Brazilian green propolis water extract up-regulates the early expression level of HO-1 and accelerates Nrf2 after UVA irradiation

Pharmacokinetics and molecular docking of the cardioprotective flavonoids in Dalbergia odorifera

The purpose of this research was to investigate the cardioprotective effects and pharmacokinetics of Dalbergia odorifera flavonoids. The cardioprotective effects were detected by hematoxylin-eosin staining histopathological observations and the detection of myocardial enzymes by kits in serum, peroxidation and antioxidant levels and ATPase activities by kits in the homogenate supernatant, and antioxidant and apoptosis-related protein expression in heart tissue by immunohistochemistry. The pharmacokinetics parameters of the flavonoids in rat plasma were investigated by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. Molecular docking of the compounds absorbed by the blood with specific proteins was carried out. D. odorifera flavonoids significantly reduced the levels of creatinine kinase, alanine transaminase, nitric oxide, and Hydrogen peroxide, elevated the levels of glutathione, superoxide dismutase, and ATPase, significantly reduced the pathological degree of heart tissue and had obvious anti-myocardial ischemia efficacy. Nine out of the 17 flavonoids were detected in rat plasma. The peak concentration and the area under the plasma concentration-time curve values of 3'-O-methylviolanone and sativanone were significantly higher than those of other ingredients. The peak time of most flavonoids (except for Genistein and Pruneion) was lower than 2 h, while the half-life of elimination of the nine flavonoids ranged from 3.32 to 21.5 h. The molecular docking results showed that daidzein, dalbergin, formononetin, and genistein had the potential to bind to the target proteins. The results of the study provide an important basis for understanding the cardioprotective effects and clinical application of D. odorifera.

3,4,5-O-tricaffeoylquinic acid alleviates ionizing radiation-induced injury in vitro and in vivo through regulating ROS/JNK/p38 signaling

Ionizing radiation (IR) brings many health problems to humans, causing damage to the digestive system, hematopoietic system, and immune system. Natural compounds derived from plants have attracted widespread attention due to their low toxicity. Here, we found that 3,4,5-O-tricaffeoylquinic acid (tCQA) extracted from natural plant Azolla imbricata could significantly alleviate the systemic damage in mice caused by IR. In order to further explore the molecular mechanism of the radioprotective effect of tCQA, in vitro experiments confirmed that tCQA could attenuate the cytotoxic effect of IR on the colonic epithelial cell line NCM460 and alleviate the IR-induced mitochondrial dysfunction characterized by the decrease of mitochondrial transmembrane potential, ROS production, and caspase-dependent apoptosis. In addition, the generation of ROS induced by H₂ O₂ could also be reversed by tCQA. Then, Western blot demonstrated that tCQA could reverse the MAPK signaling pathway activated by IR. However, the inhibitory effect of tCQA on JNK and P38 levels activated by the JNK agonist anisomycin is not obvious; meanwhile, tCQA could inhibit the activation of JNK/P38 induced by H₂ O₂ , which suggests that tCQA might inhibit the JNK/P38 signaling pathway by reducing ROS. In short, tCQA inhibits the generation of ROS caused by IR, and then regulates the activity of caspase in the mitochondrial pathway by inhibiting the JNK/P38 signaling pathway, thereby alleviating the apoptosis of NCM460. This research provides an experimental basis for the development of new types of radioprotective agents for medical diagnosis and radiotherapy.

Protective effects of propolis extract against nicotine-evoked pulmonary and hepatic damage

There is increasing interest in the use of natural products to treat many diseases, considering the minimal toxicity, availability, and low cost. Propolis, a natural resinous product produced by honeybees, has been proven for its antioxidant and anti-inflammatory properties. Therefore, this study was designed to investigate the protective potential of propolis extract against nicotine-induced pulmonary and hepatic damage in rats. Sprague Dawley rats were divided into six groups: control, propolis (200 and 300 mg/kg, p.o.), nicotine (10 mg/kg, i.p), and nicotine plus propolis-treated groups. Nicotine and propolis were given every day for 8 weeks. Then, blood and bronchoalveolar lavage fluid (BALF) were collected for assessing liver and lung functions. Liver and lung tissues were also harvested to assess oxidative stress and inflammatory biomarkers in addition to histopathological and immunohistochemical analysis. Both doses of propolis significantly decreased AST, ALT, ALP, and total and differential cell counts in a dose-dependent manner. Propolis extract significantly attenuated oxidative stress in both lung and liver tissues. The restoration of antioxidant status (GSH level, SOD activities) and reduction of nitric oxide and MDA content was more so in propolis 300-treated than propolis 200-treated group. This was parallel to the improvement seen in histopathological examination. Propolis 200 and 300 significantly decreased Nrf2 expression and increased HO-1 expression in a dose-dependent manner. Moreover, immunohistochemical examination revealed that propolis 200 and 300 decreased the expression of iNOS in lung and liver tissues while decreased TNF-α expression in lung tissues only. Propolis extract could have a protective potential against nicotine-induced pulmonary and hepatic damage via activating Nrf2/HO-1 signaling.

Flavonoids Present in Propolis in the Battle against Photoaging and Psoriasis

The skin is the main external organ. It protects against different types of potentially harmful agents, such as pathogens, or physical factors, such as radiation. Skin disorders are very diverse, and some of them lack adequate and accessible treatment. The photoaging of the skin is a problem of great relevance since it is related to the development of cancer, while psoriasis is a chronic inflammatory disease that causes scaly skin lesions and deterioration of the lifestyle of people affected. These diseases affect the patient's health and quality of life, so alternatives have been sought that improve the treatment for these diseases. This review focuses on describing the properties and benefits of flavonoids from propolis against these diseases. The information collected shows that the antioxidant and anti-inflammatory properties of flavonoids play a crucial role in the control and regulation of the cellular and biochemical alterations caused by these diseases; moreover, flavones, flavonols, flavanones, flavan-3-ols, and isoflavones contained in different worldwide propolis samples are the types of flavonoids usually evaluated in both diseases. Therefore, the research carried out in the area of dermatology with bioactive compounds of different origins is of great relevance to developing preventive and therapeutic approaches.

Effect of ultraviolet radiation on the Nrf2 signaling pathway in skin cells

PURPOSE

Excessive exposure of skin to solar radiation is associated with greatly increased production of reactive oxygen and nitrogen species (ROS, RNS) resulting in oxidative stress (OS), inflammation, immunosuppression, the production of matrix metalloproteinase, DNA damage and mutations. These events lead to increased incidence of various skin disorders including photoaing and both non-melanoma and melanoma skin cancers. The ultraviolet (UV) part of sunlight, in particular, is responsible for structural and cellular changes across the different layers of the skin. Among other effects, UV photons stimulate oxidative damage to biomolecules via the generation of unstable and highly reactive compounds. In response to oxidative damage, cytoprotective pathways are triggered. One of these is the pathway driven by the nuclear factor erythroid-2 related factor 2 (Nrf2). This transcription factor translocates to the nucleus and drives the expression of numerous genes, among them various detoxifying and antioxidant enzymes. Several studies concerning the effects of UV radiation on Nrf2 activation have been published, but different UV wavelengths, skin cells or tissues and incubation periods were used in the experiments that complicate the evaluation of UV radiation effects.

CONCLUSIONS

This review summarizes the effects of UVB (280-315 nm) and UVA (315-400 nm) radiation on the Nrf2 signaling pathway in dermal fibroblasts and epidermal keratinocytes and melanocytes. The effects of natural compounds (pure compounds or mixtures) on Nrf2 activation and level as well as on Nrf2-driven genes in UV irradiated human skin fibroblasts, keratinocytes and melanocytes are briefly mentioned as well.HighlightsUVB radiation is a rather poor activator of the Nrf2-driven pathway in fibroblastsUVA radiation stimulates Nrf2 activation in dermal fibroblastsEffects of UVA on the Nrf2 pathway in keratinocytes and melanocytes remain unclearLong-term Nrf2 activation in keratinocytes disturbs their normal differentiationPharmacological activation of Nrf2 in the skin needs to be performed carefully.

Agarwood Alcohol Extract Ameliorates Isoproterenol-Induced Myocardial Ischemia by Inhibiting Oxidation and Apoptosis

Agarwood is a traditional medicine used for treating some diseases, including painful and ischemic diseases. This study was carried out to investigate the potential cardioprotective effect of the whole-tree agarwood-inducing technique-produced agarwood alcohol extract (WTAAE) on isoproterenol- (ISO-) induced myocardial ischemia (MI) in rats and explore the underlying molecular mechanisms. Compared to the MI group, WTAAE pretreatment significantly improved ST wave abnormal-elevation, mitigated myocardial histological damage; decreased creatinine kinase (CK), lactate dehydrogenase (LDH), alanine transaminase (ALT), and aspartate transaminase (AST) levels; reduced hydrogen peroxide (H₂O₂) and lipid peroxide (LPO) production; and increased total antioxidant capacity (T-AOC) and catalase (CAT) activities. Moreover, agarwood alcohol extracts (AAEs) markedly enhanced the mRNA levels of Nrf2-ARE pathway, and Bcl-2 reduced the apoptotic Bax family mRNA expressions. In addition, the effect of WTAAE was greater than that of wild agarwood alcohol extract (WAAE) and burning-chisel-drilling agarwood alcohol extract (FBAAE). All of these data indicate that WTAAE exerted the protective effects of MI, and its mechanism was associated with upregulating Nrf2-ARE and suppressing Bcl-2 pathways.

Effect of UVA radiation on the Nrf2 signalling pathway in human skin cells

The harmful effects of low energy UVA photons (315-400 nm) are associated with the massive production of reactive oxygen species resulting in oxidative stress. In response to oxidative damage, NF-E2-related factor 2 (Nrf2) is translocated to the nucleus and drives the expression of detoxication and antioxidant enzymes. UVA's effect on Nrf2 has been quite well characterised in dermal fibroblasts. However, there is a dearth of such information for keratinocytes. This study aimed to evaluate and compare the effect of UVA radiation on the Nrf2 pathway and oxidative stress related proteins in primary human dermal fibroblasts (NHDF), epidermal keratinocytes (NHEK) and human keratinocyte cell line HaCaT. NHDF were exposed to doses of 2.5-7.5 J/cm², NHEK and HaCaT to 10-20 J/cm² using a solar simulator. Effects on Nrf2 translocation were evaluated after 1, 3 and 6 h and Nrf2-controlled proteins (heme oxygenase 1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1), glutathione reductase (GSR), glutathione-S-transferase (GST), interleukine-6 (IL-6), and matrix metalloproteinases (MMP-1, MMP-2)) after 3, 6 and 24 h. The results showed the fastest Nrf2 translocation was in UVA-irradiated HaCaT (1 h), persisting until the subsequent time interval (3 h), while in primary keratinocytes the effect of radiation was minimal. In NHDF, UVA-stimulated Nrf2 translocation was conspicuous 3 h after UVA treatment. In NHDF, most of the studied proteins (NQO1, HO-1, GSR, GSTM1 and MMP-1) showed the highest level 24 h after UVA exposure, except for MMP-2 and IL-6 which had their highest level at a shorter time incubation interval (3 h). In NHEK, NQO1, HO-1 and GST were increased 6 h after UVA exposure, GSR and MMP-2 level was slightly below or above the control level, and MMP-1 and IL-6 increased at shorter time intervals. When comparing NHEK and HaCaT, these cells displayed contrary responses in most of the Nrf2-controlled proteins. Thus, primary keratinocytes cannot be replaced with HaCaT when studying cell signalling such as the Nrf2 driven pathway and Nrf2-controlled proteins.

Brazilian Green Propolis as a Therapeutic Agent for the Post-surgical Treatment of Caseous Lymphadenitis in Sheep

As antibiotics are ineffective when used to treat caseous lymphadenitis, the surgical excision of lesions is often required. Iodine solution (10%) is currently the choice for the post-surgical treatment; however, it may cause histotoxicity. Propolis are resinous substances composed by a mixture of different plants parts and molecules secreted by bees. As green propolis has already proven to possess anti-bacterial and wound healing properties, this study aimed to evaluate the use of a green propolis-based ointment as a therapeutic agent for the post-surgical treatment of caseous lymphadenitis. The caseous lesions of 28 sheep were surgically excised before dividing animals into two groups: (1) iodine-treated animals and (2) sheep treated with an ointment made with a previously characterized green propolis extract. Clinical data of animals, size of the scar area, the presence of moisture and secretion in the surgical wound, the humoral immune response against the bacterium and the susceptibility of C. pseudotuberculosis clinical isolates to the green propolis extract were analyzed. The green propolis-treated group presented complete healing of the surgical wound 1 week before the iodine-treated group. Additionally, animals treated with the green propolis ointment had fewer cases of wound secretion, but it was not statistically different from the iodine-treated group. No clinical signs indicating green propolis toxicity or other side effects were found, associated with a faster and more organized hair recovery by propolis use. The green propolis extract was able to inhibit the growth of 23 from the 27 C. pseudotuberculosis clinical isolates, with minimum inhibitory and minimum bactericide concentrations ranging from 01 to 08 mg/mL, and did not interfere with the humoral immune response against the bacterium. In addition, green propolis was able to inhibit biofilm formation by four of the C. pseudotuberculosis clinical isolates. We concluded that green propolis is a promising therapeutic agent to be used in the post-surgical treatment of caseous lymphadenitis in small ruminants due to its effects on surgical wound healing, hair recovery, inhibition of wound contamination and bacterial growth.

Cellular and molecular effects of Baccharis dracunculifolia D.C. and Plectranthus barbatus Andrews medicinal plant extracts on retinoid metabolism in the human hepatic stellate cell LX-2

Background

Chronic hepatic diseases are serious problems worldwide, which may lead to the development of fibrosis and eventually cirrhosis. Despite the significant number of people affected by hepatic fibrosis, no effective treatment is available. In the liver, hepatic stellate cells are the major fibrogenic cell type that play a relevant function in chronic liver diseases. Thus, the characterization of components that control the fibrogenesis in the hepatic stellate cells is relevant in supporting the development of innovative therapies to treat and/or control liver fibrosis. The present study investigated the effects of Baccharis dracunculifolia D.C. and Plectranthus barbatus Andrews medicinal plant extracts in LX-2 transdifferentiation.

Methods

LX-2 is a human immortalized hepatic stellate cell that can transdifferentiate in vitro from a quiescent-like phenotype to a more proliferative and activated behavior, and it provides a useful platform to assess antifibrotic drugs. Then, the antifibrotic effects of hydroalcoholic extracts of Baccharis dracunculifolia and Plectranthus barbatus medicinal plants on LX-2 were evaluated.

Results

The results in our cellular analyses, under the investigated concentrations of the plant extracts, indicate no deleterious effects on LX-2 metabolism, such as toxicity, genotoxicity, or apoptosis. Moreover, the extracts induced changes in actin filament distribution of activated LX-2, despite not affecting the cellular markers of transdifferentiation. Consistent effects in cellular retinoid metabolism were observed, supporting the presumed activity of the plant extracts in hepatic lipids metabolism, which corroborated the traditional knowledge about their uses for liver dysfunction.

Conclusion

The combined results suggested a potential hepatoprotective effect of the investigated plant extracts reinforcing their safe use as coadjuvants in treating imbalanced liver lipid metabolism.

Agarwood Extract Mitigates Intestinal Injury in Fluorouracil-Induced Mice

Agarwood is used to treat gastrointestinal diseases. Although our previous studies demonstrated that agarwood ethanol extract produced by the whole-tree agarwood-inducing technique (WTAAE) improves intestinal peristalsis, the intestinal protective effect of WTAAE remains unclear. This study aimed to evaluate the protective effect of WTAAE on the intestinal injury induced by fluorouracil (5-FU) and explore its potential mechanism. Institute of Cancer Research (ICR) mice were given agarwood ethanol extracts (AAEs) (details in materials part), including WTAAE (0.71, 1.42 and 2.84 g/kg), wild agarwood ethanol extract (WAAE) and burning-chisel-drilling agarwood ethanol extract (FBAAE) (2.84 g/kg). A colon injury model was induced by 5-FU. After 14 d of treatment, the histopathology and biochemical and molecular parameters were measured. Our results indicated that WTAAE enhanced the intestinal advancing rate and alleviated the severity of colon injury similar the WAAE and better than FBAAE. Simultaneously, WTAAE reduced the nitric oxide (NO) concentration and increased the glutathione (GSH) and superoxide dismutase (SOD) levels. WTAAE also reduced the levels of interleukin-17 (IL-17) and IL-33 and elevated the level of IL-10. Furthermore, WTAAE upregulated the mRNA expression of the nuclear factor-E2-related factor 2-antioxidant response element (Nrf2-ARE) pathway and downregulated the mRNA levels of the nuclear factor-kappaB (NF-κB) pathway. WTAAE had a mitigating effect on intestinal damage, suggesting that it could be used as an intestinal protective and adjuvant therapy drug for intestinal injury induced by chemical drugs.

ATRA protects skin fibroblasts against UV‑induced oxidative damage through inhibition of E3 ligase Hrd1

All-trans retinoic acid (ATRA) can protect fibroblasts against ultraviolet (UV)-induced oxidative damage, however, its underlying molecular mechanism is still unclear. The present study aimed to investigate the role of 3-hydroxy-3-methylglutaryl reductase degradation (Hrd1) in the protective effect of ATRA on human skin fibroblasts exposed to UV. The expression of Hrd1 in human or mice skin was assessed by immunohistochemistry (IHC) staining and western blot analysis. Hrd1 siRNA (si-Hrd1) and Hrd1 recombinant adenoviruses (Ad-Hrd1) were used to downregulate and upregulate Hrd1 expression in fibroblasts, respectively. The interaction between Hrd1 and NF-E2-related factor 2 (Nrf2) was assessed by co-immunoprecipitation (co-IP) and immunofluorescence analysis. The results revealed that Hrd1 expression was increased but Nrf2 expression was decreased in UV-exposed human skin fibroblasts. In addition, ATRA could reverse the increase of Hrd1 expression induced by UV radiation in vivo and in vitro. ATRA or knockdown of Hrd1 could increase Nrf2 expression in fibroblasts exposed to UV radiation, and Hrd1 could directly interact with Nrf2 in skin fibroblasts. Notably, overexpression of Hrd1 abolished the protective effect of ATRA on the UV-induced decrease of Nrf2 expression, the production of reactive oxygen species (ROS) and the decrease of cell viability. In conclusion, the present data demonstrated that ATRA protected skin fibroblasts against UV-induced oxidative damage through inhibition of E3 ligase Hrd1.

Protective effect of 3,5‑dicaffeoyl‑epi‑quinic acid against UVB‑induced photoaging in human HaCaT keratinocytes

Derivatives of caffeoylquinic acid (CQA) have been studied and reported as potent bioactive molecules possessing various health benefits including antioxidant and anti‑inflammatory activities. In the present study, the protective effect of 3,5‑dicaffeoyl‑epi‑quinic acid (DCEQA) isolated from Atriplex gmelinii on UVB‑induced damages was investigated in human HaCaT keratinocytes. The effect of DCEQA against UVB‑induced oxidative stress‑mediated damages was determined measuring its ability to alleviate UVB‑induced elevation of oxidative stress, proinflammatory response and antioxidant enzyme suppression through nuclear factor‑like 2 (Nrf2). Treatment with DCEQA hindered the generation of intracellular reactive oxygen species. Increased levels of proinflammatory cytokines TNF‑α, COX‑2, IL‑6 and IL‑1β following UVB exposure were suppressed by the introduction of DCEQA. Additionally, DCEQA upregulated the mRNA and protein expression of antioxidant enzymes superoxide dismutase‑1 and heme oxygenase‑1 which were inhibited under UVB irradiation. Antioxidant enzyme regulation transcription factor Nrf2 was also upregulated in the presence of DCEQA. These results suggest that DCEQA prevents photoaging via protection of keratinocytes from UVB irradiation by ameliorating the oxidative stress and pro‑inflammatory response.

Mixing two different propolis samples potentiates their antimicrobial activity and wound healing property: A novel approach in wound healing and infection

Aim:

The study aimed to investigate whether mixing two different propolis samples can potentiate their biological activity. This hypothesis was tested by studying the effect of mixed propolis on microbial growth and wound healing and compared with the effect of each propolis individually.

Materials and Methods:

The effect of mixing two different propolis extracts (A and B) collected from different locations in Iraq on Escherichia coli, Staphylococcus aureus, and Candida albicans was studied by minimum inhibitory concentration assessment and compared with the effect of each propolis. Wound healing effect of the mixed propolis was studied. Twenty-four rabbits were used for the experiment, and they were assigned to four groups. Wounds were created on the dorsum of each rabbit and treated by topical application of 1 mL of either mixed propolis, propolis A, or propolis B extracts or were kept without treatment as a control. Macroscopic wound evaluation was performed with an assessment of wound size, wound recovery, redness, edema, discharge, granulation tissue, and epithelialization.

Results:

Propolis A was more potent than propolis B extracts to inhibit the growth of E. coli, S. aureus, and C. albicans (p<0.05). However, mixed propolis showed a higher antimicrobial activity toward all the pathogens than propolis A or propolis B extract individually (p<0.05). Furthermore, propolis A and propolis B extracts showed favorable effects on wound healing which was more pronounced with propolis A extract. Interestingly, mixed propolis accelerated wound healing faster than propolis A or propolis B extracts, and it shortened the time of reepithelialization (p<0.05).

Conclusion:

This study demonstrates for the first time that mixing different propolis samples possesses a higher antimicrobial activity and higher wound healing property than individual propolis. This approach could pave the way for the development of more effective antimicrobials and wound healing agents.

Antioxidant Potential of Propolis, Bee Pollen, and Royal Jelly: Possible Medical Application

Honeybees products comprise of numerous substances, including propolis, bee pollen, and royal jelly, which have long been known for their medicinal and health-promoting properties. Their wide biological effects have been known and used since antiquity. Bee products are considered to be a potential source of natural antioxidants such as flavonoids, phenolic acids, or terpenoids. Nowadays, the still growing concern in natural substances capable of counteracting the effects of oxidative stress underlying the pathogenesis of numerous diseases, such as neurodegenerative disorders, cancer, diabetes, and atherosclerosis, as well as negative effects of different harmful factors and drugs, is being observed. Having regarded the importance of acquiring drugs from natural sources, this review is aimed at updating the current state of knowledge of antioxidant capacity of selected bee products, namely, propolis, bee pollen, and royal jelly, and of their potential antioxidant-related therapeutic applications. Moreover, the particular attention has been attributed to the understanding of the mechanisms underlying antioxidant properties of bee products. The influence of bee species, plant origin, geographic location, and seasonality as well as type of extraction solutions on the composition of bee products extracts were also discussed.

Galangin suppresses H2 O2 -induced aging in human dermal fibroblasts

Human skin aging is a progressive process that includes intrinsic aging and extrinsic photodamage, both of which can cause an accumulation of reactive oxygen species (ROS), resulting in dermal fibrosis dysfunction and wrinkle formation. Galangin is a flavonoid that exhibits anti-inflammatory and antioxidative potential. Previous studies have reported that galangin has antioxidative activity against ROS-mediated stress. The aim of the present study is to determine the antiaging effects of galangin on dermal fibroblasts exposed to H₂ O₂ . In this study, we established a hydrogen peroxide-induced inflammation and aging model using human HS68 dermal fibroblasts. Stimulation of fibroblasts with H₂ O₂ is associated with skin aging and increased expression of inflammation-related proteins, along with downregulation of collagen I/III formation and expression of antioxidative proteins. Galangin effectively reduced NF-κB activation, the expression of inflammation-related proteins and cell aging. Galangin also reversed H₂ O₂ -activated cell senescence in HS68 cells. Our results reveal that galangin protects human dermal fibroblasts by inhibiting NF-κB activation, decreases the expression of inflammatory factors and upregulates IGF1R/Akt-related proteins, indicating that galangin may be a potential candidate for developing natural antiaging products that protect skin from damage caused by ROS.

Mechanisms underlying the wound healing potential of propolis based on its in vitro antioxidant activity

BACKGROUND

Propolis is a resinous substance collected by honeybees, Apis mellifera, from various plant sources. Having various pharmacological and biological activities, it has been used in folk medicine and complementary therapies since ancient times.

PURPOSE

To evaluate the effects and underlying mechanism of the protective effects of the ethanol extract of Chinese propolis (EECP) on L929 cells injured by hydrogen peroxide (H₂O₂).

STUDY DESIGN

The wound healing activities of EECP in L929 cells with H₂O₂-induced damage were investigated.

METHODS

The main components of EECP were analyzed by RP-HPLC, and the free radical scavenging capacity and reducing power were also measured. The effects of EECP on the expression of antioxidant-related genes in fibroblast L929 cells were determined using qRT-PCR and western blotting.

RESULTS

EECP had significant protective effects against cell death induced by H₂O₂ and significantly inhibited the decline of collagen mRNA expression caused by H₂O₂ in L929 cells.

CONCLUSION

EECP induced the expression of antioxidant-related genes, such as HO-1, GCLM, and GCLC, which has great implications for the potential of propolis to alleviate oxidative stress in wound tissues. The protective effects of propolis have great implications for using propolis as a wound healing regent.

Hepatoprotective Effect of Carboxymethyl Pachyman in Fluorouracil-Treated CT26-Bearing Mice

5-Fluorouracil (5-FU) is the chemotherapeutic agent of first choice for the treatment ofcolorectal cancer, however, treatment-related liver toxicity remains a major concern. Thereby, it is desirable to search for novel therapeutic approaches that can effectively enhance curative effects and reduce the toxic side effects of 5-FU. Carboxymethyl Pachyman (CMP) exhibits strong antitumor properties, but the antitumor and hepatoprotective effects of CMP and the molecular mechanisms behind these activities, are however poorly explored. Thereby, the purpose of the present study was to evaluate the hepatoprotective effect of CMP in 5-FU-treated CT26-bearing mice, and further explore the underlying mechanism(s) of action. Initially, a CT26 colon carcinoma xenograft mice model was established. The immune organ indexes, blood indicators, liver tissue injury, and indicators associated with inflammation, antioxidant and apoptosis were then measured. Our results showed that CMP administration increased the tumor inhibitory rates of 5-FU and, meanwhile, it reversed reduction of peripheral white blood cells (WBC) and bone marrow nucleated cells (BMNC), increase of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and decrease of superoxide dismutase (SOD), catalase (CAT), GSH-Px and glutathione(GSH) induced by 5-FU. Moreover, CMP in combination with 5-FU alleviated severe liver injury induced by 5-FU via reducing the levels of ROS, IL-1β, and IL-6, decreasing expression of p-IκB-α, NF-κB, p-NF-κB, pp38 and Bax, and elevating levels of Nrf2, GCL, HO-1 and Bcl-2. Collectively, these outcomes suggested that CMP effectively enhanced the curative effects of 5-FU and simultaneously reduced the liver injuries induced by 5-FU in CT26-bearing mice, and the mechanism may be associated with regulation of NF-κB, Nrf2-ARE and MAPK/P38/JNK pathways.

23-Hydroxytormentic acid protects human dermal fibroblasts by attenuating UVA-induced oxidative stress

BACKGROUND

Ultraviolet A (UVA), one of the major components of sunlight, can penetrate the dermal layer of the skin and generate reactive oxygen species (ROS). It causes alterations in the dermal connective tissue and gene expression, inflammation, photoaging, and DNA damage.

AIMS

Therefore, the harmful effects of UVA and strategies to reduce it have been consistently investigated. 23-Hydroxytormentic acid (23-HTA) has been demonstrated to improve drug-induced nephrotoxicity and exhibit several free radical scavenging effects with other molecules. Therefore, the aim of this study was to investigate the anti-inflammatory effects and extracellular matrix (ECM) reconstructive activity of 23-HTA in UVA-irradiated normal human dermal fibroblasts (NHDFs).

MATERIALS AND METHODS

The antioxidant capacity of 23-HTA was determined by examining its scavenging activities against hydrogen peroxide, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), and diphenylpicrylhydrazyl in vitro. Its effect on cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tertazolium bromide, and 2,7-dichlorofluorescin diacetate was used to investigate intracellular ROS scavenging activity. The mRNA levels of antioxidant enzymes and pro-inflammatory cytokines were detected using quantitative real-time polymerase chain reaction. A senescence-associated β-galactosidase (SA-β-gal) staining kit was used to assess senescent cells.

RESULTS

23-HTA showed antioxidant capacity mediated by ROS scavenging and regulation of antioxidant-related gene expression. Further, the SA-β-gal analysis and mRNA expression of matrix metalloproteinases and type I procollagen suggested that 23-HTA regulates the gene expression of ECM proteins and cellular senescence under UVA-irradiated conditions.

CONCLUSION

In conclusion, 23-HTA protects against and attenuates UVA-induced oxidative stress in NHDFs likely via the nuclear factor erythroid-derived 2-like 2 signaling pathway.

Pretreatment of Ferulic Acid Protects Human Dermal Fibroblasts against Ultraviolet A Irradiation

Background

Approximately 90%~99% of ultraviolet A (UVA) ray reaches the Earth's surface. The deeply penetrating UVA rays induce the formation of reactive oxygen species (ROS), which results in oxidative stress such as photoproducts, senescence, and cell death. Thus, UVA is considered a primary factor that promotes skin aging.

Objective

Researchers investigated whether pretreatment with ferulic acid protects human dermal fibroblasts (HDFs) against UVA-induced cell damages.

Methods

HDF proliferation was analyzed using the water-soluble tetrazolium salt assay. Cell cycle distribution and intracellular ROS levels were assessed by flow cytometric analysis. Senescence was evaluated using a senescence-associated β-galactosidase assay, while Gadd45α promoter activity was analyzed through a luciferase assay. The expression levels of superoxide dismutase 1 (SOD1), catalase (CAT), xeroderma pigmentosum complementation group A and C, matrix metalloproteinase 1 and 3, as well as p21 and p16 were measured using quantitative real-time polymerase chain reaction.

Results

Inhibition of proliferation and cell cycle arrest were detected in cells that were irradiated with UVA only. Pretreatment with ferulic acid significantly increased the proliferation and cell cycle progression in HDFs. Moreover, ferulic acid pretreatment produced antioxidant effects such as reduced DCF intensity, and affected SOD1 and CAT mRNA expression. These effects were also demonstrated in the analysis of cell senescence, promoter activity, expression of senescent markers, and DNA repair.

Conclusion

These results demonstrate that ferulic acid exerts protective effects on UVA-induced cell damages via anti-oxidant and stress-inducible cellular mechanisms in HDFs.

Overexpression of miR-200a protects cardiomyocytes against hypoxia-induced apoptosis by modulating the kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor 2 signaling axis

The kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) signaling axis plays an important role in regulating oxidative stress in ischemic cardiomyocytes. Targeting Keap1 in order to promote Nrf2 activation is considered a potential method for protecting cardiomyocytes against ischemic injury. In recent years, microRNAs (miRNAs or miRs) have emerged as powerful tools for controlling gene expression. The present study aimed to determine whether Keap1-Nrf2 was regulated by specific miRNAs in cardiomyocytes under hypoxic conditions. We demonstrated that miR-200a was significantly downregulated in ischemic myocardial tissues and hypoxic cardiomyocytes. The overexpression of miR-200a was found to protect cardiomyocytes from hypoxia-induced cell damage and the excessive production of reactive oxygen species. Through bioinformatics analysis and a dual-luciferase report assay, miR-200a was found to interact with the 3'-untranslated region of Keap1, the native regulator of Nrf2. Reverse transcription-quantitative polymerase chain reaction and western blot analysis revealed that miR-200a negatively regulated the expression of Keap1. The overexpression of miR-200a significantly increased the nuclear translocation of Nrf2 as well as downstream antioxidant enzyme gene expression. The inhibition of miR-200a displayed the opposite effects. Restoring the expression of Keap1 significantly abrogated the protective effect of miR‑200a. Taken together, these findings indicate that the suppression of Keap1 by miR-200a exerted a cardioprotective effect against hypoxia-induced oxidative stress and cell apoptosis, and suggest that the activation of Nrf2 signaling by miR‑200a represents a novel and promising therapeutic strategy for the treatment of ischemic heart disease.