The HMG-CoA reductase inhibitor fluvastatin inhibits insect juvenile hormone biosynthesis

Fluvastatin (Sandoz Compound XU 62-320), a synthetic HMG-CoA reductase inhibitor, was assayed in vitro and in vivo for its ability to suppress juvenile hormone (JH) biosynthesis by corpora allata of Locusta migratoria migratorioides. Fluvastatin inhibited JH biosynthesis by corpora allata in vitro. Exogenous mevalonic acid lactone restored JH biosynthesis in corpora allata inhibited by fluvastatin. Fluvastatin injected into locusts in vivo inhibited JH biosynthesis, but maximal inhibition lasted for only 6 hr. There were no discernible effects on either JH-regulated metamorphosis or oocyte maturation. Lengthening of the fourth larval stadium was observed and increased doses (single or repeated injections) were fatal.