Inhibitory Effects of Amorphigenin on the Mitochondrial Complex I of Culex pipiens pallens Coquillett (Diptera: Culicidae)

Abstract

Previous studies in our laboratory found that the extract from seeds of Amorpha fruticosa in the Leguminosae family had lethal effects against mosquito larvae, and an insecticidal compound amorphigenin was isolated. In this study, the inhibitory effects of amorphigenin against the mitochondrial complex I of Culex pipiens pallens (Diptera: Culicidae) were investigated and compared with that of rotenone. The results showed that amorphigenin and rotenone can decrease the mitochondrial complex I activity both in vivo and in vitro as the in vivo IC50 values (the inhibitor concentrations leading to 50% of the enzyme activity lost) were determined to be 2.4329 and 2.5232 μmol/L, respectively, while the in vitro IC50 values were 2.8592 and 3.1375 μmol/L, respectively. Both amorphigenin and rotenone were shown to be reversible and mixed-I type inhibitors of the mitochondrial complex I of Cx. pipiens pallens, indicating that amorphigenin and rotenone inhibited the enzyme activity not only by binding with the free enzyme but also with the enzyme-substrate complex, and the values of KI and KIS for amorphigenin were determined to be 20.58 and 87.55 μM, respectively, while the values for rotenone were 14.04 and 69.23 μM, respectively.

Hydroxylated Rotenoids Selectively Inhibit the Proliferation of Prostate Cancer Cells

“…No comprehensive study has been made of the inhibitory properties of hydroxylated rotenoids against complex I or their ability to selectively target prostate cancer cells, though a number of reports have been made on the cytotoxicity of certain hydroxylated rotenoids. − Thus, a library of 29 hydroxylated rotenoids was prepared from rotenone ( 1 ) and deguelin ( 2 ) to identify inhibitors of complex I that might be better suited to development as therapeutics than the parent compounds. The inhibitory effect of each hydroxylated rotenoid on complex I was determined and its hydrophobicity predicted.…”

Amorpha fruticosa – A Noxious Invasive Alien Plant in Europe or a Medicinal Plant against Metabolic Disease?

“…In another work, the inhibitory action of amorphigenin against the mitochondrial complex I of C. pipiens pallens was studied in comparison to rotenone ( Mingshan et al, 2015 ). It was observed that both compounds abolish mitochondrial complex I activity in vitro and in vivo.…”

The invasive alien species Amorpha fruticosa in Bulgaria and its potential as economically prospective source of valuable essential oil

“…Additionally A. fruticosa is attacked only by several more or less specialized insects (Petrova et al 2012) because the plant contains compounds with insecticide activity (Brett 1946). These compounds are the rotenoids (Moring and McChesney 1979;Berenbaum 1989;Kole et al 1992;Konoshima et al 1993;Fang and Casida 1998;Ivanescu et al 2014;Kariuki et al 2014;Mingshan et al 2015). In fact rotenone is a botanical insecticide, which has been used for centuries and is still used worldwide (Gupta 2007).…”