Screening Of Chinese Herbal Compounds For Bacterial Yak Diarrhea And Pharmacodynamic Study Of Granule Preparations

Bacterial calf diarrhea can cause serious economic losses to the cattle industry,and the most common pathogenic bacteria in bacterial calf diarrhea of E.coli and Salmonella account for more than 70%of the incidence.Traditional Chinese medicine(TCM)has a long history in the treatment of calf diarrhea.It contains a wide range of ingredients with a wide range of biological activity,nutrition and drug dual role,not only in the anti-inflammatory,bactericidal effect and enhance the body’s immune function.Previous studies in our laboratory have shown that some Chinese herbs such as Camelina seed,pomegranate peel,gallnut,coptis chinensis,tamarix chincnsis,berberis,pomegranate flower,ferula,safflower,etc.have broad-spectrum antibacterial effect.The purpose of this study was to study the antibacterial effect of the formula composed of these single agents on E.coli and Salmonella causing diarrhea in calves and the therapeutic effect of E.coli diarrhea model animals,and developed the compound drug granules,and evaluated the antibacterial effect and safety of the granules.1.Punching and broth dilution tests were used to determine the in vitro antibacterial effect of four kinds of compound drug water preparations on E.coli and Salmonella causing diarrhea in calves,respectively,and gentamicin was used as a drug control;and mouse diarrhea model was established,and four kinds of compound drug water preparations were used to treat diarrhea model mice,respectively,and oxytetracycline was used as a drug control.Results:Compound 1 was superior to other compound preparations and gentamicin in in vitro bacteriostatic effect against two pathogenic bacteria,and the minimum inhibitory concentration(MIC)was 31.25 mg·mL-1 Minimum bactericidal concentration(MBC)of 62.5 mg·mL-1.And in the experiment to treat diarrhea model mice,the diarrhea index and diarrhea rate were significantly decreased in the TCM compound 1 group compared with other TCM compound preparations(P<0.01)and significantly higher body weight than the other groups(P<0.05),and compound group 1 showed less sloughing,deformation,massive crypt bleeding and disappearance of lacteal ducts in the intestinal mucosa of mice.2.The optimal excipient extract ratio was screened by comprehensive analysis of granulating evaluation and molding rate determination,and the herbal compound granule preparation was prepared by manual wet method;and the quality of granules was examined according to the Chinese Pharmacopoeia(2015 Edition)(manual double sieving method,loss on drying method,soluble granule test method,and measuring cylinder method).Results:The best prescription of excipient and extract was dextrin:sucrose:extract(1:3.5:1).The particle size of Chinese medicine compound granules is 24 mesh,the color is tan,and the particle size,moisture content,solubility,bulk density,angle of repose and other indicators of granules comply with the requirements of Chinese Pharmacopoeia(Edition 2015).3.In vitro antibacterial effect of granule preparation on E.coli and Salmonella causing diarrhea in calves was determined by test tube broth dilution method;and acute toxicity test was performed to test drug safety.Results:The MIC of TCM compound granules against two kinds of pathogenic bacteria causing calf diarrhea was 15.625 mg·mL-1,31.25 mg·mL-1,31.25 mg·mL-1 for MBC,62.5 mg·mL-1.Compared with the results of in vitro bacteriostasis test of compound 1 extract,it was found that the Chinese medicine compound granules had no effect on bacteriostasis and bactericidal effect.The maximum dose of TCM compound granules 10000 mg·kg-1.There were no abnormalities in appetite,spirit,weight,organ index,etc.According to WHO regulations,Chinese medicine compound granules are actually non-toxic drugs,safe and reliable in clinical use.Conclusion,from Among the four compounds,compound 1 was the most effective in the treatment of bacterial calf diarrhea.The dextrin:sucrose:extract(In the proportion of 1:3.5:1),the quality of the herbal compound granules prepared by manual wet method complies with the requirements of Chinese Pharmacopoeia(Edition 2015),which is safe and controllable.