Effect of Kaempferol on Modulation of Vascular Contractility Mainly through PKC and CPI-17 Inactivation.

In this study, we investigated the efficacy of kaempferol (a flavonoid found in plants and plant-derived foods such as kale, beans, tea, spinach and broccoli) on vascular contractibility and aimed to clarify the detailed mechanism underlying the relaxation. Isometric contractions of divested muscles were stored and linked with western blot analysis which was carried out to estimate the phosphorylation of myosin phosphatase targeting subunit 1 (MYPT1) and phosphorylation-dependent inhibitory protein for myosin phosphatase (CPI-17) and to estimate the effect of kaempferol on the RhoA/ROCK/CPI-17 pathway. Kaempferol conspicuously impeded phorbol ester-, fluoride- and a thromboxane mimetic-derived contractions regardless of endothelial nitric oxide synthesis, indicating its direct effect on smooth muscles. It also conspicuously impeded the fluoride-derived elevation in phospho-MYPT1 rather than phospho-CPI-17 levels and phorbol 12,13-dibutyrate-derived increase in phospho-CPI-17 and phospho-ERK1/2 levels, suggesting the depression of PKC and MEK activities and subsequent phosphorylation of CPI-17 and ERK1/2. Taken together, these outcomes suggest that kaempferol-derived relaxation incorporates myosin phosphatase retrieval and calcium desensitization, which appear to be modulated by CPI-17 dephosphorylation mainly through PKC inactivation.

The Effect of Luteolin on the Modulation of Vascular Contractility via ROCK and CPI-17 Inactivation.

In this investigation, we made a study of the efficacy of luteolin (a flavonoid found in plants such as vegetables, herbs and fruits) on vascular contractibility and to elucidate the mechanism underlying the relaxation. Isometric contractions of denuded muscles were stored and combined with western blot analysis which was conducted to assess the phosphorylation of myosin phosphatase targeting subunit 1 (MYPT1) and phosphorylation-dependent inhibitory protein for myosin phosphatase (CPI-17) and to examine the effect of luteolin on the RhoA/ROCK/CPI-17 pathway. Luteolin significantly alleviated phorbol ester-, fluoride- and thromboxane mimetic-elicited contractions regardless of endothelial nitric oxide synthesis, implying its direct effect on smooth muscle. It also significantly alleviated the fluoride-elicited elevation in pCPI-17 and pMYPT1 levels and phorbol 12,13-dibutyrate-elicited increase in pERK1/2 level, suggesting depression of ROCK and PKC/MEK activity and ensuing phosphorylation of MYPT1, CPI-17 and ERK1/2. Taken together, these results suggest that luteolin-elicited relaxation includes myosin phosphatase reactivation and calcium desensitization, which seems to be arbitrated by CPI-17 dephosphorylation via ROCK/PKC inhibition.

Safety and effectiveness of 4-week therapy with aceclofenac controlled release once a day.

Aceclofenac controlled-release (CR) is a once-a-day tablet with 200 mg of aceclofenac, and is bioequivalent to conventional aceclofenac. However, its safety in humans has not been well studied in Korea. Therefore, we aimed to evaluate the overall incidence and patterns of adverse events (AEs), the effectiveness of aceclofenac CR, and the differences in incidence rates of the AEs based on each patient's baseline charateristics. This study was conducted on patients receiving aceclofenac CR in clinical practice at each investigational institution to treat musculoskeletal pain and inflammation. The subjects were administered one tablet of aceclofenac CR (200 mg once-a-day) and were observed for 4 weeks post-administration. Factors affecting the occurrence of AEs were evaluated, and the Visual Analogue Scale (VAS) was used to measure the pain intensity. Among 14,543 subjects, the incidence rate of AEs was 0.86%, and that of adverse drug reactions was 0.74%. No serious AEs and unexpected adverse drug reactions were monitored. The incidence rates of AEs were significantly higher in females, inpatient treatment, individuals with concurrent disorders, and those receiving concomitant medications, respectively (all P < 0.05). Four weeks post-using aceclofenac CR, the mean changes in VAS was significantly decreased compared to prior administration. The overall clinical efficacy rate was 91.63%. This study confirmed that no severe adverse reactions were observed for aceclofenac CR exceeding those previously reported for safety results of conventional formulation of this drug in routine clinical practice settings. The use of aceclofenac CR might not violate the previously reported information on the safety and effectiveness of aceclofenac.

The Aqueous Extract of Humulus japonicus Ameliorates Cognitive Dysfunction in Alzheimer's Disease Models via Modulating the Cholinergic System.

Humulus japonicus (HJ) is an herbal medicine, which has been reported as being antioxidative and anti-inflammatory. The present study aimed to investigate the effect of oral administration of HJ water extract (HJW) on cognitive function through the cholinergic system in Alzheimer's disease (AD) mouse models. Institute of Cancer Research mice injected with beta-amyloid (Aß) (1-42) (i.c.v.) and APP/PS1 transgenic (TG) mice were orally administered with HJW at 500 mg/kg/day for 3 weeks. Aß-injected mice and APP/PS1 TG mice showed cognitive dysfunction, which was evaluated by various behavioral tests. HJW treatment significantly attenuated memory impairments in Aß-injected mice and APP/PS1 TG mice. Aß injection decreased acetylcholine (ACh) concentrations and choline acetyltransferase (ChAT) activity, and increased acetylcholinesterase (AChE) activity. These cholinergic impairments were also found in APP/PS1 TG mice. HJW significantly attenuated cholinergic alterations in Aß-injected mice and TG mice. In addition, HJW significantly decreased Aß plaque deposition in the cerebral cortex and hippocampus of TG mice. Therefore, the present study demonstrated that HJW protected against AD-related memory impairments via enhancing the cholinergic system and inhibiting Aß plaque deposition.

Benzyl Isothiocyanate-Induced Cytotoxicity via the Inhibition of Autophagy and Lysosomal Function in AGS Cells.

Gastric adenocarcinoma is among the top causes of cancer-related death and is one of the most commonly diagnosed carcinomas worldwide. Benzyl isothiocyanate (BITC) has been reported to inhibit the gastric cancer metastasis. In our previous study, BITC induced apoptosis in AGS cells. The purpose of the present study was to investigate the effect of BITC on autophagy mechanism in AGS cells. First, the AGS cells were treated with 5, 10, or 15 µM BITC for 24 h, followed by an analysis of the autophagy mechanism. The expression level of autophagy proteins involved in different steps of autophagy, such as LC3B, p62/SQSTM1, Atg5-Atg12, Beclin1, p-mTOR/mTOR ratio, and class III PI3K was measured in the BITC-treated cells. Lysosomal function was investigated using cathepsin activity and Bafilomycin A1, an autophagy degradation stage inhibitor. Methods including qPCR, western blotting, and immunocytochemistry were employed to detect the protein expression levels. Acridine orange staining and omnicathepsin assay were conducted to analyze the lysosomal function. siRNA transfection was performed to knock down the LC3B gene. BITC reduced the level of autophagy protein such as Beclin 1, class III PI3K, and Atg5-Atg12. BITC also induced lysosomal dysfunction which was shown as reducing cathepsin activity, protein level of cathepsin, and enlargement of acidic vesicle. Overall, the results showed that the BITC-induced AGS cell death mechanism also comprises the inhibition of the cytoprotective autophagy at both initiation and degradation steps.

Abietic acid alleviates endoplasmic reticulum stress and lipid accumulation in human primary hepatocytes through the AMPK/ORP150 signaling.

Abietic acid (AA), the main component of pine resin that has been traditionally used as Asian medicine, has been reported to demonstrate anti-inflammatory activities. Despite this, little is known about the effects of AA on hepatic endoplasmic reticulum (ER) stress and lipid metabolism. This study investigated the impacts of AA on ER stress and steatosis in in vitro obesity models. We found that Treatment with AA reduced lipid deposition and lipogenesis-related proteins expression in human primary hepatocytes. Augmented expression of ER stress markers (phospho-eukaryotic initiation factor-2α (eIF2α) and C/EBP homologous protein (CHOP)) in palmitate-treated hepatocytes were reversed by AA treatment. Further, AA treatment increased the expression of phospho-AMPK and oxygen-regulated protein 150 (ORP150) in hepatocytes. siRNA-associated knockdown of AMPK or ORP150 expression reduced the effects of AA on not only hepatic ER stress but also lipogenesis and apoptosis. These results denote that AA attenuates lipid accumulation in hepatocytes in the presence of palmitate through the suppression of ER stress by AMPK/ORP150 signaling. AA could be a potential candidate for treating non-alcoholic fatty liver disease.

The Effect of Galangin on the Regulation of Vascular Contractility via the Holoenzyme Reactivation Suppressing ROCK/CPI-17 rather than PKC/CPI-17.

In this study, we investigated the influence of galangin on vascular contractibility and to determine the mechanism underlying the relaxation. Isometric contractions of denuded aortic muscles were recorded and combined with western blot analysis which was performed to measure the phosphorylation of phosphorylation-dependent inhibitory protein of myosin phosphatase (CPI-17) and myosin phosphatase targeting subunit 1 (MYPT1) and to evaluate the effect of galangin on the RhoA/ROCK/CPI-17 pathway. Galangin significantly inhibited phorbol ester-, fluoride- and thromboxane mimetic-induced vasoconstrictions regardless of endothelial nitric oxide synthesis, suggesting its direct effect on vascular smooth muscle. Galangin significantly inhibited the fluoride-dependent increase in pMYPT1 and pCPI-17 levels and phorbol 12,13-dibutyrate-dependent increase in pERK1/2 level, suggesting repression of ROCK and MEK activity and subsequent phosphorylation of MYPT1, CPI-17 and ERK1/2. Taken together, these results suggest that galangin-induced relaxation involves myosin phosphatase reactivation and calcium desensitization, which appears to be mediated by CPI-17 dephosphorylation via not PKC but ROCK inactivation.

3-hydroxymorphinan enhances mitochondrial biogenesis and adipocyte browning through AMPK-dependent pathway.

3-hydroxymorphinan (3-HM), a metabolite of dextromethorphan, has previously been reported to have anti-inflammatory, anti-oxidative stress, and neuroprotective effects. However, its effect on energy metabolism in adipocytes remains unclear. Herein, we investigated 3-hydroxymorphinan (3-HM) effects on mitochondrial biogenesis, oxidative stress, and lipid accumulation in 3T3-L1 adipocytes. Further, we explored 3-HM-associated molecular mechanisms. Mouse adipocyte 3T3-L1 cells were treated with 3-HM, and various protein expression levels were determined by western blotting analysis. Mitochondria accumulation and lipid accumulation were measured by staining methods. Cell toxicity was assessed by cell viability assay. We found that treatment of 3T3-L1 adipocytes with 3-HM increased expression of brown adipocyte markers, such as uncoupling protein-1 (UCP-1) and peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α). 3-HM promotes mitochondrial biogenesis and its-mediated gene expression. Additionally, 3-HM treatment suppressed mitochondrial ROS generation and superoxide along with improved mitochondrial complex I activity. We found that treatment of 3-HM enhanced AMPK phosphorylation. siRNA-mediated suppression of AMPK reversed all these changes in 3T3-L1 adipocytes. In sum, 3-HM promotes mitochondrial biogenesis and browning and attenuates oxidative stress and lipid accumulation in 3T3-L1 adipocytes via AMPK signaling. Thus, 3-HM-mediated AMPK activation can be considered a therapeutic approach for treating obesity and related diseases.

Capmatinib improves insulin sensitivity and inflammation in palmitate-treated C2C12 myocytes through the PPARδ/p38-dependent pathway.

Capmatinib (CAP) has been used to treat metastatic non-small lung cancer (NSCL) and suppress inflammation. It causes hypoglycemia in NSCL patients. Therefore, it is expected that CAP improves inflammation-mediated insulin resistance due to its anti-inflammatory effect. However, the impacts of CAP on insulin signaling in skeletal muscle cells have not yet been fully elucidated. Herein, we investigated the effect of CAP on insulin resistance in palmitate-treated C2C12 myocytes and explored the related molecular mechanisms. We found that treatment of C2C12 myocytes with CAP reversed palmitate-induced impairment of insulin signaling and glucose uptake. CAP treatment ameliorated phosphorylation of inflammatory markers, including NFκB and IκB, in palmitate-treated C2C12 myocytes. Further, it augmented PPARδ expression and suppressed palmitate-induced p38 phosphorylation in a dose-dependent manner. siRNA-mediated suppression of PPARδ abolished the effects of CAP on palmitate-induced insulin resistance and inflammation as well as p38 phosphorylation. Therefore, it has been shown that CAP treatment ameliorates insulin resistance in palmitate-treated C2C12 myocytes via PPARδ/p38 signaling-mediated suppression of inflammation. These results may represent a novel therapeutic approach that could halt insulin resistance and type 2 diabetes.

The Suppressive Effect of Leucine-Rich Glioma Inactivated 3 (LGI3) Peptide on Impaired Skin Barrier Function in a Murine Model Atopic Dermatitis.

This study aimed to restore the skin barrier function from atopic dermatitis (AD) via treatment with leucine-rich glioma inactivated 3 (LGI3) peptide. Male NC/Nga mice (7 weeks, 20 g) were randomly allocated into three groups (control, AD, and LGI3 group). After induction of AD skin lesions with Dermatophagoides farinae ointment, mice were treated with LGI3. The clinical score of AD was the highest and the dorsal skin thickness was the thickest in the AD group. In contrast, LGI3 treatment improved the clinical score and the dorsal skin thickness compared to the AD model. LGI3 treatment suppressed histopathological thickness of the epithelial cell layer of the dorsal skin. LGI3 treatment could indirectly reduce mast cell infiltration through restoring the barrier function of the skin. Additionally, the filaggrin expression was increased in immunohistochemical evaluation. In conclusion, the ameliorating effect and maintaining skin barrier homeostasis in the AD murine model treated with LGI3 could be attributed to complete re-epithelialization of keratinocytes. Hence, LGI3 might be considered as a new potential therapeutic target for restoring skin barrier function in AD.

Patient Accessibility and Budget Impact of Orphan Drugs in South Korea: Long-Term and Real-World Data Analysis (2007-2019).

This study aimed to identify orphan drug accessibility and impact on pharmaceutical budgets in South Korea by analyzing the status of orphan drug designation, approval, reimbursement, and pharmaceutical expenditure. We analyzed the dataset on orphan drugs designated, approved, and reimbursed from 2007 to 2019 based on long-term real-world data. The designated and approved orphan drugs were 165 and 156, respectively, and 88 out of 156 approved products were reimbursed. Total expenditure on orphan drugs increased annually to account for about 1.44% of total pharmaceutical expenditure in 2018. Orphan drug expenditure per patient increased on average by 8.7% per year. The average annual cost of orphan drugs was USD 27,000-USD 47,000, with the maximum value of USD 260,000-USD 560,000. As there are a number of orphan drugs that have not yet been reimbursable after approval, a reimbursement policy should be established that considers the characteristics of orphan drugs. Since the rapid increase in orphan drug expenditure can be a potential threat to the insurance budget, budget management should also be considered. In conclusion, it is necessary to take preemptive measures to manage the health insurance budget efficiently while improving patient accessibility to orphan drugs.

Polysaccharide-Rich Extract of Phragmites rhizome Attenuates Water Immersion Stress and Forced Swimming Fatigue in Rodent Animal Model.

Our study aimed to investigate the effects of the polysaccharide-rich extract of Phragmites rhizoma (PEP) against water immersion restraint (WIR) stress and forced swimming-induced fatigue. Exposure to WIR stress significantly increased the ulcer index, bleeding score, the weight of the adrenal gland, blood glucose concentrations, total cholesterol, cortisol, and creatine kinase (CK). The weight of the spleen decreased significantly. In addition, myeloperoxidase (MPO) and thiobarbituric acid-reactive substance (TBARS) were significantly upregulated by WIR stress. The antioxidative factors such as glutathione (GSH) and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the stomach were decreased by WIR stress. Alterations induced by WIR stress were effectively reversed by pretreatment with PEP. The swimming endurance capacity of mice was significantly prolonged by the oral administration of PEP. Swimming-induced fatigue significantly reduced the body weight; however, the injection of PEP inhibited the decrease of body weight. The PEP-treated group had significantly lower CK levels in plasma, an indicator of muscle damage. These results indicated that PEP has anti-stress and anti-fatigue effects, which are mediated by suppressing the hyperactivation of the hypothalamus-pituitary-adrenal axis, and antagonism of the oxidative damages induced by WIR stress and prolonged swimming times.

p-Coumaric acid stimulates longitudinal bone growth through increasing the serum production and expression levels of insulin-like growth factor 1 in rats.

The aim of the present study was to examine the effects of p-coumaric acid on the longitudinal growth of the long bone in adolescent male rats. Teatment with p-coumaric acid significantly increased the tibial length and the height of each growth plate zone and the ratio of 5-bromo-2'-deoxyuridine-positive cells relative to total proliferative cells. Expression of insulin-like growth factor 1 and its receptor in the proliferative and hypertrophic zones, and serum levels of growth hormone and insulin-like growth factor 1 were significantly increased as well in the p-coumaric acid-treated group. Via increasing both the serum level of insulin-like growth factor 1 and its expression, p-coumaric acid could promote cell proliferation in growth plate zones. These results suggest that p-coumaric acid has the potential to increase height and may be a feasible alternative to growth hormone therapy.

Aqueous Extract of Humulus japonicus Attenuates Hyperlipidemia and Fatty Liver in Obese Mice.

In this study, the effects of Humulus japonicus (HJ) aqueous extract on 3T3-L1 preadipocytes and HepG2 cells (in vitro model) as well as on C57BL/6 mice fed on high-fat diet (HFD) (in vivo model) were evaluated. Mice fed on HFD for 12-weeks were taken the HJ water extract (HJW) at various doses, 50, 150, and 250 mg/kg, orally for 8 weeks. We have noticed the accumulation of fat globules in preadipocytes and HepG2 cells using Oil Red O staining. In addition, supplementation with HJW considerably inhibited the weight gain, lipid accumulation, and adipogenesis and decreased the size of subcutaneous adipocytes in 3T3-L1 adipocytes. Furthermore, treatment with HJW improved hyperlipidemia via decreasing the levels of serum triglyceride (TG) and low-density lipoproteins as well as the atherogenic index. Supplementation with HJW could attenuate HFD-induced lipid accumulation, increase the mRNA expressions of fatty acid synthase (FAS) and stearoyl-CoA desaturase (SCD1), and would elevate the levels of serum aspartate aminotransferase and alanine aminotransferase in mice liver. The levels of TG and FAS mRNA in HepG2 cells treated with palmitate were reduced in a dose-dependent manner. In sum, HJW could alleviate the HFD-induced obesity and decrease the dyslipidemia profiles; the keys that could contribute to cardiovascular and nonalcoholic liver diseases.

METRNL attenuates lipid-induced inflammation and insulin resistance via AMPK or PPARδ-dependent pathways in skeletal muscle of mice.

Physical activity has many beneficial effects on metabolic disorders, such as obesity, insulin resistance, and diabetes. Meteorin-like protein (METRNL), a novel secreted protein homologous to the neurotrophin Metrn, is induced after exercise in the skeletal muscle. Herein, we investigated the effects of METRNL on lipid-mediated inflammation and insulin resistance in skeletal muscle via AMP-activated protein kinase (AMPK) or peroxisome proliferator-activated receptor δ (PPARδ). Treatment with METRNL suppressed inflammatory markers, such as nuclear factor κB (NFκB) nuclear translocation, inhibitory κBα (IκBα) phosphorylation, interleukin-6 (IL-6) expression, and pro-inflammatory cytokines (such as TNFα and MCP-1). METRNL treatment also attenuated the impaired insulin response both in palmitate-treated differentiated C2C12 cells and the skeletal muscle of high-fat diet (HFD)-fed mice. Furthermore, METRNL administration rescued glucose intolerance and reduced HFD-induced body weight gain in mice; however, METRNL did not affect calorie intake. METRNL treatment increased AMPK phosphorylation and PPARδ expression both in differentiated C2C12 cells and mouse skeletal muscle. siRNA-mediated suppression of AMPK and PPARδ abrogated the suppressive effects of METRNL on palmitate-induced inflammation and insulin resistance. Moreover, METRNL augmented the mRNA expression of fatty acid oxidation-associated genes, such as carnitine palmitoyltransferase 1 (CPT1), acyl-CoA oxidase (ACO), and fatty acid binding protein 3 (FABP3). siRNAs for AMPK and PPARδ reversed these changes. In the current study, we report for the first time that METRNL alleviates inflammation and insulin resistance and induces fatty acid oxidation through AMPK or PPARδ-dependent signaling in skeletal muscle.

The chalcone compound isosalipurposide (ISPP) exerts a cytoprotective effect against oxidative injury via Nrf2 activation.

The chalcone compound isosalipurposide (ISPP) has been successfully isolated from the native Korean plant species Corylopsis coreana Uyeki (Korean winter hazel). However, the therapeutic efficacy of ISPP remains poorly understood. This study investigated whether ISPP has the capacity to activate NF-E2-related factor (Nrf2)-antioxidant response element (ARE) signaling and induce its target gene expression, and to determined the protective role of ISPP against oxidative injury of hepatocytes. In HepG2 cells, nuclear translocation of Nrf2 is augmented by ISPP treatment. Consistently, ISPP increased ARE reporter gene activity and the protein levels of glutamate cysteine ligase (GCL) and hemeoxygenase (HO-1), resulting in increased intracellular glutathione levels. Cells pretreated with ISPP were rescued from tert-butylhydroperoxide-induced reactive oxygen species (ROS) production and glutathione depletion and consequently, apoptotic cell death. Moreover, ISPP ameliorated the mitochondrial dysfunction and apoptosis induced by rotenone which is an inhibitor of complex 1 of the mitochondrial respiratory chain. The specific role of Nrf2 activation by ISPP was demonstrated using an ARE-deletion mutant plasmid and Nrf2-knockout cells. Finally, we observed that extracellular signal-regulated kinase (ERK) and AMP-activated protein kinase (AMPK), but not protein kinase C (PKC)-δ or other mitogen-activated protein kinases (MAPKs), are involved in the activation of Nrf2 by ISPP. Taken together, our results demonstrate that ISPP has a cytoprotective effect against oxidative damage mediated through Nrf2 activation and induction of its target gene expression in hepatocytes.

Clinical effect of a polysaccharide-rich extract of Acanthopanax senticosus on alcohol hangover.

The present study aimed to examine the effects polysaccharide-rich extract of Acanthopanax senticosus (PEA) on blood alcohol concentration (BAC) and hangover as well as blood lab parameters. A randomized, placebo-controlled, double-blind crossover trial was conducted. The PEA was orally administered before and after consuming alcohol 1.75 g/kg of pure alcohol. After alcohol consumption, BAC was measured for evaluation of alcohol pharmacokinetics. In the second day morning, subjects were asked to complete the Acute Hangover Scale (AHS) questionnarie. BAC results showed little difference between placebo and PEA groups, indicating that PEA does not have an effect on the pharmacokinetics of alcohol. However, several AHS items (i.e., tired, headache, dizziness, stomachache and nausea) and AHS total score were significantly improved by PEA. Blood lab parameters were significantly altered by alcohol in the placebo group. The alteration by alcohol of glucose and C-reactive protein (CRP) level was significantly attenuated by PEA. Therefore, PEA may have potential to reduce the severity of the alcohol hangover by inhibiting the alcohol-induced hypoglycemia and inflammatory response.

Baicalin-induced Akt activation decreases melanogenesis through downregulation of microphthalmia-associated transcription factor and tyrosinase.

Scutellaria baicalensis has been used topically to treat inflammatory skin diseases in traditional East Asian medicine. Because post-inflammatory hyperpigmentation of the skin is difficult to manage, we investigated the effects of baicalin, a major component of S. baicalensis, on melanin synthesis in Mel-Ab cells. Our data showed that baicalin significantly inhibited melanin production and tyrosinase activity in a dose-dependent fashion, but it did not directly influence tyrosinase activity. Moreover, baicalin treatment triggered decreases in both mRNA and protein levels of microphthalmia-associated transcription factor (MITF) and tyrosinase. Although AMP-activated protein kinase (AMPK) and extracellular signal-regulated kinase (ERK) activation were induced in baicalin-treated Mel-Ab cells, they were not responsible for baicalin-induced hypopigmentation. Because the Akt pathway is also known to be involved in regulation of melanogenic protein expression and melanin synthesis, we examined the effects of baicalin on the Akt pathway. Our results showed that baicalin treatment stimulated Akt activation. Treatment with LY294002, a specific Akt inhibitor, restored baicalin-induced melanogenesis inhibition and abolished MITF and tyrosinase downregulation by baicalin. Taken together, our data suggest that Akt activation by baicalin inhibits melanin production via downregulation of MITF and tyrosinase in Mel-Ab cells.

Protective effects of phosphatidylcholine on oxaliplatin-induced neuropathy in rats.

AIMS: The present study was designed to investigate the therapeutic potential of phosphatidylcholine (PC) on oxaliplatin-induced peripheral neuropathy. MAIN METHODS: Male Sprague-Dawley rats were randomly divided into three groups: the control group, the oxaliplatin group (4mg/kg, twice per week for 4weeks) and the oxaliplatin+PC (300mg/kg) group. To evaluate the effect of PC, we examined the thermal nociceptive threshold changes in oxaliplatin-induced peripheral neuropathy by conducting paw pressure, hot-plate and tail-flick tests. Additional experiments on the degree of oxidative stress in the sciatic nerves were performed by measuring the level of MDA, total glutathione (GSH), glutathione peroxidase (GPx) activity and superoxide dismutase (SOD) activity. We also used histopathological and immunohistochemical methods to observe neuronal damage and glial activation. KEY FINDINGS: PC attenuated oxidative stress by increasing antioxidant levels. In histopathological evaluation, the PC administrated group maintained normal morphologic appearance of sciatic nerves, similar to the control group. In spinal cords, however, no significant difference between the oxaliplatin-alone group and the oxaliplatin+PC group was observed. In the immunohistochemical evaluation, PC administration ameliorated oxaliplatin-induced microglial activation. SIGNIFICANCE: It is suggested that PC has a therapeutic potential against oxaliplatin-induced peripheral neuropathy due to its antioxidant property and modulation of microglial activities.

Simultaneous determination of 7-O-succinyl macrolactin A and its active major metabolite, macrolactin A in dog plasma using high-performance liquid chromatography with UV detection.

We developed a method for the simultaneous quantification of 7-O-succinyl macrolactin A and its active metabolite, macrolactin A, in dog plasma. After protein precipitation with acetonitrile including flufenamic acid as an internal standard, 7-O-succinyl macrolactin A, macrolactin A, and flufenamic acid were chromatographed on a reverse-phase C18 analytical column. The mobile phase, consisting of 20 mM acetate buffer and acetonitrile, was eluted using a gradient program at 1 mL/min, and the UV absorbance was measured at 230 nm. The retention times of 7-O-succinyl macrolactin A, flufenamic acid, and macrolactin A were 3.4, 4.8, and 6.9 min, respectively. The coefficient of variation in the assay precision for both substances was less than 6%, and the accuracy ranged from 96 to 105%. This method was used to measure the concentrations of 7-O-succinyl macrolactin A and macrolactin A in dog plasma following an intravenous administration of a single dose (25 mg/kg) of 7-O-succinyl macrolactin A salt.