Anti-senescence and anti-wrinkle activities of 3-bromo-4,5-dihydroxybenzaldehyde from Polysiphonia morrowii Harvey in human dermal fibroblasts

Objective:To investigate the anti-senescence effect of 3-bromo-4,5-dihydroxybenzaldehyde(BDB)from Polysiphonia morrowii Harvey in human dermal fibroblasts(HDF).Methods:HDF were subjected to treatment of BDB and then treated with hydrogen peroxide(H2O2)to induce premature senescence.Senescence-associatedβ-galactosidase(SA-β-gal)activity in HDF was determined using the SA-β-gal staining method.Intracellular reactive oxygen species(ROS)production was measured using the 2’,7’-dichlorodihydrofluorescein diacetate assay.Western blotting assay was performed to assess the level of antioxidant enzyme glutathione peroxidase 1(GPX1).In addition,intracellular collagen and collagenase contents were analyzed using the respective ELISA kits.Elastase activity in HDF supernatants was measured from p-nitroaniline release and normalized using total protein content.Results:Treatment of HDF with H2O2 increased the activity of SA-β-gal,but BDB pre-treatment resulted in the reduction of SA-β-gal activity.Moreover,BDB significantly reduced H2O2-induced intracellular ROS production.BDB also markedly increased the level of GPX1,which was inhibited by 400μM of H2O2.Furthermore,in in vitro study,BDB significantly increased intracellular collagen content and decreased matrix metalloproteinase-1 and elastase activities in HDF.Conclusions:Our results demonstrate that BDB shows antisenescence and anti-wrinkle activities in vitro.

Induction of Sirtuin1 Activity in SH-SY5Y Cells by Cyanidin-3-O-Glucocide Induced

An increase in oxidative stress plays a key role in neurotoxicity induction and cell death, which leads to neurodegenerative diseases such as Parkinson’s disease and Alzheimer’s disease. Cyanidin-3-glucoside (C3G) is a common anthocyanin and shows antioxidant activity in neuronal cells. Silent information regulator 2-related protein 1 (Sirt1) regulates antioxidant and anti-inflammatory effects. However, the effects of C3G on Sirt1 in neuronal cells remain unclear. This study evaluated the effect of C3G on Sirt1 expression and activity in human neuroblastoma (SH-SY5Y) cells. In the study, C3G increased the expression of Sirt1 and Sirt1 activity in SH-SY5Y cells. Additionally, C3G increased the expression of nuclear factor erythroid 2-related factor 2, a vital transcription factor for regulating the expression of antioxidant genes, as well as antioxidant enzymes such as superoxide dismutase and catalase. Moreover, C3G protected SH-SY5Y cells from oxidative stress. These results suggest that C3G decreased oxidative stress-induced cell injury by increasing the expression of Sirt1 and other antioxidant factors. Therefore, C3G might merit further investigation for use in attenuating the progress of neurodegenerative diseases.

Melatonin: A master regulator of plant development and stress responses

Melatonin is a pleiotropic molecule with multiple functions in plants. Since the discovery of melatonin in plants, numerous studies have provided insight into the biosynthesis, catabolism, and physiological and biochemical functions of this important molecule. Here, we describe the biosynthesis of melatonin from tryptophan, as well as its various degradation pathways in plants. The identification of a putative melatonin receptor in plants has led to the hypothesis that melatonin is a hormone involved in regulating plant growth,aerial organ development, root morphology, and the floral transition. The universal antioxidant activity of melatonin and its role in preserving chlorophyll might explain its anti-senescence capacity in aging leaves. An impressive amount of research has focused on the role of melatonin in modulating postharvest fruit ripening by regulating the expression of ethylene-related genes.Recent evidence also indicated that melatonin functions in the plant's response to biotic stress,cooperating with other phytohormones and wellknown molecules such as reactive oxygen species and nitric oxide. Finally, great progress has been made towards understanding how melatonin alleviates the effects of various abiotic stresses, including salt, drought, extreme temperature, and heavy metal stress. Given its diverse roles, we propose that melatonin is a master regulator in plants.