Stability is essential for insecticidal activity of Vip3Aa toxin against Spodoptera exigua.

Vegetative insecticidal proteins 3A (Vip3A) were important insecticidal proteins for control of lepidopteran pests. Previous study demonstrated that Vip3Aa and Vip3Ad showed significant difference in insecticidal activities against Spodoptera exigua, while the molecular mechanism remained ambiguous. Here we demonstrated that the difference in insecticidal activities between Vip3Aa and Vip3Ad might be caused by the difference in stability of Vip3Aa and Vip3Ad in S. exigua midgut protease. Vip3Aa was quite stable while Vip3Ad could be further degraded. Molecular dynamics simulation revealed that Vip3Aa was more stable than Vip3Ad, with smaller RMSD and RMSF value. Amino acid sequence alignment indicated that three were three extra prolines (P591, P605 and P779) located on Vip3Aa. We further identified that residue P591 played a crucial role on stability and insecticidal activity of Vip3Aa. Taken together, our study demonstrated that the stability was essential for the insecticidal activity of Vip3A toxins, which might provide new insight into the action mode of Vip3A toxins and contribute to the design Vip3A variants with improved stability and insecticidal activity.

Theophylline Extracted from Fu Brick Tea Affects the Metabolism of Preadipocytes and Body Fat in Mice as a Pancreatic Lipase Inhibitor.

The dramatic increase in obesity is putting people under increasing pressure. Lipase inhibitors, as a kind of effective anti-obesity drug, have attracted more and more researchers' attention in recent years because of their advantages of acting on the intestinal tract and having no side effects on the central nervous system. In this study, lipase inhibitor Fu Brick Theophylline (FBT) was screened based on enzyme molecular dynamics, and the inhibition mechanism of lipase inhibitors on obesity was analyzed and discussed at the cellular level and animal model level. We found that FBT had high inhibition effects of lipase with an IC50 of 1.02~0.03 µg/mL. Firstly, the laboratory used 3T3-L1 proadipocytes as models, flow cytometry was used to detect the effects of FBT on the cycle, apoptosis and intracellular ROS activity of proadipocytes. To study the contents of triglyceride, total cholesterol, related metabolites and related gene and protein expression in adipocytes. The results showed that FBT could reduce ROS production and inflammatory factor mRNA expression during cell differentiation. Secondly, by establishing the animal model of high-fat feed ob nutritional obese mice, the morphological observation and gene expression analysis of body weight, fat rate, adipocyte and hepatocyte metabolism of FBT obese mice were further discussed. It was proven that FBT can effectively reduce the degree of fatty liver, prevent liver fibrosis and fat accumulation, and improve the damage of mitochondrial membrane structure. This study provides a theoretical basis for the screening and clinical treatment of lipase inhibitors.

Key residues of Bacillus thuringiensis Cry2Ab for oligomerization and pore-formation activity.

As a pore-forming toxin, activation, oligomerization and pore-formation were both required for the mode of action of Cry toxins. Previous results revealed that the helices α4-α5 of Domain I were involved in the oligomerization of Cry2Ab, however, the key residues for Cry2Ab aggregation remained ambiguous. In present studies, we built 20 Cry2Ab alanine mutants site-directed in the helices α4-α5 of Domain I and demonstrated that mutants N151A, T152A, F157A, L183A, L185A and I188A could reduce the assembly of the 250 kDa oligomers, suggesting that these mutation residues might be essential for Cry2Ab oligomerization. As expected, all of these variants showed lower insecticidal activity against P. xylostella. Furthermore, we found that the pore-forming activities of these mutants also decreased when compared to wild-type Cry2Ab. Taken together, our data identified key residues for Cry2Ab oligomerization and emphasized that oligomerization was closely related to the insecticidal activity and pore-forming activity of Cry2Ab.

Identifying FBLN1 (Gene ID: 2192) as a Potential Melanoma Biomarker for Melanoma based on an Analysis of microRNA Expression Profiles in the GEO and TCGA Databases.

Aims: We analyzed and compared the gene expression profiles (GSE92763) from normal melanocytes with malignant melanoma cell lines to identify genes that were differentially expressed that could serve as potential biomarkers for melanoma diagnosis. Materials and Methods: Gene expression profiles from the GSE92763 dataset were downloaded from the Gene Expression Omnibus (GEO) database. By comparing normal human melanocytes with multiple melanoma cell lines we identified 127 differentially expressed genes whose expression was altered. These data were used to identify hub genes associated with protein-protein interaction networks using Cytoscape software. To explore the biological functions of the aforementioned hub genes, we utilized the clusterProfiler package in R studio to perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. We then used the Gene Expression Profiling Interactive Analysis (GEPIA) website to determine the association of these hub genes with overall survival (OS). In addition, we utilized the Oncomine and Cancer Cell Line Encyclopedia (CCLE) databases to further analyze and compare the expression of these key genes associated with melanoma with other tumor types. Results: The hub genes included three upregulated and seven downregulated genes, which were linked with extracellular junctions, migration, paracrine and proliferation functions based on GO. In addition, we performed a confirmatory analysis of the hub genes using The Cancer Genome Atlas (TCGA) database. This analysis revealed that the expression of the Fibulin 1 (FBLN1; gene ID: 2192) gene was significantly downregulated in melanomas, and that its expression level in melanoma patients was significantly associated with OS with high expressors having better OS (log-rank p = 0.0034, hazard ratio = 1.5, p = 0.0036). We further analyzed the expression of FBLN1 in melanoma using the TCGA and Oncomine databases, and confirmed that FBLN1 is expressed at lower levels than in other cells (p = 2.03E-15, t = -15.586). FBLN1 has extremely high DNA copy number and low messenger RNA expression in melanoma cell lines according to the CCLE analysis. Conclusion: These results suggest that FBLN1 expression may be utilized as a biomarker and essential prognostic factor for melanoma; as well as provide an important theoretical basis for the development of melanoma treatments.

Protective effects of orally administered shark compound peptides from Chiloscyllium plagiosum against acute inflammation.

The anti-inflammatory effects of shark compound peptides (SCP) from Chiloscyllium plagiosum were investigated. Results showed that SCP enhanced the viability of RAW 264.7 macrophages in vitro in a dose-dependent manner. Orally administered SCP exhibited potent anti-inflammatory activity in lipopolysaccharide (LPS)-challenged mice by suppressing serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), as well as nitric oxide (NO). Moreover, SCP significantly inhibited the inflammatory rise of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and creatinine (CRE), while blocking the decline of cholinesterase (CHE), with an efficacy close to aspirin. This research showed that orally administered SCP from C. plagiosum notably downregulated uncontrolled inflammatory responses, and conferred substantial protection from endotoxin-induced acute hepatic damage and renal functional impairment. Therefore, oral supplementation of SCP can be used as a preventive approach to reduce the risk of inflammatory-related diseases.

Repair function of essential oil from Crocodylus Siamensis (Schneider, 1801) on the burn wound healing via up-regulated growth factor expression and anti-inflammatory effect.

ETHNOPHARMACOLOGICAL RELEVANCE: Crocodile oil has been used by traditional physicians around the world to treat wound healing and inflammation. However, the scientific rationale and mechanism behind its use in vivo has not been fully researched. AIMS OF THE STUDY: We mainly investigated the mechanism during crocodile oil treatment of up-regulated growth factor expression and anti-inflammatory on burn wound healing in rats. MATERIALS AND METHODS: The moisture and nitric oxide (NO) levels in the skin of rats were analyzed in the first 14 days after burn and the changes of the structure of the skin tissues in the wound healing were studied by hematoxylin-eosin (H.E.) staining within 21 days after scald. The inflammatory factor on burn wound healing in rats was dected by ELISA kits and Q-PCR. the expression of a variety of growth factors (TGF-ß1, VEGE-α, EGF) and PCNA in the skin tissue after burns was evaluated using immunohistochemistry. The down-regulated phosphorylation of p38 MAPK in the wound healing was confirmed by Western-blot analysis. In addition, TEM was used to observe the ultrastructure of scalded skin. RESULTS: This study showed that crocodile oil could significantly reduce the protein and mRNA levels of TNF-α, IL-1ß and IL-6. And it was found that the phosphorylation of p38 MAPK was down-regulated in the wound healing (p < 0.05). Meanwhile, crocodile oil can promote the expression of a variety of growth factors (TGF-ß1, VEGE-α, EGF) and PCNA in the skin tissue after burns, and promote the repair of collagen fibers in the dermis, preventing the production of melanin and maintain the appearance of repaired skin.

Establishment of an immortalized stromal cell line derived from human Endometriotic lesion.

BACKGROUND: Endometriosis is a benign gynecological disease with obviously feature of estrogen-dependence and inflammatory response. The applications of primary endometriotic stromal cells in research of endometriosis are restricted for short life span, dedifferentiation of hormone and cytokine responsiveness. The objective of this study was to establish and characterize immortalized human endometriotic stromal cells (ihESCs). METHODS: The endometriotic samples were from a patient with ovarian endometriosis and the primary endometriotic stromal cells were isolated from the endometriotic tissues. The primary cells were infected by lentivirus to establish telomerase reverse transcriptase (hTERT)-induced immortalized cells. Quantification of mRNA and proteins was examined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western Blot. CCK-8 assay and EdU labeling assay were assigned to assess the growth of ihESCs. Karyotype assay was performed to detect the chromosomes of ihESCs. Colony formation assay and nude mouse tumorigenicity assay were used to evaluate colony-formation and tumorigenesis abilities. RESULTS: ihESCs continuously overexpressed hTERT via infection of lentivirus and significant extended the life span reaching 31 passages. The morphology, proliferation and karyotype of ihESCs remained unchanged. The expression of epithelial-mesenchymal transition (EMT) markers, estrogen-metabolizing proteins and estrogen/progesterone receptors (ERs and PRs) were unaltered. Furthermore, the treatment of estrogen increased the proliferation and EMT of ihESCs. Lipopolysaccharides (LPS) and IL-1ß remarkably induced inflammatory response. The clonogenesis ability of ihESCs was consistent with primary cells, which were much lower than Ishikawa cells. In addition, nude mouse tumorigenicity assay demonstrated that ihESCs were unable to trigger tumor formation. CONCLUSION: This study established and characterized an immortalized endometriotic stromal cell line that exhibited longer life span and kept the cellular morphology and physiological function as the primary cells. The immortalized cells remained normal feedback to estrogen and inflammatory response. Moreover, the immortalized cells were not available with tumorigenic ability. Therefore, ihESCs would be serviceable as in vitro cell tool to investigate the pathogenesis of endometriosis.

Inhibitory kinetics and bioactivities of Nuciferine and Methyl Ganoderate on Mucor miehei lipase and 3T3-L1 preadipocytes.

In this study, inhibitory kinetics of Nuciferine and Methyl Ganoderate extrated from Lotus Leaves and Ganoderma lucidum on Mucor miehei Lipase were studied first. The molecular structure of Nuciferine and Methyl Ganoderate were determined. The inhibitory effects of two extracts on lipase were reversible, with the IC50 values of 0.194 and 0.332 mg/mL, respectively. The inhibition kinetic analysis by Lineweaver-Burk plots showed that they were a mixed-type inhibitor of lipase, with inhibition constants KI of 0.16 and 0.29 mg/mL, and KIS of 0.36 and 0.49 mg/mL, respectively. Results of spectral analysis showed that the UV absorption and the molecule fluorescence spectrum of the lipase hydrolyzate were significantly decreased after the inhibitor was added. The molecular docking further suggested that the interaction site between the active substance and inhibitor was located in an α-helix and a ß-sheet of the lipase, and the lipase active site was interfered by the inhibitor near the cap structure. In addition, the proliferation and differentiation of 3 T3-L1 preadipocytes were inhibited by two extracts. Total triglycerides and cholesterol were significantly reduced in the cells. The results confirmed that Nuciferine and Methyl Ganoderate can be used as potential obesity treatment drugs.

RhoA/ROCK pathway mediates the effect of oestrogen on regulating epithelial-mesenchymal transition and proliferation in endometriosis.

Endometriosis is a benign gynaecological disease appearing with pelvic pain, rising dysmenorrhoea and infertility seriously impacting on 10% of reproductive-age females. This research attempts to demonstrate the function and molecular mechanism of RhoA/ROCK pathway on epithelial-mesenchymal transition (EMT) and proliferation in endometriosis. The expression of Rho family was abnormally changed in endometriotic lesions; in particular, RhoA and ROCK1/2 were significantly elevated. Overexpression of RhoA in human eutopic endometrial epithelial cells (eutopic EECs) enhanced the cell mobility, epithelial-mesenchymal transition (EMT) and proliferation, and RhoA knockdown exhibited the opposite function. Oestrogen up-regulated the RhoA activity and expression of RhoA and ROCK1/2. RhoA overexpression reinforced the effect of oestrogen on promoting EMT and proliferation, and RhoA knockdown impaired the effect of oestrogen. oestrogen receptor α (ERα) was involved with the regulation of oestrogen on EMT and proliferation and up-regulated RhoA activity and expression of RhoA and ROCK1/2. The function of ERα was modulated by the change in RhoA expression. Furthermore, phosphorylated ERK that was enhanced by oestrogen and ERα promoted the protein expression of RhoA/ROCK pathway. Endometriosis mouse model revealed that oestrogen enhanced the size and weight of endometriotic lesions. The expression of RhoA and phosphorylated ERK in mouse endometriotic lesions was significantly elevated by oestrogen. We conclude that abnormal activated RhoA/ROCK pathway in endometriosis is responsible for the function of oestrogen/ERα/ERK signalling, which promoted EMT and proliferation and resulted in the development of endometriosis.

Lipase Inhibitors for Obesity: A Review.

With the rapid increase in the population of obese individuals, obesity has become a global problem. Many kinds of chronic metabolic diseases easily caused by obesity have received increasing attention from researchers. People are also striving to find various safe and effective treatment methods as well as anti-obesity medicines. Pancreatic lipase (PL) inhibitors have received substantial attention from researchers in recent years, and PL inhibitors from natural products have attracted much attention due to their structural diversity, low toxicity and wide range of sources. They have been used in the intestinal tract, blood, and the central nervous system with no side effects, and these advantages could lead to a new generation of diet pills or health care products with great development potential. This article is mainly aimed at discussing the research of obesity drug treatment with PL inhibitors and offers a brief review of related properties and the use of PL inhibitors in the field of weight loss.

Strong inhibitory activities and action modes of lipopeptides on lipase.

Lipopeptides have been reported to exhibit anti-obesity effects. In this study, we obtained a Bacillus velezensis strain FJAT-52631 that could coproduce iturins, fengycins, and surfactins. Results showed that the FJAT-52631 crude lipopeptide, purified fengycin, iturin, and surfactin standards exhibited strong inhibition activities against lipase with dose-dependence manners (half maximal inhibitory concentration (IC50) = 0.011, 0.005, 0.056, and 0.005 mg/mL, respectively). Moreover, fengycin and surfactin had the comparable activities with orlistat, but iturin not. It was revealed that the inhibition mechanism and type of the lipopeptides were reversible and competitive. The quenching mechanism of lipase was static and only one binding site between lipase and lipopoeptide was inferred from the fluorescence analysis. The docking analysis displayed that fengycin and surfactin could directly interact with the active amino acid residues (Ser or Asp) of lipase, but not with iturin. Our work suggests that the B. velezensis lipopeptides would have great potential to act as lipase inhibitors.

Bone-strengthening effects and safety of compound peptides from skin of Chiloscyllium plagiosum and Mustelus griseus.

Fish processing produces a lot of by-products highly containing large amount of proteins which mainly consist of collagen, implying great potential value for application as nutraceutical ingredients. In present study, two kinds of sharks, Chiloscyllium plagiosum and Mustelus griseus, were used as raw material to gain three kinds of "compound peptides" (CPs) by enzymolysis, FCP (CPs from the flesh of C. plagiosum), SCP (CPs from the skin of C. plagiosum), and SMG (CPs from the skin of M. griseus). According to a series of constituent analysis, the molecule weights of FCP, SCP, and SMG were under 800 Da; amino acids composition analysis of FCP, SCP, and SMG showed that there were high glycine, proline, and hydroxyproline and low cysteine contents in SCP and SMG, which is the characteristic of collagen peptides; their total protein contents were 87.500%, 91.875%, and 95.625%, respectively; and heavy metal contents of CPs were all beneath national standards. After three kinds of CPs were administrated intragastrically to C57BL/6 mice at a total dosage of 15 g/kg, bone-strengthening effects of SCP and SMG were manifested by osteoblasts activity promotion, bone mineral density (BMD) increase, and marrow adipocyte number decrease, yet nonsignificant effects were shown in FCP group. No index showed toxicity of SCP and SMG in subacute toxicology trial, indicating their safety as functional foods. Herein, industrial application foundation of the skins from these two sharks was explored but more efforts should subsequently be implemented for further exploitation.

The inhibitory kinetics and mechanism of glycolic acid on lipase.

Obesity is prone to cause a variety of chronic metabolic diseases, and it has aroused people's attention that the rapid increase in the global population of obese people in the past years. As a kind of weight-loss drug acting in the intestine, lipase inhibitor does not enter the bloodstream without producing central nervous side effects. Because they do not affect the metabolism system, lipase inhibitors and obesity have become one of the hot spots in recent years. Glycolic acid is a new substrate analog inhibitor with the value of the semi-inhibitory concentration of lipase is estimated to be 17.29 ± 0.14 mM. Using the plots of Lineweaver-Burk, the inhibition mechanism of lipase by glycolic acid was reversible and the inhibition type belongs to competitive inhibition with a KI value of 19.61 ± 0.26 mM. The inhibitory kinetics assay showed that the microscopic velocity constant k+0 of inhibition kinetics is 1.79 × 10-3 mM-1s-1, and k-0 is 0.73 × 10-3 s-1. The results of UV full-wavelength scanning on product cumulative, fluorescence quenching and molecular simulation also indicated that glycolic acid and substrate competitive with lipase by binding to Lys137. Thereby glycolic acid inhibiting the oxidation-catalyzed reaction and reducing the product of the enzyme and substrate. This adds a new direction for the search for lipase inhibitors and provides new ideas about the development of anti-obesity drugs.Communicated by Ramaswamy H. Sarma.

Establishment and characterization of immortalized human eutopic endometrial stromal cells.

PROBLEM: The application of primary eutopic endometrial cells from endometriosis patients in research is restricted for short life span, dedifferentiation of hormone responsiveness. METHOD OF STUDY: Human telomerase reverse transcriptase (hTERT)-induced immortalized cells (iheESCs) were infected by lentivirus. mRNA level was examined by qRT-PCR, and protein expression was quantified by Western blot. CCK-8 and EdU assay were assigned to assess the proliferation. The migration and invasion of cells were assessed by transwell assay. Clone formation assay and nude mouse tumorigenicity assay were used to evaluate colony-formation and tumorigenesis abilities. RESULTS: hTERT mRNA and protein were significantly expressed higher in iheESCs compared to primary cells. iheESCs grew without morphological change for 42 passages which is much longer than 18 passages of primary cells. There was no obvious difference between primary cells and iheESCs in growth, mobility, and chromosome karyotype. Furthermore, the expression of epithelial-mesenchymal transition (EMT) markers and estrogen/progesterone receptors remained unchanged. The decidualization of iheESCs could be induced by progesterone and cAMP. Estrogen increased the proliferation and mobility of iheESCs, and lipopolysaccharides (LPS) induced the IL-1ß and IL-6 promoting inflammatory response. The colony-forming ability of iheESCs, like primary cells, was lower than Ishikawa cells. In addition, tumorigenicity assay indicated that iheESCs were unable to trigger tumor formation in BALB/c nude mouse. CONCLUSIONS: This study established and characterized iheESCs that kept the cellular physiology of primary cells and were not available with tumorigenic ability. Thus, iheESCs would be useful as in vitro cell model to investigate pathogenesis of endometriosis.

Diosgenin Suppresses Cholangiocarcinoma Cells Via Inducing Cell Cycle Arrest And Mitochondria-Mediated Apoptosis.

PURPOSE: Diosgenin (DSG) is the precursor of steroid hormones and plays a crucial part in the proliferation of various carcinomas including human colorectal cancer and gastric carcinoma. Nevertheless, its specific features and mechanisms in human cholangiocarcinoma (CCA) remain unknown. METHODS: MTS assay, colony-forming assay, and EdU assay were performed to determine the role of DSG on the progression of human CCA cells. The distributions of cell cycle, the ratio of apoptosis, and the mitochondrial membrane potential (ΔΨm) were studied by flow cytometry (FCM). AO/EB and Hoechst 33258 staining were performed to observe the morphological features of cell apoptosis. TEM was performed to observe the ultrastructures of QBC939 and HuCCT1 cells. The mRNA and protein expression of mitochondrial apoptotic pathway and GSK3ß/ß-catenin pathway were further confirmed by qPCR and Western blotting. The xenograft tumor model of HuCCT1 cells was built. Immunohistochemistry of tumor tissues was performed. RESULTS: Our results indicated that DSG inhibited the progression of six CCA cell lines. In vivo tumor studies also indicated that DSG significantly inhibited tumor growth in xenografts in nude mice. The expression of mitosis-promoting factor cyclinB1 was decreased along with the elevating level of cell cycle inhibitor p21, resulting in arresting CCA cell cycles at G2/M phase. Furthermore, DSG induced apoptosis with the increased expressions of cytosol cytochrome C, cleaved-caspase-3, cleaved-PARP1 and the Bax/Bcl-2 ratio. Mechanistically, our study showed that GSK3ß/ß-catenin pathway was involved in the apoptosis of CCA cells. Thus, DSG might provide a new clue for the drug therapy of CCA. CONCLUSION: In our data, DSG was found to have efficient antitumor potential of human CCA cells in vitro and in vivo.

Synthesis and Characterization of Cry2Ab-AVM Bioconjugate: Enhanced Affinity to Binding Proteins and Insecticidal Activity.

Bacillus thuringiensis insecticidal proteins (Bt toxins) have been widely used in crops for agricultural pest management and to reduce the use of chemical insecticides. Here, we have engineered Bt toxin Cry2Ab30 and bioconjugated it with 4"-O-succinyl avermectin (AVM) to synthesize Cry2Ab-AVM bioconjugate. It was found that Cry2Ab-AVM showed higher insecticidal activity against Plutella xylostella, up to 154.4 times compared to Cry2Ab30. The binding results showed that Cry2Ab-AVM binds to the cadherin-like binding protein fragments, the 10th and 11th cadherin repeat domains in the P. xylostella cadherin (PxCR10-11), with a much higher affinity (dissociation equilibrium constant KD = 3.44 nM) than Cry2Ab30 (KD = 28.7 nM). Molecular docking suggested that the macrolide lactone group of Cry2Ab-AVM ligand docking into the PxCR10-11 is a potential mechanism to enhance the binding affinity of Cry2Ab-AVM to PxCR10-11. These findings offer scope for the engineering of Bt toxins by bioconjugation for improved pest management.

Kinetic and computational molecular docking simulation study of novel kojic acid derivatives as anti-tyrosinase and antioxidant agents.

The novel kojic acid derivatives KAD1 and KAD2 have been demonstrated that they exhibited potent anti-melanogenesis activity in our previous report. In this study, we further study the inhibitory mechanism on mushroom tyrosinase. The inhibitory types of both KADs on diphenolase were classified as mixed type based on the results of the kinetic model. The interaction between KADs and tyrosinase was illustrated by fluorescence quenching, molecular docking and copper chelate activity. The KADs were also evaluated with respect to their antioxidant activities by DPPH and ABTS+ assays. The results showed that KADs have more potent antioxidant activities than kojic acid. Our study could provide new ideas for the development of new anti-tyrosinase and antioxidant agents.

Retinoic acid receptor α facilitates human colorectal cancer progression via Akt and MMP2 signaling.

Purpose: Retinoic acid α (RARα) is overexpressed in various tumors and facilitates cancer progression. Although RARα has been shown to facilitate colorectal cancer (CRC) progression, more efforts to characterize mechanisms of RARα in CRC are needed in order to develop better target-based drugs for tumor therapy. Methods: RARα expression in CRC was assessed by IHC. EdU, QPCR, Western blotting, dual-luciferase reporter assay and ChIP were performed to explore the role of RARα in CRC and the mechanism involoved. Results: Here, we show an overexpression of RARα in 73.5% (i.e., 25 of 34 human CRC specimens). RARα knockdown decreased cell proliferation, migration, and invasion. Such phenotypic manifestations can be correlated to lowered activation of Akt and expression of PCNA (proliferating cell nuclear antigen) as well as MMP2 (matrix metallopeptidase). Mechanistically, RARα facilitates CRC growth through Akt signaling activation to cause levels of PCNA to be upregulated. Furthermore, RARα promotes migration and invasion of CRC cells by directly recruiting the MMP2 promoter to enhance the expression of MMP2. Conclusions: These findings demonstrate that CRC carcinogenesis is promoted by RARα via an enhanced Akt signaling and by increasing MMP2 transcription. CRC therapy can examine the use of RARα as a prospective molecular target.

Evaluation of the Structure and Biological Activities of Condensed Tannins from Acanthus ilicifolius Linn and Their Effect on Fresh-Cut Fuji Apples.

Condensed tannins (CTS) have been isolated and purified from leaves of Acanthus ilicifolius Linn. And their structures were investigated by three methods: 13C nuclear magnetic resonance (13C NMR), reversed-phase high-performance liquid chromatography (RP-HPLC), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The results showed that the CTS were a mixture of catechin/epicatechin, galatechin/epicatechin, and amphicin/epigalin, and that the polymer chain lengths were 3-mers to 14-mers. Antityrosinase activities and antioxidant activities of the CTS from A. ilicifolius leaves were further studied. The IC50 of the CTS on mushroom tyrosinase activity was determined to be 19.7 ± 0.13 µg/mL, and inhibition type analyses indicated that the CTS were mixed type inhibitors and their inhibition CTS was reversible. The CTS from A. ilicifolius leaves also exhibited potential antioxidant activity. The IC50 of DPPH and ABTS scavenging activities were 104 ± 0.894 µg/mL and 86 ± 0.616 µg/mL, respectively. And the FRAP value was 758.28 ± 2.42 mg AAE/g. In addition, we found that the CTS from A. ilicifolius leaves had an excellent effect on preserving the quality of fresh-cut apples by preventing apples from browning through reducing polyphenol oxidase activities in apples.

Anti-melanogenesis of novel kojic acid derivatives in B16F10 cells and zebrafish.

Novel kojic acid derivatives (KADs) with the potential ability to inhibit tyrosinase were synthesized and were further identified by Q-Exactive, IR and NMR. Among these compounds, KAD2 showed the best inhibitory effects on diphenolase activity and monophenolase activity, with IC50 of 7.50 µM and 20.51 µM, respectively. The anti-melanogenic activity of KAD2 was further confirmed by assessing the inhibition of melanin content and intracellular tyrosinase activity in B16F10 cells and zebrafish model. It demonstrated that KAD2 suppressed the expression of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase related protein-1 and 2 (TRP-1 and TRP-2) in a concentration-dependent manner. Furthermore, KAD2 dose-dependently suppressed the expression of the phosphorylation of protein kinase A (PKA) and cAMP-response element binding protein (CREB) and rescued the phosphorylation of Akt. Additionally, KAD2 could inhibit body pigmentation in zebrafish. Taken together, our findings elucidated that KAD2 has significant anti-melanogenic activity via CREB and Akt pathway-mediated suppression the expression of MITF and TYR family proteins in B16F10 cells. It could provide new insight into the development of novel anti-melanogenic agents to apply in the fields of food sciences, agriculture, cosmetics and medicine.