Cardioactive properties of Solanaceae plant extracts and pure glycoalkaloids on Zophobas atratus

Abstract

Glycoalkaloids, the biologically active secondary metabolites produced by Solanaceae plants, are natural defenses against animals, insects and fungi. In this paper, the effects of glycoalkaloids present in extracts of Solanaceae plants (potato, tomato and black nightshade) or pure commercial glycoalkaloids on the coleopteran Zophobas atratus F. were evaluated by in vitro and in vivo bioassays using heart experimental models. Each tested extract induced a dose-dependent cardioinhibitory effect. The perfusion of Zophobas atratus semi-isolated heart using the highest potato and tomato extract concentration (1 mmol/L) caused irreversible cardiac arrests, while extract from black nightshade produced fast but reversible arrests. Pure commercial glycoalkaloids caused similar but less evident effects compared with extracts. Our results showed that the bioactivity of tested compounds depended on their structure and suggested the existence of synergistic interactions when combinations of the main glycoalkaloids of potato and black nightshade were used for trials. Surprisingly, injection of tomato and potato extracts in 1-day-old pupae of Zophobas atratus induced reversible positive chronotropic effects and decreased the duration of the both phases (anterograde and retrograde) of the heart contractile activity. Furthermore, these extracts affected the amplitude of the heart contractions.

Growth performance and feed conversion efficiency of three edible mealworm species (Coleoptera: Tenebrionidae) on diets composed of organic by-products

“…Potato starch is more resistant to digestion by Tenebrionidae than starch from wheat or maize (Applebaum, 1966;Mereiles et al, 2009). Furthermore, potato glycoalkaloids, which persist after processing (Po and Sinha, 2010) can have a toxic effect on insects that do not consume potato in nature (Nenaah, 2011;Ventrella et al, 2014). Longtime exposure to a high content of potato steam peelings could in part explain the high mortality of Z. atratus on diet LPHS, which predominantly occurred after 20 weeks.…”

Heart mechanical and hemodynamic parameters of a beetle, Tenebrio molitor, at selected ages

“…Semi‐isolated heart preparations were used for the measurement of chrono‐ and inotropic changes in the activity of the myocardium. Hearts were prepared according to the microdensitometric method described previously by Rosiński and Gäde () and elsewhere (Marciniak et al., ; Śliwowska, Rosiński, & Nässel, ; Ventrella et al., ). In brief, insects were decapitated and the abdomen was removed from the thorax and used for the preparation.…”

POTATO LEAF EXTRACT AND ITS COMPONENT, α‐SOLANINE, EXERT SIMILAR IMPACTS ON DEVELOPMENT AND OXIDATIVE STRESS IN Galleria mellonella L.

“…However, leaves, unripe fruits, and flowers have the highest GA concentrations (Friedman, 2006). Potato GAs make up a plant defense mechanism (Friedman, 2006;Adamski et al, 2009;Marciniak et al, 2010;Büyükgüzel et al, 2013), and although knowledge regarding their activities on insect physiology and mechanisms of action is still limited (Krishnan and Kodrik, 2006), crude plant extracts may exert a greater effect than the individual allelochemicals due to possible synergisms of multiple compounds (Nenaah, 2011a;Ventrella et al, 2014). This led us to pose the hypothesis that the dried, total extracts of fresh potato leaves (EPL) exert more deleterious impact on wax moth larvae than pure α-solanine, a major GA component of potato leaves.…”