Ethanol extract of peanut sprout induces Nrf2 activation and expression of antioxidant and detoxifying enzymes in human dermal fibroblasts: implication for its protection against UVB-irradiated oxidative stress

Antioxidant Properties of Plant-Derived Phenolic Compounds and Their Effect on Skin Fibroblast Cells

Plants are rich sources of a diverse range of chemicals, many of which have significant metabolic activity. One large group of secondary compounds are the phenolics, which act as inter alia potent reactive oxygen scavengers in cells, including fibroblasts. These common dermis residue cells play a crucial role in the production of extracellular matrix components, such as collagen, and maintaining the integrity of connective tissue. Chronic wounds or skin exposure to UV-irradiation disrupt fibroblast function by the generation of reactive oxygen species, which may damage cell components and modify various signaling pathways. The resulting imbalance may be reversed by the antioxidant activity of plant-derived phenolic compounds. This paper reviews the current state of knowledge on the impact of phenolics on fibroblast functionality under oxidative stress conditions. It examines a range of compounds in extracts from various species, as well as single specific plant-derived compounds. Phenolics are a good candidate for eliminating the causes of skin damage including wounds and aging and acting as skin care agents.

Protective effect of oral treatment with Cordia verbenacea extract against UVB irradiation deleterious effects in the skin of hairless mouse

Photochemoprotection of the skin can be achieved by inhibiting inflammation and oxidative stress, which we tested using Cordia verbenacea extract, a medicinal plant known for its rich content of antioxidant molecules and anti-inflammatory activity. In vitro antioxidant evaluation of Cordia verbenacea leaves ethanolic extract (CVE) presented the following results: ferric reducing antioxidant power (886.32 μM equivalent of Trolox/g extract); IC50 of 19.128 μg/ml for scavenging 2,2-diphenyl-1-picrylhydrazyl; IC50 of 12.48 μg/mL for scavenging 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid); decrease of hydroperoxides from linoleic acid (IC50 of 10.20 μg/mL); inhibition of thiobarbituric acid reactive substances (IC50 8.90 μg/mL); iron-chelating ability in bathophenanthroline iron assay (IC50 47.35 μg/mL); chemiluminescence triggered by free radicals in the H2O2/horseradish peroxidase/luminol (IC50 0.286 μg/mL) and xanthine/xanthine oxidase/luminol (IC50 0.42 μg/mL) methods. CVE (10-100 mg per kg, 30 min before and immediately after UVB exposure) treatment was performed by gavage in hairless mice. CVE inhibited skin edema, neutrophil infiltration, and overproduction of MMP-9; reduced levels of TNF-α, IL-1β, and IL- 6; numbers of skin mast cells, epidermal thickening, number of epidermal apoptotic keratinocytes, and collagen degradation. CVE increased the skin's natural antioxidant defenses as observed by Nrf-2, NAD(P)H quinone oxidoreductase 1, and heme oxygenase 1 mRNA expression enhancement. Furthermore, CVE inhibited lipid peroxidation and superoxide anion production and recovered antioxidant reduced glutathione, catalase activity, and ROS scavenging capacity of the skin. Concluding, CVE downregulates the skin inflammatory and oxidative damages triggered by UVB, demonstrating its potentialities as a therapeutic approach.

Peanut Sprout Extracts Cultivated with Fermented Sawdust Medium Inhibits Benign Prostatic Hyperplasia In Vitro and In Vivo

PURPOSE

In this study, we tested whether the resveratrol-enriched peanut sprout extracts cultivated with fermented sawdust medium (PSEFS) could suppress benign prostatic hyperplasia (BPH) in vitro and in vivo.

MATERIALS AND METHODS

The mode of action of PSEFS was estimated by employing high-performance liquid chromatography analysis, MTT assay, cell counting, cell cycle analysis, immunoblots, and immunoprecipitation and electrophoretic mobility shift assay. In vivo efficacy of PSEFS was analyzed in BPH animal model via immunostaining and enzyme-linked immunosorbent assay.

RESULTS

We selected the Yesan peanut sprout variety, which contains the highest level of resveratrol. The resveratrol levels in PSEFS were higher than those obtained with hydroponic technology. PSEFS treatment induced cell cycle arrest at the G1-phase by downregulating CDK4 and cyclin D1 via p21WAF1 induction in the RWPE-1 and WPMY prostate cells, thereby decreasing their proliferation. Treatment with PSEFS decreased ERK1/2 phosphorylation and increased JNK phosphorylation. The levels of DNA-bound transcription factors associated with proliferation (nuclear factor-κB, Sp-1, and AP-1) decreased upon PSEFS treatment in both prostate cells. Additionally, the levels of the molecular markers of BPH development (5α-reductase, androgen receptor, fibroblast growth factor, Bcl-2, and Bax) also changed by the addition of PSEFS. Finally, in a testosterone propionate-induced BPH model in rats, PSEFS administration attenuated the size, weight, and thickness of prostate tissues with no signs of death.

CONCLUSIONS

These results showed that PSEFS inhibited BPH both in vitro and in vivo and might be useful in the development of a potential BPH therapy.

Chemical characterization of balloon flower (Platycodon grandiflorum) sprout extracts and their regulation of inflammatory activity in lipopolysaccharide-stimulated RAW 264.7 murine macrophage cells

The balloon flower (BF) is a potent natural source of phytochemical compounds and is associated with our health. The sprouting process is accompanied by significant changes in phytochemical compounds in comparison with their original plants. Even though many studies are conducted with BF, there are not yet reports of BF sprouts. In the present study, we determined the chemical composition and biological activity of BF sprouts that had been cultivated for 50 days. Kaempferol-3-O-galactoside and 1-O-caffeoylquinic acid were identified as major components of whole BF sprouts. The leaves/stems of the sprouts had higher total phenolic and flavonoid contents and lower IC50 values in DPPH• and ABTS•+ scavenging assays than whole sprouts or roots. The roots of the sprouts had the highest polygalacin D content (1.44 mg/g). We also determined the effects of different parts of BF sprouts on RAW 264.7 macrophage cells. When these cells were stimulated with lipopolysaccharide (LPS), their nitrite and pro-inflammatory cytokine production increased. BF sprouts suppressed the LPS-induced production of nitrite, tumor necrosis factor-α, and interleukin-6 in a concentration-dependent manner without causing any cytotoxic effects. Nitrite and pro-inflammatory cytokine production were significantly inhibited by the roots and leaves/stems, respectively. The inhibitory effects of BF sprouts on LPS-stimulated inflammatory responses in RAW 264.7 macrophage cells were associated with suppressed NF-κB activation. These findings suggest that BF sprouts could be a valuable source of bioactive compounds and exert anti-inflammatory effects due to their polygalacin D, deapi-platycodin D3, and polyphenol content.

Peanut leaf extract has antioxidant and anti-inflammatory activity but no acute toxic effects

Arachis hypogaea L. (peanut) leaves have been popularly used for the treatment of insomnia and inflammation, but no toxicological study has been performed for this plant preparation. This study aimed to examine the phytochemical composition of peanut leaf hydroalcoholic extract (PLHE) and describe its potential toxic effects and antioxidant and anti-inflammatory properties. The qualitative chemical analysis of PLHE by UHPLC-ESI-HRMS allowed the identification of eight metabolites types (totaling 29 compounds). The 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay revealed that PLHE had strong antioxidant effects; it also exhibited nitric oxide (NO)-scavenging capacity. Human peripheral blood mononuclear cells (PBMCs) exposed to PLHE showed no reduced cell viability or increased free double-stranded DNA, NO, or reactive species production. PLHE reversed the cytotoxicity, pro-inflammatory (release of interleukin-1β), and pro-oxidant effects of H₂O₂ on human PBMCs. Acute PLHE toxicity analysis was performed in vivo using the Organization for Economic Co-operation and Development (OECD) 423 guidelines. PLHE single injection (2000 mg/kg, intragastric) did not cause mortality or morbidity or induce changes in hematological or biochemical parameters after 14 days of administration. Thus, PLHE could be a source of bioactive compounds and possesses antioxidant and anti-inflammatory properties without elicitin cytotoxicity or genotoxicity in human PBMCs or acute toxicity in rats.

Peanut Sprout Extracts Attenuate Triglyceride Accumulation by Promoting Mitochondrial Fatty Acid Oxidation in Adipocytes

Peanut sprouts (PS), which are germinated peanut seeds, have recently been reported to have anti-oxidant, anti-inflammatory, and anti-obesity effects. However, the underlying mechanisms by which PS modulates lipid metabolism are largely unknown. To address this question, serial doses of PS extract (PSE) were added to 3T3-L1 cells during adipocyte differentiation. PSE (25 µg/mL) significantly attenuated adipogenesis by inhibiting lipid accumulation in addition to reducing the level of adipogenic protein and gene expression with the activation of AMP-activated protein kinase (AMPK). Other adipocyte cell models such as mouse embryonic fibroblasts C3H10T1/2 and primary adipocytes also confirmed the anti-adipogenic properties of PSE. Next, we investigated whether PSE attenuated lipid accumulation in mature adipocytes. We found that PSE significantly suppressed lipogenic gene expression, while fatty acid (FA) oxidation genes were upregulated. Augmentation of FA oxidation by PSE in mature 3T3-L1 adipocytes was confirmed via a radiolabeled-FA oxidation rate experiment by measuring the conversion of [³H]-oleic acid (OA) to [³H]-H₂O. Furthermore, PSE enhanced the mitochondrial oxygen consumption rate (OCR), especially maximal respiration, and beige adipocyte formation in adipocytes. In summary, PSE was effective in reducing lipid accumulation in 3T3-L1 adipocytes through mitochondrial fatty acid oxidation involved in AMPK and mitochondrial activation.

The Lipid Mediator Resolvin D1 Reduces the Skin Inflammation and Oxidative Stress Induced by UV Irradiation in Hairless Mice

UV irradiation-induced oxidative stress and inflammation contribute to the development of skin diseases. Therefore, targeting oxidative stress and inflammation might contribute to reduce skin diseases. Resolvin D1 (RvD1) is a bioactive metabolite generated during inflammation to actively orchestrate the resolution of inflammation. However, the therapeutic potential of RvD1 in UVB skin inflammation remains undetermined, which was, therefore, the aim of the present study. The intraperitoneal treatment with RvD1 (3-100 ng/mouse) reduced UVB irradiation-induced skin edema, myeloperoxidase activity, matrix metalloproteinase 9 activity, and reduced glutathione depletion with consistent effects observed with the dose of 30 ng/mouse, which was selected to the following experiments. RvD1 inhibited UVB reduction of catalase activity, and hydroperoxide formation, superoxide anion production, and gp91phox mRNA expression. RvD1 also increased the Nrf2 and its downstream targets NQO1 and HO-1 mRNA expression. Regarding cytokines, RvD1 inhibited UVB-induced production of IL-1β, IL-6, IL-33, TNF-α, TGF-β, and IL-10. These immuno-biochemical alterations by RvD1 treatment had as consequence the reduction of UVB-induced epidermal thickness, sunburn and mast cell counts, and collagen degradation. Therefore, RvD1 inhibited UVB-induced skin oxidative stress and inflammation, rendering this resolving lipid mediator as a promising therapeutic agent.

Phytochemicals for the Prevention of Photocarcinogenesis

Ultraviolet (UV) exposure has an array of damaging effects and is the main cause of skin cancer in humans. Nonmelanoma skin cancer (NMSC), including basal cell carcinoma and squamous cell carcinoma, is the most common type of cancer. Incidence of NMSC has increased due to greater UV radiation, increased life expectancy and other changes in lifestyle; the annual cost of skin cancer treatment in the United States has increased concurrently to around eight billion dollars. Because of these trends, novel approaches to skin cancer prevention have become an important area of research to decrease skin cancer morbidity and defray the costs associated with treatment. Chemoprevention aims to prevent or delay the development of skin cancer through the use of phytochemicals. Use of phytochemicals as chemopreventive agents has gained attention due to their low toxicity and anticarcinogenic properties. Phytochemicals also exhibit antioxidant, anti-inflammatory and antiproliferative effects which support their use as chemopreventive agents, particularly for skin cancer. Preclinical and human studies have shown that phytochemicals decrease UV-induced skin damage and photocarcinogenesis. In this review article, we discuss the selected phytochemicals that may prevent or delay UV-induced carcinogenesis and highlight their potential use for skin protection.

Nrf2- and Bach1 May Play a Role in the Modulation of Ultraviolet A-Induced Oxidative Stress by Acetyl-11-Keto-β-Boswellic Acid in Skin Keratinocytes

BACKGROUND

Exposure of human skin to solar ultraviolet A (UVA) irradiation causes severe oxidative stress with damage to various cellular components and concomitant inflammation and carcinogenesis.

OBJECTIVE

The aim of this study is to investigate the protective effect of acetyl-11-keto-β-boswellic acid (AKBA) against UVA radiation on human skin keratinocytes.

METHODS

HaCaT cells were pretreated with AKBA followed by UVA irradiation. Radiation effects on cell morphology, cell viability, intracellular reactive oxygen species (ROS) levels, and antioxidant enzymes were examined.

RESULTS

AKBA reduces UVA irradiation-induced cell viability loss, accompanied by a decreased production of UVA-induced ROS, decreased malondialdehyde, and increased superoxide dismutase expression. In addition, AKBA increased basal and UVA-induced levels of Nrf2 (NF-E2-related factor 2), the redox-sensitive factor, and its target genes NQO1 and heme oxygenase-1 (HO-1), whereas expression of the transcriptional repressor Bach1 (BTB and CNC homology 1) was reduced. Furthermore, the cytoprotective effects of AKBA against UVA-derived oxidative damage were accompanied by modulating expression of inflammatory mediators (i.e., cyclooxygenase-2 and nuclear factor-κB) and NOX1.

CONCLUSIONS

AKBA protects skin cells from UVA-induced damage by modulating inflammatory mediators and/or ROS production. Therefore, AKBA has potential in the development of skin care products.

Preventive Effects of Resveratrol-enriched Extract of Peanut Sprout on Bacteria- and Estradiol-induced Prostatitis in Mice

The present study investigated the effect of peanut sprout extract (PSE) as a natural resveratrol supplement on chronic bacterial prostatitis (CBP) and estradiol-induced benign prostatic hyperplasia (BPH). PSE contained a high level of resveratrol (148.51 ± 3.05 μg/g), and was tested on the mouse models of CBP (induced by Escherichia coli 292 infection) and BPH (induced by treatment with β-estradiol and dihydrotestosterone). PSE toxicity was assessed on the basis of changes in body weight, alanine aminotransferase activity (an indicator of hepatotoxicity), and expression of the kidney injury marker KIM-1. The effects of PSE on the histopathology of prostate tissue, the proportion of neutrophils, and immune cell profiles in the blood and spleen were examined. PSE administration did not result in any toxicity but reduced the bacterial burden and histopathological changes in the prostate. In addition, lymphocytes (CD4+, CD8+, and CD19+) in the spleen were significantly increased after PSE administration in CBP mice, suggesting immune enhancement. PSE treatment of bone marrow–derived macrophages increased the expression of CD40, which is related to the pro-inflammatory function and host defense against pathogens. It is concluded that PSE would be a good supplement for the mitigation of prostate hyperplasia and prostatitis.

Peanut sprout extract attenuates cisplatin-induced ototoxicity by induction of the Akt/Nrf2-mediated redox pathway

OBJECTIVE

Cisplatin is commonly used to treat solid tumors. However, permanent hearing loss is a major side effect of cisplatin chemotherapy and often results in dose reduction of the cisplatin chemotherapy. Peanut sprouts show cytoprotective properties owing to their antioxidant activities. This study was designed to investigate the effect of peanut sprout extract (PSE) on cisplatin-induced ototoxicity in an auditory cell line, HEI-OC1 cells.

METHODS

Cells were exposed to cisplatin for 24 h, with or without pre-treatment with PSE, cell viability was examined using the MTT assay. Apoptotic cells were identified by double staining with Hoechst 33258 and propidium iodide. Western blot analysis was performed to examine apoptotic proteins including C-PARP and C-caspase, anti-apoptotic protein Bcl-2, and Nrf2 redox system activation. Mitochondrial reactive oxygen species (ROS) were investigated to examine whether PSE could scavenge cisplatin-induced ROS. Real-time PCR analyses were performed to investigate the mRNA levels of antioxidant enzymes including NQO1, HO-1, GPx2, Gclc, and catalase.

RESULTS

The cisplatin-treated group showed reduced cell viability, increased apoptotic properties and markers, and increased ROS levels. PSE pre-treatment before cisplatin exposure significantly increased cell viability and reduced apoptotic properties and ROS production. These effects resulted from the up-regulation of antioxidant genes, including NQO1, HO-1, GPx2, Gclc, and catalase through Akt phosphorylation and Nrf2 activation.

CONCLUSION

Our results demonstrate that PSE protects from cisplatin-induced cytotoxicity by activating the antioxidant effects via the Akt/Nrf-2 pathway in this auditory cell line, and indicate that PSE may provide novel treatment to prevent cisplatin-induced ototoxicity.

Ultraviolet-B Protective Effect of Flavonoids from Eugenia caryophylata on Human Dermal Fibroblast Cells

BACKGROUND

The exposure of skin to ultraviolet-B (UV-B) radiations leads to deoxyribonucleic acid (DNA) damage and can induce production of free radicals which imbalance the redox status of the cell and lead to increased oxidative stress. Clove has been traditionally used for its analgesic, anti-inflammatory, anti-microbial, anti-viral, and antiseptic effects.

OBJECTIVE

To evaluate the UV-B protective activity of flavonoids from Eugenia caryophylata (clove) buds on human dermal fibroblast cells.

MATERIALS AND METHODS

Protective ability of flavonoid-enriched (FE) fraction of clove was studied against UV-B induced cytotoxicity, anti-oxidant regulation, oxidative DNA damage, intracellular reactive oxygen species (ROS) generation, apoptotic morphological changes, and regulation of heme oxygenase-1 (HO-1) gene through nuclear factor E2-related factor 2 antioxidant response element (Nrf2 ARE) pathway.

RESULTS

FE fraction showed a significant antioxidant potential. Pretreatment of cells with FE fraction (10-40 μg/ml) reversed the effects of UV-B induced cytotoxicity, depletion of endogenous enzymatic antioxidants, oxidative DNA damage, intracellular ROS production, apoptotic changes, and overexpression of Nrf2 and HO-1.

CONCLUSION

The present study demonstrated for the first time that the FE fraction from clove could confer UV-B protection probably through the Nrf2-ARE pathway, which included the down-regulation of Nrf2 and HO-1. These findings suggested that the flavonoids from clove could potentially be considered as UV-B protectants and can be explored further for its topical application to the area of the skin requiring protection.

SUMMARY

Pretreatment of human dermal fibroblast with flavonoid-enriched fraction of Eugenia caryophylata attenuated effects of ultraviolet-B radiationsIt also conferred protection through nuclear factor E2-related factor 2-antioxidant response pathway and increased tolerance of cells against oxidative stressFlavonoid-enriched fraction can be explored further for topical application to the skin as a ultraviolet-B protectant. Abbreviations used: ABTS: 2,2'-azino-bis-(3-ethylbenzothiazoline- 6-sulphonic acid), AO: Acridine orange,

ANOVA

Analysis of variance, ARE: Antioxidant response elements, BSA: Bovine serum albumin, CAPE: Caffeic acid phenethyl ester, CAT: Catalase, DCFH-DA: 2',7'-dichlorofluorescein diacetate, DMEM: Dulbecco's Modified Eagle's Medium, DMSO: Dimethyl sulfoxide, DNA: Deoxyribonucleic acid, DPBS: Dulbecco's phosphate buffered saline, DPPH: 2,2-diphenyl-1-picrylhydrazyl, ECL: Enhanced chemiluminescence, EDTA: Ethylenediaminetetraacetic acid, ELISA: Enzyme-linked immunesorbent assay, EtBr: Ethidium bromide, FBS: Fetal bovine serum, FE fraction: Flavonoid-enriched fraction, FRAP: Ferric reducing antioxidant power, GPx: Glutathione peroxidase, GR: Glutathione reductase, GST: Glutathione-S-transferase, GSH: Reduced glutathione, GSSG: Oxidized glutathione, HDF: Human dermal fibroblast, HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulphonic acid, HRP: Horseradish peroxidase, HO-1: Heme oxygenase-1, HPTLC: High-performance thin layer chromatography, Keap-1: Kelch-like ECH-associated protein-1, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, NaCl: Sodium chloride, NFDM: Nonfat dry milk, Nrf2: Nuclear factor E2-related factor 2, NQO1: NAD (P) H: Quinine oxidoreductase 1, OH: Hydroxyl ions, PBST: Phosphate buffered saline with 0.1% tween 20, PCR: Polymerase chain reaction, PMSF: Phenylmethanesulfonyl fluoride, Rf: Retention factor, ROS: Reactive oxygen species, rRNA: Ribosomal ribonucleic acid, SDS: Sodium dodecyl sulfate, SOD: Superoxide dismutase, TLC: Thin layer chromatography, TLC-DPPH: Thin layer chromatography-2,2-diphenyl-1-picrylhydrazyl, UV: Ultraviolet, UV-A: Ultraviolet-A, UV-B: Ultraviolet-B, UV-C: Ultraviolet-C, and qPCR: Quantitative polymerase chain reaction.

The supplementation effects of peanut sprout on reduction of abdominal fat and health indices in overweight and obese women

BACKGROUD/OBJECTIVES

This study was conducted in order to investigate the effect of peanut sprout extracts (PSE) on health indices in overweight and obese women (BMI ≥ 23 kg/m²).

SUBJECTS/METHODS

Subjects were divided into three groups by double-blind randomized trial; the Placebo group (n = 15) and the Low PSE group (2.6 g PSE/day, n = 15), and the High PSE group (5.8 g PSE/day, n = 15). Subjects consumed 12 capsules per day, three times a day, 30 min before meals, for 4 weeks. Anthropometric data, blood biochemical variables, and dietary intake were evaluated before and after the experiments.

RESULTS

In the Low and High PSE group, the waist circumference showed a significant decrease between pre- and post-test. In the Low PSE group, the reduction of systolic blood pressure between pre- and post-test was statistically significant. Serum LDL or triglyceride levels in both Low and High PSE groups were significantly decreased, and serum alanine transaminase and aspartate transaminase were significantly decreased only in the Low PSE group. The parameters regarding erythrocyte and leucocyte counts showed no significant differences between pre- and post-test among groups, which suggested the safety of intake of peanut sprouts as a dietary supplement.

CONCLUSIONS

This study indicates that PSE supplementation improves abdominal obesity and overall health indices. Therefore, an appropriate amount of peanut sprouts may be a plausible effective agent for obesity and obesity related health problems in obese women.

Ethanol Extract of Peanut Sprout Lowers Blood Triglyceride Levels, Possibly Through a Pathway Involving SREBP-1c in Rats Fed a High-Fat Diet

The hypothesis of this study was that peanut sprout extracts (PSE) could reduce fat accumulation through activating the transcription of SREBP-1c genes. Sprague-Dawley (SD) were randomly assigned into two groups and fed the following diet for 4 weeks; 10 normal fat (NF, 7 g of fat/100 g diet) and 30 high fat (HF, 20 g of fat/100 g diet). After 4 weeks, the HF group was divided into three groups; HF, HF with 15 mg of PSE/kg diet (HF+low PSE, 0.025% resveratrol), and HF with 30 mg of PSE/kg diet (HF+high PSE, 0.05% resveratrol) and fed for an additional 5 weeks. The HF+high PSE group had significantly lower weight gain than the HF group. Plasma triglyceride (TG) level and the hepatic total lipid level were significantly lower in the HF+high PSE group compared to the HF group. Fecal excretions of total lipids, cholesterol, and TG in the HF+high PSE group tended to be higher than in the HF group, but these differences were not significant. The mRNA expressions of fatty acid synthase, glucose-6-phosphate dehydrogenase, and sterol regulatory element binding protein-c (SREBP-1c) were significantly lower in the HF+high PSE group than in the HF group. The mRNA expressions of hydroxy-3-methylglutaryl coenzyme A reductase and acyl-CoA cholesterol acyltransferase were significantly lower in the HF+high PSE groups compared to the HF group. The mRNA expression of cholesterol 7α-hydroxylase1 was significantly higher than the HF group in both the HF+low PSE and HF+high PSE groups, with much greater increase observed in the HF+high PSE group. In conclusion, consumption of PSE was effective for improving blood lipid levels, possibly by suppressing the expression of SREBP-1c, in rats fed a high-fat diet.

Ethanol Extract of Peanut Sprout Exhibits a Potent Anti-Inflammatory Activity in Both an Oxazolone-Induced Contact Dermatitis Mouse Model and Compound 48/80-Treated HaCaT Cells

Background

We developed an ethanol extract of peanut sprouts (EPS), a peanut sprout-derived natural product, which contains a high level of trans-resveratrol (176.75 µg/ml) and was shown to have potent antioxidant activity.

Objective

We evaluated the potential anti-inflammatory activity of EPS by measuring its antioxidant potential in skin.

Methods

The anti-inflammatory activity of EPS was tested using two models of skin inflammation: oxazolone (OX)-induced contact dermatitis in mice and compound 48/80-treated HaCaT cells. As biomarkers of skin inflammation, cyclooxygenase-2 (COX-2) and nerve growth factor (NGF) levels were measured.

Results

OX-induced contact dermatitis was suppressed markedly in mice that were treated with an ointment containing 5% EPS as evidenced by a decrease in the extent of scaling and thickening (p<0.05) and supported by a histological study. COX-2 (messenger RNA [mRNA] and protein) and NGF (mRNA) levels, which were upregulated in the skin of OX-treated mice, were suppressed markedly in the skin of OX+EPS-treated mice. Consistent with this, compound 48/80-induced expression of COX-2 (mRNA and protein) and NGF (mRNA) in HaCaT cells were suppressed by EPS treatment in a dose-dependent manner. As an inhibitor of NF-κB, IκB protein levels were dose-dependently upregulated by EPS. Fluorescence-activated cell sorting (FACS) analysis revealed that EPS scavenged compound 48/80-induced reactive oxygen species (ROS) in HaCaT cells.

Conclusion

EPS exerts a potent anti-inflammatory activity via its anti-oxidant activity in both mouse skin and compound 48/80-treated HaCaT cells in vitro. Compound 48/80-treated HaCaT cells are a useful new in vitro model of skin inflammation.

The role of transcription factor Nrf2 in skin cells metabolism

Skin, which is a protective layer of the body, is in constant contact with physical and chemical environmental factors. Exposure of the skin to highly adverse conditions often leads to oxidative stress. Moreover, it has been observed that skin cells are also exposed to reactive oxygen species generated during cell metabolism particularly in relation to the synthesis of melanin or the metabolism in immune system cells. However, skin cells have special features that protect them against oxidative modifications including transcription factor Nrf2, which is responsible for the transcription of the antioxidant protein genes such as antioxidant enzymes, small molecular antioxidant proteins or interleukins, and multidrug response protein. In the present study, the mechanisms of Nrf2 activation have been compared in the cells forming the various layers of the skin: keratinocytes, melanocytes, and fibroblasts. The primary mechanism of control of Nrf2 activity is its binding by cytoplasmic inhibitor Keap1, while cells have also other controlling mechanisms, such as phosphorylation of Nrf2 and modifications of its activators (e.g., Maf, IKKβ) or inhibitors (e.g., Bach1, caveolae, TGF-β). Moreover, there are a number of drugs (e.g., ketoconazole) used in the pharmacotherapy of skin diseases based on the activation of Nrf2, but they may also induce oxidative stress. Therefore, it is important to look for compounds that cause a selective activation of Nrf2 particularly natural substances such as curcumin, sulforaphane, or extracts from the broccoli leaves without side effects. These findings could be helpful in the searching for new drugs for people with vitiligo or even melanoma.

Enhancement of Alcohol Metabolism by Sprouted Peanut Extract in SD Rats

Excessive ethanol intake is known to induce a number of physiological symptoms, including headache, dizziness and vertigo. In this study, we investigated the attenuation effect of sprouted peanut extract (SPE) on ethanol-induced hangover in male Sprague-Dawley rats. The animals were divided into five groups: the control group, which was administered ethanol only; the ethanol plus SPE experimental groups, which were administered ethanol and 100, 200, or 400 mg SPE/kg b.w.; and the positive control group, which was administered ethanol plus DAWN808^®, a commercial product. SPE-suspended water was delivered to rats via gavage 15 h and 30 min before the administration of ethanol. Blood was collected from the tail 0, 1, 3, and 5 h after ethanol administration. The results showed that serum ethanol concentrations were significantly lower in SPE treated groups than in the control group. Furthermore, hepatic alcohol and acetaldehyde dehydrogenase activities were enhanced by SPE in a dose dependent manner. These results suggest that SPE could be useful in attenuating hangover after alcohol consumption.

Protection from UVB Toxicity in Human Keratinocytes by Thailand Native Herbs Extracts

Thai traditional medicine employs a wide range of indigenous herbs in the forms of tincture or tea for the cure of skin and systemic inflammatory diseases. The protection by Thai plants extracts against UVB DNA damage and cytotoxicity was investigated in human keratinocytes. Petroleum ether, dichloromethane and ethanol extracts were prepared from 15 Thai herb species, and the total phenolic and flavonoid contents, the antioxidant and UV-absorbing properties were assessed by standard procedures. Cytoprotective effects were evaluated on the basis of cell survival, caspase-3 activity and pyrimidine dimers determination. High total phenolic and flavonoid contents were found in the ethanol and dichloromethane fractions. Dichloromethane extract of turmeric was shown to possess the highest antioxidant activity. The maximum UV absorptions were found in the ethanol extract of turmeric and in the dichloromethane extract of ginger. These extracts stimulated the synthesis of Thioredoxin 1, an antioxidant protein, and could protect human HaCaT keratinocytes from UV-induced DNA damage and cytotoxicity. The present data support the utilization of turmeric and ginger extracts in anti-UV cosmetic pharmaceuticals.

Laxative effect of peanut sprout extract

Certain phenolic compounds are known to exhibit laxative properties. Seed sprouts, such as those of peanut, are known to promote de novo biosynthesis of phenolic compounds. This study was conducted to examine the potential laxative properties of 80% (v/v) ethanolic extract of peanut sprout (PSE), which contains a high concentration of phenolic compounds such as resveratrol. For this, SD rats were orally administered PSE while a control group was incubated with saline. Laxative effects were examined in both groups of rats. Constipation induced by loperamide in SD rats was improved by administration of PSE. Constipated rats showed increased intestinal movement of BaSO₄ upon administration of PSE compared to the control, and the groups administered 100 or 1,000 mg PSE/kg bw were not significantly different in transit time of the indicator. However, colon length was not statistically different among the experimental groups, although it was longer in the group incubated with 1 g PSE/kg bw compared to other groups. Further, there was no significant difference in stool number among the experimental groups. Taken together, these findings show that PSE has a laxative effect in a rat model of loperamide-induced constipation.