Molecular Identification, Chemical Composition, and In Vitro Anthelmintic Activity of Sargassum duplicatum Against Haemonchus contortus

The resistance of the Haemonchus contortus , a parasite causing severe anemia in ruminants, to commercial anthelmintics emphasizes the need for alternative bio-anthelmintics. This study aimed to identify the molecular, chemical composition, and in vitro anthelmintic activity of Sargassum duplicatum against H. contortus . Molecular identification employed the Chelex method, with DNA diversity and phylogeny assessed using maximum likelihood in IQ-tree. The analyzed chemical composition included proximate, total flavonoid, and total phenols. Adult worm motility test (AWMT) and egg hatch inhibiting test (EHIT) were conducted at concentrations of 2, 4, and 6 mg/mL of S. duplicatum ethanolic extract. AWMT followed a completely randomized factorial design (5 replications, each with 5 worms), while EHIT used a completely randomized one-way design (5 replications, each with H. contortus egg batches from 3 adult female worms). The cox1 gene sequence revealed the Sargassum sample as S. duplicatum (KP101270.1) with 99.83% similarity. The results indicated that the identified concentrations of S. duplicatum ethanolic extract, and the observation time significantly influenced motility and egg hatchability (p<0.05). Both factors exhibited a significant interaction (p<0.05). Concentrations of 4-6 mg/mL reduced worm motility by up to 50% (LD50) within 6-8 hours, while concentrations of 2-6 mg/mL inhibited egg hatchability by more than 87% during 24 hours of incubation. In conclusion, S. duplicatum holds significant potential as a bio-anthelmintic agent.