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

Anti-photoaging effect and the mechanism of Coreopsis tinctoria okanin against UVB-induced skin damage in mice

Long-term exposure to ultraviolet radiation may cause photoaging of skin tissues. Coreopsis tinctoria Nutt. riches a variety of flavonoids with strong antioxidant activities. In the present study, the main antioxidant flavonoid was isolated from C. tinctoria and identified as okanin by Mass spectrum and Nuclear Magnetic Resonance Spectroscopy. Okanin was found to effectively reduce the malondialdehyde content, increase various intracellular antioxidant enzyme activities, relieve epidermal hyperplasia and dermal damage caused by UVB irradiation, and increase the collagen fibers' content in the dorsal skin tissue of mice. Immunohistochemical analysis showed that okanin effectively counteracted the photoaging effect of UVB-induced by down-regulating IL-1, IL-6, TNF-α, and COX-2, and up-regulating COL-1, COL-3, and HYP expression. In addition, okanin can inhibit skin photoaging by regulating TNF-β/Smad2-3, MAPK, P13K/AKT, and NF-κB signaling pathways. In particular, the three key markers of photoaging, MMP (MMP-1/-3/-9), were down-regulated and five collagen synthesis genes (COL1A1, COL3A1, COL5A2, COL6A1, and COL7A1) were up-regulated, underlines the direct anti-photoaging mechanism of okanin in preventing collagen degradation and promoting collagen synthesis. The current investigation provides new insights into the great potential of okanin in alleviating skin photoaging and lays theoretical references for the development ofanti-photoaging products.

Clinical efficacy of intradermal type I collagen injections in treating skin photoaging in patients from high-altitude areas

BACKGROUND

Photoaging, a result of chronic sun exposure, leads to skin damage and pigmentation changes. Traditional treatments may have limitations in high-altitude areas like Yunnan Province. Intradermal Col Ι injections stimulate collagen production, potentially improving skin quality. This study aims to assess the efficacy and safety of this treatment for photoaging.

AIM

To evaluate the efficacy and safety of intradermal type Ι collagen (Col Ι) injection for treating photoaging.

METHODS

This prospective, self-controlled study investigated the impact of intradermal injections of Col Ι on skin photodamage in 20 patients from the Yunnan Province. Total six treatment sessions were conducted every 4 wk ± 3 d. Before and after each treatment, facial skin characteristics were quantified using a VISIA skin detector. Skin thickness data were assessed using the ultrasound probes of the Dermalab skin detector. The Face-Q scale was used for subjective evaluation of the treatment effect by the patients.

RESULTS

The skin thickness of the right cheek consistently increased after each treatment session compared with baseline. The skin thickness of the left cheek significantly increased after the third through sixth treatment sessions compared with baseline. The skin thickness of the right zygomatic region increased after the second to sixth treatment sessions, whereas that of the left zygomatic region showed a significant increase after the fourth through sixth treatment sessions. The skin thickness of both temporal regions significantly increased after the fifth and sixth treatment sessions compared with baseline (P < 0.05). These findings were also supported by skin ultrasound images. The feature count for the red areas and wrinkle feature count decreased following the treatment (P < 0.05). VISIA assessments also revealed a decrease in the red areas after treatment. The Face-Q-Satisfaction with Facial Appearance Overall and Face-Q-Satisfaction with Skin scores significantly increased after each treatment session. The overall appearance of the patients improved after treatment.

CONCLUSION

Intradermal Col Ι injection improves photoaging, with higher patient satisfaction and fewer adverse reactions, and could be an effective treatment method for populations residing in high-altitude areas.

Preventive and Therapeutic Benefits of Natural Ingredients in Photo-Induced Epidermal Dysfunction

BACKGROUND

The skin, particularly the epidermis, is subjected to various external stresses, including ultraviolet (UV) irradiation. UV irradiation, mainly UVB at wavelength of 280-315 nm, can alter several epidermal functions, including cutaneous inflammation, epidermal hyperproliferation, DNA damage, disruption of epidermal permeability barrier and reduction in stratum corneum hydration levels. Because of the negative impacts of UVB irradiation on epidermal functions, great efforts have been made to develop regimens for the protection of alterations in epidermal function induced by UV irradiation.

SUMMARY

While sunscreen can provide physical barrier to UV light, some natural ingredients can also effectively protect the skin from UVB irradiation-induced damages. Studies have demonstrated that either topical or oral administrations of some natural ingredients attenuate UVB irradiation-induced alterations in the epidermal function. The underlying mechanisms by which natural ingredients improve epidermal functions are attributable to antioxidation, stimulation of keratinocyte differentiation, increases in the content of epidermal natural moisturizers and inhibition of inflammation.

KEY MESSAGE

Some natural ingredients exhibit protective and therapeutical benefits in photo-induced epidermal dysfunctions via divergent mechanisms.

Compound collagen peptide powder improves skin photoaging by reducing oxidative stress and activating TGF-β1/Smad pathway

Fish collagen peptide (FCP) has been extensively investigated as a natural product that can combat photoaging; however, its efficacy is limited by its singular composition. Compound collagen peptide powder (CCPP) is a novel functional food formulation that exhibits photoprotective properties and comprises FCP and a blend of natural botanical ingredients. The objective of this study was to investigate the efficacy of CCPP and its molecular mechanism. CCPP had a low molecular weight, facilitating its efficient absorption, and was abundant in amino acids, total polyphenols, and total flavonoids. The results of in vivo studies demonstrated that CCPP exhibited significant efficacy in reducing skin wrinkles, enhancing the contents of water and oil in the skin, and ameliorating histopathological alterations in mice. The results of in vitro studies demonstrated that CCPP effectively mitigated photoaging in human skin fibroblasts by attenuating oxidative stress and promoting extracellular matrix (ECM) synthesis. Moreover, we clearly demonstrated that the TGF β1/Smad pathway was involved in the promotion of ECM synthesis and cell proliferation by CCPP in human skin fibroblasts. These findings suggest that, compared with single collagen, CCPP has a more comprehensive range of antiphotoaging properties.

Antioxidant, Anti-Tyrosinase, and Anti-Skin Pathogenic Bacterial Activities and Phytochemical Compositions of Corn Silk Extracts, and Stability of Corn Silk Facial Cream Product

Zea mays L. Poaceae stigma (corn silk, CS) is a byproduct of agricultural waste and is used as a traditional herb in many countries. CS is rich in chemical compounds known to benefit human health and is also a remedy for infectious diseases and has anti-proliferative effects on human cancer cell lines. In the present study, CS extract has been evaluated for its antioxidant, antibacterial, and anti-tyrosinase activities and its phytochemical composition. The higher total phenolic and flavonoid contents were found in the ethanolic extract of corn silk (CSA), at 28.27 ± 0.86 mg gallic acid equivalent/g extract and 4.71 ± 0.79 mg quercetin equivalent/g extract, respectively. Moreover, the antioxidant content of CSA was found at 5.22 ± 0.87 and 13.20 ± 0.42 mg gallic acid equivalent/g extract using DPPH and reducing power assays. Furthermore, the ethanolic extract of corn silk showed tyrosinase inhibition with an IC50 value of 12.45 µg/mL. The bacterial growth inhibition of CSA was tested using agar disc diffusion and broth dilution assays against Cutibacterium acnes and Staphylococcus epidermidis. It was found that CSA inhibited C. acnes and S. epidermidis with an inhibition zone of 11.7 ± 1.2 and 9.3 ± 0.6 mm, respectively. Moreover, the CSA showed MIC/MBC of 15.625 mg/mL against C. acnes. The following phytochemical compounds were detected in CSA: cardiac glycosides; n-hexadecanoic acid; hexadecanoic acid, ethyl ester; oleic acid; and 9,12-octadecadienoic acid, ethyl ester. After the corn silk cream product was formulated, the product demonstrated stability without phase separation. This research is beneficial for promoting effective ways to use agricultural waste while utilizing the antioxidant, anti-tyrosinase, and antibacterial activities of corn silk. Moreover, the use of technology and innovation to obtain high-value CS extract will benefit the development of commercial cosmetic products by providing safe, natural, and quality ingredients to the consumer.

Anti-cancerous effect of corn silk: a critical review on its mechanism of action and safety evaluation

Cancer is a broad collection of diseases that can begin in almost any organ or tissue of the body. Corn silk is the hair-like stigmata of female maize flowers which is generally discarded as waste from maize cultivation. The current study targets the anti-cancer potential of corn silk and its bioactive compounds namely, polyphenols, flavonoids, and sterols. The polyphenols and flavonoids like quercetin, rutin, apigenin and beta-sitosterol are a range of compounds from corn silk which were investigated for their anticancer effect. Corn silk showed apoptotic and antiproliferative effects in cancer cells through different signalling pathways, essentially the serine/threonine kinases (Akt)/lipid kinases (PI3Ks) pathway. The study revealed that corn silk compounds target immune cell responses, induce cell cytotoxicity, and upregulate the expression of proapoptotic genes p53, p21, caspase 9, and caspase 3 in certain cancer cell lines including HeLa cervical cancer cells, MCF-7 breast cancer cells, PANC-02 pancreatic cancer cells and Caco-2 colon cancer cells. Flavonoids derived from corn silk enhance T cell mediated immune response and decrease inflammatory factors. Corn silk bioactive compounds were found to reduce the side effects of cancer therapy. Antioxidants of corn silk, quercetin and rutin help in reducing the nephrotoxicity of chemotherapeutic drugs. The study also suggests that corn silk has anti-cancerous potential as it targets tumour suppression and inhibits metastasis A dose of 500 mg/kg body weight of corn silk has been found safe for human consumption. Corn silk extract can be used as a preventive or therapeutic step to cure cancer. The anti-cancer property, mechanism and role of corn silk in controlling cancer-related side effects have been critically reviewed providing new scope for the use of corn silk in cancer therapy.

A Physicochemical Study of the Antioxidant Activity of Corn Silk Extracts

Corn silk (CS) extracts are reported to contain flavonoids (appx. 59.65 mg quercetin/g), polysaccharides (appx. 58.75 w.%), steroids (appx. 38.3 × 10^-3 to 368.9 × 10^-3 mg/mL), polyphenols (appx. 77.89 mg/GAE/g) and other functional biological substances. This study investigated the antioxidant activity of corn silk extracts related to their functional compounds. The radical scavenging effect of corn silk extracts was evaluated by the spin-trapping electron paramagnetic resonance (EPR) technique, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonate) (ABTS^•+) free radical measurement, ferric ion-reducing antioxidant power, and copper ion reductive capacity. It was found that the maturity stage of CS plant materials and the applied extraction procedure of their bioactive compounds have a profound effect on the radical scavenging capacity. Differences in the antioxidant activity of the studied corn silk samples based on their maturity were also confirmed. The strongest DPPH radical scavenging effect was observed for the corn silk mature stage (CS-M)stage (CS-MS) (65.20 ± 0.90)%, followed by the silky stage (CS-S) (59.33 ± 0.61)% and the milky stage (CS-M) (59.20 ± 0.92)%, respectively. In general, the final maturity stage (CS-MS) provided the most potent antioxidant effect, followed by the earliest maturity stage (CS-S) and the second maturity stage (CS-M).

Authentication, chemical profiles analysis, and quality evaluation of corn silk via DNA barcoding and UPLC-LTQ/Orbitrap MS chemical profiling

Corn silk is commonly consumed in teas, food ingredients, and herbal medicines. Several varieties of corn silk are grown in different habitats in China. However, as information regarding their phytochemistry and genetic diversity is limited, their medicinal potential has not been utilized thoroughly. Thus, we aimed to use a combination of DNA barcoding based on specific primer ITSC sequences and ultra-performance liquid chromatography coupled with linear trap quadrupole-Orbitrap mass spectrometry (UPLC-LTQ/Orbitrap MS) approach for identifying and evaluating corn silk. ITSC barcoding helped us to identify that 52 samples could be classified into 7 groups of corn silk varieties, but the widely used nrITS and psbA-trnH barcodes failed to identify these varieties. UPLC-LTQ/Orbitrap MS was used to study the components in alcohol extracts derived from different corn silk varieties, and the detected chemical components were analyzed via bioinformatics techniques. We proposed 199 components using untargeted UPLC-LTQ/Orbitrap MS-based metabolomics analysis and identified 67 components. PCA and OPLS-DA analysis revealed two distinct chemotypes by selecting 27 components that could act as difference indicators. KEGG analysis showed that the 199 components were enriched in 12 metabolic pathways. The results showed that corn silk is rich in many types of chemicals and DNA barcoding is better than UPLC-LTQ/Orbitrap MS in distinguishing the differences between different varieties of corn silk. Our findings provide new insights into the chemical and molecular characteristics of different varieties of corn silk, which play a crucial role in the utilization of corn silk resources.

Protective effect of oligosaccharides isolated from Panax ginseng C. A. Meyer against UVB-induced skin barrier damage in BALB/c hairless mice and human keratinocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Skin barrier dysfunction can lead to water and electrolyte loss, triggering homeostatic imbalances that can trigger atopic dermatitis and anaphylaxis. Panax ginseng C.A. Meyer is a traditional Chinese medicinal herb with known therapeutic benefits for the treatment of skin diseases, including photodamage repair effects and reduction of pigmentation. However, few reports exist that describe effectiveness of ginseng active components for repair of skin barrier damage.

MATERIALS AND METHODS

Ginseng oligosaccharide extract (GSO) was prepared from P. ginseng via water extraction followed by ethanol precipitation and resin and gel purification. GSO composition and structural characteristics were determined using LC-MS, HPLC, FT-IR, and NMR. To evaluate GSO as a skin barrier repair-promoting treatment, skin of UVB-irradiated BALB/c hairless mice was treated with or without GSO then skin samples were evaluated for epidermal thickness, transepidermal water loss (TEWL), and stratum corneum water content. In addition, UVB-exposed skin samples and HaCaT cells were analyzed to assess GSO treatment effects on levels of epidermal cornified envelope (CE) protein and other skin barrier proteins, such as filaggrin (FLG), involucrin (IVL), and aquaporin-3 (AQP3). Meanwhile, GSO treatment was also evaluated for effects on UVB-irradiated hairless mouse skin and HaCaT cells based on levels of serine protease inhibitor Kazal type-5 (SPINK5), trypsin-like kallikrein-related peptidase 5 (KLK5), chymotrypsin-like KLK7, and desmoglein 1 (DSG1). These proteins are associated with UVB-induced skin barrier damage manifesting as dryness and desquamation.

RESULTS

GSO was shown to consist of oligosaccharides comprised of seven distinct types of monosaccharides with molecular weights of approximately 1 kDa that were covalently linked together via β-glycosidic bonds. In vivo, GSO applied to dorsal skin of BALB/c hairless mice attenuated UVB-induced epidermal thickening and moisture loss. Furthermore, GSO ameliorated UVB-induced reductions of levels of FLG, IVL, and AQP3 proteins. Additionally, GSO treatment led to increased DSG1 protein levels due to decreased expression of KLK7. In vitro, GSO treatment of UVB-irradiated HaCaT cells led to increases of FLG, IVL, and AQP3 mRNA levels and corresponding proteins, while mRNA levels of desquamation-related proteins SPINK5, KLK5, KLK7, and DSG1 and associated protein levels were restored to normal levels.

CONCLUSION

A P. ginseng oligosaccharide preparation repaired UVB-induced skin barrier damage by alleviating skin dryness and desquamation symptoms, highlighting its potential as a natural cosmetic additive that can promote skin barrier repair after UVB exposure.

Ameliorative effects of corn silk extract on acetaminophen-induced renal toxicity in rats

The current study aimed to investigate the protective effect of corn silk methanolic extract (CSME) against acetaminophen (APAP)-induced nephrotoxicity. The present study was carried out on 40 male Wistar albino rats, which were randomly divided into four groups (n = 10): control group, orally administered with a single dose of 1.8 ml 0.9% normal saline at the last day of the experiment; CSME group, orally received CSME (400 mg/kg BW daily for 5 weeks); APAP group, orally administered with a single dose of APAP (2 g/kg BW); and CSME and APAP group, orally administered with CSME, followed by a single oral dose of APAP. The results of this study revealed that APAP caused a significant increase in serum urea, creatinine concentrations, and malondialdehyde (MDA) concentrations in renal tissues. In addition, APAP caused a significant decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities in renal tissues compared with the control group. Furthermore, APAP caused marked renal damage as revealed by alterations in histopathological architectures of kidney tissues. APAP resulted in a marked expression of caspase 3 and nuclear factor κB (NFĸβ) within the renal tubules, while caused marked decrease of proliferating cell nuclear antigen (PCNA) immunostaining and transforming growth factor beta 1 (TGFβ 1) expression within the epithelial lining of the renal tubules. However, pre-treatment with CSME returned all biochemical parameters, histopathological changes, and immunohistochemical parameters toward normal levels as the control group. In conclusion, oral administration of CSME protected rats against APAP renal toxicity through its antioxidant, anti-apoptotic, and anti-inflammatory protective mechanisms.

Special Issue "Plant Extracts: Biological and Pharmacological Activity"

The use of plant extracts for therapeutic purposes knows a wide diffusion [...].

Maysin plays a protective role against α-Synuclein oligomers cytotoxicity by triggering autophagy activation

Parkinson's disease (PD) is a widespread neurodegenerative disorder characterized by the progressive loss of neurons. The accumulation of aggregated forms of the α-Synuclein (Syn) protein is the main cause of neurotoxicity in PD by disrupting cellular homeostasis until neuronal death. Scientific research is constantly looking for natural products as preventive agents against the progression of several neurodisorders due their safety and non-toxic nature. Neuroprotective phytochemicals include Maysin (Mys), the most abundant C-glycosilflavone in corn silk. In this work, the Mys protective role against damage by Syn amyloid aggregates - oligomers and fibrils - was investigated in SH-SY5Y human neuroblastoma cells obtaining novel and interesting information concerning the Mys molecular mechanism of action. Mys showed effectiveness in preventing the typical toxic events induced by Syn amyloid aggregates, i.e. oxidative stress and imbalance of intracellular calcium homeostasis. Mys exhibited a cytoprotective role, especially against Syn oligomers injury, activating an autophagic degradative process, thus playing a key role on several features of amyloid neurotoxicity. Therefore, Mys could be proposed for the first time to the scientific community as an interesting novel natural compound that might allow to develop alternative strategies to prevent the damage of Syn oligomers involved in Parkinson's disease.

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

Continuous exposure to ultraviolet B (UVB) can cause photodamage of the skin. This photodamage can be inhibited by the overexpression of the non-coding RNA, nc886, via the protein kinase RNA-activated (PKR) pathway. The study aims to identify how UVB inhibits nc886 expression, and it also seeks to determine whether substances that can control nc886 expression can influence UV-induced inflammation, and the mechanisms involved. The results suggest that UVB irradiation accelerates the methylation of the nc886 gene, therefore, reducing its expression. This induces the activation of the PKR, which accelerates the expression of metalloproteinase-9 (MMP-9) and cyclooxygenase (COX-2), and the production of MMP-9, prostaglandin-endoperoxide synthase (PGE2), and certain pro-inflammatory cytokines, specifically interleukin-8 (IL-8), and tumor necrosis factor- (TNF-). Conversely, in a model of nc886 overexpression, the expression and production of those inflammatory factors are inhibited. In addition, Laminaria japonica extract (LJE) protect the levels of nc886 against UVB irradiation then subsequently inhibit the production of UV-induced inflammatory factors through the PKR pathway.

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

Astaxanthin is a xanthophyll carotenoid with high beneficial biological activities, such as antioxidant function and scavenging oxygen free radicals, but its application is limited because of poor water solubility and low bioavailability. Here, we prepared and optimized poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with astaxanthin using the emulsion solvent evaporation technique and investigated the anti-photodamage effect in HaCaT cells. The four-factor three-stage Box-Behnken design was used to optimize the nanoparticle formulation. The experimental determination of the optimal nanoparticle size was 154.4 ± 0.35 nm, the zeta potential was 22.07 ± 0.93 mV, encapsulation efficiency was 96.42 ± 0.73% and drug loading capacity was 7.19 ± 0.12%. The physico-chemical properties of the optimized nanoparticles were characterized by dynamic light scattering, scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and thermo-gravimetric analyser. In vitro study exhibited the excellent cell viability and cellular uptake of optimized nanoparticles on HaCaT cells. The anti-photodamage studies (cytotoxicity assay, reactive oxygen species content and JC-1 assessment) demonstrated that the optimized nanoparticles were more effective and safer than pure astaxanthin in HaCaT cells. These results suggest that our PLGA-coated astaxanthin nanoparticles synthesis method was highly feasible and can be used in cosmetics or the treatment of skin diseases.