Stability study of thymoquinone, carvacrol and thymol using HPLC-UV and LC-ESI-MS

The aim of this study was to investigate the stability of three major antioxidants of Nigella sativa: thymoquinone (TQ), carvacrol (CR) and thymol (THY), under different stress conditions using HPLC and LC-MS/MS. Forced degradation for each compound was performed under different conditions, including oxidation, hydrolysis, photolysis and thermal decomposition. The results showed that both CR and THY were stable under the studied conditions, whereas TQ was not affected by acidic, basic and oxidative forced conditions but the effect of light and heat was significant. The degradation products of TQ were further investigated and characterized by LC-MS/MS. HPLC-UV method has been fully validated in terms of linearity and range, the limit of detection and quantitation, precision, selectivity, accuracy and robustness. The method was successfully applied to quantitative analysis of the principal antioxidants of Nigella sativa TQ, CR and THY in different phytopharmaceuticals

Arginase overexpression and NADPH oxidase stimulation underlie impaired vasodilation induced by advanced glycation end products

Background: Advanced glycation endproducts (AGEs) play a major role in the development of many vascular complications that are mediated by endothelial dysfunction. The present work aimed to investigate the mechanism by which AGEs impair vasodilation.Methods: The effect of AGEs on vasodilation induced by acetylcholine or D NONOate was examined by incubating isolated rat aortae with different AGEs concentrations. ACh-induced nitric oxide generation was assessed using the fluorescent probe diaminofluorecein (DAF-FM). The effect of AGEs on expressionof mRNA for arginase 2, NADPH oxidase and endothelial nitric oxide synthase (eNOS) were determined by real-time PCR.Results: One-hour in vitro incubation of rat aortae with AGEs impaired endothelial-dependent vasodilation produced by ACh, while increasing D NONOate-induced vasodilation. Preincubation of aortae with L-ornithine, an arginase 2-inhibitor, prevented the impairment effect induced by AGEs on endothelial dependent vasodilation. Superoxide scavenging by tempol or NADPH oxidase inhibition by apocynin also blocked the effect of AGEs. AGEs decreased ACh-induced NO production and this was inhibited by both L-ornithine and apocynin. Furthermore, AGEs exposure increased arginase mRNA expression butdecreased mRNA expression for eNOS in isolated rat aortae.Conclusion: The present results indicate that AGEs impairs endothelial-dependent vasodilation, and this effect is mediated via arginase overexpression and NADPH oxidase stimulation

Whole genome microarray analysis of DUSP4-deletion reveals a novel role for MAP kinase phosphatase-2 (MKP-2) in macrophage gene expression and function

Background: Mitogen-activated protein kinase phosphatase-2 (MKP-2) is a type 1 nuclear dual specific phosphatase (DUSP-4). It plays an important role in macrophage inflammatory responses through the negative regulation of Mitogen activated protein kinase (MAPK) signalling. However, information on the effect of MKP-2 on other aspect of macrophage function is limited. Methods: We investigated the impact of MKP-2 in the regulation of several genes that are involved in function while using comparative whole genome microarray analysis in macrophages from MKP-2 wild type (wt) and knock out (ko) mice. Results: Our data showed that the lack of MKP-2 caused a significant down-regulation of colony-stimulating factor-2 (Csf2) and monocyte to macrophage-associated differentiation (Mmd) genes, suggesting a role of MKP-2 in macrophage development. When treated with macrophage colony stimulating factor (M-CSF), Mmd and Csf2 mRNA levels increased but significantly reduced in ko cells in comparison to wt counterparts. This effect of MKP-2 deletion on macrophage function was also observed by cell counting and DNA measurements. On the signalling level, M-CSF stimulation induced extracellular signal-regulated kinases (ERK) phosphorylation, which was significantly enhanced in the absence of MKP-2. Pharmacological inhibition of ERK reduced both Csf2 and Mmd genes in both wild type and ko cultures, which suggested that enhanced ERK activation in ko cultures may not explain effects on gene expression. Interestingly other functional markers were also shown to be reduced in ko macrophages in comparison to wt mice; the expression of CD115, which is a receptor for M-CSF, and CD34, a stem/progenitor cell marker, suggesting global regulation of gene expression by MKP-2. Conclusions: Transcriptome profiling reveals that MKP-2 regulates macrophage development showing candidate targets from monocyte-to-macrophage differentiation and macrophage proliferation. However, it is unclear whether effects upon ERK signalling are able to explain the effects of DUSP-4 deletion on macrophage function

Effects of the CB1 receptor antagonists AM6545 and AM4113 on metabolic syndrome-induced prostatic hyperplasia in rats

Metabolic syndrome (MetS) is a combination of metabolic disorders that can predispose individuals to benign prostatic hyperplasia (BPH). The inhibition of the cannabinoid 1 (CB1) receptor has been used to treat metabolic disorders in animal models. This study reports the use of a peripherally restricted CB1 antagonist (AM6545) and a neutral CB1 antagonist (AM4113) to improve MetS-related BPH in rats. Animals were divided into three control groups to receive either a normal rodent diet, AM6545, or AM4113. MetS was induced in the fourth, fifth, and sixth groups using a concentrated fructose solution and high-salt diet delivered as food pellets for eight weeks. The fifth and sixth groups were further given AM6545 or AM4113 for additional four weeks. Body and prostate weights were measured and prostate sections were stained with hematoxylin eosin. Cyclin D1, markers of oxidative stress and inflammation, and levels of the endocannabinoids were recorded. BPH in rats with MetS was confirmed through increased prostate weight and index, as well as histopathology. Treatment with either AM6545 or AM4113 significantly decreased prostate weight, improved prostate histology, and reduced cyclin D1 expression compared with the MetS group. Groups treated with CB1 antagonists experienced reduced lipid peroxidation, recovered glutathione depletion, restored catalase activity, and had lower inflammatory markers interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α). MetS rats treated with either AM6545 or AM4113 showed reduced concentrations of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in the prostate compared with the MetS group. In conclusion, the CB1 antagonists AM6545 and AM4113 protect against MetS-induced BPH through their anti-proliferative, antioxidant, and anti-inflammatory effects

Delayed inflammatory reaction to hyaluronic acid lip filler after the Pfizer-BioNTech COVID-19 vaccine: A case report

Hypersensitivity reactions can be a side effect to any vaccine, but they are usually rare. The COVID-19 vaccination may cause hypersensitivity, and several cases of delayed hypersensitivity (DH) to hyaluronic acid (HA) dermal filler have been documented. The current report presents a case of a 36-year-old female patient with DH to HA dermal filler after receiving the Pfizer-BioNTech COVID-19 vaccine. Symptoms, including dryness, swelling, and a painless nodule, appeared after the first and second doses of the vaccine. The patient was treated with intralesional hyaluronidase and triamcinolone in the outpatient clinic. Although HA is relatively safe and routinely used in aesthetic medicine, DH reactions must be considered. Therefore, an appropriate patient history should be obtained, and physicians should provide counselling on the potential reactions to avoid these adverse effects

The role of mitogen-activated protein kinase phosphatase-2 (MKP-2) in macrophage development and gene expression

Mitogen-activated protein kinase phosphatase-2 (MKP-2) is a type 1 nuclear dual specific phosphatase (DUSP4) and an important immune regulator. It specifically dephosphorylates the MAP kinases ERK and JNK to influence pro- and antiinflammatory cytokine production. MKP-2 has recently been shown to play a significant role in controlling Leishmania mexicana infection (Al-Mutairi et al., 2010) primarily by influencing macrophage activity. However, information on the effect of MKP-2 deletion at the molecular level on macrophage development and function is limited. This project utilised a novel DUSP4 gene knockout mouse and investigated the effects of MKP-2 deletion on M-CSF induced MAPK signalling and macrophage development as well as macrophage gene expression. Experiments in bone marrow derived macrophages demonstrated that in response to M-CSF macrophage, proliferation was reduced following to MKP-2 deletion. This was correlated with ERK phosphorylation, the expression of CD115 and CD34 on macrophage progenitors as well as the induction of genes related to macrophage differentiation and proliferation, colony stimulating factor-2 (Csf2) and monocyte to macrophage differentiation associated (Mmd) genes. In addition a comparative microarray gene expression analysis was conducted on MKP-2-/- and MKP-2+/+ macrophages following (LPS) or (IL-4) activation. As demonstrated previously, and associated with a role for MKP-2 in antimicrobial activity, arginase-1 expression was up-regulated in MKP-2-/- compared with MKP- 2+/+ macrophages. Surprisingly, and in contrast, we found that other alternative activation markers Ym1 (Chi3l3) and Fizz1/Retnla (Relm-α) were significantly reduced in MKP-2-/- macrophages when compared with their wild-type counterparts. As both Ym1 and Fizz1 have been implicated to play a major role in extracellular matrix disposition this suggests a significant role for MKP-2 in wound healing. Collectively, the findings in the current study have established that MKP-2 plays an important role in macrophage development and immune function.Mitogen-activated protein kinase phosphatase-2 (MKP-2) is a type 1 nuclear dual specific phosphatase (DUSP4) and an important immune regulator. It specifically dephosphorylates the MAP kinases ERK and JNK to influence pro- and antiinflammatory cytokine production. MKP-2 has recently been shown to play a significant role in controlling Leishmania mexicana infection (Al-Mutairi et al., 2010) primarily by influencing macrophage activity. However, information on the effect of MKP-2 deletion at the molecular level on macrophage development and function is limited. This project utilised a novel DUSP4 gene knockout mouse and investigated the effects of MKP-2 deletion on M-CSF induced MAPK signalling and macrophage development as well as macrophage gene expression. Experiments in bone marrow derived macrophages demonstrated that in response to M-CSF macrophage, proliferation was reduced following to MKP-2 deletion. This was correlated with ERK phosphorylation, the expression of CD115 and CD34 on macrophage progenitors as well as the induction of genes related to macrophage differentiation and proliferation, colony stimulating factor-2 (Csf2) and monocyte to macrophage differentiation associated (Mmd) genes. In addition a comparative microarray gene expression analysis was conducted on MKP-2-/- and MKP-2+/+ macrophages following (LPS) or (IL-4) activation. As demonstrated previously, and associated with a role for MKP-2 in antimicrobial activity, arginase-1 expression was up-regulated in MKP-2-/- compared with MKP- 2+/+ macrophages. Surprisingly, and in contrast, we found that other alternative activation markers Ym1 (Chi3l3) and Fizz1/Retnla (Relm-α) were significantly reduced in MKP-2-/- macrophages when compared with their wild-type counterparts. As both Ym1 and Fizz1 have been implicated to play a major role in extracellular matrix disposition this suggests a significant role for MKP-2 in wound healing. Collectively, the findings in the current study have established that MKP-2 plays an important role in macrophage development and immune function

Design, synthesis and in vitro antiproliferative activity of new thiazolidinedione-1,3,4-oxadiazole hybrids as thymidylate synthase inhibitors

Thymidylate synthase (TS) has been an attention-grabbing area of research for the treatment of cancers due to their role in DNA biosynthesis. In the present study, we have synthesised a library of thiazolidinedione-1,3,4-oxadiazole hybrids as TS inhibitors. All the synthesised hybrids followed Lipinski and Veber rules which indicated good drug likeness properties upon oral administration. Among the synthesised hybrids, compound 9 and 10 displayed 4.5 and 4.4 folds activity of 5-Fluorouracil, respectively against MCF-7 cell line whereas 3.1 and 2.5 folds cytotoxicity against HCT-116 cell line. Furthermore, compound 9 and 10 also inhibited TS enzyme with IC50 = 1.67 and 2.21 µM, respectively. Finally, the docking studies of 9 and 10 were found to be consistent with in vitro TS results. From these studies, compound 9 and 10 has the potential to be developed as TS inhibitors

Nano Ellagic Acid Counteracts Cisplatin-Induced Upregulation in OAT1 and OAT3: A Possible Nephroprotection Mechanism

Cisplatin is an anticancer drug commonly used for solid tumors. However, it causes nephrotoxicity. OAT1 and OAT3 are organic anion transporters known to contribute to the uptake of cisplatin into renal tubular cells. The present study was designed to examine the protective role of ellagic acid nanoformulation (ellagic acid nano) on cisplatin-induced nephrotoxicity in rats, and the role of OAT1/OAT3 in this effect. Four groups of male Wistar rats were used (n = 6): (1) control, (2) cisplatin (7.5 mg/kg single dose, intraperitoneal), (3) cisplatin + ellagic acid nano (1 mg/kg), and (4) cisplatin + ellagic acid nano (2 mg/kg). Nephrotoxic rats treated with ellagic acid nano exhibited a significant reduction in elevated serum creatinine, urea, and oxidative stress marker, malondialdehyde (MDA). Additionally, ellagic acid nano restored renal glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Ellagic acid nano improved the histopathological changes induced by cisplatin, such as tubular dilatation, necrosis, and degeneration. Interestingly, OAT1 and OAT3 showed significantly lower expression at both mRNA and protein levels following ellagic acid nano treatment relative to the cisplatin-exposed group. These findings reveal a potential inhibitory role of ellagic acid antioxidant on OAT1 and OAT3 expression and thus explains its nephroprotective effect against cisplatin nephrotoxicity

Anti-angiogenic agents for the treatment of solid tumors: Potential pathways, therapy and current strategies – A review

Recent strategies for the treatment of cancer, other than just tumor cell killing have been under intensive development, such as anti-angiogenic therapeutic approach. Angiogenesis inhibition is an important strategy for the treatment of solid tumors, which basically depends on cutting off the blood supply to tumor micro-regions, resulting in pan-hypoxia and pan-necrosis within solid tumor tissues. The differential activation of angiogenesis between normal and tumor tissues makes this process an attractive strategic target for anti-tumor drug discovery. The principles of anti-angiogenic treatment for solid tumors were originally proposed in 1972, and ever since, it has become a putative target for therapies directed against solid tumors. In the early twenty first century, the FDA approved anti-angiogenic drugs, such as bevacizumab and sorafenib for the treatment of several solid tumors. Over the past two decades, researches have continued to improve the performance of anti-angiogenic drugs, describe their drug interaction potential, and uncover possible reasons for potential treatment resistance. Herein, we present an update to the pre-clinical and clinical situations of anti-angiogenic agents and discuss the most recent trends in this field