Green tea catechins as sustainable treatment to albendazole resistant Hamonchus contortus isolates: determination of phytochemicals, antioxidants, cytotoxic effects and anthelmintic potency in natural infected sheep

H. contortus remains the main multidrug resistant strongyle threatened livestock productivity. The phyto-biomedical components of green tea beverage (GT) may constrain the resistant parasite. So, this study aimed to evaluate the anthelmintic effect of catechins rich GT against albendazole resistant H. contortus among naturally infected sheep. Albendazole resistance was detected through egg hatch inhibition assay. Assessment of phytochemicals, antioxidant ability, anthelmintic effect and cytotoxicity MTT assay of the GT were achieved. Fecal examination of sheep revealed prevalence of H. contortus 75%, Trichostrongylus spp 15% and Ostertagia spp 10%. Resistance to albendazole was monitored; LC ₅₀ was at 0.172 µg/ml. The GT was of high Total Phenolic Content; 555.32 mg gallic acid equivalents /g. Remarkable GT antioxidant qualities were noted where, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (85.14%), DPPH antioxidant activity as 907.57 mg vitamin C/g equivalents, and Ferric Reducing Antioxidant Power (8991.04 µg Trolox/g). High Performance Liquid Chromatography showed rich profile of phenolics mainly catechine (70,190.8 µg/g). A potent anthelmintic activity of the GT was noted at 50 mg/ml; complete inhibition of egg hatchability (LC ₅₀ ; 0.144 mg/ml), significant larval motility inhibition (LC ₅₀ ; 0.127 mg/ml) and severe structural deformity on H. contortus eggs and larvae. Additionally, 100% worm motility inhibition and mortality index 1 were recorded at 400 mg/ml in 2h incubation (LC ₅₀ ; 13.387mg/ml). The light and electron scanning microscopy of the treated adult proved distortion in the muscular layer of the cuticle wall with severe degenerative changes. The GT maintained viability of the BJ1 cell lines without cytotoxic effect at (0.78 to 200 µg/ml) concentrations. Overall, green tea catechins could be offered as safe and potent alternative anthelmintic to combat the albendazole-resistance isolates of H. contortus