Echinatin induces reactive oxygen species-mediated apoptosis via JNK/p38 MAPK signaling pathway in colorectal cancer cells.

Colorectal cancer (CRC) is a very common and deadly cancer worldwide, and oxaliplatin is used as first-line chemotherapy. However, resistance usually develops, limiting treatment. Echinatin (Ech) is the main component of licorice and exhibits various therapeutic effects on inflammation-mediated diseases and cancer, ischemia/reperfusion, and liver injuries. The present study elucidated the underlying molecular mechanism of Ech-induced apoptosis in both oxaliplatin-sensitive (HT116 and HT29) and -resistant (HCT116-OxR and HT29-OxR) CRC cells. To evaluate the antiproliferative activities of Ech, we performed MTT and soft agar assays. Ech reduced viability, colony size, and numbers of CRC cells. The underlying molecular mechanisms were explored by various flow cytometry analyses. Ech-induced annexin-V stained cells, reactive oxygen species (ROS) generation, cell cycle arrest, JNK/p38 MAPK activation, endoplasmic reticulum (ER) stress, mitochondrial membrane potential depolarization, and multi-caspase activity. In addition apoptosis-, cell cycle-, and ER stress-related protein levels were confirmed by western blotting. Moreover, we verified ROS-mediated cell death by treatment with inhibitors such as N-acetyl-L-cysteine, SP600125, and SB203580. Taken together, Ech exhibits anticancer activity in oxaliplatin-sensitive and -resistant CRCs by inducing ROS-mediated apoptosis through the JNK/p38 MAPK signaling pathway. This is the first study to show that Ech has the potential to treat drug-resistant CRC, providing new directions for therapeutic strategies targeting drug-resistant CRC.

Spermidine Attenuates High Glucose-Induced Oxidative Damage in Retinal Pigment Epithelial Cells by Inhibiting Production of ROS and NF-κB/NLRP3 Inflammasome Pathway.

Diabetic retinopathy (DR) is the leading cause of vision loss and a critical complication of diabetes with a very complex etiology. The build-up of reactive oxygen species (ROS) due to hyperglycemia is recognized as a primary risk factor for DR. Although spermidine, a naturally occurring polyamine, has been reported to have antioxidant effects, its effectiveness in DR has not yet been examined. Therefore, in this study, we investigated whether spermidine could inhibit high glucose (HG)-promoted oxidative stress in human retinal pigment epithelial (RPE) cells. The results demonstrated that spermidine notably attenuated cytotoxicity and apoptosis in HG-treated RPE ARPE-19 cells, which was related to the inhibition of mitochondrial ROS production. Under HG conditions, interleukin (IL)-1ß and IL-18's release levels were markedly increased, coupled with nuclear factor kappa B (NF-κB) signaling activation. However, spermidine counteracted the HG-induced effects. Moreover, the expression of nucleotide-binding oligomerization domain-like receptor (NLR) protein 3 (NLRP3) inflammasome multiprotein complex molecules, including TXNIP, NLRP3, ASC, and caspase-1, increased in hyperglycemic ARPE-19 cells, but spermidine reversed these molecular changes. Collectively, our findings demonstrate that spermidine can protect RPE cells from HG-caused injury by reducing ROS and NF-κB/NLRP3 inflammasome pathway activation, indicating that spermidine could be a potential therapeutic compound for DR treatment.

Phloroglucinol Inhibits Oxidative-Stress-Induced Cytotoxicity in C2C12 Murine Myoblasts through Nrf-2-Mediated Activation of HO-1.

Phloroglucinol is a class of polyphenolic compounds containing aromatic phenyl rings and is known to have various pharmacological activities. Recently, we reported that this compound isolated from Ecklonia cava, a brown alga belonging to the family Laminariaceae, has potent antioxidant activity in human dermal keratinocytes. In this study, we evaluated whether phloroglucinol could protect against hydrogen peroxide (H2O2)-induced oxidative damage in murine-derived C2C12 myoblasts. Our results revealed that phloroglucinol suppressed H2O2-induced cytotoxicity and DNA damage while blocking the production of reactive oxygen species. We also found that phloroglucinol protected cells from the induction of apoptosis associated with mitochondrial impairment caused by H2O2 treatment. Furthermore, phloroglucinol enhanced the phosphorylation of nuclear factor-erythroid-2 related factor 2 (Nrf2) as well as the expression and activity of heme oxygenase-1 (HO-1). However, such anti-apoptotic and cytoprotective effects of phloroglucinol were greatly abolished by the HO-1 inhibitor, suggesting that phloroglucinol could increase the Nrf2-mediated activity of HO-1 to protect C2C12 myoblasts from oxidative stress. Taken together, our results indicate that phloroglucinol has a strong antioxidant activity as an Nrf2 activator and may have therapeutic benefits for oxidative-stress-mediated muscle disease.

Preclinical activities of Cassia tora Linn against aging-related diseases.

Globally, an aging population is increasing, and aging is a natural physiological process and a major risk factor for all age-related diseases. It seriously threatens personal health and imposes a great economic burden. Therefore, there is a growing scientific interest in strategies for well-aging with prevention and treatment of age-related diseases. The seed, root, stem or leaves of Cassia tora Linn. are useful for anti-bacteria, anti-hyperlipidemia and anti-obesity due to its pharmacological activities such as anti-inflammation and anti-oxidant both in vitro and in vivo. Nevertheless, no clinical trials have been attempted so far, therefore here we would like to understand the current preclinical activities for aging-related disease models including cataract, metabolic dysfunction and neurodegeneration, then discuss their preparation for clinical trials and perspectives.

Targeting LIMK1 with luteolin inhibits the growth of lung cancer in vitro and in vivo.

Lung cancer is the leading cause of cancer-related deaths. LIM domain kinase (LIMK) 1 is a member of serine/threonine kinase family and highly expressed in various cancers. Luteolin, a polyphenolic plant flavonoid, has been reported to suppress tumour proliferation through inducing apoptosis and autophagy via MAPK activation in glioma. However, the mechanism of luteolin on suppressing lung cancer growth is still unclear. We found that luteolin targeted LIMK1 from the in silico screening and significantly inhibited the LIMK1 kinase activity, which was confirmed with pull-down binding assay and computational docking models. Treatment with luteolin inhibited lung cancer cells anchorage-independent colony growth and induced apoptosis and cell cycle arrest at G1 phase. Luteolin also decreased the expression of cyclin D1 and increased the levels of cleaved caspase-3 by down-regulating LIMK1 signalling related targets, including p-LIMK and p-cofilin. Furthermore, luteolin suppressed the lung cancer patient-derived xenograft tumour growth by decreasing Ki-67, p-LIMK and p-cofilin expression in vivo. Taken together, these results provide insight into the mechanism that underlies the anticancer effects of luteolin on lung cancer, which involved in down-regulation of LIMK1 and its interaction with cofilin. It also provides valuable evidence for translation towards lung cancer clinical trials with luteolin.

Janus kinase 2 inhibition by Licochalcone B suppresses esophageal squamous cell carcinoma growth.

Esophageal cancer (EC) is one of the leading causes to cancer death in the worldwide and major population of EC is esophageal squamous cell carcinoma (ESCC). Still, ESCC-targeted therapy has not been covered yet. In the present study we have identified that Licochalcone B (Lico B) inhibited the ESCC growth by directly blocking the Janus kinase (JAK) 2 activity and its downstream signaling pathway. Lico B suppressed KYSE450 and KYSE510 ESCC cell growth, arrested cell cycle at G2/M phase and induced apoptosis. Direct target of Lico B was identified by kinase assay and verified with in vitro and ex vivo binding. Computational docking model predicted for Lico B interaction to ATP-binding pocket of JAK2. Furthermore, treatment of JAK2 clinical medicine AZD1480 to ESCC cells showed similar tendency with Lico B. Thus, JAK2 downstream signaling proteins phosphorylation of STAT3 at Y705 and S727 as well as STAT3 target protein Mcl-1 expression was decreased with treatment of Lico B. Our results suggest that Lico B inhibits ESCC cell growth, arrests cell cycle and induces apoptosis, revealing the underlying mechanism involved in JAK2/STAT3 signaling pathways after Lico B treatment. It might provide potential role of Lico B in the treatment of ESCC.

Dual inhibition of EGFR and MET by Echinatin retards cell growth and induces apoptosis of lung cancer cells sensitive or resistant to gefitinib.

Patients with non-small-cell lung cancer (NSCLC) containing epidermal growth factor receptor (EGFR) amplification or sensitive mutations initially respond to tyrosine kinase inhibitor gefitinib; however, the treatment is less effective over time. Gefitinib resistance mechanisms include MET gene amplification. A therapeutic strategy targeting MET as well as EGFR can overcome resistance to gefitinib. In the present study we identified Echinatin (Ecn), a characteristic chalcone in licorice, which inhibited both EGFR and MET and strongly altered NSCLC cell growth. The antitumor efficacy of Ecn against gefitinib-sensitive or -resistant NSCLC cells with EGFR mutations and MET amplification was confirmed by suppressing cell proliferation and anchorage-independent colony growth. During the targeting of EGFR and MET, Ecn significantly blocked the kinase activity, which was validated with competitive ATP binding. Inhibition of EGFR and MET by Ecn decreases the phosphorylation of downstream target proteins ERBB3, AKT and ERK compared with total protein expression or control. Ecn induced the G2/M cell cycle arrest, and apoptosis via the intrinsic pathway of caspase-dependent activation. Ecn induced ROS production and GRP78, CHOP, DR5 and DR4 expression as well as depolarized the mitochondria membrane potential. Therefore, our results suggest that Ecn is a promising therapeutic agent in NSCLC therapy.

Alternative Options for Skin Cancer Therapy via Regulation of AKT and Related Signaling Pathways.

Global environmental pollution has led to human exposure to ultraviolet (UV) radiation due to the damaged ozone layer, thereby increasing the incidence and death rate of skin cancer including both melanoma and non-melanoma. Overexpression and activation of V-akt murine thymoma viral oncogene homolog (AKT, also known as protein kinase B) and related signaling pathways are major factors contributing to many cancers including lung cancer, esophageal squamous cell carcinoma and skin cancer. Although BRAF inhibitors are used to treat melanoma, further options are needed due to treatment resistance and poor efficacy. Depletion of AKT expression and activation, and related signaling cascades by its inhibitors, decreases the growth of skin cancer and metastasis. Here we have focused the effects of AKT and related signaling (PI3K/AKT/mTOR) pathways by regulators derived from plants and suggest the need for efficient treatment in skin cancer therapy.

Picropodophyllotoxin, an Epimer of Podophyllotoxin, Causes Apoptosis of Human Esophageal Squamous Cell Carcinoma Cells Through ROS-Mediated JNK/P38 MAPK Pathways.

Esophageal squamous cell carcinoma (ESCC), a major histologic type of esophageal cancer, is one of the frequent causes of cancer-related death worldwide. Picropodophyllotoxin (PPT) is the main component of Podophyllum hexandrum root with antitumor activity via apoptosis-mediated mechanisms in several cancer cells. However, the underlying mechanism of the PPT effects in apoptosis induction in cancer remains ambiguous. Hence, in this study, we evaluate the anti-cancer effects of PPT in apoptotic signaling pathway-related mechanisms in ESCC cells. First, to verify the effect of PPT on ESCC cell viability, we employed an MTT assay. PPT inhibited the viability of ESCC cells in time- and dose-dependent manners. PPT induced G2/M phase cell cycle arrest and annexin V-stained cell apoptosis through the activation of the c-Jun N-terminal kinase (JNK)/p38 pathways. Furthermore, the treatment of KYSE 30 and KYSE 450 ESCC cells with PPT induced apoptosis involving the regulation of endoplasmic reticulum stress- and apoptosis-related proteins by reactive oxygen species (ROS) generation, the loss of mitochondrial membrane potential, and multi-caspase activation. In conclusion, our results indicate that the apoptotic effect of PPT on ESCC cells has the potential to become a new anti-cancer drug by increasing ROS levels and inducing the JNK/p38 signaling pathways.

Deoxypodophyllotoxin, a Lignan from Anthriscus sylvestris, Induces Apoptosis and Cell Cycle Arrest by Inhibiting the EGFR Signaling Pathways in Esophageal Squamous Cell Carcinoma Cells.

Deoxypodophyllotoxin (DPT) derived from Anthriscus sylvestris (L.) Hoffm has attracted considerable interest in recent years because of its anti-inflammatory, antitumor, and antiviral activity. However, the mechanisms underlying DPT mediated antitumor activity have yet to be fully elucidated in esophageal squamous cell carcinoma (ESCC). We show here that DPT inhibited the kinase activity of epidermal growth factor receptor (EGFR) directly, as well as phosphorylation of its downstream signaling kinases, AKT, GSK-3ß, and ERK. We confirmed a direct interaction between DPT and EGFR by pull-down assay using DPT-beads. DPT treatment suppressed ESCC cell viability and colony formation in a time- and dose-dependent manner, as shown by MTT analysis and soft agar assay. DPT also down-regulated cyclin B1 and cdc2 expression to induce G2/M phase arrest of the cell cycle and upregulated p21 and p27 expression. DPT treatment of ESCC cells triggered the release of cytochrome c via loss of mitochondrial membrane potential, thereby inducing apoptosis by upregulation of related proteins. In addition, treatment of KYSE 30 and KYSE 450 cells with DPT increased endoplasmic reticulum stress, reactive oxygen species generation, and multi-caspase activation. Consequently, our results suggest that DPT has the potential to become a new anticancer therapeutic by inhibiting EGFR mediated AKT/ERK signaling pathway in ESCC.

Isolinderalactone Induces Cell Death via Mitochondrial Superoxide- and STAT3-Mediated Pathways in Human Ovarian Cancer Cells.

The mortality rate of ovarian cancer (OC) worldwide increases with age. OC is an often fatal cancer with a curative rate of only 20-30%, as symptoms often appear after disease progression. Studies have reported that isolinderalactone (ILL), a furanosesquiterpene derivative extracted from the dried root of Lindera aggregata, can inhibit several cancer cell lines' growth. However, the molecular mechanisms underlying ILL activities in human OC cells remain unexplored. This study investigated the antitumor activities of ILL in human OC cells by inducing mitochondrial superoxide (mtSO) and JAK-signal transducer and activator of transcription 3 (STAT3)-dependent cell death. ILL caused cell death in SKOV-3 and OVCAR-3 cells and increased the cell proportion in the subG1 phase. Additionally, ILL significantly induced mtSO production and reduced ROS production. Moreover, ILL downregulated mitochondrial membrane potential and the expression levels of anti-apoptotic Bcl-2 family proteins and superoxide dismutase (SOD)2. Results showed that ILL decreased phosphorylation of serine 727 and tyrosine 705 of STAT3 and expression of survivin, a STAT3-regulated gene. Furthermore, ILL-induced cell death was reversed by pretreatment of Mito-TEMPO, a mitochondria-specific antioxidant. These results suggest that ILL induces cell death by upregulation of mtSO, downregulation of mitochondrial SOD2, and inactivation of the STAT3-mediated pathway.

Licochalcone D directly targets JAK2 to induced apoptosis in human oral squamous cell carcinoma.

Licochalcone (LC) families have been reported to have a wide range of biological function such as antioxidant, antibacterial, antiviral, and anticancer effects. Although various beneficial effects of LCD were revealed, its anticancer effect in human oral squamous cancer has not been identified. To examine the signaling pathway of LCD's anticancer effect, we determined whether LCD has physical interaction with Janus kinase (JAK2)/signal transducer and activator of transcription-3 (STAT3) signaling, which is critical in promoting cancer cell survival and proliferation. Our results demonstrated that LCD inhibited the kinase activity of JAK2, soft agar colony formation, and the proliferation of HN22 and HSC4 cells. LCD also induced mitochondrial apoptotic events such as altered mitochondrial membrane potential and reactive oxygen species production. LCD increased the expression of apoptosis-associated proteins in oral squamous cell carcinoma (OSCC) cells. Finally, the xenograft study showed that LCD significantly inhibited HN22 tumor growth. Immunohistochemical data supported that LCD suppressed p-JAK2 and p-STAT3 expression and induced cleaved-caspase-3 expression. These results indicate that the anticancer effect of LCD is due to the direct targeting of JAK2 kinase. Therefore, LCD can be used for therapeutic application against OSCC.

Deoxypodophyllotoxin Exerts Anti-Cancer Effects on Colorectal Cancer Cells Through Induction of Apoptosis and Suppression of Tumorigenesis.

Deoxypodophyllotoxin (DPT) is a cyclolignan compound that exerts anti-cancer effects against various types of cancers. DPT induces apoptosis and inhibits the growth of breast, brain, prostate, gastric, lung, and cervical tumors. In this study, we sought to determine the effect of DPT on cell proliferation, apoptosis, motility, and tumorigenesis of three colorectal cancer (CRC) cell lines: HT29, DLD1, and Caco2. DPT inhibited the proliferation of these cells. Specifically, the compound-induced mitotic arrest in CRC cells by destabilizing microtubules and activating the mitochondrial apoptotic pathway via regulation of B-cell lymphoma 2 (Bcl-2) family proteins (increasing Bcl-2 associated X (BAX) and decreasing B-cell lymphoma-extra-large (Bcl-xL)) ultimately led to caspase-mediated apoptosis. In addition, DPT inhibited tumorigenesis in vitro, and in vivo skin xenograft experiments revealed that DPT significantly decreased tumor size and tumor weight. Taken together, our results suggest DPT to be a potent compound that is suitable for further exploration as a novel chemotherapeutic for human CRC.

Identification and Extraction Optimization of Active Constituents in Citrus junos Seib ex TANAKA Peel and Its Biological Evaluation.

Citrus junos Seib ex TANAKA possesses various biological effects. It has been used in oriental remedies for blood circulation and the common cold. Recently, biological effects of C. junos peel have been reported. However, optimization of the biological properties of C. junos peel preparations has yet to be reported on. We developed a high-performance liquid chromatography (HPLC) method for quantification of the active constituents in C. junos peel. Hot water and ethanolic extracts of C. junos peel were prepared and their chemical profiles and biological activities were evaluated. The 80% ethanolic extract demonstrated the greatest antioxidant activity and phenolic content, while the 100% ethanolic extract had the greatest xanthine oxidase inhibitory activity. Elastase inhibition activity was superior in aqueous and 20% ethanolic extracts. The contents of two flavonoids were highest in the 100% ethanolic extract. We postulated that the antioxidant and anti-aging effects of C. junos peel extract could be attributed to phenolics such as flavonoids. Our results suggest that the flavonoid-rich extract of C. junos may be utilized for the treatment and prevention of metabolic disease and hyperuricemia while the water-soluble extract of C. junos could be used as a source for its anti-aging properties.

Retrochalcone Echinatin Triggers Apoptosis of Esophageal Squamous Cell Carcinoma via ROS- and ER Stress-Mediated Signaling Pathways.

Esophageal squamous cell carcinoma (ESCC) is a poor prognostic cancer with a low five-year survival rate. Echinatin (Ech) is a retrochalone from licorice. It has been used as a herbal medicine due to its anti-inflammatory and anti-oxidative effects. However, its anticancer activity or underlying mechanism has not been elucidated yet. Thus, the objective of this study was to investigate the anti-tumor activity of Ech on ESCC by inducing ROS and ER stress dependent apoptosis. Ech inhibited ESCC cell growth in anchorage-dependent and independent analysis. Treatment with Ech induced G2/M phase of cell cycle and apoptosis of ESCC cells. It also regulated their related protein markers including p21, p27, cyclin B1, and cdc2. Ech also led to phosphorylation of JNK and p38. Regarding ROS and ER stress formation associated with apoptosis, we found that Ech increased ROS production, whereas its increase was diminished by NAC treatment. In addition, ER stress proteins were induced by treatment with Ech. Moreover, Ech enhanced MMP dysfunction and caspases activity. Furthermore, it regulated related biomarkers. Taken together, our results suggest that Ech can induce apoptosis in human ESCC cells via ROS/ER stress generation and p38 MAPK/JNK activation.

Effects of Harvest Time on Phytochemical Constituents and Biological Activities of Panax ginseng Berry Extracts.

Ginseng (Panax ginseng) has long been used as a traditional medicine for the prevention and treatment of various diseases. Generally, the harvest time and age of ginseng have been regarded as important factors determining the efficacy of ginseng. However, most studies have mainly focused on the root of ginseng, while studies on other parts of ginseng such as its berry have been relatively limited. Thus, the aim of this study iss to determine effects of harvest time on yields, phenolics/ginsenosides contents, and the antioxidant/anti-elastase activities of ethanol extracts of three- and four-year-old ginseng berry. In both three- and fourfour-year-old ginseng berry extracts, antioxidant and anti-elastase activities tended to increase as berries ripen from the first week to the last week of July. Liquid chromatography-tandem mass spectrometry analysis has revealed that contents of ginsenosides except Rg1 tend to be the highest in fourfour-year-old ginseng berries harvested in early July. These results indicate that biological activities and ginsenoside profiles of ginseng berry extracts depend on their age and harvest time in July, suggesting the importance of harvest time in the development of functional foods and medicinal products containing ginseng berry extracts. To the best of our knowledge, this is the first report on the influence of harvest time on the biological activity and ginsenoside contents of ginseng berry extracts.

Tyrosinase Inhibition Antioxidant Effect and Cytotoxicity Studies of the Extracts of Cudrania tricuspidata Fruit Standardized in Chlorogenic Acid.

In the present study, various extracts of C. tricuspidata fruit were prepared with varying ethanol contents and evaluated for their biomarker and biological properties. The 80% ethanolic extract showed the best tyrosinase inhibitory activity, while the 100% ethanolic extract showed the best total phenolics and flavonoids contents. The HPLC method was applied to analyze the chlorogenic acid in C. tricuspidata fruit extracts. The results suggest that the observed antioxidant and tyrosinase inhibitory activity of C. tricuspidata fruit extract could partially be attributed to the presence of marker compounds in the extract. In this study, we present an analytical method for standardization and optimization of C. tricuspidata fruit preparations. Further investigations are warranted to confirm the in vivo pharmacological activity of C. tricuspidata fruit extract and its active constituents and assess the safe use of the plant for the potential development of the extract as a skin depigmentation agent.

Licochalcone C induced apoptosis in human oral squamous cell carcinoma cells by regulation of the JAK2/STAT3 signaling pathway.

Oral cancer is of an aggressive malignancy that arises on oral cavity and lip, 90% of cancers histologically originated in the squamous cells. Licochalcone (LC)C has been known as natural phenolic chalconoid substances, and its origin is the root of Glycyrrhiza glabra or Glycyrrhiza inflata. LCC inhibited oral squamous cell carcinoma (OSCC) cell viability, mitochondrial function, and anchorage-independent growth in a dose-dependent manner. To investigate the ability of LCC to target Janus kinase 2 (JAK2), we performed pull-down binding assay, kinase assay, and docking simulation. The molecular docking studies were performed between JAK2 and the potent inhibitor LCC. It was shown that LCC tightly interacted with ATP-binding site of JAK2. In addition, LCC inhibited the JAK2/signal transducer and activator of transcription 3 pathway, upregulated p21, and downregulated Bcl-2, Mcl-1, and Survivin, while it disrupted mitochondrial membrane potential and subsequently caused cytochrome c release with activation of multi-caspase, eventually leading to apoptosis in HN22 and HSC4 cells. LCC elevated the protein levels of Bax, cleaved Bid and PARP, and increased Apaf-1, and this effect was reversed by LCC treatment. Our results demonstrated that treatment of OSCC cells with LCC induced the death receptor (DR)4 and DR5 expression level with the generation of reactive oxygen species and the upregulation of CHOP protein expression. Taken together, these results could provide the basis for clinical application as a new therapeutic strategy in the treatment of oral cancer.

Optimization of the Extraction Conditions and Biological Evaluation of Dendropanax morbifera H. Lev as an Anti-Hyperuricemic Source.

Dendropanax morbifera H. Levis a medicinal plant native to South Korea, East Asia, and South America. Among some 75 species, one species grows in Korea. In previous studies, D. morbifera extracts with anti-oxidant, anti-inflammatory, anti-complementary and anti-cancer activities were reported. The present study aims to investigate optimization of extraction and evaluation of anti-hyperuricemic effects of D. morbifera leaf and the phytochemicals contained therein. Ethanol and hexane extract were found to display the best xanthine oxidase inhibition among six types of solvent and water extract. The antioxidant effect of the ethanol extract was superior to that of the hexane extract. The DPPH radical scavenging effect of the ethanol and hexane extracts were 81.52 ± 1.57% and 2.69 ± 0.16. The reducing power of the ethanol and hexane extracts were 9.71 ± 0.15 and 0.89 ± 0.01 mg/g equivalent of gallic acid. Total phenols of the ethanol and hexane extracts were 6.53 ± 0.16 and 0.63 ± 0.001 mg/g equivalent of gallic acid. In addition, we compared the two marker compounds from D. morbifera, chlorogenic acid and rutin, which were determined in the ethanol extract at 0.80 ± 0.03% and 0.52 ± 0.01%, respectively. We found that the ethanol extracts showed better xanthine oxidase inhibition than hexane extracts. Especially, ethanol extracts showed higher antioxidant activity than hexane extracts. Based on these results, we selected the ethanol extract as an effective xanthine oxidase inhibitor and confirmed whether ethanol extracts showed xanthine oxidase inhibition in animal experiments. The in vivo mouse study demonstrated that ethanol extract of D. morbifera leaf at the dose of 300 mg/kg could inhibit blood/hepatic xanthine oxidase activity and this result shows that the xanthine oxidase inhibitory activity in vitro is reproduced in vivo. The present study showed that ethanol extract was optimal xanthine oxidase inhibitor which can be applied to prevent diseases related to hyperuricemia.

Herbacetin suppresses cutaneous squamous cell carcinoma and melanoma cell growth by targeting AKT and ODC.

Herbacetin is a flavonol compound that is found in plants such as flaxseed and ramose scouring rush herb, it possesses a strong antioxidant capacity, and exerts anticancer effects on colon and breast cancer. However, the effect of herbacetin on skin cancer has not been investigated. Herein, we identified herbacetin as a dual V-akt murine thymoma viral oncogene homolog (AKT) and ornithine decarboxylase (ODC) inhibitor, and illustrated its anticancer effects in vitro and in vivo against cutaneous squamous cell carcinoma (SCC) and melanoma cell growth. To identify the direct target(s) of herbacetin, we screened several skin cancer-related protein kinases, and results indicated that herbacetin strongly suppresses both AKT and ODC activity. Results of cell-based assays showed that herbacetin binds to both AKT and ODC, inhibits TPA-induced neoplastic transformation of JB6 mouse epidermal cells, and suppresses anchorage-independent growth of cutaneous SCC and melanoma cells. The inhibitory activity of herbacetin was associated with markedly reduced NF-κB and AP1 reporter activity. Interestingly, herbacetin effectively attenuated TPA-induced skin cancer development and also exhibited therapeutic effects against solar-UV-induced skin cancer and melanoma growth in vivo. Our findings indicate that herbacetin is a potent AKT and ODC inhibitor that should be useful for preventing skin cancers.