone 5%～25%,polyethylene glycol-400 5%～20%,emulsifier OP-10 5%～15%and absolute ethanol 10%～70%had the best stability.the best stability.The content of allicin in the preparation was determined by gas chromatography.The average intra day and inter day precisions of the prepared long-acting repellent were 0.24%and 1.14%respectively,and the average recovery was 97.2%.The content of allicin in three batches of repellent samples was 100.3%～109.7%of the marked amount,and the water content was all within 1.03%.The allicin repellent prepared in this study has the advantages of simple production process,good stability and repeatability.2.in order to establish a gas chromatography method for the determination of allicin in wool,The extraction time,extraction volume,extraction temperature and soaking time of wool in repellent were optimized and screened by single factor test.The results showed that after gas chromatography with test wool soaked in 3 ml of extraction solution for 15 min and extraction at 35℃ for 15 min,allicin peak area in the obtained extract was the largest,which was beneficial to its quantitative detection.3.In order to study the sustained-release properties of different formulations of allicin repellent in wool,the allicin content in wool soaked with the corresponding repellent was detected by gas chromatography at seven time points within 18 days.The relative release rates of allicin in wool with different formulations were obtained by taking the allicin content in wool on the 0 th day as the initial value and other time points as the residual value,The time/relative release rate curve was drawn to evaluate the sustained-release performance of three allicin tick repellent preparations.In the determination of sustained release performance of allicin long-term repellent in three groups,the content of allicin at 1,2,3 and 5 days of formulation 1 was 4181.93±201.89 μg,2317.84±113.12μg,1662.96±96.03 μg,1037.51±32.07 μg,which was significantly higher than other treatment groups,and the relative release rates of allicin were 3 1.3%,61.9%,72.7%and 82.9%respectively.The content of allicin of formulation 5 at 1,2,and 5 d was 3324.70±1 94.78、1691.17±131.46、764.03±46.75μg,which was higher than formula 6 and control group and the difference was significant(P<0.05),the relative release rates were 46.6%,72.9%,87.7%;Allicin content per gram wool at 1 and 2 d of formulation 6 was 1974.46±95.52、1047.32±53.79μg,was only significantly higher than the control with relative release rates of 67.8%and 82.9%,respectively.The allicin contents at other time points were not significantly different from the control;The integral area of Formula 1 was 1450.64 in 0-18 days,which was smaller than that of other treatment groups.The results showed that all three formulations of allicin long-acting repellents formulation 1,5 and 6 delayed the release of allicin,among which formulation 1 showed the best sustained release effect,which was superior to the other two formulations.4.In order to test the in vitro tick repellent activity of the developed long-acting repellent,the self-made tick repellent device was improved and compared with the reported tick repellent device.The results showed that although the repellent rate of the self-made repellent device in the two experiments was not different from that in the literature,the hard ticks in the invalid area of the selfmade repellent device in the experiment were 0.7±0.3 and 0±0 respectively,which were significantly smaller than the two devices in the literature,making the test results more accurate.This study provides a simple and accurate device for the study of tick repellent activity in vitro.5.In order to study the repellent effect of allicin on Haemaphysalis longicornis larvae and its maximum action time,the repellent effect of 0.5,1,1.5,2,3 and 4 mg/mL allicin solution on Haemaphysalis longicornis was studied by using the repellent method in Chapter 4,and the repellent activity curve was drawn to calculate the RC50 and RC100 of allicin;In the experiment of the effective period of allicin long-acting repellent,the repellent efficacy against larvae was determined every 48 h until 20 d.and its repellent rate change curve was plotted and differentially analyzed to determine its maximum time of action.The results showed that when the concentration of allicin was between 0.5 mg/mL and 4 mg/mL,the repellent rate of allicin against Haemaphysalis longicornis larvae increased gradually,reaching the maximum at 4 mg/ml(1 00%),RC50 and RC100 were 1.79 mg/ml and 3.52 mg/ml,respectively;The repellent activity of allicin long-lasting repellents at concentrations of 0.5%.1%,3%was significantly higher than that of the respective water emulsion treatment groups in 10 days.Compared with the commercial repellents,the repellent activity of 1%and 3%allicin long-lasting repellents was better than that of the repellents in the 12 d for the tick ticks.The maximum effective period of allicin long-lasting repellents at 0.5%,1%and 3%concentrations were 12,14 and 16d respectively.6.In order to study the effects of long-acting repellents of Allicin on the control of ticks,30 adult Boza goats naturally infected with ticks were selected and randomly divided into 6 groups.The effects of 0.5%allicin long-acting repellents,0.5%allicin water emulsions,1%IR3535 longlasting repellents,1%IR3535 water solution and 0.17%cypermethrin suspension emulsion on the control of ticks were studied.The results showed that the number of Ixodes in the control group increased continuously within 28 days after one treatment,and the average number of Ixodes in each sheep increased by 31.58%on the 28th day;The number of hard ticks in the goat tested with 0.5%allicin long-acting repellent reduced by 51.67%(P<0.05)at 14 d compared with that before application,and its hard tick control efficacy was better than that of plain allicin water emulsion,indicating that the developed allicin long-acting hard tick repellent was effective in preventing hard tick infestation after use.In summary,in this study,a long-acting hard tick repellent product was successfully developed,an assay for allicin content in wool was developed,an in vitro hard tick repellent device(wood strip method and filter paper chip method)was prepared,which provided product and technical support for controlling hard tick bites and ensuring zoological safety. |
PDF Full Text Request