Solanum nigrum Extract and Solasonine Affected Hemolymph Metabolites and Ultrastructure of the Fat Body and the Midgut in Galleria mellonella

Abstract

Glycoalkaloids, secondary metabolites abundant in plants belonging to the Solanaceae family, may affect the physiology of insect pests. This paper presents original results dealing with the influence of a crude extract obtained from Solanum nigrum unripe berries and its main constituent, solasonine, on the physiology of Galleria mellonella (Lepidoptera) that can be used as an alternative bioinsecticide. G. mellonella IV instar larvae were treated with S. nigrum extract and solasonine at different concentrations. The effects of extract and solasonine were evaluated analyzing changes in carbohydrate and amino acid composition in hemolymph by RP-HPLC and in the ultrastructure of the fat body cells by TEM. Both extract and solasonine changed the level of hemolymph metabolites and the ultrastructure of the fat body and the midgut cells. In particular, the extract increased the erythritol level in the hemolymph compared to control, enlarged the intracellular space in fat body cells, and decreased cytoplasm and lipid droplets electron density. The solasonine, tested with three concentrations, caused the decrease of cytoplasm electron density in both fat body and midgut cells. Obtained results highlighted the disturbance of the midgut and the fat body due to glycoalkaloids and the potential role of hemolymph ingredients in its detoxification. These findings suggest a possible application of glycoalkaloids as a natural insecticide in the pest control of G. mellonella larvae.

A bibliometric analysis of botanical insecticides for Lepidopteran insects over the period 1985-2022

“…In Clematis patens, the anthocyanins for flower color variations have been identified as delphinidin and cyanidin glycosides (14). Later, reports are on the detection of anthocyanin and 4 flavonols from the petals of 3 species of Hibiscus (15). Further, CHS-D is suggested as the CHS gene solely responsible for anthocyanin production in the floral limbs (16,17).…”

“…Desmosstachya bipinnata (L.) Stapf., a perennial grass was analyzed and a chemical component with activity on S. litura larvae (Lepidoptera: Noctuidae) was isolated (14). In addition, a crude extract obtained from Solanum nigrum altered the physiology of Galleria mellonella (Lepidoptera) (15). Under laboratory conditions, essential oils of Ocimum gratissimum and Ocimum kilimandscharicum were analyzed for repellent and fumigant toxicity in adult stages of Tuta absoluta (Meyrick) (16).…”

Anticancer activity of glycoalkaloids from Solanum plants: A review

“…It occurs in many Solanum species, such as S. melongena L, S. berthaultii Hawkes , S. platanifolium Sims , and S. ambosinum Ochoa ( Milner et al, 2011 ). SS has insecticidal activity, e.g., against G. mellonella larvae ( Spochacz et al, 2021 ).…”

Solanum nigrum Fruit Extract Modulates Immune System Activity of Mealworm Beetle, Tenebrio molitor L.

“…is a plant native to Eurasia and introduced for example to the Americas and South Africa, which is known to produce glycoalkaloids (GAs) [ 4 ]. The research concerning the potential usage of S. nigrum fruit extract (EXT) clearly demonstrates that this compound can modulate many physiological events in the insect pest species, including their metabolism, development, and reproduction [ 4 , 5 ]. Moreover, these effects can be induced also in in vitro tests and when the EXT or GAs are administered with food [ 5 ].…”