Oat (Avena sativa) Extract against Oxidative Stress-Induced Apoptosis in Human Keratinocytes.

Oat (Avena sativa) is well known for its various health benefits. The protective effect of oat extract against oxidative stress-induced apoptosis in human keratinocytes HaCaT was determined. First, extracts of two varieties of oat, Daeyang and Choyang, were analyzed for fat-soluble antioxidants such as α-tocotrienol, γ-oryzanols, lutein and zeaxanthin using an UPLC system and for antioxidant activity using a DPPH assay. Specifically, an 80% ethanol extract of Daeyang oat (Avena sativa cv. Daeyang), which had high amounts of antioxidants and potent radical scavenging activity, was further evaluated for protective effect against oxidative stress-induced cell death, intracellular reactive oxygen species levels, the phosphorylation of DNA damage mediating genes such as H2AX, checkpoint kinase 1 and 2, and p53 and the activation of apoptotic genes such as cleaved caspase-3 and 7 and poly (ADP-ribose) polymerase in HaCaT cells. The Daeyang and Choyang oat 80% ethanol extracts had 26.9 and 24.1 mg/100 g γ-oryzanols, 7.69 and 8.38 mg/100 g α-tocotrienol, 1.25 and 0.34 mg/100 g of lutein and 1.20 and 0.17 mg/100 g of zeaxanthin, respectively. The oat 80% ethanol extract treatment (Avena sativa cv. Daeyang) had a protective effect on oxidative stress-induced cell death in HaCaT cells. In addition, the oat 80% ethanol extracts led to a significant decrease in the intracellular ROS level at a concentration of 50-200 µg/mL, the attenuation of DNA damage mediating genes and the inhibition of apoptotic caspase activities in a dose dependent manner (50-200 µg/mL). Thus, the current study indicates that an oat (Avena sativa cv. Daeyang) extract rich in antioxidants, such as polyphenols, avenanthramides, γ-oryzanols, tocotrienols and carotenoids, has a protective role against oxidative stress-induced keratinocyte injuries and that oat may a useful source for oxidative stress-associated skin damage.

Effects of gamma-aminobutyric acid and piperine on gene regulation in pig kidney epithelial cell lines.

OBJECTIVE: Gamma-aminobutyric acid (GABA) and piperine (PIP) are both nutritional supplements with potential use in animal diets. The purpose of this study is to investigate the effect of GABA and/or PIP treatment on the gene expression pattern of a pig kidney epithelial cell line. METHODS: LLCPK1 cells were treated with GABA, PIP, or both, and then the gene expression pattern was analyzed using microarray. Gene ontology analysis was done using GeneOntology (Geneontology.org), and validation was performed using quantitative real-time polymerase chain reaction. RESULTS: Gene ontology enrichment analysis was used to identify key pathway(s) of genes whose expression levels were regulated by these treatments. Microarray results showed that GABA had a positive effect on the transcription of genes related to regulation of erythrocyte differentiation and that GABA and PIP in combination had a synergistic effect on genes related to immune systems and processes. Furthermore, we found that effects of GABA and/or PIP on these selected genes were controlled by JNK/p38 MAPK pathway. CONCLUSION: These results can improve our understanding of mechanisms involved in the effect of GABA and/or PIP treatment on pig kidney epithelial cells. They can also help us evaluate their potential as a clinical diagnosis and treatment.

Thymoquinone Selectively Kills Hypoxic Renal Cancer Cells by Suppressing HIF-1α-Mediated Glycolysis.

Several reports have shown that thymoquinone (TQ) effectively attenuates angiogenesis in cancer cells, resulting in suppression of tumor growth. However, it is not yet clear whether TQ reduces hypoxia-inducible factor-1α (HIF-1α) expression in hypoxic cancer cells. Here, we found that TQ was a novel HIF-1α inhibitor through hypoxia response element (HRE)-luciferase assay-based large screening by using 502 natural compounds containing chemical library. TQ reduced HIF-1α protein levels in renal cancer cells; however, it did not affect the HIF-1α protein levels in the presence of proteasome inhibitor, MG132, indicating that the reduction effects of TQ on HIF-1α protein are mediated via the ubiquitination-proteasome dependent pathway. TQ boosted HIF-1α protein degradation, and the mechanism was revealed by inhibiting interaction between HSP90 and HIF-1α. TQ suppressed downstream genes of HIF-1α, indicating negative impact of TQ on HIF-1α transcriptional activities. In addition, TQ altered glucose, lactate, and ATP levels, leading to anaerobic metabolic disturbance. TQ induced apoptosis in hypoxic cancer cells as determined by crystal violet staining and flow cytometry for annexin V-stained cells. Taken together, we suggested that TQ is a potential anticancer agent targeting HIF-1α.

Sirtuin 1 modulates cellular responses to hypoxia by deacetylating hypoxia-inducible factor 1alpha.

To survive in hypoxic environments, organisms must be able to cope with redox imbalance and oxygen deficiency. The SIRT1 deacetylase and the HIF-1alpha transcription factor act as redox and oxygen sensors, respectively. Here, we found that SIRT1 binds to HIF-1alpha and deacetylates it at Lys674, which is acetylated by PCAF. By doing so, SIRT1 inactivated HIF-1alpha by blocking p300 recruitment and consequently repressed HIF-1 target genes. During hypoxia, SIRT1 was downregulated due to decreased NAD(+) levels, which allowed the acetylation and activation of HIF-1alpha. Conversely, when the redox change was attenuated by blocking glycolysis, SIRT1 was upregulated, leading to the deacetylation and inactivation of HIF-1alpha even in hypoxia. In addition, we confirmed the SIRT1-HIF-1alpha interaction in hypoxic mouse tissues and observed in vivo that SIRT1 has negative effects on tumor growth and angiogenesis. Our results suggest that crosstalk between oxygen- and redox-responsive signal transducers occurs through the SIRT1-HIF-1alpha interaction.

Emodin Sensitizes Hepatocellular Carcinoma Cells to the Anti-Cancer Effect of Sorafenib through Suppression of Cholesterol Metabolism.

Reduced therapeutic efficacy of sorafenib, a first-generation multikinase inhibitor, is often observed during the treatment of advanced hepatocellular carcinoma (HCC). Emodin is an active component of Chinese herbs, and is effective against leukemia, lung cancer, colon cancer, pancreatic cancer, and HCC; however, the sensitizing effect of emodin on sorafenib-based HCC therapy has not been evaluated. Here, we demonstrate that emodin significantly improved the anti-cancer effect of sorafenib in HCC cells, such as HepG2, Hep3B, Huh7, SK-HEP-1, and PLC/PRF5. Mechanistically, emodin inhibits sterol regulatory element-binding protein-2 (SREBP-2) transcriptional activity, which suppresses cholesterol biosynthesis and oncogenic protein kinase B (AKT) signaling. Additionally, attenuated cholesterol synthesis and oncogenic AKT signaling inactivated signal transducer and activator of transcription 3 (STAT3), an oncogenic transcription factor. Furthermore, emodin synergistically increased cell cycle arrest in the G1 phase and apoptotic cells in the presence of sorafenib. Animal models xenografted with HepG2 or SK-HEP-1 cells also showed that the combination of emodin and sorafenib was sufficient to inhibit tumor growth. Overall, these results suggested that the combination of emodin and sorafenib may offer a potential therapy for patients with advanced HCC.

Zerumbone, a Tropical Ginger Sesquiterpene of Zingiber officinale Roscoe, Attenuates α-MSH-Induced Melanogenesis in B16F10 Cells.

Zerumbone (ZER), an active constituent of the Zingiberaceae family, has been shown to exhibit several biological activities, such as anti-inflammatory, anti-allergic, anti-microbial, and anti-cancer; however, it has not been studied for anti-melanogenic properties. In the present study, we demonstrate that ZER and Zingiber officinale (ZO) extract significantly attenuate melanin accumulation in α-melanocyte-stimulating hormone (α-MSH)-stimulated mouse melanogenic B16F10 cells. Further, to elucidate the molecular mechanism by which ZER suppresses melanin accumulation, we analyzed the expression of melanogenesis-associated transcription factor, microphthalmia-associated transcription factor (MITF), and its target genes, such as tyrosinase, tyrosinase-related protein 1 (TYRP1), and tyrosinase-related protein 2 (TYRP2), in B16F10 cells that are stimulated by α-MSH. Here, we found that ZER inhibits the MITF-mediated expression of melanogenic genes upon α-MSH stimulation. Additionally, cells treated with different concentrations of zerumbone and ZO showed increased extracellular signal-regulated kinases 1 and 2 (ERK1/2) phosphorylation, which are involved in the degradation mechanism of MITF. Pharmacological inhibition of ERK1/2 using U0126 sufficiently reversed the anti-melanogenic effect of ZER, suggesting that increased phosphorylation of ERK1/2 is required for its anti-melanogenic activity. Taken together, these results suggest that ZER and ZO extract can be used as active ingredients in skin-whitening cosmetics because of their anti-melanogenic effect.

Enhanced Antioxidant Activity of Bioactives in Colored Grains by Nano-Carriers in Human Lens Epithelial Cells.

The use of phytochemicals for preventing chronic diseases associated with oxidative stress such as cataracts is hindered by their low bioavailability. The effects of nano-carriers on the antioxidant activities of extracts of black rice with giant embryo (BRGEx) and soybeans (SBx) have been determined in human lens epithelial B3 cells. Scanning (SEM) and transmission electron microscopy (TEM) demonstrated that rGO (reduced graphene oxide) has a flat surface unlike GO (graphene oxide), which has a distinctive wrinkled structure with defects. UPLC analysis revealed 41.9 µg/100 g of γ-oryzanols in water extract of BRGE, and 111.8 µg /100 g of lutein, 757.7 µg/100 g of γ-tocotrienol, 4071.4 µg/100 g of γ-tocopherol in 40% ethanol extract of soybeans, respectively. Even though a low concentration of BRGEx alone did not show any antioxidant activity in B3 cells, co-treatment of BRGEx with rGO together substantially reduced hydrogen peroxide and methylglyoxal-induced DNA damage, as determined by phosphorylated γH2AX. In addition, SBx with rGO also attenuated DNA damage. Furthermore, intracellular reactive oxygen species were significantly decreased by combining extracts of these colored grains with rGO. These results suggest a potential application of nanocarriers for enhancing the bioavailability of phytochemicals.

Inhibition of NAT10 Suppresses Melanogenesis and Melanoma Growth by Attenuating Microphthalmia-Associated Transcription Factor (MITF) Expression.

N-acetyltransferase 10 (NAT10) has been considered a target for the treatment of human diseases such as cancer and laminopathies; however, its functional role in the biology of melanocytes is questionable. Using a small molecule or small interfering RNA targeting NAT10, we examined the effect of NAT10 inhibition on melanogenesis and melanoma growth in human and mouse melanoma cells. Genetic silencing or chemical inhibition of NAT10 resulted in diminished melanin synthesis through the suppression of melanogenesis-stimulating genes such as those encoding dopachrome tautomerase (DCT) and tyrosinase in B16F10 melanoma cells. In addition, NAT10 inhibition significantly increased cell cycle arrest in S-phase, thereby suppressing the growth and proliferation of malignant melanoma cells in vitro and in vivo. These results demonstrate the potential role of NAT10 in melanogenesis and melanoma growth through the regulation of microphthalmia-associated transcription factor (MITF) expression and provide a promising strategy for the treatment of various skin diseases (melanoma) and pigmentation disorders (chloasma and freckles).

Vanillin Suppresses Cell Motility by Inhibiting STAT3-Mediated HIF-1α mRNA Expression in Malignant Melanoma Cells.

Recent studies have shown that vanillin has anti-cancer, anti-mutagenic, and anti-metastatic activity; however, the precise molecular mechanism whereby vanillin inhibits metastasis and cancer progression is not fully elucidated. In this study, we examined whether vanillin has anti-cancer and anti-metastatic activities via inhibition of hypoxia-inducible factor-1α (HIF-1α) in A2058 and A375 human malignant melanoma cells. Immunoblotting and quantitative real time (RT)-PCR analysis revealed that vanillin down-regulates HIF-1α protein accumulation and the transcripts of HIF-1α target genes related to cancer metastasis including fibronectin 1 (FN1), lysyl oxidase-like 2 (LOXL2), and urokinase plasminogen activator receptor (uPAR). It was also found that vanillin significantly suppresses HIF-1α mRNA expression and de novo HIF-1α protein synthesis. To understand the suppressive mechanism of vanillin on HIF-1α expression, chromatin immunoprecipitation was performed. Consequently, it was found that vanillin causes inhibition of promoter occupancy by signal transducer and activator of transcription 3 (STAT3), but not nuclear factor-κB (NF-κB), on HIF1A. Furthermore, an in vitro migration assay revealed that the motility of melanoma cells stimulated by hypoxia was attenuated by vanillin treatment. In conclusion, we demonstrate that vanillin might be a potential anti-metastatic agent that suppresses metastatic gene expression and migration activity under hypoxia via the STAT3-HIF-1α signaling pathway.

Plumbagin Suppresses α-MSH-Induced Melanogenesis in B16F10 Mouse Melanoma Cells by Inhibiting Tyrosinase Activity.

Recent studies have shown that plumbagin has anti-inflammatory, anti-allergic, antibacterial, and anti-cancer activities; however, it has not yet been shown whether plumbagin suppresses alpha-melanocyte stimulating hormone (α-MSH)-induced melanin synthesis to prevent hyperpigmentation. In this study, we demonstrated that plumbagin significantly suppresses α-MSH-stimulated melanin synthesis in B16F10 mouse melanoma cells. To understand the inhibitory mechanism of plumbagin on melanin synthesis, we performed cellular or cell-free tyrosinase activity assays and analyzed melanogenesis-related gene expression. We demonstrated that plumbagin directly suppresses tyrosinase activity independent of the transcriptional machinery associated with melanogenesis, which includes micropthalmia-associated transcription factor (MITF), tyrosinase (TYR), and tyrosinase-related protein 1 (TYRP1). We also investigated whether plumbagin was toxic to normal human keratinocytes (HaCaT) and lens epithelial cells (B3) that may be injured by using skin-care cosmetics. Surprisingly, lower plumbagin concentrations (0.5-1 µM) effectively inhibited melanin synthesis and tyrosinase activity but do not cause toxicity in keratinocytes, lens epithelial cells, and B16F10 mouse melanoma cells, suggesting that plumbagin is safe for dermal application. Taken together, these results suggest that the inhibitory effect of plumbagin to pigmentation may make it an acceptable and safe component for use in skin-care cosmetic formulations used for skin whitening.

Fascaplysin Exerts Anti-Cancer Effects through the Downregulation of Survivin and HIF-1α and Inhibition of VEGFR2 and TRKA.

Fascaplysin has been reported to exert anti-cancer effects by inhibiting cyclin-dependent kinase 4 (CDK4); however, the precise mode of action by which fascaplysin suppresses tumor growth is not clear. Here, we found that fascaplysin has stronger anti-cancer effects than other CDK4 inhibitors, including PD0332991 and LY2835219, on lung cancer cells that are wild-type or null for retinoblastoma (RB), indicating that unknown target molecules might be involved in the inhibition of tumor growth by fascaplysin. Fascaplysin treatment significantly decreased tumor angiogenesis and increased cleaved-caspase-3 in xenografted tumor tissues. In addition, survivin and HIF-1α were downregulated in vitro and in vivo by suppressing 4EBP1-p70S6K1 axis-mediated de novo protein synthesis. Kinase screening assays and drug-protein docking simulation studies demonstrated that fascaplysin strongly inhibited vascular endothelial growth factor receptor 2 (VEGFR2) and tropomyosin-related kinase A (TRKA) via DFG-out non-competitive inhibition. Overall, these results suggest that fascaplysin inhibits TRKA and VEGFR2 and downregulates survivin and HIF-1α, resulting in suppression of tumor growth. Fascaplysin, therefore, represents a potential therapeutic approach for the treatment of multiple types of solid cancer.

Targeting Reactive Carbonyl Species with Natural Sequestering Agents.

Reactive carbonyl species generated by the oxidation of polyunsaturated fatty acids and sugars are highly reactive due to their electrophilic nature, and are able to easily react with the nucleophilic sites of proteins as well as DNA causing cellular dysfunction. Levels of reactive carbonyl species and their reaction products have been reported to be elevated in various chronic diseases, including metabolic disorders and neurodegenerative diseases. In an effort to identify sequestering agents for reactive carbonyl species, various analytical techniques such as spectrophotometry, high performance liquid chromatography, western blot, and mass spectrometry have been utilized. In particular, recent advances using a novel high resolution mass spectrometry approach allows screening of complex mixtures such as natural products for their sequestering ability of reactive carbonyl species. To overcome the limited bioavailability and bioefficacy of natural products, new techniques using nanoparticles and nanocarriers may offer a new attractive strategy for increased in vivo utilization and targeted delivery of bioactives.

PRMT5 is essential for the eIF4E-mediated 5'-cap dependent translation.

It is becoming clear that PRMT5 plays essential roles in cell cycle progression, survival, and responses to external stresses. However, the precise mechanisms underlying such roles of PRMT5 have not been clearly understood. Previously, we have demonstrated that PRMT5 participates in cellular adaptation to hypoxia by ensuring 5'-cap dependent translation of HIF-1α. Given that c-Myc and cyclin D1 expressions are also tightly regulated in 5'-cap dependent manner, we here tested the possibility that PRMT5 promotes cell proliferation by increasing de novo syntheses of the oncoproteins. c-Myc and cyclin D1 were found to be noticeably downregulated by PRMT5 knock-down. A RNA immunoprecipitation analysis, which can identify RNA-protein interactions, showed that PRMT5 is required for the interaction among eIF4E and 5'-UTRs of HIF-1α, c-Myc and cyclin D1 mRNAs. In addition, PRMT5 knock-down inhibited cell proliferation by inducing cell cycle arrest at the G1 phase. More importantly, ectopic expression of eIF4E significantly rescued the cell cycle progression and cell proliferation even in PRMT5-deficeint condition. Based on these results, we propose that PRMT5 determines cell fate by regulating 5'-cap dependent translation of proteins essential for proliferation and survival.

Antioxidant activity and acetylcholinesterase inhibition of grape skin anthocyanin (GSA).

We aimed to investigate the antioxidant and acetylcholinesterase inhibitory activities of the anthocyanin rich extract of grape skin. Grape skin anthocyanin (GSA) neutralized free radicals in different test systems, such as 2,-2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, to form complexes with Fe2+ preventing 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced erythrocyte hemolysis and oxidative DNA damage. Moreover, GSA decreased reactive oxygen species (ROS) generation in isolated mitochondria thus inhibiting 2',-7'-dichlorofluorescin (DCFH) oxidation. In an in vivo study, female BALB/c mice were administered GSA, at 12.5, 25, and 50 mg per kg per day orally for 30 consecutive days. Herein, we demonstrate that GSA administration significantly elevated the level of antioxidant enzymes in mice sera, livers, and brains. Furthermore, GSA inhibited acetylcholinesterase (AChE) in the in vitro assay with an IC50 value of 363.61 µg/mL. Therefore, GSA could be an excellent source of antioxidants and its inhibition of cholinesterase is of interest with regard to neurodegenerative disorders such as Alzheimer's disease.

A novel chemically engineered multifunctional statin conjugate as self-assembled nanoparticles inhibiting bile acid transporters.

Statins are widely used to treat hyperlipidemia; however, their mechanism-inhibiting cholesterol production without promoting its utilization-causes problems, such as inducing diabetes. In our research, we develop, for the first time, a chemically engineered statin conjugate that not only inhibits cholesterol production but also enhances its consumption through its multifunctional properties. The novel rosuvastatin (RO) and ursodeoxycholic acid (UDCA) conjugate (ROUA) is designed to bind to and inhibit the core of the apical sodium-dependent bile acid transporter (ASBT), effectively blocking ASBT's function in the small intestine, maintaining the effect of rosuvastatin. Consequently, ROUA not only preserves the cholesterol-lowering function of statins but also prevents the reabsorption of bile acids, thereby increasing cholesterol consumption. Additionally, ROUA's ability to self-assemble into nanoparticles in saline-attributable to its multiple hydroxyl groups and hydrophobic nature-suggests its potential for a prolonged presence in the body. The oral administration of ROUA nanoparticles in animal models using a high-fat or high-fat/high-fructose diet shows remarkable therapeutic efficacy in fatty liver, with low systemic toxicity. This innovative self-assembling multifunctional molecule design approach, which boosts a variety of therapeutic effects while minimizing toxicity, offers a significant contribution to the advancement of drug development.

Effects of Computer-assisted Cognitive Rehabilitation Training on the Cognition and Static Balance of the Elderly.

[Purpose] The purpose of this study was to investigate the effects of a six-week-long computer-assisted cognitive rehabilitation training program on the improvement of cognition and balance abilities of the elderly. [Subjects] Thirty healthy elderly people, aged 65 to 80, were randomly assigned either to the training group (n=15) or the control group (n=15). [Methods] Cognitive functions were evaluated using MMSE-K, and the BioRescue AP 153 (RMINGENIERIE, France) was used to examine subjects' changes in static balance. [Results] The MMSE-K score showed a significant change over the course of the treatment period in the training group, but not in the control group. The sway area and sway path length decreased significantly in the training group, but it did not show any changes in the control group. [Conclusion] Computer-assisted cognitive rehabilitation training is an effective intervention method for the improvement of the cognition and balance abilities of the elderly.

Influence of the Hawthorne effect on spatiotemporal parameters, kinematics, ground reaction force, and the symmetry of the dominant and nondominant lower limbs during gait.

The Hawthorne effect is a change in behavior resulting from awareness of being observed or evaluated. This study aimed to determine whether awareness of being evaluated or presence of an observer influence gait. Twenty-one young women were asked to walk in three conditions. In the first condition (unawareness of evaluation; UE), participants were aware that it was a practice trial, and there was no observer. In the second condition (awareness of evaluation; AE), participants were aware that their gait was being evaluated. The third condition (AE + researcher observation; RO) was similar to the second condition except that an additional researcher observed the participant' gait. The spatiotemporal, kinematic, ground reaction forces, and ratio index (symmetry of both lower limbs) were compared among the three conditions. A higher ratio index indicated a relative increase in the value on left versus right. Gait speed (P = 0.012) and stride length (right and left; P = 0.006 and 0.007, respectively) were significantly increased in the AE + RO than in UE. Range of motion of the right hip and left ankle was significantly greater in AE than in UE (P = 0.039 and 0.012, respectively). The ratio index of ground reaction force during push-off was significantly higher in AE and AE + RO conditions than in UE (P < 0.001 and P = 0.004, respectively). The Hawthorne effect (awareness of being evaluated or presence of an observer) potentially influences gait. Thus, factors that influence gait analysis should be considered when evaluating normal gait.

Antihepatoma activity of chaetocin due to deregulated splicing of hypoxia-inducible factor 1α pre-mRNA in mice and in vitro.

UNLABELLED: Chaetocin, an antibiotic produced by Chaetomium species fungi, was recently found to have antimyeloma activity. Here we examined whether chaetocin has anticancer activities against solid tumors. Chaetocin inhibited the growth of mouse and human hepatoma grafts in nude mice. Immunohistochemical analyses revealed that chaetocin inhibits hypoxia-inducible factor-1α (HIF-1α) expression and vessel formation in the tumors. Chaetocin also showed antiangiogenic anticancer activities in HIF-1α(+/+) fibrosarcoma grafted in mice, but not in HIF-1α(-/-) fibrosarcoma. Biochemical analyses showed that chaetocin down-regulated HIF-1α and the transcripts of HIF-1 target genes including vascular endothelial growth factor in hepatoma tissues and in various hepatoma cell lines. Based on the reported literature, unsuccessful efforts were made to determine the mechanism underlying the action of chaetocin. Unexpectedly, chaetocin was found to cause the accumulation of HIF-1α premessenger RNA (pre-mRNA) but to reduce mature mRNA levels in hepatoma cells and tissues. Such an effect of chaetocin was not observed in cell lines derived from normal cells, and was cell type-dependent even among cancer cell lines. CONCLUSIONS: Our results suggest that chaetocin could be developed as an anticancer agent to target HIF-1 in some cancers including hepatoma. It is also suggested that the HIF-1α pre-mRNA splicing is a novel therapeutic target for controlling HIF-1-mediated pathological processes.

In vitro stability and in vivo anti-inflammatory efficacy of synthetic jasmonates.

A chlorinated methyl jasmonate analog (J7) was elaborated as an in vitro anti-inflammatory lead. However, its in vitro efficacy profile was not reproduced in a subsequent in vivo evaluation, presumably due to its rapid enzymatic hydrolysis in a biological system. In an attempt to improve the metabolic stability of the lead J7 by replacement of its labile methyl ester with reasonable ester groups, several analogs resistant to enzymatic hydrolysis were synthesized. In vivo evaluation of the stability-improved analogs showed that these compounds displayed higher efficacy than the lead J7, suggesting that these new jasmonate analogs may serve as potential anti-inflammatory leads.

Examination of Microcystin Adsorption by the Type of Plastic Materials Used during the Procedure of Microcystin Analysis.

The incidence of eutrophication is increasing due to fertilizer abuse and global warming. Eutrophication can induce the proliferation of cyanobacteria such as Microcystis, which produces microcystins. Microcystins are toxic to specific organs such as the liver and the heart. Thus, monitoring of microcystins is strongly required to control drinking water and agricultural product qualities. However, microcystins could be adsorbed by plastic materials during sample storage and preparation, hindering accurate analysis. Therefore, the current study examined the recovery rate of microcystins from six plastics used for containers and eight plastics used for membrane filters. Among the six plastics used for containers, polyethylene terephthalate showed the best recovery rate (≥81.3%) for 48 h. However, polypropylene, polystyrene, and high- and low-density polyethylenes showed significant adsorption after exposure for 1 hr. For membrane materials, regenerated cellulose (≥99.3%) showed the highest recovery rate of microcystins, followed by polyvinylidene fluoride (≥94.1%) and polytetrafluoroethylene (≥95.7%). The adsorption of microcystins appeared to be strongly influenced by various molecular interactions, including hydrophobic interaction, hydrogen bonding, and electrostatic interaction. In addition, microcystins' functional residues seemed to be critical factors affecting their adsorption by plastic materials. The present study demonstrates that polyethylene terephthalate and regenerated cellulose membrane are suitable plastic materials for the analysis of microcystins.