| Piglet white scour, being around the world and having a high incidence, sometime over50%,is an acute intestinal infectious diseases caused by pathogenic Escherichia coli (E. Coli). Itusually occurs in piglets of2to3weeks, with diarrhea, gray paste-liking feces as the mainsymptoms.. Although it does not lead to a high mortality rate, it indeed causes slow growth, or nogrowth. Thus piglet white scour may bring a huge loss to the pig industry. For now, there are stillmany problems to be solved in the piglet scour prevention and control: considering manypathogenic serotypes, there is no effective vaccine for it so far; the heavy use of antibiotics andchemical antimicrobial agents, produces a wide range of resistance to drugs, and food safetyhazards caused by drug residues excessive.Preventing or treating Pig scour in Traditional Chinese Veterinary has a long history and wehas accumulated rich experience, but the following issues still need to be solved: First,effectiveness of most Chinese Herbs is not demonstrated from the view of modern infectiousdiseases; second, the mechanisms of effectiveness in most Chinese Herbs are not clarified by theperspective of modern pharmacology; third, some forms of Chinese Herbs are not easy to be usedin modern intensive farms. Therefore, it has important economic and social significance todevelop more effective, safe and quality-controllable Chinese medicine for the prevention andcontrol of piglet scour. In this study, we tested therapeutic efficacy and toxicology of Diweng Kelion the basis of our previous medical screening, composition prescription and making apreparation.To observe the effect of Diweng Keli on lymphocyte function in vitro,3dose groups are set:high (100μg/ml), medium (10μg/ml), low (1μg/ml). Con protein a (ConA), lipopolysaccharide(LPS) induced spleen lymphocyte proliferation assays were conducted by3H method, IL-2, IL-6,IL-10, IL-12, IFN-γ and TNF-α were measured by ELISA in supernatant of splenic lymphocytesstimulated by ConA or inactivated strains of Staphylococcus aureus bacteria Cown (SAC). Theresults showed that Diweng Keli within above-mentioned concentration promoted significantlyproliferation of T and B lymphocytes; promoted the secretion of INF-γ by ConA-stimulated lymphocytes; promoted the secretion of IL-6, IL-12and INF-γ by SAC-stimulated lymphocytes;and inhibited the secretion of IL-10by SAC-stimulated lymphocytes. Diweng Keli which canregulate effectively mouse spleen lymphocyte function promotes cell-mediated immunity andhumoral immunity.Diweng Keli did not lead to death for any of the mice in the acute toxicity test when theywere dosed with5.0g/kg body weight Diweng Keli by gavage. In this case, LD50cannot bedetermined and Diweng Keli is practically non-toxic. Diweng Keli did not poison the mouse evenwhen they were dosed with8.0g/kg body weight Diweng Keli3times in24hr (24.0g/kg total dosein24hr) by gavage.Then, in subchronic toxicity test,80Wistar rats were treated with12.0g/kg、6.0g/kg、3.0g/kg body weight Diweng Keli by gavage everyday for6weeks. Diweng Keli did notpoison the Wistar rats. General health, weight, food intake, water intake, and biochemical indicesof blood cellular components, the main organs of the morphology, structure and organ coefficientof test animals treated with Diweng Keli are normal after the6-week trial and after the2-weekpost-trial observation. We also did toxicity test on piglet. Piglets were given0.2g/kg,0.6g/kg,1.0g/kg body weight Diweng Keli for7days, doses equal to1,3,5times of the recommendeddose. The results showed that Diweng Keli was harmless to piglets. It didn’t cause anyabnormality in general health, weight, food intake, water intake, red blood cell count, hemoglobin,white blood cell total and categorical counts and the serum biochemical indexes within5times therecommended dosage for one week. From observation of tissue slices, there were no pathologicalchanges to the organ morphology. The aforementioned results proved the clinical safety of DiwengKeli.In the preliminary clinical trials, we produced pig scour models with porcine ETEC K88.2.5×1010cfu E.coil was administered orally by gavage and intraperitoneally, and at the meantimeincluding various stresses: weaning, catching, injecting, reducing room temperature to18~20℃and relative humidity to70~80%. Then, in the clinical trials, our pig scour models experienced afull therapeutic effect after they take0.2g/Kg or0.4g/Kg body weight doses of Diweng Keli for5days, and the recovery rate was91.67%, with100%effectiveness and the average durations oftreatment were2.64and2.73days. Pigs administering high and medium dose (0.4g/kg&0.2g/kg)of Diweng Keli recovered in the mental condition, appetite, feces condition and weight gain.There was no difference within the high and medium dose, so0.2g/kg body weight isrecommended for clinical usage. In the expanded clinical trials carried out in Province of Heilong Jiang, Ji Lin and Liao Ning,133natural cases also experienced a full therapeutic effect after they take0.2g/Kg body weightdoses of Diweng Keli and the recovery rate was93.15%, with97.26%effectiveness and theaverage duration of treatment was3.02days. The treatment effect is better than that of controldrug Bailong Power. The expanded clinical trials contained an epidemiological investigation. Thepositive rate of ETEC virulence related genes of isolated E.coli up to34%. The positive rate ofK88is lower than that of K99. Positive rate of Enterotoxin gene is low. There are3(2.3%) strainsone of which also contain genes of EAE and EAST1contain adhesin gene and enterotoxin gene.Genes of EAE and EAST1originally belonged to EAEC. Genes that do not originally belonged toETEC occur most frequently are EAST1and Pic, followed by EAE, Stx2e.In summary, Diweng Keli composed of refined and process Euphorbiae Humifusaf Herba,Pulsatillae Radix and Coptidis Rhizoma is a Chinese veterinary medicine preparation for very highsecurity, and have a good therapeutic effect on Piglet white scour. Diweng Keli can clear heat anddry dampness, remove hot and toxin,and cool the blood to arrest dysentery. |
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