An ester extract of Cochinchina momordica seeds induces differentiation of melanoma B16 F1 cells via MAPKs signaling

Quercetin 3-O-(6″-O-E-caffeoyl)-β-D-glucopyranoside, a Flavonoid Compound, Promotes Melanogenesis through the Upregulation of MAPKs and Akt/GSK3β/β-Catenin Signaling Pathways

Quercetin 3-O-(6″-O-E-caffeoyl)-β-D-glucopyranoside is a flavonoid compound produced by various plants with reported antiprotozoal potential against E. histolytica and G. lamblia; however, its effects on skin pigment regulation have not been studied in detail. In this investigation, we discovered that quercetin 3-O-(6″-O-E-caffeoyl)-D-glucopyranoside (coded as CC7) demonstrated a more increased melanogenesis effect in B16 cells. CC7 exhibited no cytotoxicity or effective stimulating melanin content or intracellular tyrosinase activity. This melanogenic-promoting effect was accompanied by activated expression levels of microphthalmia-associated transcription factor (MITF), a key melanogenic regulatory factor, melanogenic enzymes, and tyrosinase (TYR) and tyrosinase-related protein-1 (TRP-1) and 2 (TRP-2) in the CC7-treated cells. Mechanistically, we found that CC7 exerted melanogenic effects by upregulating the phosphorylation of stress-regulated protein kinase (p38) and c-Jun N-terminal kinase (JNK). Moreover, the CC7 upregulation of phosphor-protein kinase B (Akt) and Glycogen synthase kinase-3 beta (GSK-3β) increased the content of β-catenin in the cell cytoplasm, and subsequently, it translocated into the nucleus, resulting in melanogenesis. Specific inhibitors of P38, JNK, and Akt validated that CC7 promotes melanin synthesis and tyrosinase activity by regulating the GSK3β/β-catenin signaling pathways. Our results support that the CC7 regulation of melanogenesis involves MAPKs and Akt/GSK3β/β-catenin signaling pathways.

SNA077, an Extract of Marine Streptomyces sp., Inhibits Melanogenesis by Downregulating Melanogenic Proteins via Inactivation of cAMP/PKA/CREB Signaling

Excess melanin in skin is known to be the main cause of hyper-pigmentary skin diseases such as freckles and lentigo. This study aimed to evaluate the depigmenting efficacy of an extract from the marine microorganism strain, Streptomyces sp. SNA077. To determine the anti-melanogenic efficacy of SNA077, we assessed the melanin contents of SNA077-treated B16, Melan-a, and MNT-1 cells. We observed the expression of key enzymes in melanogenesis via qRT-PCR and Western blot analyses. We further estimated the skin-whitening effect of SNA077 using a skin-equivalent model. SNA077 dramatically decreased the melanin production of B16 cells, Melan-a, and MNT-1 cells. In B16 cells treated with SNA077, the activity of cellular tyrosinase was clearly inhibited. In addition, the mRNA and protein expression levels of melanogenic genes were suppressed by SNA077 treatment in B16 and MNT-1 cells. Upstream of tyrosinase, the expression levels of phospho-CREB, phospho-p38, PKA activity, cyclic AMP production, and MC1R gene expression were inhibited by SNA077. Finally, SNA077 clearly showed a skin-brightening effect with a reduced melanin content in the skin tissue model. Collectively, our results suggest for the first time that an extract of marine Streptomyces sp. SNA077 could be a novel anti-melanogenic material for skin whitening.

Physiological and Metabolic Responses of Gac Leaf (Momordica cochinchinensis (Lour.) Spreng.) to Salinity Stress

Gac is a carotenoid-rich, healthful tropical fruit; however, its productivity is limited by soil salinity, a growing environmental stress. This study aimed to evaluate the effects of salinity stress on key physiological traits and metabolites in 30-day-old gac seedling leaves, treated with 0, 25-, 50-, 100-, and 150-mM sodium chloride (NaCl) for four weeks to identify potential alarm, acclimatory, and exhaustion responses. Electrolyte leakage increased with increasing NaCl concentrations (p < 0.05) indicating loss of membrane permeability and conditions that lead to reactive oxygen species production. At 25 and 50 mM NaCl, superoxide dismutase (SOD) activity, starch content, and total soluble sugar increased. Chlorophyll a, and total chlorophyll increased at 25 mM NaCl but decreased at higher NaCl concentrations indicating salinity-induced thylakoid membrane degradation and chlorophyllase activity. Catalase (CAT) activity decreased (p < 0.05) at all NaCl treatments, while ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) activities were highest at 150 mM NaCl. GC-MS-metabolite profiling showed that 150 mM NaCl induced the largest changes in metabolites and was thus distinct. Thirteen pathways and 7.73% of metabolites differed between the control and all the salt-treated seedlings. Salinity decreased TCA cycle intermediates, and there were less sugars for growth but more for osmoprotection, with the latter augmented by increased amino acids. Although 150 mM NaCl level decreased SOD activity, the APX and GPX enzymes were still active, and some carbohydrates and metabolites also accumulated to promote salinity resistance via multiple mechanisms.

A noncoding regulatory RNA Gm31932 induces cell cycle arrest and differentiation in melanoma via the miR-344d-3-5p/Prc1 (and Nuf2) axis

Emerging evidence has shown that long non-coding RNAs (lncRNAs) play an important role in inhibiting tumor cell proliferation and inducing differentiation. In this study, integrative analysis of whole transcriptome sequencing data demonstrated that lncRNA-Gm31932 is significantly decreased in all-trans retinoic acid (ATRA)-induced and sodium 4-phenylbutanoate (PB-4)-induced mouse melanoma B16 cells. Silencing lncRNA-Gm31932 could inhibit B16 cell proliferation, with cell cycle arrest at the G0/G1 phase and obvious differentiation characteristics, e.g., increased cell volume, melanin content and tyrosinase (Tyr) activity. Furthermore, a series of experiments (luciferase reporter assay, RNA pull-down assay, and western blotting) showed that lncRNA-Gm3932 down-regulated Prc1 and Nuf2 by competitively sponging miR-344d-3-5p, which subsequently reduced the expression of cell cycle-related proteins CDK2, CDC2, and Cyclin B1, and increased the expression of P21 and P27. Moreover, silencing lncRNA-Gm31932 could significantly inhibit tumor growth in B16 melanoma-bearing mice. Taken together, these results indicate that as a possible signaling pathway for ATRA and PB-4, lncRNA-Gm31932 can induce cell cycle arrest and differentiation via miR-344d-3-5p/Prc1 (and Nuf2) axis.

Anticancer Activity and Molecular Mechanism of Momordica cochinchinensis Seed Extract in Chronic Myeloid Leukemia Cells

Targeting Bcr-Abl is the key to the treatment of chronic myeloid leukemia. Despite great progress in the treatment of patients with chronic CML, advanced CML patients are still unable to obtain effective and safe drugs. Momordica cochinchinensis seed is the dried ripe seed of Momordica cochinchinensis, which is a kind of fruit and consumed for dietary as well as medicinal uses. This study aimed to investigate the anticancer activity of Momordica cochinchinensis seed extract (MCSE) in CML cells. CML cells (KBM5 and KBM5-T315I) were treated with MCSE and analyzed for growth, apoptosis, and signal transduction. Nude mouse xenograft model was used to evaluate the antitumor activity of MCSE In Vivo. MCSE significantly reduced the cell viability of CML cells, triggered G0/G1 phase arrest in KBM5 cells and S phase arrest in KBM5-T315I cells. Concurrently, MCSE caused the activation of caspase-3, -8, -9, PARP and the degradation of Mcl-1, ultimately triggering endogenous and exogenous cell apoptosis. Meanwhile, MCSE downregulated Bcr-Abl levels and its downstream signaling pathways. Additionally, MCSE inhibited the growth of CML cells in nude mouse xenografts. Taken together, this study demonstrated the anticancer mechanism of MCSE, namely blocking Bcr-Abl and downregulating Mcl-1, and finally induced apoptosis of CML cells.

Ultrasound-Assisted Extraction of GAC Peel: An Optimization of Extraction Conditions for Recovering Carotenoids and Antioxidant Capacity

The peel of Gac fruit (Momordica cochinchinensis Spreng.), which is considered as waste of Gac processing, has been found to possess high levels of carotenoids and other antioxidants. This study aimed at determining the optimal conditions of an ultrasound-assisted extraction for recovering carotenoids and antioxidant capacity from Gac peel. A response surface methodology using the Box–Behnken design was employed to investigate the impact of extraction time, temperature and ultrasonic power on the recovery of total carotenoid and antioxidant capacity. The results showed that an extraction time of 76 min, temperature of 50 °C and ultrasonic power of 250 W were the optimal conditions for the extraction. The experimental carotenoid yield and antioxidant capacity obtained under the optimal extraction conditions were validated as 269 mg/100 g DW (dry weight) and 822 µM TE (Trolox equivalent)/100 g DW, respectively. These values were not significantly different from the values predicted by the models. The HPLC analysis for carotenoid composition showed that β-carotene, lycopene and lutein were the principal carotenoids of the extract, which constitute 86% of the total carotenoid content. Based on the obtained results, the ultrasound-assisted extraction using ethyl acetate under the above optimal conditions is suggested for the simultaneous recovery of carotenoids and antioxidant capacity from Gac peel.

p-Hydroxylcinnamaldehyde from cochinchinamomordica seed reverses resistance to TRAIL in human oesophageal squamous cell carcinoma via the activation of the p38 mitogen-activated protein kinase signalling pathway

BACKGROUND

Our previous studies have showed that p-Hydroxylcinnamaldehyde (CMSP) could induce the differentiation of ESCC cells via the cAMP-RhoA-MAPK signalling pathway, which suggests a new potential strategy for ESCC treatment. Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent inducer of apoptosis in several tumour cells by binding to the death receptors DR4 and DR5. However, TRAIL has little effect on oesophageal squamous cell carcinoma (ESCC) cells due to the loss of the receptors. The present study determined the effect of CMSP, the firstly found chemical constituent of Cochinchinamomordica seed (CMS), on TRAIL-induced apoptosis and its mechanism in ESCC cells.

METHODS

MTS assays were performed to examine the CMSP- and TRAIL-mediated inhibition of ESCC cell growth. Flow cytometry and Hoechst 33258 staining assays were used to detect apoptosis in ESCC cells treated with CMSP combined with TRAIL. Western blotting was used to determine the effect of CMSP on the expression of p38, p-p38, DR4, DR5, Bid and caspase-3/8 in ESCC cells treated with CMSP combined with TRAIL. Additionally, immunodeficient Balb-c/null mouse model was used to determine the chemotherapeutic efficacy of CMSP and TRAIL against ESCC tumour xenograft growth in vivo.

RESULTS

We found that the combination of CMSP and TRAIL had a greater inhibitory effect on ESCC cell viability in vitro than CMSP or TRAIL alone. CMSP enhanced the TRAIL-induced apoptosis in ESCC cells by upregulating the expression of DR4 and DR5 via the p38 MAPK signalling pathway. Furthermore, the increased expression of DR4 and DR5 upon TRAIL-induced apoptosis in ESCC cells was mediated at least in part by subsequent caspase-3 and caspase-8 activation. Moreover, the in vivo model showed that tumour growth was significantly slower in CMSP and TRAIL combination-treated mice than in mice treated with CMSP or TRAIL alone.

CONCLUSION

Taken together, our findings indicate that CMSP as an extract from TCM, might be as a potential sensitizer of TRAIL and thus provide a novel strategy for the clinical treatment of ESCC.

A Potential Anti-Tumor Herb Bred in a Tropical Fruit: Insight into the Chemical Components and Pharmacological Effects of Momordicae Semen

Gac fruit (Momordica cochinchinensis Spreng) is a popular tropical fruit in southeast Asia. What is amazing is that its seeds (Momordicae Semen) and arils are traditional herbs with anti-tumor activity, and have protected human health for more than 1000 years. In recent years, its anti-tumor activity has received extensive attention and research. This manuscript summarized the chemical composition of saponins, fatty acids, volatile constituents, proteins, peptides, and other components from Momordicae Semen (MSE). The effect and mechanism of MSE and its extract on breast cancer, gastric cancer, lung cancer, esophagus cancer, melanomas, and human cervical epithelial carcinoma were discussed. In addition, its antioxidant, anti-inflammatory, and other pharmacological effects were also analyzed. We hope that this review will provide new ideas for the treatment of cancer and other diseases, and become a reference for the further research into complementary and alternative medicine.

p-Hydroxylcinnamaldehyde slows the progression of 4NQO-induced oesophageal tumourigenesis via the RhoA-MAPK signaling pathway

p-Hydroxylcinnamaldehyde isolated from the Cochinchina momordica seed (CMSP) has been identified to inhibit growth and metastasis in oesophageal squamous cell carcinoma (ESCC) by inducing differentiation. The aim of the present study was to evaluate the effect and underlying mechanism of CMSP on 4-nitroquinoline 1-oxide (4NQO)-induced oesophageal tumourigenesis. In the present study, a mouse model of oesophageal preneoplastic lesions was established by providing 4NQO-containing drinking water to C57BL/6 mice. The effect of CMSP on tumourigenesis induced by the chemical mutagen and the effect of CMSP on immune function were investigated. The results showed that the incidence and pathological stage of atypical hyperplasia in oesophageal tissues were significantly reduced in CMSP-treated mice compared with untreated mice. Immunohistochemistry and pull-down assay results revealed that the expression levels of p-ERK1/2, p-SAPK/JNK, and GTP-RhoA were significantly decreased in the oesophageal tissue of CMSP-treated mice. In addition, the proportions of CD4⁺ T cells, CD8⁺ T cells, and NK cells were increased, while the proportion of CD4⁺ CD25⁺ regulatory T cells (Tregs) was decreased, in the peripheral blood of CMSP-treated mice. These results indicated that CMSP could hamper 4NQO-induced oesophageal tumourigenesis by regulating the RhoA-ERK/JNK signaling pathway and promoting immune system function, thus providing a new potential strategy for treating preneoplastic lesions of the oesophagus.

Icariin induces cell differentiation and cell cycle arrest in mouse melanoma B16 cells via Erk1/2-p38-JNK-dependent pathway

Icariin (ICA) is a major component isolated from Epimedium brevicornum. Emerging evidence shows that ICA can inhibit tumor cell proliferation, invasion and migration. However, the anti-cancer effect of ICA on B16 cells has not been fully investigated. Here we found that the proliferation of B16 cells was inhibited by ICA in a concentration- and time-dependent manner, and the colony formation of B16 cells was also inhibited by ICA in a concentration-dependent manner. Further study showed that the melanin content was increased and the tyrosinase (Tyr) activity was enhanced after ICA treatment in B16 cells. Furthermore, compared with the control group, the mRNA levels of Tyr, Trp1 and Trp2 and the protein level of MITF were increased in ICA-treated B16 cells. In addition, the percentage of G0/G1 phase cells was increased and the protein levels of Cyclin A, CDK2 and p21 were decreased in ICA-treated B16 cells. Finally, we found that ICA increased down-regulated the Erk1/2, p-Erk1/2, p38, p-p38, and p-JNK protein levels in B16 cells when compared with the control group. Taken together, these results indicated that ICA could induce B16 cell differentiation and cell cycle arrest at G0/G1 phase through inhibiting Erk1/2-p38-JNK-dependent signaling molecules.

p-Hydroxylcinnamaldehyde induces the differentiation of oesophageal carcinoma cells via the cAMP-RhoA-MAPK signalling pathway

p-Hydroxylcinnamaldehyde (CMSP) has been identified as an inhibitor of the growth of various cancer cells. However, its function in oesophageal squamous cell carcinoma (ESCC) and the underlying mechanism remain unclear. The aim of the present study was to characterize the differentiation effects of CMSP, as well as its mechanism in the differentiation of ESCC Kyse30 and TE-13 cells. The function of CMSP in the viability, colony formation, migration and invasion of Kyse30 and TE-13 cells was determined by MTS, colony-formation, wound healing and transwell assays. Western blotting and pull-down assays were used to investigate the effect of CMSP on the expression level of malignant markers of ESCC, as well as the activity of MAPKs, RhoA and GTP-RhoA in Kyse30 and TE-13 cells. We found that CMSP could inhibit proliferation and migration and induce Kyse30 and TE-13 cell differentiation, characterized by dendrite-like outgrowth, decreased expression of tumour-associated antigens, as well as the decreased expression of malignant markers. Furthermore, increased cAMP, p-P38 and decreased activities of ERK, JNK and GTP-RhoA, were detected after treatment with CMSP. These results indicated that CMSP induced the differentiation of Kyse30 and TE-13 cells through mediating the cAMP-RhoA-MAPK axis, which might provide new potential strategies for ESCC treatment.

Differentiation of bel-7402 human hepatocarcinoma cells induced by aqueous extracts of fresh gecko (AG) and its anti-tumor activity in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Gecko, a kind of reptile, has been widely used as a traditional Chinese medicine to treat various diseases including cancer in China for thousands of years. The aim of this study was to investigate the anti-tumor effect of AG (aqueous extracts of fresh gecko) on human hepatocellular carcinoma cell Bel-7402 in vitro and mouse H22 hepatocellular in vivo. Further to underlie the molecular mechanism of AG inducing the differentiation of Bel-7402 cells.

MATERIALS AND METHODS

AG was obtained by water extracting method and qualitatively analyzed through High Performance Liquid Chromatography. The total protein concentration of AG was measured by BCA (bicinchoninic acid disodium) assay. The anti-tumor activities in vivo were analyzed through H22 (mouse hepatocellular carcinoma cell line H22) tumor xenografts mice. The cytotoxic activity of AG on Bel-7402 cells was evaluated by MTT assays. AFP (alpha fetoprotein) was detected by radioimmunoassay. ALB (albumin), ALP (alkaline phosphatase) and γ-GT (γ-glutamyl transpeptidase) were detected by biochemical methods with commercial kits. While morphological changes were observed through an inverted microscope. Moreover, the expression level of the proteins involved in MAPK (mitogen-activated protein kinase) signal pathway which was closely related to cellular differentiation was assessed by Western blot.

RESULTS

AG showed obviously anti-tumor activity in vivo and anti-proliferative activity on Bel-7402 cells in vitro both dose-dependently. The number of clones of Bel-7402 cells treated with AG reduced and the cells were displaying differentiation state such as relatively bigger size and dispersed growth. The biochemical function markers of the cells were significantly changed after being treated with AG. The data showed that AFP secretion of the cells decreased 42.5%, ALB secretion increased 58.9%, the activity of ALP and γ-GT markedly decreased 67.0% and 48.5% separately when the concentration of AG was 10μl/ml, and those effects were all in a dose-dependent manner. The major original and phosphorylated signal proteins (ERK1/2 (extracellular sigal-regualted kinase 1/2), P38 (p38 MAPK) and JNK1/2 (c-Jun N-terminal kinase 1/2)) involved in MAPK signal pathway were measured and the results showed that AG activated the ERK1/2 of Bel-7402 cells.

CONCLUSIONS

AG has anti-tumor activity in vivo and inhibits Bel-7402 cell proliferation in vitro through inducing cell differentiation, and the mechanism involves the activation of ERK1/2.

The melanogenesis alteration effects of Achillea millefolium L. essential oil and linalyl acetate: involvement of oxidative stress and the JNK and ERK signaling pathways in melanoma cells

The mitogen-activated protein kinase (MAPK) family, including extracellular signal-regulated kinase (ERK)1/2, c-Jun N-terminal kinase (JNK)1/2 and p38 MAPK, is known to be activated by ultraviolet (UV) radiation in melanocytes to regulate melanin production. Reactive oxygen species (ROS) play important roles in the pathway of ERK and JNK activation. It has been established that the essential oil of Achillea millefolium L. (AM-EO) has activities that suppress the oxidative stress and inflammatory responses. Thus, we analyzed the effects of AM-EO on melanogenesis in melanocyte stimulating hormone (α-MSH) treated melanoma cells. The results demonstrated that AM-EO suppresses melanin production by decreasing tyrosinase activity through the regulation of the JNK and ERK signaling pathways. This effect might be associated with the AM-EO activity leading to the suppression of ROS, and linalyl acetate is its major functional component. Therefore, we propose that AM-EO has the potential to treat hyperpigmentation in the future.