Effects Of Compound Chinese Medicinal Preparations On Eimeria Tenella Disease

Avian coccidiosis is an epidemic parasitic disease caused by Eimeria species which are parasitic on the intestinal mucosa of chickens.Up to now,there are 14 species of coccidia found in the world.In China,9 cases are reported,seven of which only infect chicken.There is no intermediate host for coccidia.Among them,E.tenella has the strongest virulence,parasitizing on the cecum of chicken.The important economic losses caused by coccidiosis are not ony due to poor productivity but also the expensive costs of treatment.Currently,vaccine for the control of coccidiosis in our country has its limitation.Antibiotics and chemosynthesis drugs are widely available in clinical but result in non-negligible drug residue and resistance as well,while with good development prospect,Chinese medicinal herbs can effectively solve these problems.To obtain a better compound Chinese medicinal preparations to prevent coccidiosis,we summarized domestic data on controlling coccidiosis.According to these data and clinical features of avian coccidiosis,we selected 28 single Chinese herbs with the features of detoxication,desinsectization,hemostasis,anti-diarrhea,eliminating dampness and tonifying spleen.Based on the result that single herb can restrain oocyst from sporulating in vitro,we confirmed the suitable concentration and efficiency of restraining sporulation.Using most efficient single herbs on controlling coccidiosis with the principle of compatible regulation of traditional Chinese medicine,we presented three groups of compound prescription.Then,the assays of restraining oocyst from sporulating in vitro and resisting coccidiosis in vivo with compound were performed to verify both the impact and effect on sporulating.Finally,we tested the content of IgG and SIgA and made pathological section of cecum in order to verify the effect of controlling coccidiosis.We obtained a compound Chinese medicine preparation with significant treatment effects on E.tenella,which provides comprehensive information on controlling avian coccidiosis and further contributes to clinical application.The results are as follows:Given previous research on clinical sign and pathogenesis of E.tenella,we selected 28 single Chinese herbs with the features of desinsectization,hemostasis,anti-diarrhea,antibacteria,clearing heat and removing toxicity.All the single herbs converted to 1g/mL extractions in water,and the extractions were diluted into four concentrations including 0.2g/ml,0.15g/ml,0.1g/ml or 0.05g/ml.The diluents were incubated with unsporulated oocysts of E.tenella at 29 ℃for 18 h,24h,36 h,42h or 48 h : the sporulated efficiency of oocysts was analyzed.We presented three groups of compound prescription that combined the most efficient single herbs on controlling coccidiosis with the principle of compatible regulation of traditional Chinese medicine.We added adjuvants into 16 Chinese herbs with good efficiency and formed three compounds.The first prescription was composed of 20 g antifebrile dichroa,20 g fructus cnidii,10 g sophora flavescens,10 g lalang grass rhizome,10 g pericarpium granati,12 g radix bupleuri,10 g rheum officinale and 8g liquorice.The second prescription was composed of 20 g rhizoma atractylodis,20 g mother chrysanthemum,10 g the root of Chinese pulsatilla,20 g bighead atractylodes rhizome,10 g smoked plum,10 g hairyvein agrimony and 10 g Coix Seed.The third prescription was composed of 20 g areca,20 g antifebrile dichroa,10 g the root of Chinese pulsatilla,10 g sanguisorba officinalis,20 g dangshen,10 g bighead atractylodes rhizome and 10 g Angelica sinensis.Afterwards,the previous three precsriptions were weighed in proportion and then converted to 1g/mL extractions in water.The extractions were diluted into five concentrations including 1g/ml,0.7g/ml,0.5g/ml,0.3g/ml or 0.1g/ml and we incubated them with unsporulated oocysts of E.tenella at 29 for 18 h,24h,36 h,42h ℃or 48 h.Then,we determined the sporulated efficiency of oocysts and compared the effect of three precsriptions.At the same time,320 10-day-old chicken with similar weights were divided into 7 groups(40 chicken per group)called first precsription group,second precsription group,third precsription group,Necoxine group,Diclazuril group,coccidia infection group(infected with coccidiosis but not feeded medicines)and blank group(not infected coccidiosis and not feeded medicines).There were still 40 chicken standby.All except the blank group were orally inoculated with 5×104 sporulated oocysts of E.tenella.At 12 h post infection(pi),first precsription group,second precsription group or third precsription group orally took 0.3mL precsription soups,respectively;in the Necoxine and Diclazuril group,necoxine or diclazuril was diluted into solution as described previously and chicken drunk freely;in the coccidia infection and blank,water with high temperature sterilizing was provided for chicken to drink.The chickens were monitored each day for overt clinical signs and deaths.At day 7 pi,all of the chickens were killed after measuring weight and collecting blood from the heart.We then assessed the lesion scores in cecum,pathological change value,oocyst value,survival rate and weight gain rate,and calculated the index of anticoccidial.We also detected the content of IgG in serum and SIgA in chyme of cecal as well as made histopathologic slides of cecum in order to observe histological changes.Consequently,the first,second or third precsription has the lowest sporulated efficiency with the concentration of 0.1 g/ml,0.1 g/ml or 1 g/ml,respectively.The sporulated efficiency of 0.1 g/ml second precsription only reached 33.38% which was lower than that of first precsription(0.1g/ml)and that of third precsription(0.1g/ml).This result showed that the second precsription had the better inhibiting effect than the first and third.The relative weight gain of the second precsription was 83.15% and between the second precsription and coccidia infection group appeared significant difference(P<0.01).The expressing rate of OPG was 6.24*104 which above only Diclazuril group,which means the second precsription effectively reduced oocysts and lesion score in cecum.The anticoccidial index(ACI)of the second preparation was 139 which was higher than the first,third and Necoxine group,but lower than Diclazuril group,and that indicated the second had a higher anticoccidial effect than the first,third and necoxine group,but lower than diclazuril group and the second precsription reached the level of moderate anti-coccidia;the second preparation obviously increased the content of IgG and SIgA in the sick chickens and improved the cecal damage of oocysts,meantime,the first and third preparation were not improved.