Potential Photoprotective Effect of Dietary Corn Silk Extract on Ultraviolet B-Induced Skin Damage

Abstract

Ultraviolet B (UVB) irradiation causes adverse effects on the skin. Corn silk contains flavonoids and other bioactive compounds and antioxidants, which may prevent skin photoaging through antioxidant and anti-inflammatory effects. We aimed to investigate the potential photoprotective effects of dietary corn silk on UVB-induced skin damage in mice and the mechanisms behind these effects on human skin cells. Oral administration of corn silk water extract (CS) (2 or 4 g/kg/day) for 19 weeks decreased epidermal thickness, wrinkle formation, and positive staining for PCNA, Ki67, and 8-OHdG, and increased collagen staining in UVB-irradiated SKH-1 hairless mice compared with controls. The pro-inflammatory NF-κB target genes (IL-1β, iNOS, and COX-2) and MMP-9 expressions were lower in the CS groups, and TGF-β/Smad signaling increased. Low skin lipid peroxidation and blood DNA oxidation levels and high blood glutathione were detected. Antioxidant transcription factor Nrf2-related catalase and SOD1 proteins and glutaredoxin mRNA levels increased. The results of CS extract treatment and UVB irradiation in HaCaT cells showed the same results in Nrf2 and NF-κB target genes. An LC-MS/MS analysis showed that the CS extract contained potential antioxidants, which might have contributed to its anti-photoaging effects in tissues and cells. CS extract may reduce UVB-induced skin damage through antioxidant and anti-inflammatory mechanisms.

Inhibition of UVB-Induced Inflammation by Laminaria japonica Extract via Regulation of nc886-PKR Pathway

“…The skin is the first layer of protection against a wide range of environmental hazards, such as ultraviolet (UV) radiation, heat, and infection [ 6 , 10 ]. Most notable of these hazards is ultraviolet B (UVB) radiation, a major external stressor to the skin—one that can cause photoaging, inflammation, and cancer—with its intensity increasing in the face of worsening environmental pollution and ozone depletion [ 9 , 11 , 12 ].…”

Optimization and characterization of poly(lactic-co-glycolic acid) nanoparticles loaded with astaxanthin and evaluation of anti-photodamage effect in vitro

“…Skin, the largest organ in the human body, plays a major role as the protective barrier against harmful external agents, such as ultraviolet (UV) radiation, dehydration, temperature changes and pathogens [21]. Excessive exposure to UV radiation remains a major risk factor for melanoma and non-melanoma skin cancers, especially, exposure to UVB radiation can generate excessive reactive oxygen species (ROS) in cells, that can induce many deleterious effects, including DNA damage, oxidative stress, photoaging, inflammation and carcinogenesis [22,23]. The anti-wrinkle and anti-oxidation effects of astaxanthin reflect its various health benefits and important nutritional health applications in dermatology [24].…”

Corn silk methanolic extract improves oxidative stress and inflammatory responses in rats’ excision wound model

“…A dose range of 50 to 300 mg/kg and 0.5 to 4.0 g/kg have been administered in rodents for various biological activities for a period of 2 to 4 weeks. The single dose of the corn silk extracts (500 mg/kg), administered orally to the animals in the current study, is far below the high doses used in the previous studies that investigated the antioxidant and anti-inflammation properties of the corn silk extract in different animal models (Wang et al, 2012;Ha et al, 2018;Kim et al, 2019;Wang and Zhao, 2019). More so, the no-observed-adverse-effect level (NOAEL) of corn silk is reportedly 8.0% w/w when administered orally for 90 days.…”

“…Twenty rats were randomly assigned into four groups of five rats per group (n = 5/group): (i) Control (distilled H 2 O)-treated normal group, (ii) excision wound-inflicted (wounded) and treated with distilled H 2 O group, (iii) excision wound-inflicted and aqueous corn-silk extract (ACSE 500 mg/kg body weight)-treated group, and (iv) excision wound-inflicted and methanol corn-silk extract (MCSE 500 mg/kg body weight)-treated group. The selected dose was based on the previous studies by Wang et al, (2012); Ha et al, (2018); and Kim et al, (2019). It was shown that Corn silk extract, administered per oral (p.o.)…”