Loline Alkaloid Effects on Gastrointestinal Nematodes.

Loline, an alkaloid with several derivatives, has suggested antimicrobial and anthelmintic properties. Therefore, loline was investigated as a natural anthelmintic against , , and . Preliminary in vitro studies had reduced L3 establishment but no effect on L3 larvae migration or establishment. While loline-treated lambs had lower establishment of L4 and adult and L4 , L4 and adult appeared unaffected. Following preliminary study, an in vivo experiment examined lambs infected with a mix of L4 , , and adult . These lambs were treated with either a loline seed extract (LOL, = 7), nothing (CON, = 7), or a non-loline seed extract (NIL, = 2). There were no differences in worm burdens, fecal egg counts, weight gain, or feed intake between treatments. However, an average growth efficiency (kg LWG/kg DM intake) was detected ( = 0.01) in CON (0.18) which was less than LOL (0.24) or NIL (0.23). There was limited evidence to support an in vivo anti-parasitic effect of loline despite in vitro studies indicating potential benefits. Discrepancies between in vivo and in vitro studies results were potentially a result of loline contact time with larvae, mode of ingestion or the forms of loline present.