Utilization of Cratoxylum formosum crude extract for synthesis of ZnO nanosheets: Characterization, biological activities and effects on gene expression of nonmelanoma skin cancer cell.

Cratoxylum formosum Dyer is a medicinal plant widely found in Asia and commonly consumed for food and folk medicine. It is rich in phenolic compounds. The present study utilized water crude extract of C. formosum leaves to synthesize zinc oxide nanoparticles (ZnO NPs) by green synthesis. The synthesized ZnO NPs with the average electronic band gap ∼3  eV were obtained and found to either have spherical shape or sheet-like structures depending on synthesis process and concentration of crude extract. Higher concentration of C. formosum extract also eliminates impurity of Zn(OH)2 during the synthesis. Results from an agar disk diffusion assay demonstrated that all synthesized ZnO samples inhibited growth of Gram-positive bacteria, Bacillus subtilis and Staphylococcus epidermidis and Gram-negative bacterium, Escherichia coli. Furthermore, all synthesized ZnO demonstrated potent anti-cancer activity against non-melanoma skin cancer cells (A431) and the intermediary of cancerous keratinocytes (HaCaT) without affecting normal cell lines (Vero). In addition, we observed that the ZnO nanosheet offered stronger cytotoxicity effects against A431 than spherical shaped ZnO particles. Analysis of RNA-sequencing data revealed that synthesized ZnO nanosheets altered the number of genes in pathways involved in cancer and MAPK signaling pathways in A431 cells. Several isoforms of metallothionein transcripts were upregulated including transcripts involved in inflammatory responses whereas transcripts promoted cell proliferation and apoptosis were downregulated. Therefore, these studies firstly reported potential usage of the green-synthesized ZnO nanosheets from C. formosum extract for development of antibacterial substances or anticancer drugs.

In vitro evaluation of anti-epidermoid cancer activity of Acanthus ebracteatus protein hydrolysate and their effects on apoptosis and cellular proteins.

Acanthus ebracteatus Vahl. is commonly consumed with the aim of curing cancer, inflammatory conditions and skin diseases in traditional Thai medicine. It is known to contain various phytochemicals; however, very little is known about the effects of A. ebracteatus protein hydrolysate on cancer cells, including its molecular mechanisms. The present study therefore investigated the anti-cancer activity of A. ebracteatus protein hydrolysates against epidermoid cancer of the skin cell line A431. Their effects on the apoptosis pathway and expression of proteins involved in the regulation of apoptosis, cell proliferation or cell cycle were also investigated. Crude extract of protein hydrolysate, partially purified peptides and purified peptides extracted from the aerial part of A. ebracteatus were administered to the A431 cells. The cytotoxicity effects were then determined using an MTT assay. As a result, A. ebracteatus protein hydrolysate significantly inhibited A431 cells with half inhibitory concentration equals to 425.9 ng protein/ml. By performing Annexin V assay, the partially purified peptides of A. ebracteatus were demonstrated to enhance the apoptosis pathway. Furthermore, western blot analysis revealed that the partially purified peptides of A. ebracteatus increased protein expression levels of RelA (p65) and Cyclin D1 proteins. However, A. ebracteatus did not increase the expression levels of p53-serine 15 phosphorylation (Ser15P).