Insect silk has been widely studied for its application in regenerative medicine. However, the data about Plodia interpunctella silk as a biomaterial and its anticancer properties are insufficient. Thus, the aim of this study was to investigate native silk as a substrate for growing normal human fibroblasts MRC-5, and test potential cytotoxic effects of the two silk extracts (with DMSO and Trypsin for sericin isolation) on HCT-116 colorectal carcinoma cells and MRC-5 fibroblasts as a control. Fifth-instar larval silk, collected for 15 and 30 days, was used for testing of proliferation and adhesion of MRC-5, 24 h and 72 h after seeding. Light- and fluorescence-microscope showed cell adhesion and spread on silk, as well as enhanced number of cells after 72 compared to 24 h and nonsignificant percentage of apoptotic cells on the silk. Although insoluble, P. interpunctella silk showed remarkable cytotoxic activity on HCT-116 cells, without significant cytotoxity on normal fibroblasts after 24 h and weak effects after 72 h. This study provides significant information about P. interpunctella silk as a potential biomaterial and shows the presence of some active constituents with anticancer properties, thus pointing to the possibility for exploitation of this worldwide pest insect in biomedical application.
Our research of the genus Ceutorhynchus associated with oilseed rape was conducted in northern parts of Serbia (Stari Zednik, Subotica). A specific assemblage of eight weevil species was found. The most numerous were stem weevils Ceutorhynchus napi with 81% of all trapped specimens, followed by C. pallidactylus with 18%. The remaining six weevil specimens were C. obstrictus, C.erysimi, C. minutus, C. picitarsis, C. sulcicollis and C. typhae, comprising 1% of all trapped insects. Stem weevils C. napi and C. pallidactylus began to immigrate into the oilseed rape fields in autumn, as early as November 10 (BBCH 17-18). The maximum flight was recorded at the beginning of oilseed rape stem elongation (BBCH 22-25) on March 23. A new generation of C. pallidactylus emerged from oilseed rape fields in June (BBCH 76-88), while individual specimens occurred during the autumn. The majority of C. napi emerged in March next year, sporadically until May 7. As a consequence of C. napi dominance insecticide treatment should be performed earlier than usual, i.e. when C. pallidactilus is the primary target.