A B S T R A C T Ultraviolet radiation (UVR) exposure causes various injurious effects to human skin by generating reactive oxygen species (ROS). Excessive ROS production can lead to oxidative stress which may damage cellular components... more
A B S T R A C T Ultraviolet radiation (UVR) exposure causes various injurious effects to human skin by generating reactive oxygen species (ROS). Excessive ROS production can lead to oxidative stress which may damage cellular components like lipids and proteins and causing photoaging. The use of natural photochemopreventive agents with antioxidant properties is an important alternative to improve the effectiveness of sunscreens and reduce skin photodamage. A crude extract (CE) from the leaves of Arrabidaea chica underwent partition by a liquid-liquid method. The hexane fraction (FH), chloroform fraction (FC), and ethyl acetate fraction (FEA) were obtained. The antioxidant capacity of the CE, FH, FC, and FEA was studied in a cell-free system using the 2,2-diphenyl-1-picrylhydrazyl (DPPH %) method and the xanthine/luminol/xanthine oxidase system. The FC had the best antioxidant activity. We also evaluated the photochemoprotective effect of A. chica in protecting L929 fibroblasts against UV-A-and UV-B-induced cell damage. A. chica inhibited the extended production of ROS up to 3 h. Posttreatment with the CE and FC attenuated UV-induced cell damage through scavenging mechanisms, including the quenching of intracellular ROS and mitochondrial O 2 %− and preventing lipid peroxidation. These results suggest that A. chica may be a promising non-sunscreen photoprotector that can improve the effectiveness of commercial sunscreens.
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A B S T R A C T Ultraviolet B (UVB) irradiation increases the risk of various skin disorders, leading to inflammation and oxi-dative stress and thereby increasing the risk of skin photoaging and carcinogenesis. The use of... more
A B S T R A C T Ultraviolet B (UVB) irradiation increases the risk of various skin disorders, leading to inflammation and oxi-dative stress and thereby increasing the risk of skin photoaging and carcinogenesis. The use of photo-chemoprotectors such as natural products with antioxidant and anti-inflammatory properties represents a strategy for preventing UVB-induced skin damage. We investigated the photochemoprotective effect of a fraction of a partially purified extract of Byrsonima crassifolia leaves (BCF) on fibroblasts and hairless mice exposed to UVB radiation. The mixture of phenolic compounds in BCF prevented the decrease in reduced glutathione (GSH) levels in fibroblast cultures induced by UVB radiation more than some of their individual standards ((+)-ca-techin (CAT), epigallocatechin gallate and quercetin 3-O-β-D-glucopyranoside). Prepared gel formulations increased skin antioxidant activity, and BCF components and the CAT standard were retained in the HRS/J hairless mice epidermis 2 h after application. Topical treatment with the BCF or CAT formulations (1%) significantly reduced the decrease in GSH levels and decreased myeloperoxidase activity and the secretion of pro-in-flammatory cytokines IL-1β and IL-6 induced by UVB radiation (P < 0.05), indicating that both BCF and CAT had anti-inflammatory effects. BCF inhibited UVB-induced metalloproteinase (MMP)-9 secretion/activity, whereas CAT had no effect on MMP-9 activity in the skin of treated animals. These results therefore suggest that BCF can be used as a photochemoprotective agent and antioxidant in the prevention/treatment of inflammation and oxidative stress of the skin induced by UVB radiation.
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Remirea maritima is a tropical plant with a reticulated root system belonging to the family Cyperaceae, also known to have biologically active secondary metabolites. However, very few data on R. maritima's biological actions are available... more
Remirea maritima is a tropical plant with a reticulated root system belonging to the family Cyperaceae, also known to have biologically active secondary metabolites. However, very few data on R. maritima's biological actions are available and there are no 11700 reports regarding the redox-active profile of this plant. In this study, we examined the total phenolic content of Remirea maritima hydroalcoholic (RMHA) extracts, redox properties against different reactive species generated in vitro and their cytotoxic effect against fibroblasts (L929) and melanoma (B16F10) cells. Total reactive antioxidant potential index (TRAP) and total antioxidant reactivity (TAR) results revealed that RMHA at all concentrations tested showed significant antioxidant capacity. RMHA was also effective against hydroxyl radical formation, reduction of Fe 3+ to Fe 2+ and in scavenging nitric oxide (NO) radicals. In vitro, the level of lipid peroxidation was reduced by RMHA extract and the data showed significant oxidative damage protection. The RMHA cytotoxicity was evaluated by a neutral red assay in fibroblast (L929) and melanome (B16F10) cells. The obtained results showed that the RMHA (40 and 80 µg/mL, respectively) reduced 70% of the viable cells. In conclusion, this study represents the first report regarding the antioxidant and anti-proliferative potential of R. maritima against B16F10 melanoma cells.
A B S T R A C T Solar ultraviolet radiation exposure, particularly UVB rays (280–320 nm), can lead to skin lesions, photo-carcinogenesis and acceleration of skin photoaging since UVB radiation may reach both the epidermal and dermal... more
A B S T R A C T Solar ultraviolet radiation exposure, particularly UVB rays (280–320 nm), can lead to skin lesions, photo-carcinogenesis and acceleration of skin photoaging since UVB radiation may reach both the epidermal and dermal layers of the skin. Treatments that can ameliorate UVB-induced skin damage include natural extracts, which can act as skin photochemoprotective agents. Byrsonima crassifolia is widely used in the folk medicine. Previously studies have shown high antioxidant activity of BC leaves extracts. In this study we described the first photochemoprotective potential of Byrsonima crassifolia extract (BCP) and fraction (BCF) against UVB-induced damage in keratinocytes and the ability of topical formulations with BCP or BCF to increase the antioxidant activity in pig ear skin. The results of characterization of BCP and BCF indicate that the phenolic content was increased twofold after an enrichment process for obtaining BCF. Despite differences in the phenolic content, both BCP and BCF exhibited similar IC 50 values for lipid peroxidation and the DPPH% method during the an-tioxidant activity study. However, for the chemiluminescence assay using the xanthine/luminol/XOD, BCF exhibited higher antioxidant activity than BCP. The different phenolic content in BCP and BCF did not influence their photochemoprotective activity in HaCaT cells, and both samples exhibited similar levels of protection. After treatment with BCP and BCF (1.2–5 μg/mL) and UVB irradiation exposure, the effect of lipid peroxidation in vitro was maintained in cell culture, and both IL-6 and TNF-α secretion and NF-κB activation were suppressed. After the development of the different formulations, BCP and BCF increased the antioxidant activity on skin and the formulation containing BCF showed higher skin retention, especially for (+) catechin, which was able to pass through the stratum corneum. Based on these findings, BCF could be topically applied to prevent/treat the damage induced by UVB radiation in the skin.
In order to exhibit photochemoprotective effect a cosmetic formulation is supposed to display both the ability to absorb UVA/UVB radiation and exhibit a biological effect to protect the skin against the damage caused by the radiation.... more
In order to exhibit photochemoprotective effect a cosmetic formulation is supposed to display both the ability to absorb UVA/UVB radiation and exhibit a biological effect to protect the skin against the damage caused by the radiation. Because animal tests are no longer acceptable for cosmetic development, the present study evaluated the photochemoprotective potential of Cecropia obtusa leaf extract against UVA-induced damage in keratinocytes and explored, in detail, the antioxidant capacity using in vitro systems. The extract exhibited a high antioxidant capacity, particularly towards superoxide radical and singlet oxygen. The EC 50 values for DPPH • , superoxide radical and singlet oxygen were 1.63 g/mL, 0.34 g/mL and 0.55 g/mL, respectively. In addition, the total polyphenol content and total flavonoid content were 371.5 mg of gallic acid equivalent/g and 66.68 mg of quercetin equivalent/g, respectively. Through the cell model, the extract was able to protect the UVA radiation-induced damage. For lipid peroxidation and superoxide dismutase activity, the group that was treated for 24 h and irradiated in the absence of the extract exhibited better protection than the group that underwent the same treatment and was irradiated in the presence of the extract. The opposite pattern was observed for the reduced glutathione levels, catalase activity and reactive oxygen species formation. In addition to protecting keratinocytes from UVA-induced damage and balancing the redox cellular state, the extract was also capable of absorbing UV radiation. Therefore, the C. obtusa extract would be able to improve the absorption spectrum of formulations containing UV filters and provide a biological effect by protecting against oxidative damage.
Investigations have explored that ultraviolet radiation induces skin damage through reactive oxygen species (ROS) generation and endogenous antioxidant depletion, leading to photoaging and photocarcinogenesis. In this behalf, the proposal... more
Investigations have explored that ultraviolet radiation induces skin damage through reactive oxygen species (ROS) generation and endogenous antioxidant depletion, leading to photoaging and photocarcinogenesis. In this behalf, the proposal of this study was to investigate the ability of an enriched polyphenol extract, obtained from Byrsonima crassifolia (Bc) leaves, to avoid the UVA induced oxidative damage in L929 fibroblast cell line. Firstly, the antioxidant activity of the extract was assessed by the DPPH • , the inhibition of chemiluminescence (xanthine/luminol/xanthine oxidase) and the inhibition of lipid peroxidation methods. The cytotoxicity of the extract was evaluated by neutral red assay. Furthermore, the cells pre-treated with the extract were exposed to a single UVA radiation dose in order to examine the extract photochemoprotection. For this purpose, it was assessed the inhibition of the ROS generation, the lipid peroxide levels and the recovery of the endogenous antioxidant glutathione. Bc extract presented antioxidant activities in a dose-dependent manner with IC 50 values of: 1.82 μg/mL (DPPH •); 0.17 μg/mL (xanthine/luminol/xanthine oxidase) and 0.27 μg/mL (lipid peroxidation). It was observed that Bc extract at 10 µg/mL or at lower concentrations did not alter the cell viability. Bc extract at 1.25µg/mL extensively reduced the intracellular ROS formation and the lipid peroxide release to the cell culture medium; decreases of 50% and 35%, respectively. Additionally, Bc extract was able to avoid GSH level depletion in 50% at 1.25µg/mL, whilst presenting a pro-oxidant effect at the concentrations of 2.5 and 5µg/mL. The results demonstrated that regarding the in vitro antioxidant activity against different radicals, Bc extract presents similar or even lower IC 50 values when compared to quercetin; and for this fact it is in accordance with the results obtained in the photochemoprotection experiments, that have demonstrated the ability of this extract in decreasing the UVA induced oxidative stress in L929 fibroblast cell line.