Wasso Shukuru, Maina Naomi, Kagira John
Department of Molecular Biology and Biotechnology, Pan African University, Institute of Basic Sciences, Technology and Innovation, P.O. Box 62000-00200, Nairobi, Kenya.
Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya.
Vet World. 2020 Jan;13(1):177-183. doi: 10.14202/vetworld.2020.177-183. Epub 2020 Jan 25.
The development of resistance to anthelmintic drugs has prompted research into alternative methods of controlling intestinal nematodes in ruminants. This study aimed at evaluating the and anthelmintic efficacy and toxicity of chitosan encapsulated bromelain in Small East African goats in Kenya.
Adult mortality assay was performed using live worms treated with encapsulated bromelain solution ranging from 0.125 mg/ml to 2 mg/ml. Percentage mortality of worms was calculated after 24 h and the lethal concentration 50% (LC) determined. For the study, 18 healthy male indigenous goats were divided into six groups of three goats each. The encapsulated bromelain was orally administered in increasing dosages (3-30 mg kg) once daily, for 14 days. The packed cell volume (PCV), aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea, creatinine, and fecal egg count (FEC) were determined on a weekly basis. At the end of the study, the goats were sacrificed and gross pathology and histopathology of main organs assessed.
Albendazole had the highest (p<0.05) anthelmintic effect on the worms. An LC of 0.05 mg/ml, 0.445 mg/ml, and 0.155 mg/ml was observed for albendazole, plain bromelain, and encapsulated bromelain, respectively. The PCV of treated and untreated goats did not show any significant difference (p>0.05), varied from 29.3% to 35.1%, and was within the normal range of the animal. Likewise, no significant differences (p>0.05) were observed between the AST, ALT, urea, and creatinine levels of treated and the control (non-treated) goats. No adverse clinical symptoms, toxicity of the main organs, and mortality in goats were associated with the chitosan encapsulated bromelain after administration of dose up to 30 mg/kg for 14 days. Therefore, the lethal dose 50 of encapsulated bromelain may be considered to be >30 mg/kg. On day 28 post-treatment, the encapsulated bromelain showed a higher FEC reduction (68.8%) as compared to the plain bromelain (32.4%).
Our results show that bromelain encapsulated in chitosan may be safe and effective in reducing the burden of gastrointestinal tract strongyle nematodes in goats. However, there is a need for further studies to establish the dosage of the encapsulated bromelain to be administered in a single dose for the treatment of goats against gastrointestinal strongyles. In addition, species-specific studies on the efficacy of encapsulated bromelain on strongyles are necessary to evaluate its effectiveness against the entire Strongyloididae family.
抗蠕虫药物耐药性的出现促使人们研究反刍动物肠道线虫的替代控制方法。本研究旨在评估壳聚糖包裹的菠萝蛋白酶对肯尼亚小体型东非山羊的驱虫效果和毒性。
采用经浓度范围为0.125毫克/毫升至2毫克/毫升的包裹菠萝蛋白酶溶液处理的活蠕虫进行成虫死亡率测定。24小时后计算蠕虫的死亡率,并确定半数致死浓度(LC50)。在驱虫研究中,将18只健康的雄性本地山羊分为6组,每组3只。以递增剂量(3 - 30毫克/千克)每天口服一次包裹菠萝蛋白酶,持续14天。每周测定血细胞压积(PCV)、天冬氨酸转氨酶(AST)、丙氨酸转氨酶(ALT)、尿素、肌酐和粪便虫卵计数(FEC)。研究结束时,处死山羊并评估主要器官的大体病理学和组织病理学。
阿苯达唑对蠕虫的驱虫效果最高(p<0.05)。阿苯达唑、普通菠萝蛋白酶和包裹菠萝蛋白酶的LC50分别为0.05毫克/毫升、0.445毫克/毫升和0.155毫克/毫升。治疗组和未治疗组山羊的PCV没有显著差异(p>0.05),在29.3%至35.1%之间,处于动物正常范围内。同样,治疗组和对照组(未治疗)山羊的AST、ALT、尿素和肌酐水平之间也没有显著差异(p>0.05)。在给予高达30毫克/千克剂量持续14天后,壳聚糖包裹的菠萝蛋白酶未引起山羊出现不良临床症状、主要器官毒性和死亡。因此,包裹菠萝蛋白酶的半数致死剂量可能被认为>30毫克/千克。治疗后第28天,包裹菠萝蛋白酶的粪便虫卵计数减少率(68.8%)高于普通菠萝蛋白酶(32.4%)。
我们的结果表明,壳聚糖包裹的菠萝蛋白酶在减轻山羊胃肠道圆线虫负担方面可能是安全有效的。然而,需要进一步研究确定用于治疗山羊胃肠道圆线虫的包裹菠萝蛋白酶单剂量给药剂量。此外,有必要针对包裹菠萝蛋白酶对圆线虫的有效性进行种属特异性研究,以评估其对整个类圆线虫科的有效性。