Inhibition of Exosome Release Sensitizes U937 Cells to PEGylated Liposomal Doxorubicin

Aims

Acute myeloblastic leukemia (AML) is the most common type of acute leukemia in adults. Despite numerous treatment strategies including chemotherapy and radiotherapy, a large number of patients do not respond to treatment and experience relapse. The main problem of these patients is the development of resistance to anti-cancer drugs. Therefore, any endeavor to reduce drug resistance in these patients is of high priority. In general, several mechanisms such as changes in drug metabolic pathways, drug inactivation, drug target alterations and reduced drug accumulation in the cells contribute to drug resistance of cancer cells. In this context, evidence suggests that exosomes could reduce drug resistance by removing drugs from their parent cells. In the present study, we aimed to investigate the effects of exosome release inhibition on the resistance of U937 cells to PEGylated liposomal doxorubicin (PLD).

Main Methods

In order to find a suitable ABCG2 (ATP-binding cassette sub-family G member 2) transporter substrate, virtual screening was performed among a list of drugs used in leukemia and PLD was selected. U937 cells were treated with PLD with/without co-treatment with the exosome release inhibitor, GW4869. Released exosomes within different study groups were isolated and characterized to determine the differences between groups. Doxorubicin presence in the isolated exosomes was also measured by high performance liquid chromatography (HPLC) to confirm drug export through the exosomes. Finally, the effect of exosome inhibition on the cytotoxicity of PLD on U937 cells was determined using different cytotoxicity assays including the standard lactate dehydrogenase (LDH) release assay and the flow cytometric analysis of apoptotic and non-apoptotic cell death.

Key Findings

GW4869 treatment caused a significant decrease in the exosome release of U937 cells compared to the untreated cells, as evidenced by the reduction of the protein content of the isolated exosomes (P<0.05). Co-treatment with GW4869 significantly increased cytotoxic cell death in the groups treated with 0.5 and 1 µM PLD, compared to the same groups without GW4869 co-treatment (P<0.05). Interestingly, co-treatment with GW4896 and 0.5 µM PLD was enough to induce the same cytotoxic effect as that of the sole 1 µM PLD group.

Significance

Our findings showed that U937 cells increase their resistance against the cytotoxic effects of PLD through the exosome-mediated expelling of the drug. Inhibition of exosome release could prevent PLD efflux and consequently increase the vulnerability of the U937 cells to the cytotoxic effects of PLD. Our results along with prior studies indicate that the integration of exosome release inhibitors into the common PLD-containing chemotherapy regimens could significantly lower the required concentrations of the drug and consequently reduce its associated side effects. Further studies are warranted to identify clinically safe inhibitors and investigate their clinical efficacy.

Chromone-lipoic acid conjugate: Neuroprotective agent having acceptable butyrylcholinesterase inhibition, antioxidant and copper-chelation activities

PURPOSE

Alzheimer's disease (AD) is a multifaceted neurodegenerative disease. To target simultaneously multiple pathological processes involved in AD, natural-origin compounds with unique characteristics are promising scaffolds to develop novel multi-target compounds in the treatment of different neurodegenerative disease, especially AD. In this study, novel chromone-lipoic acid hybrids were prepared to find a new multifunctional lead structure for the treatment of AD.

METHODS

Chromone-lipoic acid hybrids were prepared through click reaction and their neuroprotection and anticholinesterase activity were fully evaluated. The anti-amyloid aggregation, antioxidant and metal-chelation activities of the best compound were also investigated by standard methods to find a new multi-functional agent against AD.

RESULTS

The primary biological screening demonstrated that all compounds had significant neuroprotection activity against H2O2-induced cell damage in PC12 cells. Compound 19 as the most potent butyrylcholinesterase (BuChE) inhibitor (IC50 = 7.55 μM) having significant neuroprotection activity as level as reference drug was selected for further biological evaluations. Docking and kinetic studies revealed non-competitive mixed-type inhibition of BuChE by compound 19. It could significantly reduce formation of the intracellular reactive oxygen species (ROS) and showed excellent reducing power (85.57 mM Fe+2), comparable with quercetin and lipoic acid. It could also moderately inhibit Aβ aggregation and selectively chelate with copper ions in 2:1 M ratio.

CONCLUSION

Compound 19 could be considered as a hopeful multifunctional agent for the further development gainst AD owing to the acceptable neuroprotective and anti-BuChE activity, moderate anti-Aβ aggregation activity, outstanding antioxidant activity as well as selective copper chelation ability. A new chromone-lipoic acid hybrid was synthesized as anti-Alzheimer agent with BuChE inhibitory activity, anti-Aβ aggregation, metal-chelation and antioxidant properties.

Impact of Acrylamide on Cellular Senescence Response and Cell Cycle Distribution via an In-vitro Study

Exposure to certain environmental toxins has been shown to be associated with cellular senescence mainly through induction of oxidative stress and impact on cellular systems. Acrylamide (ACR) has raised worldwide concerns regarding the high risk of human dietary exposure to its hazardous effect. Although there is ample evidence about the carcinogenicity of ACR, limited studies have focused on its impact on cellular aging. The levels of β-galactosidase (SA-β-gal) activity, cell cycle distribution, and the expression of the senescence-associated gene and inflammatory markers were evaluated following exposure of embryonic fibroblast cells to ACR. A significant elevation in SA-β-gal activity after exposure to different concentrations of ACR was accompanied by a considerably increased level of reactive oxygen species and lipid peroxidation. ACR-treated cells showed a noticeable decline in the total antioxidant capacity and thiol molecules. Moreover, the expression of cellular senescence-related genes including p38, p53, and p21 significantly upregulated at the high concentration of 5 mM ACR. ACR also induced G0/G1 phase arrest in embryonic fibroblast cells. The current study results revealed that exposure to ACR could enhance senescence response, contributing to increased oxidative stress and cellular damage.

Short-term Effects of Metformin on Cardiac and Peripheral Blood Cells Following Cecal Ligation and Puncture-induced Sepsis

AIM OF THE STUDY

Sepsis has well-documented inflammatory effects on cardiovascular and blood cells. This study is designed to investigate potential anti-inflammatory effects of metformin on cardiac and blood cells 12 and 24 h following cecal ligation and puncture (CLP)-induced sepsis.

METHODS

For the purpose of this study, 36 male Wistar rats were divided into six groups: two groups underwent CLP, two groups underwent CLP and received metformin, and two groups only received sham operations. 12 h later, 18 rats (half of rats in each of the three aforementioned groups) were sacrificed and cardiac and blood cells were harvested. Subsequently, 12 h later, the rest of the rats were euthanatized. In all harvested blood and cardiac cells, oxidative stress indicators, antioxidant properties, count of blood cells, neutrophil infiltration, percentage of weight loss and pathological assessment were conducted.

RESULTS

In our experiment, metformin elevated antioxidant levels, improved function of blood cells and percentage of weight loss. Moreover, in the groups which received metformin, oxidative stress and neutrophil infiltration markers were decreased significantly. Moreover, pathological investigations of cardiac cell injury were reduced in the metformin group.

CONCLUSIONS

Our findings suggest that in CLP induced sepsis model, metformin can improve the function of blood and cardiac cells through alleviating inflammation, improvement of anti-inflammation properties, and enhancement of blood profile, and all these effects are more pronounced after 24 h in comparison with 12 h after induction of sepsis.

Therapeutic Effects of Gallic Acid in Regulating Senescence and Diabetes; an In Vitro Study

Gallic acid (GA), a plant-derived ubiquitous secondary polyphenol metabolite, can be a useful dietary supplement. This in vitro study’s primary purpose was to assess the anti-aging properties of GA using rat embryonic fibroblast (REF) cells, antidiabetic effects via pancreatic islet cells, and finally, elucidating the molecular mechanisms of this natural compound. REF and islet cells were isolated from fetuses and pancreas of rats, respectively. Then, several senescence-associated molecular and biochemical parameters, along with antidiabetic markers, were investigated. GA caused a significant decrease in the β-galactosidase activity and reduced inflammatory cytokines and oxidative stress markers in REF cells. GA reduced the G0/G1 phase in senescent REF cells that led cells to G2/M. Besides, GA improved the function of the β cells. Flow cytometry and spectrophotometric analysis showed that it reduces apoptosis via inhibiting caspase-9 activity. Taken together, based on the present findings, this polyphenol metabolite at low doses regulates different pathways of senescence and diabetes through its antioxidative stress potential and modulation of mitochondrial complexes activities.

Evaluation the cardiopulmonary markers in cecal ligation and puncture induced sepsis in Wistar rats

Objective: Sepsis is a clinical problem caused by host immune disability against pathogens. Rodent Cecal Ligation and Puncture (CLP) models mimic sepsis in humans. Gauges needle size in CLP is related to cytokine storm, inflammation, and organ failure. This study focus, for the first time, on precise and inexpensive biochemical markers to evaluate the difference of sepsis severity in the heart and lung tissues, one day after cecal ligation and puncture-induced sepsis with needle gauge 18 (G-18). Methods: Twelve adult male Wistar rats were randomly allocated into two groups of 6 animals. These groups include; sham operation as the control group and underwent CLP procedure with G-18. All rats were sacrificed 24 hours after CLP then lungs and heart samples were collected for biochemical and histological assessment. Following the procedure, reactive oxygen species (ROS), Myeloperoxidase Activity (MPO), Tumor Necrosis Factor-Alpha (TNF-α), High Mobility Group Box 1 (HMGB1), lactate generation, caspases (-3 and -9), gene expression of autophagy and cellular hypoxia and pathological assessment of both tissues were measured. Results: Increased level of ROS, MPO, pro-inflammatory cytokines, hyperlactatemia, caspases production, overexpression of hypoxia (PRKAA1 gene), and autophagy (MAP1LC3B gene) in the lungs were higher compared to heart 24 hours after the procedure. Moreover, hyperplasia of pneumocyte and inflammatory cells, and myocardial necrosis were found in the pathological assessment. Conclusion: The purpose of  study was to determine the severity of sepsis by means of cost effective and precise inflammatory markers. Our findings demonstrated that injury-related indicators in lungs meaningfully increased compared to heart 24 hours after CLP.

Gene-Environmental Interplay in Bisphenol A Subchronic Animal Exposure: New Insights into the Epigenetic Regulation of Pancreatic Islets

Endocrine-disrupting chemicals (EDCs) such as bisphenol A (BPA), which is widely used in the plastic industry, have recently been considered to be involved in the pathogenesis of metabolic disorders, including obesity and diabetes. The present study aimed to examine the potentially detrimental effects of BPA on glucose and energy metabolism at the epigenetic level. The blood glucose profile of Wistar rats receiving different oral doses of BPA over 28 days was assessed. At the end of the treatment, the islets of Langerhans were isolated and purified, and their RNA content was extracted. MicroRNA (miRNA) profiling was evaluated using the next generation sequencing (NGS) method. After performing bioinformatic analysis of the NGS data, the gene ontology and data enrichment in terms of significantly disturbed miRNAs were evaluated through different databases, including Enrichr and DIANA tools. Additionally, the DNA methylation and the level of expression of two critical genes in glucose metabolism (PPARγ, Pdx1) were assessed. Subchronic BPA exposure (406 mg/kg/day) disturbed the blood glucose profile (fasting blood glucose and oral glucose tolerance) of Wistar rats and resulted in considerable cytotoxicity. NGS data analyses revealed that the expression of some crucial miRNAs involved in β-cell metabolism and diabetes occurrence and development, including miR-375, miR-676, miR-126-a, and miR-340-5p, was significantly disrupted. According to the DNA methylation evaluation, both PPARγ and Pdx1 genes underwent changes in the methylation level at particular loci on the gene's promoter. The expression levels of these genes were upregulated and downregulated, respectively. Overall, subchronic BPA exposure could cause epigenetic dysregulation at the gene level and interfere with the expression of key miRNAs and the methylation process of genes involved in glucose homeostasis. Understanding the exact underlying mechanisms by which BPA and other EDCs induce endocrine disturbance could be of great importance in the way of finding new preventive and therapeutic approaches.

Assessment of arsenic-induced modifications in the DNA methylation of insulin-related genes in rat pancreatic islets

Extended exposure to inorganic arsenic through contaminated drinking water has been linked with increased incidence of diabetes mellitus. The most common exposure occurs through the consumption of contaminated drinking water mainly through geogenic sources of inorganic arsenic. Epigenetic modifications are important mechanisms through which environmental pollutants could exert their toxic effects. Bisulfite sequencing polymerase chain reaction method followed by Sanger sequencing was performed for DNA methylation analysis. Our results showed that sodium arsenite treatment significantly reduced insulin secretion in pancreatic islets. It was revealed that the methylation of glucose transporter 2 (Glut2) gene was changed at two cytosine-phosphate-guanine (CpG) sites (-1743, -1734) in the promoter region of the sodium arsenite-treated group comparing to the control. No changes were observed in the methylation status of peroxisome proliferator-activated receptor-gamma (PPARγ), pancreatic and duodenal homeobox 1 (Pdx1) and insulin 2 (Ins2) CpG sites in the targeted regions. Measuring the gene expression level showed increase in Glut2 expression, while the expression of insulin (INS) and Pdx1 were significantly affected by sodium arsenite treatment. This study revealed that exposure to sodium arsenite changed the DNA methylation pattern of Glut2, a key transporter of glucose entry into the pancreatic beta cells (β-cells). Our data suggested possible epigenetic-mediated toxicity mechanism for arsenite-induced β-cells dysfunction. Further studies are needed to dissect the precise epigenetic modulatory activity of sodium arsenite that affect the biogenesis of insulin.

Metformin Attenuates Brain Injury by Inhibiting Inflammation and Regulating Tight Junction Proteins in Septic Rats

OBJECTIVE

Metformin has a potent inhibitory activity against inflammation and oxidative stress, which inevitably occur in sepsis-associated encephalopathy (SAE). The precise mechanisms underlying neuroprotective effects of metformin in SAE, are still unclear. In the present work, the protective effect of metformin on SAE using cecal ligation and puncture (CLP) model of sepsis, was assessed.

MATERIALS AND METHODS

In this experimental study, CLP procedure was performed in Wistar rats and 50 mg/kg metformin was administered immediately. Specific markers of sepsis severity, inflammation, blood brain barrier (BBB) dysfunction, and brain injury, were investigated. Specific assay kits and real-time polymerase chain reaction (RT-PCR) were used. Histopathological assessment was also carried out.

RESULTS

Treatment with metformin decreased murine sepsis score (MSS), lactate, platelet lymphocyte ratio (PLR), and high mobility group box (HMGB1) levels. The expression levels of claudin 3 (Cldn3) and claudin 5 (Cldn5) were increased following treatment with metformin. Metformin decreased the expression of S100b, neuron specific enolase (Nse), and glial fibrillary acidic protein (Gfap).

CONCLUSION

Our study suggests that metformin may inhibit inflammation and increase tight junction protein expressions which may improve BBB function and attenuate CLP-induced brain injury. Hence, the potential beneficial effects of metformin in sepsis, should be considered in future.

Cannabinoids as anti-ROS in aged pancreatic islet cells

AIMS

Cannabinoids are the chemical compounds with a high affinity for cannabinoid receptors affecting the central nervous system through the release of neurotransmitters. However, the current knowledge related to the role of such compounds in the regulation of cellular aging is limited. This study aimed to investigate the effect of cannabidiol and tetrahydrocannabinol on the function of aged pancreatic islets.

MAIN METHODS

The expression of p53, p38, p21, p16, and Glut2 genes and β-galactosidase activity were measured as hallmarks of cell aging applying real-time PCR, ELISA, and immunocytochemistry techniques. Pdx1 protein expression, insulin release, and oxidative stress markers were compared between young and aged rat pancreatic islet cells.

KEY FINDINGS

Upon the treatment of aged pancreatic islets cells with cannabidiol and tetrahydrocannabinol, the expression of p53, p38, p21 and the activity of β-galactosidase were reduced. Cannabidiol and tetrahydrocannabinol increase insulin release, Pdx1, Glut2, and thiol molecules expression, while the oxidative stress parameters were decreased. The enhanced expression of Pdx1 and insulin release in aged pancreatic islet cells reflects the extension of cell healthy aging due to the significant reduction of ROS.

SIGNIFICANCE

This study provides evidence for the involvement of cannabidiol and tetrahydrocannabinol in the oxidation process of cellular aging.

Alteration of gene expression profile in mouse embryonic stem cells and neural differentiation deficits by ethephon

Ethephon, a member of the organophosphorus compounds, is one of the most widely used plant growth regulators for artificial ripening. Although million pounds of this chemical is being used annually, the knowledge regarding its molecular toxicity is yet not sufficient. The purpose of this study was to evaluate the potential developmental toxicity of ethephon using embryonic stem cell model. The mouse embryonic stem cells (mESCs) were exposed to various concentrations of ethephon and the viability, cell cycle alteration and changes in the gene expression profile were evaluated using high-throughput RNA sequencing. Further, the effect of ethephon on neural differentiation potential was examined. The results showed that ethephon at noncytotoxic doses induced cell cycle arrest in mESCs. Gene ontology enrichment analysis showed that terms related to cell fate and organismal development, including neuron fate commitment, embryo development and cardiac cell differentiation, were markedly enriched in ethephon-treated cells. Neural induction of mESCs in the presence of ethephon was inhibited and the expression of neural genes was decreased in differentiated cells. Results obtained from this work clearly demonstrate that ethephon affects the gene expression profile of undifferentiated mESCs and prevents neural differentiation. Therefore, more caution against the frequent application of ethephon is advised.

Phytochemical profiling and ameliorative effects of Achillea cretica L. on rat model of endometriosis

ETHNOPHARMACOLOGICAL RELEVANCE

Achillea cretica (AC) is a medicinal plant emphasized for treatment of gynecological disorders and pathological symptoms similar to endometriosis in traditional Persian medicine. Since information about its chemical constituents is limited, the aim of this study is to investigate phenolic composition of AC extract as well as its effect on experimental model of endometriosis.

MATERIALS AND METHODS

RP-HPLC-PDA-ESI-MS/MS analysis was used for the determination of polyphenolic compounds. Endometriosis was induced in rats by suturing of uterus segments to abdominal wall of same rat, after eight weeks when the model was induced, it was followed by 28 days of treatment with 100, 200, and 400 mg/kg/day of hydroethanolic extract of the plant. Blood samples and implanted tissues were collected in the final day, and area of foci, tumor necrosis factor-α, vascular endothelial growth factor, interleukin-6, and serum total thiol molecules were measured and compared with positive group (0.2 mg/kg/day letrozole) and control group (solvent of extract: normal saline). Implanted tissue sections of the sacrificed rats were also assessed histopathologically.

RESULTS

Nine polyphenolic compounds were identified in AC extract including 7 flavonoids and 2 phenolic acids. Plant extract decreased area of foci and cytokine levels in serum and local tissue. Histopathological assessments confirmed the effectiveness of treatments by decreasing the thickness of epithelial layer and increasing the infiltration of leukocytes into this layer. Doses of 100 mg/kg and 400 mg/kg of extract showed better effects in comparison with the dose of 200 mg/kg in reduction of cytokine levels and size of implanted tissue. Extract and letrozole did not demonstrate significant effect on thiol level.

CONCLUSION

AC aerial extract may be a favorable medicine for management of endometriosis by modulating inflammatory cytokines; however, further studies are needed for more conclusive and reliable decision about its efficacy and safety.

Estrogens counteract tributyltin-induced toxicity in the rat islets of Langerhans

Background

Tributyltin (TBT) is known as an endocrine disruptor able to interfere with estrogen receptors (ERs) leading to toxic effects on the related endocrine pathways. TBT is an obesogen, reported to disrupt glucose homeostasis leading to diabetes. The aim of this study was to assess the influence of TBT and β-estradiol on the pancreatic islets of Langerhans in simultaneous exposures.

Experimental

Pancreatic islets of 15 male rat were isolated and exposed to TBT (10 μM), β-estradiol, and TBT plus β-estradiol for 24 h. Therewith, cellular viability, oxidative stress, apoptosis, and insulin secretion markers were investigated.

Results

TBT decreased the viability and increased the apoptosis, reactive oxygen species, and insulin secretion TBT led to increased amounts of apaptosis, reactive oxygen species (ROS), and insulin secretion in pancreatic islets; however, cellular viability was reduced. Co-exposure with β-estradiol ameliorated the entire mentioned variables near to the control level.

Conclusion

These results showed that β-estradiol protect pancreatic islets of Langerhans against TBT-induced toxicity by counteracting oxidative stress and apoptosis as well as insulin secretion. In this way, it is postulated that pancreatic ER pathways particularly in β-cells might be the determinant target of toxic effects of xenoestrogens like TBT. Hence, evaluation of xenoestrogens-induced ER dysfunction in the endocrine pancreas can be helpful in diabetic risk assessment of these contaminants. Pharmacological modifications of ER pathway in the β-cells seems promising for better management of diabetes.

Development of a Novel Anti-Obesity Compound with Inhibiting Properties on the Lipid Accumulation in 3T3-L1 Adipocytes

Background:

Obesity as a developing global challenge can be characterized by increase in adipocyte number and size arising from adipogenesis. Control of adipogenesis, as a potential strategy, can prevent and manage obesity. So far, the effectiveness of herbal medicine and active ingredients therapies for obesity and metabolic syndrome treatment has been investigated. In this study, a novel combination of berberine, catechin, and capsaicin was developed, and their effect on 3T3-L1 adipocytes was investigated.

Methods:

The effect of active ingredient on the cell viability was assessed by MTT assay. Adipocytes were treated with various concentrations of berberine (3 and 6.25 μM), catechin (6.25 and 12.5 μM), and capsaicin (6.25 and 12.5 μM) alone and in combination.

Results:

All active ingredients did not affect the cell viability by MTT assay at different concentrations. The dual and triple combinations of three active ingredients showed excellent potential as anti-obese without any toxicity. The inhibitory effect of berberine, catechin, and capsaicin on the differentiation of 3T3-L1 preadipocytes was found to be dose-dependent. These results indicate that catechin in both doses may have a stronger effect than the two other active ingredients on the intracellular lipid accumulation. Also, the triple combination of the aforementioned ingredients showed better responses than their dual combination.

Conclusion:

This work is the first report to simultaneously investigate these three active ingredients in a single, dual, and triple formats. The berberine, catechin, and capsaicin co-treatment inhibits the adipogenesis during the differentiation process. This compound can be a prospective therapy for obesity and relevant diseases such as dyslipidemia.

Mechanistic assessment of cadmium toxicity in association with the functions of estrogen receptors in the Langerhans islets

Objectives

Diabetes is a metabolic disease with an increasing prevalence for which finding new and efficient therapeutic approaches has always been a challenge. Preserving integrity and functionality of pancreatic β-cells as the only source of insulin in the body is such a case. To achieve this goal different cellular targets have been proposed among which pancreatic estrogen receptors have gotten much attention. In this work, we evaluated the integrity and function of islets of Langerhans under the influence of factors known to intervene with estrogen receptors. Cadmium, a toxic heavy metal, has been recently shown to interact with estrogen receptors but its toxicity in the pancreatic islets regarding this mechanism remains unclear.

Materials and Methods

Isolated islets of Langerhans from the pancreas of rats were grouped and treated with cadmium chloride and also cadmium chloride plus β-estradiol. After 24 hr incubation, parameters of cellular viability, oxidative stress, apoptosis, and insulin secretion were measured .

Results

The results indicated that cadmium reduced viability of the islets along with an increase in the formation of reactive oxygen species and apoptosis markers, and β-estradiol, in turn, was able to alleviate these disturbances to some extent, implicating the protective role of β-estradiol against pancreatic toxicity of cadmium.

Conclusion

It can be concluded that modification of estrogen receptors in the endocrine pancreas and especially β-cells may be a promising target to find a new therapeutic strategy for diabetes and even uncovering mechanisms of environmental toxicants that have been known as risk factors of diabetes.

Biochemical evidence on the potential role of methyl mercury in hepatic glucose metabolism through inflammatory signaling and free radical pathways

Methylmercury (MeHg) is an extremely important environmental toxicant posing serious health risks to human health and a big source of environmental pollutant. Numerous evidence available showing a link between nervous system toxicity and MeHg exposure. Other forms of mercury are reason of metabolic toxic effects and alteration of DNA in the human body. The sources of exposure could be occupational or other environmental settings. In the present study MeHg was orally gavaged to mice, at doses of 2.5, 5, and 10 mg/kg for 4 weeks. Fasting hyperglycemia, activity of hepatic phoshphoenolpyruvate carboxykinase and glucose 6-phoshphate were reported high as compared to control group. Inflammatory markers like, tumor necrosis factor α, the actual end product of inflammatory mediators' cascade pathway was also raised in comparison to control group. Hyperinsulinemia observed in serum showed clear understanding of mercury induced insulin resistance. Moreover, tissue damage due to increased oxidative stress markers like, hepatic lipid peroxidation, 8-deoxygunosine, reactive oxygen species, and carbonyl groups was significantly higher as compared to control group. MeHg caused a significant reduction in antioxidant markers like ferric reducing antioxidant power and total thiol molecules. The present study highlighted that activity of key enzymes involved in glucose metabolism is changed, owing to MeHg induced toxicity in the liver. Induction of similar toxic effects assumed to be stimulated by the production of high quantity free radicals.

Evaluation of anti-tyrosinase activity of Allium ursinum extracts and their metal complexes

BACKGROUND

A. ursinum is found to contain high levels of some beneficial phenolic and poly phenolic compounds were found to be effective in scavenging DPPH radicals and tyroinase inhibition. The aim of this study was to evaluate the anti-tyrosinase and antioxidant activity of three different extracts from the ultrasound-assisted method and their metal complexes from A. ursinum to discover new candidates for food additives, cosmetic and pharmaceutical products.

METHODS

Water, 70% ethanol and absolute ethanol extract of Allium ursinum and their man- ganese and zinc-complexes were characterized by FT-IR and UV-Vis spectra and their antioxidant and anti- tyrosinase activity determined using DPPH radical scavenging and mushroom tyrosinase assay.

RESULTS

The antioxidant activity of the water extract was superior to other samples, while the 70% ethanol extract exhibited the highest anti-tyrosinase activity. Metal complex formation of the extracts led to a signifi- cantly lower antioxidant effect. The tyrosinase inhibition strongly related to the metal ion and extraction sol- vent. All the zinc complexes had lower anti-tyrosinase activity than their extracts, while the manganese com- plex of the water and absolute ethanol extracts exhibited higher anti-tyrosinase activity than related extracts.

CONCLUSIONS

This study shows that Mn complex of A. ursinum extracts, based on the solvent extraction, could increase tyrosinase inhibition activity and could be a good candidate for intended cosmetic applications and food additives.

The role of minocycline in alleviating aluminum phosphide-induced cardiac hemodynamic and renal toxicity

Poisoning with aluminum phosphide (AlP) has been attributed to the high rate of mortality among many Asian countries. It affects several organs, mainly heart and kidney. Numerous literature demonstrated the valuable effect of minocycline in mitigating pathological symptoms of heart and kidney disease. The aim of the present study was to evaluate the probable protective effect of minocycline on cardiac hemodynamic parameters abnormalities and renal toxicity induced by AlP-poisoning in the rat model. AlP was administered by gavage at 12 mg/kg body weight followed by injection of minocycline for two interval times of 12 and 24 h, at 40, 80, 120 mg/kg body weight. Electrocardiographic (ECG) parameters were monitored, 30 min after AlP gavage for 6 h using an electronic cardiovascular monitoring device. Kidney tissue and serum were collected for the study of histology, mitochondrial complexes I, II, IV, lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activity, ADP/ATP ratio, mitochondrial cytochrome c release, apoptosis, lactate, BUN, and Cr levels. The results demonstrated that AlP induces ECG abnormalities, and failure of heart rate and blood pressure, which improved significantly by minocycline. Minocycline treatment significantly improved complexes I, IV, MPO and LDH activities, and also reduced the ADP/ATP ratio, lactate level, release of cytochrome c, and apoptosis in the kidney following AlP-poisoning. Also, the histological results showed an improvement of kidney injury in minocycline treated groups. In conclusion, the findings of this study showed that minocycline could improve cardiac hemodynamic abnormalities and kidney injury following AlP-poisoning, suggesting minocycline might be a possible candidate for the treatment of AlP-poisoning.

Bio-guided fractionation and isolation of active component from Tragopogon graminifolius based on its wound healing property

ETHNOPHARMACOLOGICAL RELEVANCE

Tragopogon graminifolius (T. graminifolius) from Asteraceae family has been used as a remedy in Persian traditional medicine for the treatment of various disorders such as wound healing.

AIM OF THE STUDY

The purpose of this study is to investigate the compounds of T. graminifolius, which are responsible for its wound healing activity.

MATERIALS AND METHODS

The experiment was performed in three phases; each phase consisted of fractionation of extracts followed by scratch assay. The results of the scratch assay were expressed using scratch closure index (SCI), representing the contraction of scratch.

RESULTS

In phase I, Ethyl acetate fraction (E) showed the maximum SCI (61.7 ± 3.5) that was selected for more fractionation in the next phase. In phase II, 12 fractions were obtained and labeled as fractions E- A to L, respectively. Based on the SCI of fractions, EF (SCI=68.9 ± 0.6) was the most active fraction in phase II and selected for further fractionation in phase III. In phase III, 8 fractions were resulted by fractionation of EF and labeled as EF- 1-8. Fraction EF5 with the highest SCI (30.8 ± 3.0) was the most effective fraction and Luteolin was the main component. Luteolin significantly improved viability of fibroblast cells and increased cell population that was accompanied by decreased cell apoptosis. Luteolin-induced cell number increase in the S and G2M phases of the cell cycle, further confirms the proliferative effect of this compound.

CONCLUSION

The results showed that the total extract and fractions of T. graminifolius stimulate proliferation and migration of skin fibroblast cells and Luteolin is one of the active compounds responsible for these effects.