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Triple negative breast cancer (TNBC) is one of the leading causes of cancer death in the world and lacks an effective targeted therapy. G-protein-coupled receptor 161 (GPR161) has been demonstrated to perform the functional regulations on TNBC progression and might be a potential new target for TNBC therapy. This study showed the effects of bisdemethoxycurcumin (BDMC) on GPR161 regulation, indicating that BDMC effectively inhibited GPR161 expression and downregulated GPR161-driven signaling. BDMC showed the potent inhibitory effects on TNBC proliferation through suppressing GPR161-mediated mammalian target of rapamycin (mTOR)/70 kDa ribosomal protein S6 kinase (p70S6K) activation. Besides, in this study, we discover the mechanism of GPR161-driven TNBC metastasis, linking to GPR161-mediated twist-related protein 1 (Twist1)/matrix metallopeptidase 9 (MMP9) contributing to the epithelial-mesenchymal transition (EMT). BDMC effectively repressed GPR161-mediated TNBC metastasis via inhibiting Twist1/MMP9-induced EMT. The three-dimensional invasion assay also showed that BDMC significantly inhibited TNBC invasion. The combination treatment of BDMC and rapamycin enhanced the inhibition of TNBC proliferation and metastasis through increasing the blockage of mTOR activation. Furthermore, this study also observed that BDMC activated the caspase 3/9 signaling pathway to induce TNBC apoptosis. Therefore, BDMC could be applicable to anticancer therapy, especially targeting on the GPR161-driven cancer type.

A traditional Chinese medicinal fungus, Antrodia salmonea (AS), with antioxidant properties is familiar in Taiwan but anti-cancer activity of AS in human colon cancer is ambiguous. Hence, we explored the anti-cancer activity of AS in colon cancer cells. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that AS showed a remarkable effect on cell viability in colon cancer cells; SW620, HCT116, and HT29. Annexin V/propidium iodide (PI) stained cells indicated that AS induced both early/late apoptosis in SW620 cells. Additionally, cells treated with AS induced caspase-3 activation, poly (ADP-ribose) polymerase (PARP) cleavage, mitochondrial dysfunction, and Bcl-2 associated X (Bax)/B-cell lymphoma (Bcl-2) dysregulation. Microtubule- associated protein 1A/1B-light chain 3B (LC3-II) accumulation, sequestosome 1 (p62/SQSTM1) activation, autophagy related 4B cysteine peptidase (ATG4B) inactivation, acidic vesicular organelles (AVOs) formation, and Beclin-1/Bcl-2 dysregulation revealed that AS-induced autophagy. Interestingly, cells pretreated with 3-methyladenine (3-MA) strengthened AS-induced caspase-3/apoptosis. Suppression of apoptosis by z-Val-Ala-Asp fluoromethyl ketone (Z-VAD-FMK) did not however block AS-induced autophagy, suggesting that autophagy was not attenuated by the AS-induced apoptosis. Application of N-acetylcysteine (NAC) prevented AS-induced cell death, caspase-3 activation, LC3-II accumulation, and AVOs formation, indicating that AS-induced apoptosis and autophagy was mediated by reactive oxygen species (ROS). Furthermore, AS-induced cytoprotective autophagy and apoptosis through extracellular signal-regulated kinase (ERK) signaling cascades. Moreover, in vivo data disclosed that AS inhibited colitis-associated tumorigenesis in azoxymethane (AOM)-dextran sodium sulphate (DSS)-treated mice. For the first time, we report the anti-cancer properties of this potentially advantageous mushroom for the treatment of human colon cancer.

Ultraviolet C (UVC) has been applied to treatment of infections in wounds for at least the last two decades, however, cells being treated can be damaged if exposure is prolonged, which calls for protective measures, such as drug or herbal pre-treatment, to minimize damage. Ocimum gratissimum contains plant polyphenols such as isoflavones and caffeic acid, which have antioxidant effects. We hypothesize that Ocimum gratissimum aqueous extracts (OGE) can inhibit UVC-induced oxidative damage on skin cells. In this study, HaCaT skin cells are used to test the protective effects of OGE on cell proliferation and migration after exposure to UVC radiation. Pretreatment with OGE (50~150μg/mL) before 40 J/m2 UVC exposure was able to restore survival from 32.25% to between 46.77% and 68.00%, and 80 J/m2 UVC exposure from 11.49% to between 19.07% and 43.04%. Morphological observation of primarily apoptotic cell death confirms the above findings. The flow cytometry analysis revealed that UVC increased the number of cells at the sub-G1 phase in a dose dependent manner, and when pre-treated with OGE the changes were partially reversed. Moreover, the wound healing test for observing migration showed that UVC 40-80 J/m2 decreased cell migration to 47-28% activity and 100 μg/mL OGE was able to restore cell activity to81-69% at day 3. Based on the above results, we suggest that OGE has a protective effect on UVC-induced inhibition of cell proliferation and migration of skin cells and thus has potential application in wound care.

Oxidative stress is an important contributing factor for inflammation. Piper methysticum, also known as Kava-kava, is a shrub whose root extract has been consumed as a drink by the pacific islanders for a long time. Flavokawain A (FKA) is a novel chalcone derived from the kava plant that is known to have medicinal properties. This study was aimed at demonstrating the antioxidant molecular mechanisms mediated by FKA on lipopolysaccharide- (LPS-) induced inflammation in BALB/c mouse-derived primary splenocytes. In vitro data show that the nontoxic concentrations of FKA (2-30 μM) significantly suppressed the proinflammatory cytokine (TNF-α, IL-1β, and IL-6) release but induced the secretion of interleukin-10 (IL-10), an anti-inflammatory cytokine. It was also shown that FKA pretreatment significantly downregulated the LPS-induced ROS production and blocked the activation of the NFκB (p65) pathway leading to the significant suppression of iNOS, COX-2, TNF-α, and IL-1β protein expressions. Notably, FKA favored the nuclear translocation of Nrf2 leading to the downstream expression of antioxidant proteins HO-1, NQO-1, and γ-GCLC via the Nrf2/ARE signaling pathway signifying the FKA’s potent antioxidant mechanism in these cells. Supporting the in vitro data, the ex vivo data obtained from primary splenocytes derived from the FKA-preadministered BALB/c mice (orally) show that FKA significantly suppressed the proinflammatory cytokine (TNF-α, IL-1β, and IL-6) secretion in control-, LPS-, or Concanavalin A- (Con A-) stimulated cells. A significant decrease in the ratios of pro- and anti-inflammatory cytokines (IL-6/IL-10; TNF-α/IL-10) showed that FKA possesses strong anti-inflammatory properties. Furthermore, BALB/c mice induced with experimental pancreatitis using cholecystokinin- (CCK-) 8 showed decreased serum lipase levels due to FKA pretreatment. We conclude that with its potent antioxidant and anti-inflammatory properties, chalcone flavokawain A could be a novel therapeutic agent in the treatment of inflammation-associated diseases.

UVA irradiation induced ROS-mediated photo damage to the human skin leading to coarseness, wrinkling, pigmentation, and cutaneous malignancies. We investigated the dermatoprotective efficacies of submicromolar concentrations of ergothioneine (EGT, 0.125-0.5 μM), which occurs naturally as a sulfur-containing amino acid, in the mechanisms in human skin fibroblast (HSF) cells. UVA-induced AP-1 (c-Fos and c-Jun) translocation was found to be inhibited by EGT treatments with the parallel inhibition of the collagenolytic matrix metalloproteinase- (MMP-) 1 activation and type I procollagen degradation. Moreover, EGT mitigated UVA-induced ROS generation. An increase in the amount of antioxidant genes (HO-1, NQO-1, and γ-GCLC) from EGT and were associated with upregulated Nrf2 expressions in a dose-dependent or time-dependent manner. We confirmed this from Nrf2 translocation and increased nuclear ARE promoter activity that underlie EGT dermatoprotective activities. Also, glutathione (GSH) levels (from γ-GCLC) were significantly increased. Moreover, we showed that mediated by ERK, JNK, and PKC, signaling cascades mediate Nrf2 translocation. We confirmed this phenomenon by the suppressed nuclear Nrf2 activation in cells that were treated with respective inhibitors (PD98059, SP600125, and GF109203X). However, antioxidant protein expressions were impaired in Nrf2 knockdown cells to confirm that ARE/Nrf2 pathways and the inhibition of AP-1 had significant roles in EGT-mediated protective effects. We can conclude that ergothioneine ameliorated UVA-induced skin aging and is a useful food supplement for skin care products.

Treatment of advanced hepatocellular carcinoma (HCC) has exhibited a poor overall survival rate of only six to ten months, and the urgency of the development of more effective novel agents is ever present. In this line of research, we aimed to investigate the effects and inhibitive mechanisms of aqueous Ocimum gratissimum leaf extract (OGE), the extract of Ocimum gratissimum, which is commonly used as a therapeutic herb for its numerous pharmacological properties, on malignant HCC cells. Our results showed that OGE decreased the cell viability of HCC SK-Hep1 and HA22T cells in a dose-dependent manner (from 400 to 800 µg/mL), while there is little effect on Chang liver cells. Moreover, cell-cycle analysis shows increased Sub-G1 cell count in SK-Hep1 and HA22T cells which is not observed in Chang liver cells. These findings raise suspicion that the OGE-induced cell death may be mediated through proteins that regulate cell cycle and apoptosis in SK-Hep1 and HA22T cells, and further experimentation revealed that OGE treatment resulted in a dose-dependent decrease in caspase 3 and PARP expressions and in CDK4and p-ERK1/2expressions. Moreover, animal tests also exhibited decreased HCC tumor growth by OGE treatment. We therefore suggest that the inhibition of cell viability and tumor growth induced by OGE may be correlated to the alteration of apoptosis-related proteins.

Coenzyme Q (CoQ) analogs with a variable number of isoprenoid units have exhibited as anti-inflammatory as well as antioxidant molecules. Using novel quinone derivative CoQ0 (2,3-dimethoxy-5-methyl-1,4-benzoquinone, zero side chain isoprenoid), we studied its molecular activities against LPS/ATP-induced inflammation and redox imbalance in murine RAW264.7 macrophages. CoQ0’s non- or subcytotoxic concentration suppressed the NLRP3 inflammasome and procaspase-1 activation, followed by downregulation of IL1β expression in LPS/ATP-stimulated RAW264.7 macrophages. Similarly, treatment of CoQ0 led to LC3-I/II accumulation and p62/SQSTM1 activation. An increase in the Beclin-1/Bcl-2 ratio and a decrease in the expression of phosphorylated PI3K/AKT, p70 S6 kinase, and mTOR showed that autophagy was activated. Besides, CoQ0 increased Parkin protein to recruit damaged mitochondria and induced mitophagy in LPS/ATP-stimulated RAW264.7 macrophages. CoQ0 inhibited LPS/ATP-stimulated ROS generation in RAW264.7 macrophages. Notably, when LPS/ATP-stimulated RAW264.7 macrophages were treated with CoQ0, Mito-TEMPO (a mitochondrial ROS inhibitor), or N-acetylcysteine (NAC, a ROS inhibitor), there was a significant reduction of LPS/ATP-stimulated NLRP3 inflammasome activation and IL1β expression. Interestingly, treatment with CoQ0 or Mito-TEMPO, but not NAC, significantly increased LPS/ATP-induced LC3-II accumulation indicating that mitophagy plays a key role in the regulation of CoQ0-inhibited NLRP3 inflammasome activation. Nrf2 knockdown significantly decreased IL1β expression in LPS/ATP-stimulated RAW264.7 macrophages suggesting that CoQ0 inhibited ROS-mediated NLRP3 inflammasome activation and IL1β expression was suppressed due to the Nrf2 activation. Hence, this study showed that CoQ0 might be a promising candidate for the therapeutics of inflammatory disorders due to its effective anti-inflammatory as well as antioxidant properties.

Head and neck squamous cell carcinoma (HNSCC) is a relatively common malignancy, characterized by lethal morbidity. Herein, we attempted to investigate the autophagy/apoptosis activities of the submerged fermented broths of Antrodia salmonea (AS) in HNSCC Twist-overexpressing (OECM-1 and FaDu-Twist) cells. AS (0-150 μg/mL) effectively reduced cell viability, colony formation, and downregulated Twist expression in OECM-1 and FaDu-Twist cells compared to FaDu cells. AS- induced apoptosis was mainly associated with activation of caspase-3, PARP cleavage, increased expression of VDAC-1 and disproportionation of Bax/Bcl-2. Annexin V/PI staining suggested late apoptosis induction by AS treatment. AS exhibits enhanced autophagy process mediated via LC3-I/II accumulation, increased acidic vesicular organelles (AVOs) formation and p62/SQSTM1 expression feeding into the apoptotic program. However, pre-treatment with autophagy blockers 3-MA and CQ significantly diminished AS-induced cell death. Additionally, suppression of AS-induced ROS release by treatment with antioxidant N-acetylcysteine (NAC) resulted in reduction of apoptotic and autophagic cell death. In vivo studies strengthened the above observations and showed that AS effectively reduced the tumor volume and tumor weight in OECM-1-xenografted nude mice. This study discovered that Antrodia salmonea exhibits a novel anti-cancer mechanism which could be harnessed as a new potent drug for HNSCC treatment.

Pterostilbene (Pt) is a natural polyphenol found in blueberries and several grape varieties. Pt's pharmacological importance was well documented. Nevertheless, the depigmenting effects are not demonstrated. We evaluated the Pt's depigmenting effects through autophagy induction in B16F10 cells and inhibition of UVA (3 J/cm2)-irradiated α-MSH in keratinocyte HaCaT cells via Nrf2-mediated antioxidant pathways. Pt (2.5–5μM) attenuated ROS production and downregulated the POMC/α-MSH pathway in HaCaT cells. The conditioned medium-derived from UVA-irradiated HaCaT pretreated with Pt suppressed melanogenesis in B16F10 through MITF-CREB-tyrosinase pathway downregulation. Interestingly, Pt-induced HaCaT autophagy was revealed by enhanced LC3-II accumulation, p62/SQSTM1 activation, and AVO formation. Pt significantly decreased melanosome gp100 but increased LC3-II levels in HaCaT cells exposed to B16F10-derived melanin. Pt activated and facilitated the Nrf2 antioxidant pathway in HaCaT cells leading to increased HO-1, γ-GCLC, and NQO-1 antioxidant protein expression. ERK, AMPK, and ROS pathways mediate the Nrf2 activation. However, Nrf2 knockdown suppressed Pt's antioxidant ability leading to uncontrolled ROS and α-MSH levels after UVA-irradiation suggested the essentiality of the Nrf2 pathway. Moreover, in α-MSH-stimulated B16F10 cells, Pt (10–30 μM) downregulated the MC1R, MITF, tyrosinase, TRP-1/-2, and melanin expression. Further, Pt showed potent anti-melanogenic effects through autophagy induction mechanism in B16F10 cells, verified by increased LC3-II/p62 levels, AVO formation, and Beclin-1/Bcl-2 ratio, decreased ATG4B levels and PI3K/AKT/mTOR pathway. Transmission electron microscopy provided direct evidence by showing autophagosomes engulfing melanosomes following Pt treatment in α-MSH-stimulated B16F10 cells. Moreover, Pt-induced anti-melanogenic activity through the downregulation of CREB-MITF pathway-mediated TRP-1/-2, tyrosinase expressions, melanosome formation, and melanin synthesis was substantially reversed due to 3-MA (autophagy inhibitor) pretreatment or LC3 silencing in B16F10 cells. In vivo results also confirmed that Pt-inhibited tyrosinase expression/activity and endogenous pigmentation in the zebrafish model. Therefore, pterostilbene is a potent skin-whitening and antioxidant agent and could be used in skin-whitening formulations as a topical applicant., Graphical abstract Image 1, Highlights • Pt inhibits ROS-mediated POMC/α-MSH pathway in UVA-irradiated HaCaT cells. • Pt activates Nrf2-mediated HO-1, γ-GCLC, and NQO-1 expression in HaCaT cells. • Pt-induces autophagy in B16F10 cells leading to melanogenesis inhibition. • Pt-mediates anti-melanogenic mechanisms in α-MSH-stimulated B16F10 cells. • Pt-inhibits tyrosinase expression and endogenous pigmentation in zebrafish model.

Ultraviolet A (UVA) irradiation (320-400 nm range) triggers deleterious consequences in skin cell microenvironment leading to skin damage, photoaging (premature skin aging), and cancer. The accumulation of intracellular reactive oxygen species (ROS) plays a key role in this effect. With rapid progress in cosmetic health and quality of life, use of safe and highly effective phytochemicals has become a need of the hour. Zerumbone (ZER), a natural sesquiterpene, from Zingiber zerumbet rhizomes is well-known for its beneficial effects. We investigated the antiphotoaging and dermatoprotective efficacies of ZER (2-8 μM) against UVA irradiation (3 J/cm2) and elucidated the underlying molecular mechanisms in human skin fibroblast (HSF) cells. ZER treatment prior to low dose of UVA exposure increased cell viability. UVA-induced ROS generation was remarkably suppressed by ZER with parallel inhibition of MMP-1 activation and collagen III degradation. This was due to the inhibition of AP-1 (c-Fos and c-Jun) translocation. Furthermore, ZER alleviated UVA-induced SA-β-galactosidase activity. Dose- or time-dependent increase of antioxidant genes, HO-1 and γ-GCLC by ZER, was associated with increased expression and nuclear accumulation of Nrf2 as well as decreased cytosolic Keap-1 expressions. Altered luciferase activity of ARE could explain the significance of Nrf2/ARE pathway underlying the dermatoprotective properties of ZER. Pharmacological inhibition of various signaling pathways suppressed nuclear Nrf2 activation in HSF cells confirming that Nrf2 translocation was mediated by ERK, JNK, PI3K/AKT, PKC, AMPK, casein kinase II, and ROS signaling pathways. Moreover, increased basal ROS levels and Nrf2 translocation seem crucial in ZER-mediated Nrf2/ARE signaling pathway. This was also evidenced from Nrf2 knocked-out studies in which ZER was not able to suppress the UVA-induced ROS generation in the absence of Nrf2. This study concluded that in the treatment of UVA-induced premature skin aging, ZER may consider as a desirable food supplement for skin protection and/or preparation of skin care products.

Background Breast cancer is the most prevalent cancer among women. In triple-negative breast cancer (TNBC) cells, a novel quinone derivative, coenzyme Q0 (CoQ0), promotes apoptosis and cell-cycle arrest. This study explored the anti-epithelial–mesenchymal transition (EMT) and antimetastatic attributes of CoQ0 in TNBC (MDA-MB-231). Methods Invasion, as well as MTT assays were conducted. Lipofectamine RNAiMAX was used to transfect cells with β-catenin siRNA. Through Western blotting and RT-PCR, the major signaling pathways’ protein expressions were examined, and the biopsied tumor tissues underwent immunohistochemical and hematoxylin and eosin staining as well as Western blotting. Results CoQ0 (0.5–2 μM) hindered tumor migration, invasion, and progression. Additionally, it caused MMP-2/− 9, uPA, uPAR, and VEGF downregulation. Furthermore, in highly metastatic MDA-MB-231 cells, TIMP-1/2 expression was subsequently upregulated and MMP-9 expression was downregulated. In addition, CoQ0 inhibited metastasis and EMT in TGF-β/TNF-α-stimulated non-tumorigenic MCF-10A cells. Bioluminescence imaging of MDA-MB-231 luciferase–injected live mice demonstrated that CoQ0 significantly inhibited metastasis of the breast cancer to the lungs and inhibited the development of tumors in MDA-MB-231 xenografted nude mice. Silencing of β-catenin with siRNA stimulated CoQ0-inhibited EMT. Western blotting as well as histological analysis established that CoQ0 reduced xenografted tumor development because apoptosis induction, cell-cycle inhibition, E-cadherin upregulation, β-catenin downregulation, and metastasis and EMT regulatory protein modulation were observed. Conclusions CoQ0 inhibited the progression of metastasis as well as EMT (in vitro and in vivo). The described approach has potential in treating human breast cancer metastasis. Electronic supplementary material The online version of this article (10.1186/s13046-019-1196-x) contains supplementary material, which is available to authorized users.

Chalcones found in fruits and vegetables have promising cancer chemopreventive properties. This study attempts to identify the anticancer efficacies of chalcone flavokawain B (FKB) in the rhizomes of Alpinia pricei Hayata by examining key molecular events in non-small-cell lung cancer (A549) cells. Our results indicated that in human A549 cells, FKB (0-15 μg/ml) decreases cell viability and colony formation, dysregulates the Bax:B-cell lymphoma 2 ratio and increases apoptotic DNA fragmentation. Mitochondrial (caspase-9/-3 and poly ADP ribose polymerase [PARP]) signaling was found to be involved in FKB-induced apoptosis. In addition, FKB-induced reactive oxygen species (ROS) generation, and N-acetylcysteine attenuated FKB-induced apoptotic cell death. Moreover, FKB triggered autophagy, as evidenced by the improved acidic vesicular organelle formation, lipidated light chain 3 (microtubule-related light chain 3) accumulation, and ATG7 expression and the decreased mammalian target of rapamycin phosphorylation. Furthermore, FKB suppressed ROS-mediated ATG4B expression. Inhibiting autophagy using 3-methyladenine/chloroquine diminished FKB-induced cell death, indicating that autophagy is triggered as a death mechanism by FKB. In summary, FKB has a crucial role in the execution and propagation of ROS-mediated apoptotic and autophagic cell death of lung adenocarcinoma cells.

TGF-β1 plays a crucial role in the pathogenesis of vascular fibrotic diseases. Chalcones are reportedly cancer chemo-preventive food components that are rich in fruits and vegetables. In this study, flavokawain A (FKA, 2-30 μM), a naturally occurring chalcone in kava extracts, was evaluated for its anti-fibrotic and antioxidant properties in TGF-β1-stimulated vascular smooth muscle (A7r5) cells, as well as its underlying molecular mechanism of action. Immunofluorescence data showed down-regulated F-actin expression with FKA treatment in TGF-β1-stimulated A7r5 cells. Western blotting demonstrated that FKA treatment suppressed the expression of α-SMA and fibronectin proteins under TGF-β1 stimulation. Findings from wound-healing and invasion experiments showed that FKA inhibits TGF-β1-mediated migration and invasion. Western blotting demonstrated that treatment with FKA down-regulated MMP-9 and MMP-2 and up-regulated TIMP-1 expression. Further evidence showed that FKA decreased TGF-β1-mediated phosphorylation and the transcriptional activity of Smad3. TGF-β1-induced excessive ROS production was remarkably reversed by FKA treatment in A7r5 cells, and inhibition by FKA or N-acetylcysteine (NAC) substantially diminished TGF-β1-induced p-Smad3 activation and wound-healing migration. Interestingly, FKA-mediated antioxidant properties were associated with increased nuclear translocation of Nrf2 and elevated antioxidant response element (ARE) luciferase activity. Activation of Nrf2/ARE signaling was accompanied by the induction of HO-1, NQO-1 and γ-GCLC genes in FKA-treated A7r5 cells. Notably, silencing of Nrf2 (siRNA transfection) significantly diminished the FKA-mediated antioxidant effects, indicating that FKA may inhibit TGF-β1-induced fibrosis through suppressing ROS generation in A7r5 cells. Our results suggested that anti-fibrotic and antioxidant activities of the chalcone flavokawain A may contribute to the development of food-based chemo-preventive drugs for fibrotic diseases.

Coenzyme Q

3-O-ethyl ascorbic acid (EAA) is an ether-derivative of ascorbic acid, known to inhibit tyrosinase activity, and is widely used in skincare formulations. Nevertheless, the molecular mechanisms underlying the EAA's effects are poorly understood. Here, the anti-melanogenic activity of EAA was demonstrated through Nrf2-mediated α-MSH inhibition in UVA-irradiated keratinocytes (HaCaT) and autophagy induction and inhibition of α-MSH-stimulated melanogenesis in melanocytes (B16F10). EAA pretreatment increased the HaCaT cell viability but suppressed ROS-mediated p53/POMC/α-MSH pathways in UVA-irradiated cells. Further, the conditioned medium from EAA-pretreated and UVA-irradiated HaCaT cells suppressed the MITF-CREB-tyrosinase pathways leading to the inhibition of melanin synthesis in B16F10 cells. EAA treatment increased nuclear Nrf2 translocation via the p38, PKC, and ROS pathways leading to HO-1, γ-GCLC, and NQO-1 antioxidant expression in HaCaT cells. However, Nrf2 silencing reduced the EAA-mediated anti-melanogenic activity, evidenced by impaired antioxidant gene expression and uncontrolled ROS (H202) generation following UVA irradiation. In B16F10 cells, EAA-induced autophagy was shown by enhanced LC3-II levels, AVO formation, Beclin-1 upregulation, and activation of p62/SQSTM1. Further, EAA-induced anti-melanogenic activity was substantially decreased in autophagy inhibitor (3-MA) pretreated or LC3 knockdown B16F10 cells. Notably, transmission electron microscopy data showed increased melanosome-engulfing autophagosomes in EAA-treated B16F10 cells. Moreover, EAA also down-regulated MC1R, TRP-1/-2, tyrosinase expressions, and melanin synthesis by suppressing the cAMP-CREB-mediated MITF expression in B16F10 cells stimulated with α-MSH. In vivo studies on the zebrafish model further confirmed that EAA inhibited tyrosinase expression/activity and endogenous pigmentation. In conclusion, 3-O-ethyl ascorbic acid is an effective skin-whitening agent and could be used as a topical agent for cosmetic purposes.

Melanoma is the most prevalent type of skin cancer with high mortality rates. This study demonstrates the

Simple Summary Melanoma is the most dangerous type of skin cancer that develops from the pigment-producing cells known as melanocytes. One of the primary causes of melanoma is ultraviolet light (UV) exposure in those with low levels of the skin pigment melanin. Flavokawain B (FKB) is a naturally occurring chalcone, which is known to possess anti-proliferative pharmacological activity on various cancer cells. However, the effect of FKB on the anti-melanoma pharmacological role has not been investigated. Therefore, in this study, we explored the anti-melanoma properties of FKB on human melanoma cells and the cell death mechanisms that were mediated through the induction of reactive oxygen species (ROS) were investigated via in vitro and in vivo approaches. Our study results support promising application prospects of FKB in the treatment of human melanoma cancer. Abstract Melanoma is the most prevalent type of skin cancer with high mortality rates. This study demonstrates the in vitro and in vivo anticancer properties of chalcone flavokawain B (FKB) induced ROS-mediated apoptosis and autophagy in human melanoma (human epithelial melanoma cell line A375 and/or human skin lymph node derived melanoma cell line A2058) cells. Cell viability was calculated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the expression patterns of various apoptosis, autophagy-associated proteins were determined by Western blot methods. Annexin V was detected by flow cytometry, whereas acidic vesicular organelles (AVOs) and intracellular ROS levels were measured by fluorescence microscopy. The in vivo anticancer properties of FKB were evaluated by xenografting the A375 cells into nude mice. The results convey that FKB inhibited cell viability, B-Raf proto-oncogene, serine/threonine kinase (BRAF)/extracellular signal-regulated kinase (ERK) expression in human melanoma cells. Caspase-3 activation, poly (ADP-ribose) polymerase (PARP) cleavage pathway, and Bcl2 associated X (Bax)/B-cell lymphoma 2 (Bcl-2) dysregulation were involved in the execution of apoptosis. Moreover, FKB-induced autophagy was observed through increased microtubule-associated protein 1A/1B-light chain 3B (LC3-II) accumulation and AVOs formation, which was also associated with an increase in sequestosome 1 (SQSTM1/p62), decreased protein kinase B (AKT)/mammalian target of rapamycin (mTOR) expressions, and dysregulated Beclin-1/Bcl-2 levels. Autophagy inhibitors [3-methyladenine (3-MA)/chloroquine (CQ)] and LC3 silencing suppressed FKB-induced apoptosis by decreasing caspase-3 in melanoma cells. The antioxidant N-acetylcysteine (NAC) diminished FKB-induced apoptotic and autophagic cell death. However, the inhibition of apoptosis decreased FKB-induced autophagy (LC3-I/II). The in vivo study confirmed that FKB inhibited melanoma growth in A375-xenografted nude mice. This study concluded that FKB is critically associated with the execution and generation of ROS-modulated apoptotic and autophagic cell death of melanoma cells. FKB also repressed tumor growth in xenografted nude mice. Therefore, flavokawain B might be a potential anti-tumor agent in human melanoma treatment.

Chalcone flavokawain B (FKB) possesses a chemopreventive and anti-cancer activity. Doxorubicin is a chemotherapeutic DNA intercalating agent widely used in malignancy treatment. The present study investigated whether synergistic effects exist between the combination of FKB (1.25&ndash, 5 &micro, g/mL) and doxorubicin (0.5 &micro, g/mL) on the apoptosis and autophagy in human gastric cancer (AGS) cells, and the possible in vitro and in vivo mechanisms. The MTT assay measured cell viability. Various apoptotic-, autophagy-associated protein expression was determined by the Western blot technique. FKB+doxorubicin synergy was estimated by the Chou-Talalay combination index (CI) method. In vivo studies were performed on BALB/c mice. Results showed that compared to FKB/doxorubicin treatments, low doses of FKB+doxorubicin suppressed AGS cell growth. FKB potentiated doxorubicin-induced DNA fragmentation, apoptotic cell death, and enhanced doxorubicin-mediated mitochondrial, death receptor pathways. FKB+doxorubicin activated increased LC3-II accumulation, p62/SQSTM1 expression, and AVO formation as compared to the FKB/doxorubicin alone treatments indicating autophagy in these cells. The death mechanism in FKB+doxorubicin-treated AGS cells is due to the activation of autophagy. FKB+doxorubicin-mediated dysregulated Bax/Bcl-2, Beclin-1/Bcl-2 ratios suggested apoptosis, autophagy induction in AGS cells. FKB+doxorubicin-induced LC3-II/AVOs downregulation was suppressed due to an apoptotic inhibitor Z-VAD-FMK. Whereas, 3-methyladenine/chloroquine weakened FKB+doxorubicin-induced apoptosis (decreased DNA fragmentation/caspase-3). Activation of ERK/JNK may be involved in FKB+doxorubicin-induced apoptosis and autophagy. FKB+doxorubicin-triggered ROS generation, but NAC attenuated FKB+doxorubicin-induced autophagic (LC3 accumulation) and apoptotic (caspase-3 activation and PARP cleavage) cell death. FKB+doxorubicin blocked gastric cancer cell xenografts in nude mice in vivo as compared to FKB/doxorubicin alone treatments. FKB and doxorubicin wielded synergistic anti-tumor effects in gastric cancer cells and is a promising therapeutic approach.

Oxidative stress is an important contributing factor for inflammation. Piper methysticum, also known as Kava-kava, is a shrub whose root extract has been consumed as a drink by the pacific islanders for a long time. Flavokawain A (FKA) is a novel chalcone derived from the kava plant that is known to have medicinal properties. This study was aimed at demonstrating the antioxidant molecular mechanisms mediated by FKA on lipopolysaccharide- (LPS-) induced inflammation in BALB/c mouse-derived primary splenocytes. In vitro data show that the nontoxic concentrations of FKA (2-30 μM) significantly suppressed the proinflammatory cytokine (TNF-α, IL-1β, and IL-6) release but induced the secretion of interleukin-10 (IL-10), an anti-inflammatory cytokine. It was also shown that FKA pretreatment significantly downregulated the LPS-induced ROS production and blocked the activation of the NFκB (p65) pathway leading to the significant suppression of iNOS, COX-2, TNF-α, and IL-1β protein expressions. Notably, FKA favored the nuclear translocation of Nrf2 leading to the downstream expression of antioxidant proteins HO-1, NQO-1, and γ-GCLC via the Nrf2/ARE signaling pathway signifying the FKA's potent antioxidant mechanism in these cells. Supporting the in vitro data, the ex vivo data obtained from primary splenocytes derived from the FKA-preadministered BALB/c mice (orally) show that FKA significantly suppressed the proinflammatory cytokine (TNF-α, IL-1β, and IL-6) secretion in control-, LPS-, or Concanavalin A- (Con A-) stimulated cells. A significant decrease in the ratios of pro- and anti-inflammatory cytokines (IL-6/IL-10; TNF-α/IL-10) showed that FKA possesses strong anti-inflammatory properties. Furthermore, BALB/c mice induced with experimental pancreatitis using cholecystokinin- (CCK-) 8 showed decreased serum lipase levels due to FKA pretreatment. We conclude that with its potent antioxidant and anti-inflammatory properties, chalcone flavokawain A could be a novel therapeutic agent in the treatment of inflammation-associated diseases.

Ultraviolet A (UVA)-irradiation induced reactive oxygen species (ROS) production mediates excessive melanogenesis in skin cells leading to pigmentation. We demonstrated the depigmenting and anti-melanogenic effects of Ectoine, a natural bacterial osmolyte, in UVA-irradiated human (HaCaT) keratinocytes, and the underlying molecular mechanisms were elucidated. HaCaT cells were pre-treated with low concentrations of Ectoine (0.5&ndash, 1.5 &mu, M) and assayed for various depigmenting and anti-melanogenic parameters. This pre-treatment significantly downregulated ROS generation, &alpha, melanocyte-stimulating hormone (&alpha, MSH) production, and proopiomelanocortin (POMC) expression in UVA-irradiated HaCaT cells. Also, antioxidant heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase [quinone 1] (NQO-1), and &gamma, glutamate-cysteine ligase catalytic subunit (&gamma, GCLC) protein expressions were mediated via the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) whose knockdown indeed impaired this effect signifying the importance of the Nrf2 pathway. Ectoine was mediating the activation of Nrf2 via the p38, protein kinase B (also known as AKT), protein kinase C (PKC), and casein kinase II protein kinase (CKII) pathways. The conditioned medium obtained from the Ectoine pre-treated and UVA-irradiated HaCaT cells downregulated the tyrosinase, tyrosinase-related protein-1 and -2 (TRP-1/-2), cyclic AMP (c-AMP) protein kinase, c-AMP response element-binding protein (CREB), and microphthalmia-associated transcription factor (MITF) expressions leading to melanoma B16F10 cells having inhibited melanin synthesis. Interestingly, this anti-melanogenic effect in &alpha, MSH-stimulated B16F10 cells was observable only at 50&ndash, 400 &mu, M concentrations of Ectoine, signifying the key role played by Ectoine (0.5&ndash, 1 &mu, M)-treated keratinocytes in skin whitening effects. We concluded that Ectoine could be used as an effective topical natural cosmetic agent with depigmenting and anti-melanogenic efficacy.

Background UVA irradiation-induced skin damage/photoaging is associated with redox imbalance and collagen degradation. Objective Dermato-protective efficacies of trans-cinnamic acid (t-CA), a naturally occurring aromatic compound have been investigated against UVA irradiation, and elucidated underlying molecular mechanism. Methods Human foreskin fibroblast-derived (Hs68) cells and nude mice were treated with t-CA prior to UVA exposure, and assayed the anti-photoaging effects of t-CA. Results We found t-CA (20–100 μM) pretreatment substantially ameliorated UVA (3 J/cm2)-induced cytotoxicity, and inhibited intracellular ROS production in Hs68 cells. UVA-induced profound upregulation of metalloproteinase (MMP)-1/-3 and degradation of type I procollagen in dermal fibroblasts were remarkably reversed by t-CA, possibly through inhibition of AP-1 (c-Fos, but not c-Jun) translocation. The t-CA-mediated anti-photoaging properties are associated with increased nuclear translocation of Nrf2. Activation of Nrf2 signaling is accompanied with induction of HO-1 and γ-GCLC expressions in t-CA-treated fibroblasts. Furthermore t-CA-induced Nrf2 translocation is mediated through PKC, AMPK, CKII or ROS signaling cascades. This phenomenon was confirmed with respective pharmacological inhibitors, GF109203X, Compound C, CKII inhibitor or NAC, which blockade t-CA-induced Nrf2 activation. Silencing of Nrf2 signaling with siRNA showed no anti-photoaging effects of t-CA against UVA-induced ROS production, loss of HO-1 and type I collagen degradation in fibroblasts. In vivo evidence on nude mice revealed that t-CA pretreatment (20 or 100 mM/day) significantly suppressed MMP-1/-3 activation and maintained sufficient type I procollagen levels in biopsied skin tissue against UVA irradiation (3 J/cm2/day for 10-day). Conclusion t-CA treatment diminished UVA-induced photoaging/collagen degradation, and protected structural integrity of the skin.

Coenzyme Q0 (CoQ0, 2,3-dimethoxy-5-methyl-1,4-benzoquinone) derived from Antrodia camphorata exerts anticancer activities against breast, melanoma, and ovarian carcinoma. Glioblastoma multiforme is a common tumor affecting the central nervous system. This study explored anticancer properties of CoQ0 on human glioblastoma both in vitro and in vivo, and explained the molecular mechanism behind it. CoQ0 treatment retarded the growth and suppressed colony formation in glioblastoma (U87MG and GBM8401) cells. CoQ0 induced apoptosis by activation of caspase-3, cleavage of PARP, and dysregulation of Bax and Bcl-2 in both cell lines. Annexin V/PI staining indicated CoQ0 mediated necrosis and apoptosis. Interestingly, AVOs were increased trough induction of autophagy by CoQ0, LC3-II accumulation, and p62/SQSTM1 expression, leading to death mechanism. Z-VAD-FMK has no effect on CoQ0-induced autophagy but autophagy inhibition by 3-methyladenine (3-MA)/chloroquine (CQ) led to CoQ0-induced apoptosis. N-acetylcysteine (NAC) inhibited CoQ0-mediated ROS production and diminished CoQ0-induced apoptotic and autophagic cell death. Further, CoQ0 inhibited PI3K/AKT/mTOR signaling pathways. CoQ0 reduced the tumor burden in U87MG and GBM8401 xenografted athymic nude mice and significantly modulated tumor xenograft by inducing apoptosis and autophagy. CoQ0 generated ROS-mediated apoptotic and autophagic cell death for effective glioblastoma treatment.

Pearl powder, a well-known traditional mineral medicine, is reported to be used for well-being and to treat several diseases from centuries in Taiwan and China. We investigated the in vitro antihemolytic and antioxidant properties of pearl powder that could protect erythrocytes against 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative damage to membrane proteins/lipids. Human erythrocytes were incubated with different concentrations of pearl powder (50-200 μg/mL) for 30 minutes and then exposed to AAPH for 2-6 hours. We found that AAPH alone time dependently increased the oxidative hemolysis of erythrocytes, while pearl powder pretreatment substantially inhibited the hemolysis in a concentration-/time-dependent manner. AAPH-induced oxidative damage to erythrocyte membrane lipids was evidenced by the elevated malondialdehyde (MDA) levels. However, pearl powder remarkably inhibited the malondialdehyde formation, and the 200 μg/mL concentration showed almost similar malondialdehyde values to the control. Furthermore, pearl powder suppressed the AAPH-induced high-molecular-weight protein formation and concomitantly increased the low-molecular-weight proteins in erythrocytes. Antioxidant potential that was measured as superoxide dismutase activity and glutathione content was significantly dropped by AAPH incubation, which suggests the vulnerability of erythrocytes to AAPH-induced oxidative stress. Noteworthy, erythrocytes pretreated with pearl powder showed restored superoxide dismutase activity and glutathione levels against AAPH-induced loss. Our findings conclude that pearl powder attenuate free radical-induced hemolysis and oxidative damage to erythrocyte membrane lipids/proteins. The potent antioxidant property of pearl powder may offer protection from free radical-related diseases.

Coenzyme Q (CoQ) analogs with variable numbers of isoprenoid units have been demonstrated as anticancer and antioxidant/pro-oxidant molecules. This study examined the in vitro and in vivo antitumor and apoptosis activities of CoQ0 (2,3-dimethoxy-5-methyl-1,4-benzoquinone, zero isoprenoid side-chains) through upregulation of the Voltage-dependent anion channel 1 (VDAC1) signaling pathway on human promyelocytic leukemia. CoQ0 (0-40 μg/mL) treatment significantly reduced HL-60 cell viability, and up-regulated mitochondrial VDAC1 expression. CoQ0 treatment triggers intracellular ROS generation, calcium release, ΔΨm collapse and PTP opening in HL-60 cells. CoQ0 treatment induced apoptosis, which was associated with DNA fragmentation, cytochrome c release, caspase-3 and PARP activation, and Bax/Bcl-2 dysregulation. Annexin V-PI staining indicated that CoQ0 promotes late apoptosis. Furthermore, the blockade of CoQ0-induced ROS production by antioxidant NAC pretreatment substantially attenuated CoQ0-induced apoptosis. The activation of p-GSK3β expression, cyclophilin D inhibition, and p53 activation through ROS are involved in CoQ0-induced HL-60 apoptotic cell death. Notably, ROS-independent p38 activation is involved in CoQ0-mediated apoptosis in HL-60 cells. In addition, the silencing of VDAC1 also prevented CoQ0-induced mitochondrial translocation of Bax, activation of caspase-3, and reduction in Bcl-2. Intriguingly, VDAC1 silencing did not prevent ROS production induced by CoQ0, which in turn indicates that CoQ0 induced ROS-mediated VDAC1 and then mitochondrial apoptosis in HL-60 cells. In vivo results revealed that CoQ0 is effective in delaying tumor incidence and reducing the tumor burden in HL-60-xenografted nude mice. Taken together, CoQ0 could be a promising anticancer agent for the treatment of human promyelocytic leukemia through upregulation of VDAC1 signaling pathways.

We investigated the in vitro and in vivo anticancer properties of Antrodia salmonea (AS), a well-known edible/medicinal mushroom in Taiwan, on human triple-negative breast cancer (MDA-MB-231) cells and xenografted nude mice; and revealed the underlying molecular mechanisms involved in autophagic- and apoptotic-cell death. Treatment of MDA-MB-231 cells with fermented culture broth of AS (0-200 μg/mL) inhibited cell viability/growth. AS-induced autophagy was evidenced via increased LC3-II accumulation, GFP-LC3 puncta and AVOs formation in MDA-MB-231 cells. These events are associated with increased ATG7, decreased p-mTOR, vanished SQSTM1/p62 expressions and dysregulated Beclin-1/Bcl-2 ratio. AS-induced apoptosis/necrosis through increased DNA fragmentation, Annexin-V/PI stained cells and Bax expression. Both mitochondrial (caspase-9/caspase-3/PARP) and death-receptor (caspase-8/FasL/Fas) signaling pathways are involved in execution of apoptosis. Interestingly, blockade of AS-induced ROS production by N-acetylcysteine pretreatment substantially attenuated AS-induced autophagy, mitochondrial dysfunction and autophagic/apoptotic-cell death. Inhibition of apoptosis by Z-VAD-FMK suppressed AS-induced autophagic-death (decreased LC3-II/AVOs). Similarly, inhibition of autophagy by 3-methyladenine/chloroquine diminished AS-induced apoptosis (decreased DNA fragmentation/caspase-3) in MDA-MB-231 cells. Bioluminescence imaging further confirmed that AS inhibited breast tumor growth in living MDA-MB-231-luciferase-injected nude mice. Taken together, AS crucially involved in execution/propagation of autophagic- or apoptotic-death of MDA-MB-231 cells, and decreased tumor growth in xenografted nude mice.

Cigarette smoke exposure activates several cellular mechanisms predisposing to atherosclerosis, including oxidative stress, dyslipidemia, and vascular inflammation. Antrodia camphorata, a renowned medicinal mushroom in Taiwan, has been investigated for its antioxidant, anti-inflammatory, and antiatherosclerotic properties in cigarette smoke extracts (CSE)-treated vascular smooth muscle cells (SMCs), and ApoE-deficient mice. Fermented culture broth of Antrodia camphorata (AC, 200-800 µg/mL) possesses effective antioxidant activity against CSE-induced ROS production. Treatment of SMCs (A7r5) with AC (30-120 µg/mL) remarkably ameliorated CSE-induced morphological aberrations and cell death. Suppressed ROS levels by AC corroborate with substantial inhibition of CSE-induced DNA damage in AC-treated A7r5 cells. We found CSE-induced apoptosis through increased Bax/Bcl-2 ratio, was substantially inhibited by AC in A7r5 cells. Notably, upregulated SOD and catalase expressions in AC-treated A7r5 cells perhaps contributed to eradicate the CSE-induced ROS generation, and prevents DNA damage and apoptosis. Besides, AC suppressed AP-1 activity by inhibiting the c-Fos/c-Jun expressions, and NF-κB activation through inhibition of I-κBα degradation against CSE-stimulation. This anti-inflammatory property of AC was accompanied by suppressed CSE-induced VEGF, PDGF, and EGR-1 overexpressions in A7r5 cells. Furthermore, AC protects lung fibroblast (MRC-5) cells from CSE-induced cell death. In vivo data showed that AC oral administration (0.6 mg/d/8-wk) prevents CSE-accelerated atherosclerosis in ApoE-deficient mice. This antiatherosclerotic property was associated with increased serum total antioxidant status, and decreased total cholesterol and triacylglycerol levels. Thus, Antrodia camphorata may be useful for prevention of CSE-induced oxidative stress and diseases. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 2070-2084, 2017.

Lucidone, which comprises a naturally occurring cyclopentenedione, has been investigated for its in vitro and in vivo wound healing properties, and the underlying molecular signaling cascades in the wound healing mechanism have been elucidated. We demonstrated the cell-/dose-specific responses of lucidone (0.5-8μM) on proliferation and migration/invasion of keratinocyte HaCaT and fibroblast Hs68 cells. In keratinocytes, lucidone-induced nuclear translocation of β-catenin was accompanied by increased transcriptional target genes, including c-Myc and cyclin-D1, through GSK3β-dependent pathway. Correspondingly, lucidone promoted the cell-cycle by increasing PCNA/CDK4 and decreasing p21/p27 expressions. Lucidone induced EMT through the downregulation of epithelial (E-cadherin/occludin) and upregulation of mesenchymal (vimentin/Twist/Snail) marker proteins. Activated MMP-9/-2 and uPA/uPAR as well as suppressed TIMP-1/-2 and PAI-1 expressions by lucidone may promote the migration/invasion of keratinocytes. Notably, lucidone activated NF-κB signaling via IKK-mediated-IκB degradation, and its inhibition abolished MMP-9 activation and keratinocyte migration. Inhibition of PI3K/AKT signaling impaired the lucidone-induced proliferation/migration with corresponding suppression of β-catenin/c-Myc/cyclin-D1 and NF-κB/MMP-9 expressions. Results indicate that lucidone-induced PI3K/AKT signaling anchored the β-catenin/NF-κB-mediated healing mechanism. β-catenin knockdown substantially diminished lucidone-induced keratinocyte migration. Furthermore, lucidone increased endothelial cell proliferation/migration and triggered angiogenesis (MMP-9/uPA/ICAM-1). In macrophages, lucidone-activated NF-κB-mediated inflammation (COX-2/iNOS/NO) and VEGF, which may contribute to the growth of keratinocytes/fibroblasts and endothelial cells. Punched wounds on mice were rapidly healed with the topical application of lucidone (5mM) compared with control ointment-treated mice. Taken together, lucidone accelerates wound healing through the cooperation of keratinocyte/fibroblast/endothelial cell growth and migration and macrophage inflammation via PI3K/AKT, Wnt/β-catenin and NF-κB signaling cascade activation.