Effect of root-tuber extract of Flemingia vestita, a leguminous plant, on Artyfechinostomum sufrartyfex and Fasciolopsis buski: a scanning electron microscopy study
The tegumental surface of Artyfechinostomum sufrartyfex as viewed under the scanning electron microscope revealed the presence of double rows of spines in the collar. The dorsal surface (6–8 rows) and the ventral surface are provided with posteriorly directed spines. The normal body surface of Fasciolopsis buski shows posteriorly directed scales throughout the ventral surface; the dorsal surface is free of any scales but has domed, coarsely distributed papillae. When treated in vitro with ethanol root-tuber extract of Flemingia vestita, an indigenous medicinal plant in Meghalaya, India, at a concentration of 5, 10, and 20 mg/ml phosphate-buffered saline (PBS), A. sufrartyfex became paralyzed within 1.1–1.4, 0.8–1.0, and 0.3–0.5 h, respectively. Following similar treatment, F. buski took 3.0–3.6, 1.5–2.0, and 0.6–0.8 h, respectively, to reach a paralytic state. Oxyclozanide B.P. was used as the reference drug and paralyzed the worm, taking slightly less time than the crude extract for both species of flukes. Stereoscanning observations on the tegumental surface of treated (20 mg extract/ml PBS) A. sufrartyfex revealed sloughing off of most of the spines or their deformation as well as wrinkles and rupture of the general tegument. Severe tegumental alterations and deformities were also displayed by F. buski exposed to 20 mg extract/ml PBS.