Role of Natural Product Eriocalyxin B in Promoting Apoptosis of Colon Cancer Cells through ERK1/2 Pathway

[Objectives] To investigate the role of Eriocalyxin B (EriB) in promoting colon cancer cell apoptosis through ERK1/2 pathway in vitro, and to provide a natural candidate drug for colon cancer treatment. [Methods] Colon cancer cells treated with different concentrations of EriB were detected by CCK-8 assay;cell scratch assay and crystal violet staining were used to detect the invasion and migration of colon cancer cell;cell apoptosis was detected by Annexin V/PI double staining, and cell cycle was detected by PI staining;Western Blotting was used to detect epithelial-mesenchymal transition and apoptosis-related proteins in colon cancer cells treated with EriB. [Results] After EriB treatment, the proliferation, migration and apoptosis of colon cancer cells were significantly inhibited, and the ratio of P-ERK1/2 to ERK was significantly decreased. [Conclusions] EriB can effectively inhibit the proliferation of colon cancer cells and promote the apoptosis of colon cancer cells through ERK1/2 pathway.

Insights into the mechanism of Sub3 inhibiting Fusarium moniliforme infection in maize

Fusarium moniliforme(F.moniliforme) and its secondary metabolite fumonisin pose a severe threat to food safety,and searching for effective antimicrobial agents is a focus of current research.In this study,the secondary structure of Sub3 was analyzed by circular dichroism,meanwhile,the inhibition rate of Sub3 against spores,mycelia of F.moniliforme and infected maize was studied.To explore the possible inhibition mechanisms,morphological and structural changes of spores treated with Sub3 at0,1/2 MIC(minimum inhibitory concentration) and MIC were observed by scanning electron microscopy and transmission electron microscopy;the cell wall integrity,membrane integrity,reactive oxygen species,mitochondrial membrane potential,ATP synthase activity,redox reactions,and the nuclear damage of F.moniliforme were also investigated.The results showed that Sub3 was mostly in the state of random in deionized water,while mainly showed the β-sheet structure in the hydrophobic environment of 50% Trifluoroethanol(TFE) solution,indicating that Sub3 might generate partial structure deformation when acting on the cell membrane;and its MIC on F.moniliforme spores was 0.2 g/L.Under the 1/2 MIC and MIC,the inhibition rates of Sub3 against F.moniliforme infected maize were 34.3% and75.6%,respectively.The results of inhibition mechanisms revealed that the defective pathogenicity of F.moniliforme caused by Sub3 was attributed to damages on both the cell wall and the cell membrane,which might upset balance of intracellular redox system and mitochondrial energy metabolism and trigger nucleus damage,ultimately leading to cell death.Meanwhile,Sub3 could diminished ATP synthase enzyme activity in a dose-dependent manner.The results provided direct evidence for inhibition of F.moniliforme infection of maize by Sub3,and useful knowledge applicable for food preservation.

Anti-fungal properties of Puroindoline A against Aspergillus glaucus

Aspergillus glaucus can grow in low moisture grain,and is one of the main fungi responsible for agricultural product losses.Puroindoline A(PINA)is a tryptophan-rich alkaline adiponectin that can effectively inhibit numerous plant bacteria and fungi.However,the mechanism of PINA against A.glaucus remains unclear.Herein,we found that recombinant PINA(rPINA)could inhibit A.glaucus mycelia growth on salt Czapek dox agar(SCDA)medium and spore germination on Czapek dox(CD)medium.Scanning electron microscopy revealed that incomplete morphological characteristics of both A.glaucus spores and mycelia occurred following rPINA treatment.Laser scanning confocal microscopy(LSCM)showed that rPINA could enter the interior of spores.Flow cytometry and propidium iodide(PI)staining illustrated membranes of spores were severely damaged,especially after treatment with 0.9 mg/mL rPINA for 12 h,and spores with intact membranes were reduced by 30.7%.Additionally,rPINA reduced the mitochondrial membrane potential(MMP)by 5,5′,6,6′-tetrachlorr-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide(JC-1)staining,and caused DNA damage by 4′,6-diamidino-2-phenylindole(DAPI)staining.These results indicated that rPINA may damage cell membranes and DNA structure and reduceMMP,thereby inhibiting the growth of A.glaucus.The antifungal mechanism has been demonstrated in this study,and results show that rPINA has application potential in preventing postharvest loss in the agricultural industry.