Trans-cinnamaldehyde inhibits Penicillium italicum by damaging mitochondria and inducing apoptosis mechanisms

Plant-derived essential oils have excellent antifungal effects and can be used for the preservation of fresh foods such as fruits and vegetables, but the detailed mechanism has not been fully elucidated. In this study, we investigated the inhibitory effects of trans-cinnamaldehyde on Penicillium italicum, a common pollution fungus in citrus, and explored the antifungal mechanism of trans-cinnamaldehyde by detecting fungal oxidative damage, mitochondrial metabolism, and cell apoptosis. These results showed that transcinnamaldehyde made the carboxylic acid cycle deregulated by altering the related enzyme activities(succinate dehydrogenase, malate dehydrogenase) and mid product. Moreover, the level of reactive oxygen species rose sharply while the redox level was out of regulation. The mitochondrial membrane potential collapsed, leading to the leakage of cytochrome c, and then triggering the activation of apoptotic protease, which was further confirmed by the significant increase in caspase-3 activity from(3.6 ± 0.6) U to(8.8 ± 1.1) U(P < 0.05). The cytochrome c in mitochondria was detected by confocal Raman microspectroscopy, the characteristic intensity index(I750/I2944) was decreased, indicating that the cytochrome c in mitochondria was reduced and leakage. Besides, the strong negative correlation between Raman intensity and the amount of cytochrome c leakage was established with the correlation coefficient of-0.981 7. This study revealed that destroying the integrity of the mitochondrial membrane, activating the mitochondrial-mediated apoptosis pathway was the in-depth antifungal mechanism of trans-cinnamaldehyde;and Raman spectroscopy technology provided new ideas to study this process with high sensitivity determination of cytochrome c.

Trans-cinnamaldehyde promotes nitric oxide release via the protein kinase-B/v-Akt murine thymoma viral oncogene-endothelial nitric oxide synthase pathway to alleviate hypertension in SHR.Cg-Lepr^(cp)/NDmcr rats

OBJECTIVE:To evaluate whether endothelial dysfunction and hypertension are prevented by trans-cinnamaldehyde(t CA) through the activation of endothelial nitric oxide synthase(e NOS).METHODS:Human umbilical vein endothelial cells(HUVECs) were cultured in vitro and stimulated with t CA to determine cell viability using the methyl thiazolyl tetrazolium assay.The effect of t CA on nitric oxide(NO) production was determined by diaminofluorescein-dyes in the absence or presence of inhibitors of e NOS,AMPK,PKA,and AKT.The effect of t CA on blood pressure was determined by the tail-cuff method in obesity spontaneous hypertension(SHR.Cg-Leprcp/NDmcr) rats.The phosphorylation of e NOS and protein expression of the insulin-signaling pathway(Ins R-IRS1-PI3 K-AKT)were measured by western blot.RESULTS:t CA at concentrations less than 100 μM did not affect cell viability in cultured HUVECs.Stimulation with t CA promoted NO release in a time-dependent manner compared with the control group.t CA-treated HUVECs also significantly increased AKT-Ser473 and e NOS-Ser1177 phosphorylation.In SHR-CP rats,treatment with t CA at a dose of 40 mg/kg/day for 6 weeks markedly reduced the systolic blood pressure and diastolic blood pressure,increased the phosphorylation of AKT and e NOS,and increased urinary nitric oxidation.CONCLUSION:t CA attenuated endothelial dysfunction and reduced blood pressure in SHR-CP rats.The underlying mechanisms may involve the increase in AKT and e NOS phosphorylation and the release of e NOS-derived NO.