Kanidta Sooklert

Leptospira infection can cause potential hazards to human health by stimulating inflammation, which is mediated mainly through the Toll-like receptor 2 (TLR2) pathway. Gold nanoparticles (AuNPs) are promising for medical applications, as they display both bioinert and noncytotoxic characteristics. AuNPs have been shown to have the ability to modify immune responses. To understand the in vitro immunomodulatory effect of AuNPs in a Leptospira infection model, the activation of TLR2 expression was examined in HEK-Blue-hTLR2 cells treated with Leptospira serovars and/or AuNPs (10 and 20 nm). The ability of AuNPs to modulate an inflammatory response induced by Leptospira was examined in terms of transcript expression level modulation of three proinflammatory cytokines (tumor necrosis factor-α, interleukin (IL)-1β and IL-6) using two-stage quantitative real-time reverse transcriptase PCR. The results revealed that the administration of 10 nm AuNPs could augment the Leptospira-induced TLR2 signaling response and upregulate the expression of all three cytokine gene transcripts, whereas the 20 nm AuNPs attenuated the TLR2 activation and expression of proinflammatory cytokines. This indicates that AuNPs can modulate inflammatory parameters in Leptospira infection and different-sized AuNPs had different immunomodulatory functions in this model.

Copper oxide nanoparticles (CuONPs) have attracted considerable attention, because of their biocide potential and capability for optical imaging, however CuONPs were shown to be highly toxic in various experimental model systems. In this study, mechanism underlying CuONP-induced toxicity was investigated using Drosophila as an in vivo model. Upon oral route of administration, CuONPs accumulated in the body, and caused a dose-dependent decrease in egg-to-adult survivorship and a delay in development. In particular, transmission electron microscopy analysis revealed CuONPs were detected inside the intestinal epithelial cells and lumen. A drastic increase in apoptosis and reactive oxygen species was also observed in the gut exposed to CuONPs. Importantly, we found that inhibition of the transcription factor Nrf2 further enhances the toxicity caused by CuONPs. These observations suggest that CuONPs disrupt the gut homeostasis and that oxidative stress serves as one of the primary causes of CuONP-induced toxicity in Drosophila.

The objective of this study is to investigate the anticancer potential of the extract of Colocasia gigantea C. gigantea), a plant member of the Araceae family. In the present study, we investigated the cytotoxic activity of C. gigantea extract on cervical cancer (Hela) and human white blood cells (WBC) in vitro. The authors then identified the bioactive ingredients that demonstrated cytotoxicity on tested cells and evaluated those bioactive ingredients using the bioassay-guided fractionation method. The results showed that not all parts of C. gigantea promote cytotoxic activity. The dichloromethane leaf fraction showed significant cell proliferation effect on Hela cells, but not on WBCs. Only the n-hexane tuber fraction (Fr. 1T) exhibited significant cytotoxicity on Hela cells (IC50 = 585 μg/ml) and encouraged WBC cell proliferation. From GC-Mass spectrometry, 4,22-Stigmastadiene-3-one, Diazoprogesterone, 9-Octadecenoic acid (Z)-, hexyl ester and Oleic Acid were the components of Fr 1T that demonstrated cytotoxic potential. In conclusion, C. gigantea's Fr 1T shows potential for cervical cancer treatment.