Protective role of sinapic acid against arsenic: induced toxicity in rats

Investigating the effects of solvent polarity and temperature on the molecular, photophysical, and thermodynamic properties of sinapic acid using DFT and TDDFT

Sinapic acid (SA) is widely used in cosmetics, foods, and pharmaceuticals due to its antioxidant, anti-inflammatory, neuroprotective, antimicrobial, antifungal, anticancer, and cardioprotective properties. However, environmental factors such as solvent polarity and temperature can influence its biological activity. This work determined how solvent polarity and temperature affected the molecular, photophysical, and thermodynamic properties of SA in gas and various solvents using semi-empirical (MP6), Hartree-Fock (HF) with the B3LYP method and a 6-311++G(d,p) basis set, and density functional theory (DFT) with various basis sets, such as 3TO-3G*, 3-21G+, 6-31G++G(d,p), 6-311++G(d,p), aug-CC-PVDZ, LanL2DZ, SDD, and DGD2VP. The results indicated that solvent polarity influences molecular and spectroscopic properties, such as bond angles, dihedral angles, bond lengths, FTIR spectra, solvation energy, dipole moments, HOMO-LUMO band gaps, chemical reactivity, and thermodynamic properties, resulting from interactions between the drug and solvent molecules. The findings suggested that increasing the temperature within the range of 100 to 1000 Kelvin leads to an increase in heat capacity, enthalpy, and entropy due to molecular vibrations, ultimately causing degradation and instability in SA. Furthermore, the results showed that SA underwent a redshift in the absorption peak (from 320.18 to 356.26 nm) and a shift in the fluorescence peak (from 381 to 429 nm) in the solvent phase compared to those in the gas phase. Overall, this study provides background knowledge on how solvent polarity and temperature affect the properties of SA molecules.

Sinapic acid protects against lead acetate-induced lung toxicity by reducing oxidative stress, apoptosis, inflammation, and endoplasmic reticulum stress damage

Lead acetate (PbAc) is a compound that produces toxicity in many tissues after exposure. Sinapic acid (SNP) possesses many biological and pharmacological properties. This study aimed to investigate the efficacy of SNP on the toxicity of PbAc in lung tissue. PbAc was administered orally at 30 mg/kg and SNP at 5 or 10 mg/kg for 7 days. Biochemical, genetic, and histological methods were used to investigate inflammatory, apoptotic, endoplasmic reticulum stress, and oxidative stress damage levels in lung tissue. SNP administration induced PbAc-reduced antioxidant (GSH, SOD, CAT, and GPx) and expression of HO-1 in lung tissue. It also reduced MDA, induced by PbAc, and thus alleviated oxidative stress. SNP decreased the inflammatory markers NF-κB, TNF-α and IL-1β levels induced by PbAc in lung tissue and exhibited anti-inflammatory effect. PbAc increased apoptotic Bax, Apaf-1, and Caspase-3 mRNA transcription levels and decreased anti-apoptotic Bcl-2 in lung tissues. SNP decreased apoptotic damage by reversing this situation. On the other hand, SNP regulated these markers and brought them closer to the levels of the control group. PbAc caused prolonged ER stress by increasing the levels of ATF6, PERK, IRE1α, GRP78 and this activity was stopped and tended to retreat with SNP. After evaluating all the data, While PbAc caused toxic damage in lung tissue, SNP showed a protective effect by reducing this damage.

Ameliorative impacts of sinapic acid against mercuric chloride-induced renal toxicity: role of antioxidants and inflammatory cytokines

Because of their beneficial properties, natural products, especially medicinal plants, are becoming increasingly popular worldwide and play a significant role in research. This study was aimed to evaluate the nephroprotective effect of sinapic acid against mercuric chloride-induced renal toxicity in mice. The mice were allocated to four groups named a normal group (G1), model group (G2; received HgCl2, 1 mg/kg bw), treatments groups (G3 and G4: received 50 and 100 mg/kg bw of sinapic acid together with HgCl2). Mice received HgCl2 remarkably showed alteration in all examined biochemical biomarkers (urea, creatinine, and bilirubin), and induced alteration in blood cell picture and anemia. HgCl2 intoxication decreased both systemic and renal antioxidant activity and induced over all oxidative stress as indicated by alteration in inflammation and oxidative stress associated markers. HgCl2 affected renal histology with leukocytic and inflammatory cell infiltration, fibrosis and tubular necrosis. Administration of sinapic acid (50 and 100 mg/kg bw) markedly restored the HgCl2-induced oxidative stress (serum and renal: MDA, GSH, CAT, SOD, and T-AOC), proinflammatory cytokines (serum and renal: TNF-α, IL-6, IL-1β, and PGE2) and restored the changes on biochemical markers, and hematological parameters (hemoglobin, erythrocytes, platelets, and leukocytes). Taken together, the results of the present study disclose that sinapic acid has the potential to attenuate HgCl2-induced renal toxicity and may be an ideal choice against mercury poisoning.

The Use of Bioactive Compounds in Hyperglycemia- and Amyloid Fibrils-Induced Toxicity in Type 2 Diabetes and Alzheimer’s Disease

It has become increasingly apparent that defective insulin signaling may increase the risk for developing Alzheimer’s disease (AD), influence neurodegeneration through promotion of amyloid formation or by increasing inflammatory responses to intraneuronal β-amyloid. Recent work has demonstrated that hyperglycemia is linked to cognitive decline, with elevated levels of glucose causing oxidative stress in vulnerable tissues such as the brain. The ability of β-amyloid peptide to form β-sheet-rich aggregates and induce apoptosis has made amyloid fibrils a leading target for the development of novel pharmacotherapies used in managing and treatment of neuropathological conditions such as AD-related cognitive decline. Additionally, deposits of β-sheets folded amylin, a glucose homeostasis regulator, are also present in diabetic patients. Thus, therapeutic compounds capable of reducing intracellular protein aggregation in models of neurodegenerative disorders may prove useful in ameliorating type 2 diabetes mellitus symptoms. Furthermore, both diabetes and neurodegenerative conditions, such as AD, are characterized by chronic inflammatory responses accompanied by the presence of dysregulated inflammatory biomarkers. This review presents current evidence describing the role of various small bioactive molecules known to ameliorate amyloidosis and subsequent effects in prevention and development of diabetes and AD. It also highlights the potential efficacy of peptide–drug conjugates capable of targeting intracellular targets.

Sinapic acid restores blood parameters, serum antioxidants, and liver and kidney functions in obesity

Obesity is an additional body fat that causes a harmful effect on human health while sinapic acid (SA) is a phyto-constituent presents in spices, citrus, berry fruits, and vegetables. This study evaluates SA to amend blood parameters, serum glucose, proteins, lipids, and antioxidants, and liver and kidney functions in obese rats. Thirty male albino rats were divided into 2 groups (normal and obese rats). The normal, non-obese rats subdivided into 2 subgroups; Control and SA (40 mg/kg) subgroup: daily oral intake of 1 ml saline and 40 mg/kg SA, respectively once a day. The obese rats subdivided also into 3 subgroups; Obese, Obese + SA (20 mg/kg), and Obese + SA (40 mg/kg)-treated groups which received no treatment, 20 mg/kg SA, and 40 mg/kg SA, respectively once a day. All treatments were orally administrated for 1 month. The results showed that obesity caused an increase in body and organ weight, serum total cholesterol, triglycerides, low density lipoproteins, malondialdehyde, nitric oxide, glucose, bilirubin and blood urea nitrogen while decrease serum superoxide dismutase, glutathione peroxidase, glutathione, glutathione reductase, glutathione-S-transferase, hemoglobin, hematocrite, red blood cells, white blood cells, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, urea, creatinine, and uric acid compared to control group. Obesity caused disappearance of prothrombin and fibrinogen proteins and damages to liver and kidney tissues. The oral administration with SA daily for 1 month in obese rats returned all these parameters to the control values where the higher dose of SA was more effective than the lower dose. In conclusion, SA restores body and organ weight, blood parameters, serum glucose, proteins, lipids, antioxidants, and liver and kidney functions in obesity.

Ubiquitinated gasdermin D mediates arsenic-induced pyroptosis and hepatic insulin resistance in rat liver

As an environmental toxicant, arsenic exposure may cause insulin resistance (IR). Previous studies have shown that pyroptosis plays an important role in the occurrence and development of IR. Although gasdermin D (GSDMD) functions as an executor of pyroptosis, the relationship between GSDMD-mediated pyroptosis and hepatic IR remains unclear. Here, we observed that sodium arsenite (NaAsO₂) activated NOD-like receptors containing pyrin domain 3 (NLRP3) inflammasomes, promoted GSDMD activation, induced pyroptosis and hepatic IR, while GSDMD knockdown attenuated pyroptosis and hepatic IR caused by NaAsO₂. However, GSDMD interference did not affect NLRP3 activation. Ubiquitination modification is widely involved in protein regulation and intracellular signal transduction, and whether it regulates GSDMD and affects its degradation, and exerts effects on arsenic-induced pyroptosis remain unclear. We observed that NaAsO₂ reduced the K48- and K63-linked ubiquitination of GSDMD, thereby inhibiting its degradation through the ubiquitin-proteasome system (UPS) and the autophagy-lysosome pathway (ALP), causing GSDMD to accumulate and lyse into GSDMD-N, which promoted pyroptosis. In summary, we demonstrated that GSDMD participated in arsenic-induced hepatic IR. Moreover, NaAsO₂ reduced GSDMD ubiquitination and decreased its intracellular degradation, aggravating pyroptosis and hepatic IR. We have revealed the molecular mechanism underpinning arsenic-induced IR, and we provide potential solutions for the prevention and treatment of type 2 diabetes (T2D).

NLRP3 inflammasome blocked the glycolytic pathway via targeting to PKLR in arsenic-induced hepatic insulin resistance

Arsenic exposure is related to insulin resistance (IR). However, the underlying mechanism is still uncertain. NOD-like receptors containing pyrin domain 3 (NLRP3) inflammasome is a key driving factor of IR. We found that NaAsO₂ caused hepatic IR, activated NLRP3 inflammasome, and inhibited glycolysis pathway in vivo. We also found that tricarboxylic acid cycle (TCA cycle) was inhibited, and the content of hepatic lactate was upregulated with the treatment of arsenic. Consistent with these findings, we found that NLRP3 inflammasome and glycolysis were involved in the development of IR in L-02 cells. Besides, inhibiting NLRP3 inflammasome upregulated aerobic glycolysis and inhibited anaerobic glycolysis. Moreover, we demonstrated that NLRP3 inflammasome could bind to pyruvate kinase, liver and RBC (PKLR). Simultaneously, insulin signaling rather than NLRP3 inflammasome activation was altered by overexpressing PKLR. In summary, after treatment with NaAsO₂, NLRP3 inflammasome blocked the glycolytic pathway via binding to PKLR, which in turn caused hepatic IR_. This study shed new light on the molecular mechanism underlying arsenic-induced IR.

Protective effects of sinapic acid against cyclophosphamide-induced testicular toxicity via inhibiting oxidative stress, caspase-3 and NF-kB activity in BALB/c mice

Cyclophosphamide (CP), as a chemotherapeutic agent, with the generation of oxidative stress leads to testicular toxicity. Sinapic acid (SA), as a phenylpropanoid compound has therapeutic activities. This research was planned to evaluate the improving effects of SA versus testicular injury induced by CP. Forty-eight mice were distributed into six groups: untreated, SA (5 and 10 mg/kg), CP (200 mg/kg) and CP + SA (5 and 10 mg/kg). SA was administrated for 7 successive days and CP was administered intraperitoneally on the 3rd day of study. On the 10th day of research, testicular toxicity was evaluated by sperm parameters test, tissue (oxidative stress parameters) and serum (testosterone) biochemical, histopathological, and immunohistochemical (Caspase-3 and NF-kB) assays. The findings illustrated that CP induces atypical appearance in tissue structure, disorder of sperm parameters dysfunction, decrease of testosterone, oxidative stress (an increase of MDA and decrease of GSH), apoptosis and inflammation in testicular tissue. SA administration protected testis from oxidative stress and improves testosterone level and structure. Moreover, immunohistochemical findings also showed that SA can inhibit Caspase-3 and NF-kB activity. Data have confirmed that SA could protect testis structure and its functions against CP-induced injury through antioxidant, anti-inflammatory and anti-apoptotic activities.

Pharmacological and therapeutic applications of Sinapic acid-an updated review

Phenolic compounds, present in plants, are considered to be indispensable parts of human dietary sources. Sinapic acid, is a natural herbal compound containing phenolic acid. It is found in oranges, grapefruits, and cranberries and in herbs like canola, mustard seed and rapeseed. Sinapic acid is chemically studied as a cinnamic acid derivative that contains 3, 5-dimethoxyl and 4-hydroxyl substitutions in the phenyl group of cinnamic acid. Sinapic acid has been pharmacologically evaluated for its potent antioxidant, anti-inflammatory, anti-cancer, hepatoprotective, cardioprotective, renoprotective, neuroprotective, anti-diabetic, anxiolytic and anti-bacterial activities. In this review we have summarized the potential pharmacological and therapeutic effects of Sinapic acid in various models.

Therapeutic effects of biochanin A, phloretin, and epigallocatechin-3-gallate in reducing oxidative stress in arsenic-intoxicated mice

One of the most common toxicant prevailing in our environment is the arsenic. The present study is an attempt to investigate the effects of some of the common flavonoids, such as biochanin A (BCA), phloretin, and epigallocatechin-3-gallate (EGCG), on arsenic toxicity in the Swiss albino mice. For this purpose, mice were orally treated with sodium meta-arsenite (20 mg/kg bw/day), along with co-administration of BCA (50 mg/kg bw/day), phloretin (50 mg/kg bw/day), and EGCG (40 mg/kg bw/day) for the 2-week duration. All the mice were euthanized at the end of the treatment period, and the observations were made in the following parameters. Arsenic reduced the sperm motility as compared with the control (p < 0.05) and was restored back to the normal status with the flavonoids treatment significantly (p < 0.05). The arsenic concentrations in the kidney and liver tissues were found significantly reduced with all the flavonoids co-treatment (p < 0.001). There was a reduction in the levels of superoxide dismutase (SOD), reduced glutathione (GSH), and glutathione S-transferase (GST) antioxidant markers, with the increased lipid peroxidation (LPO), protein carbonyl content (PCC), and catalase (CAT) levels in the arsenic-intoxicated mice performed in the different tissues. The biochemical homeostasis alterations were well correlated with the estimations of cholinesterase enzyme levels in the brain tissues (p < 0.05) along with DNA damage analysis (Comet) carried out in the blood cells (p < 0.05). These above results are well corroborated with the histopathological findings performed in the brain tissue, along with the increased upregulation seen in the Nrf2 signalling, with all the flavonoid co-treatment carried in the kidney tissue. The administration of BCA, phloretin, and EGCG, in a major way, reversed the alterations in the abovementioned parameters in the arsenic-intoxicated mice. Our findings revealed the beneficial effects of the flavonoids against the arsenic-induced toxicity, due to their ability to enhance the intracellular antioxidant response system by modulating the Nrf2 signaling pathway.

Sinapic Acid Inhibits Cardiac Hypertrophy via Activation of Mitochondrial Sirt3/SOD2 Signaling in Neonatal Rat Cardiomyocytes

Sinapic acid (SA) is a naturally occurring phenolic compound with antioxidant properties. It also has a wide range of pharmacological properties, such as anti-inflammatory, anticancer, and hepatoprotective properties. The present study aimed to evaluate the potential pharmacological effects of SA against hypertrophic responses in neonatal rat cardiomyocytes. In order to evaluate the preventive effect of SA on cardiac hypertrophy, phenylephrine (PE)-induced hypertrophic cardiomyocytes were treated with subcytotoxic concentrations of SA. SA effectively suppressed hypertrophic responses, such as cell size enlargement, sarcomeric rearrangement, and fetal gene re-expression. In addition, SA significantly inhibited the expression of mitogen-activated protein kinase (MAPK) proteins as pro-hypertrophic factors and protected the mitochondrial functions from hypertrophic stimuli. Notably, SA activated Sirt3, a mitochondrial deacetylase, and SOD2, a mitochondrial antioxidant, in hypertrophic cardiomyocytes. SA also inhibited oxidative stress in hypertrophic cardiomyocytes. However, the protective effect of SA was significantly reduced in Sirt3-silenced hypertrophic cardiomyocytes, indicating that SA exerts its beneficial effect through Sirt3/SOD signaling. In summary, this is the first study to reveal the potential pharmacological action and inhibitory mechanism of SA as an antioxidant against cardiac hypertrophy, suggesting that SA could be utilized for the treatment of cardiac hypertrophy.

Natural antioxidants of plant origin

Interest in the content of natural antioxidants in plant-based foods can be from the human health perspective, in terms of how these compounds might help promote one's health and wellness, or from the storage point-of-view, as the endogenous antioxidant constituents aid to extend a foodstuff's shelf-life. This chapter reports essential information about the mechanism of antioxidant action and methods employed for determination of their activity, classes of phenolic compounds (phenolic acids, flavonoids, lignans, stilbenes, tannins), sources of plant antioxidants (oil seeds, cereals, legumes, plants of the Lamiaceae family, tea and coffee, tree nuts, fruits, and berries), extraction strategies of phenolic compounds from plant material, and the influence of processing and storage on the content of natural antioxidants in foods and their antioxidant activity. Thermal processing, if not releasing bound phenolics from the structural matrices of the food, tends to decrease the antioxidant potential or, in the best case scenario, has no significant negative impact. Gentler sterilization processes such as high-pressure processing tend to better retain the antioxidant potential of a foodstuff than thermal treatments such as steaming, boiling, or frying. The impact of processing can be assessed by determining the antioxidant potential of foodstuffs either at the point of formulation or after different periods of storage under specified conditions.

Amelioration of CCl4-Induced Hepatotoxicity in Rabbits by Lepidium sativum Seeds

The current study aimed to evaluate the probable protective effect of Lepidium sativum seeds (LSS) against CCl₄ induced hepatic injury in New-Zealand rabbits. Rabbits were randomly divided into two main groups; group-A (noninjured group, n=15) was divided to subgroups A1 (untreated control) and A2 and A3 which received 200 & 400 mg/kg bw of LSS, respectively, in their diet daily. Group-B (injured group, n=30) were subcutaneously injected with CCl₄ (0.5 ml/kg bw) starting from day one of the experiment and were equally divided into 3 subgroups: B1 received normal standard diet and B2 & B3 received 200 & 400 mg/kg bw of LSS, respectively, in their diet daily. Five rabbits of all subgroups were decapitated 5 and 10 weeks after experimental running. Biochemical analysis revealed significant decrease in serum levels of transaminases, γ-GT, ALP, total bilirubin, cholesterol, triglycerides associated with significant increase in the serum levels of T protein and albumin of 200 and 400 mg/kg bw of LSS protected rabbits for 5 and 10 weeks as compared with CCl₄ treated rabbits. Oxidative stress and depressed antioxidant system of the liver tissues were markedly obvious in the CCl₄ treated group. LSS administration reversed these results towards normalization. Histopathological examination of LSS protected rabbits (200 mg/kg bw of LSS for 10 weeks) showed improvement of the histoarchitectural changes of the liver induced by CCl₄ to the normal aspect, showing regenerating hepatocytes with no steatosis, discrete chronic venous congestion, and discrete inflammatory infiltrate. The current findings provide new evidence that LSS could reverse the hepatotoxic effects of CCl₄ and repair the liver functions.

Sinapic acid ameliorates bleomycin-induced lung fibrosis in rats

BACKGROUND

Pulmonary fibrosis is a multifaceted disease with high mortality and morbidity, and it is commonly nonresponsive to conventional therapy.

PURPOSE

We explore the possible discourse of sinapic acid (SA) against the prevention of bleomycin (BLM)-instigated lung fibrosis in rats through modulation of Nrf2/HO-1 and NF-κB signaling pathways.

DESIGN/METHODS

Lung fibrosis was persuaded in Sprague-Dawley rats by a single intratracheal BLM (6.5 U/kg) injection. Then, these rats were treated with SA (10 and 20 mg/kg, p.o.) for 28 days. The normal control rats provided saline as a substitute of BLM. The lung function and biochemical, histopathological, and molecular alterations were studied in serum, bronchoalveolar lavage fluid (BALF), and the lungs tissues.

RESULTS

SA treatment significantly restored BLM-induced alterations in body weight index and serum biomarkers [lactate dehydrogenase (LDH) and alkaline phosphatase (ALP)]. SA (10 and 20 mg/kg) treatment appeared to show a pneumoprotective effect through upregulation of antioxidant status, downregulation of inflammatory cytokines and MMP-7 expression, and reduction of collagen accumulation (hydroxyproline). Nrf2, HO-1, and TGF-β expression was downregulated in BLM-induced fibrosis model, while the reduced expression levels were significantly and dose-dependently upregulated by SA (10 and 20 mg/kg) treatment. We demonstrated that SA ameliorates BLM-induced lung injuries through inhibition of apoptosis and induction of Nrf2/HO-1-mediated antioxidant enzymes via NF-κB inhibition. The histopathological findings also revealed that SA treatment (10 and 20 mg/kg) significantly ameliorated BLM-induced lung injury.

CONCLUSION

The present results showed the ability of SA to restore the antioxidant system and to inhibit oxidative stress, proinflammatory cytokines, extracellular matrix, and TGF-β. This is first report demonstrating that SA amoleriates BLM induced lung injuries through inhibition of apoptosis and induction of Nrf2 and HO-1 mediated antioxidant enzyme via NF-κB inhibition. The histopathological finding reveals that SA treatment (10 and 20 mg/kg) significantly ameliorates BLM induced lung injuries.

Involvement of Phenolics, Flavonoids, and Phenolic Acids in High Yield Characteristics of Rice (<i>Oryza Sativa</i> L.)

The present study examined the correlation between phenolic acids and flavonoids with high rice yield traits of rice. It was observed that the difference of phenolic contents among the tested rice lines occurred only in the vegetative stage. The concentrations of phenolic acids were higher in the rice high yield cultivars than low yield variety in the vegetative stage, but they either decreased dramatically or disappeared during the development stage. Caffeic acid was found only in high yield rice, whereas chlorogenic acid was detected only in low yield rice. Sinapic acid was the dominant phenolic acid in high yield cultivars at vegetative stage (3.7 mg/g), followed by ferulic acid (1.2 mg/g). These findings suggest that caffeic acid, ferulic acid, sinapic acid and chlorogenic acid may play a particular role in forming yield components in rice. The cultivar B3 contained high amount of sinapic acid may be used as a natural source for pharmaceutical use.

Involvement of Phenolics, Flavonoids, and Phenolic Acids in High Yield Characteristics of Rice (Oryza Sativa L.)

The present study examined the correlation between phenolic acids and flavonoids with high rice yield traits of rice. It was observed that the difference of phenolic contents among the tested rice lines occurred only in the vegetative stage. The concentrations of phenolic acids were higher in the rice high yield cultivars than low yield variety in the vegetative stage, but they either decreased dramatically or disappeared during the development stage. Caffeic acid was found only in high yield rice, whereas chlorogenic acid was detected only in low yield rice. Sinapic acid was the dominant phenolic acid in high yield cultivars at vegetative stage (3.7 mg/g), followed by ferulic acid (1.2 mg/g). These findings suggest that caffeic acid, ferulic acid, sinapic acid and chlorogenic acid may play a particular role in forming yield components in rice. The cultivar B3 contained high amount of sinapic acid may be used as a natural source for pharmaceutical use.

Oxidative Damage Induced by Arsenic in Mice or Rats: A Systematic Review and Meta-Analysis

In this meta-analysis, studies reporting arsenic-induced oxidative damage in mouse models were systematically evaluated to provide a scientific understanding of oxidative stress mechanisms associated with arsenic poisoning. Fifty-eight relevant peer-reviewed publications were identified through exhaustive database searching. Oxidative stress indexes assessed included superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), glutathione-s-transferase (GST), glutathione reductase (GR), oxidized glutathione (GSSG), malondialdehyde (MDA), and reactive oxygen species (ROS). Our meta-analysis showed that arsenic exposure generally suppressed measured levels of the antioxidants, SOD, CAT, GSH, GPx, GST, and GR, but increased levels of the oxidants, GSSG, MDA, and ROS. Arsenic valence was important and GR and MDA levels increased to a significantly (P < 0.05) greater extent upon exposure to As³⁺ than to As⁵⁺. Other factors that contributed to a greater overall oxidative effect from arsenic exposure included intervention time, intervention method, dosage, age of animals, and the sample source from which the indexes were estimated. Our meta-analysis effectively summarized a wide range of studies and detected a positive relationship between arsenic exposure and oxidative damage. These data provide a scientific basis for the prevention and treatment of arsenic poisoning.

Effect of Acetyl-L-Carnitine on Antioxidant Status, Lipid Peroxidation, and Oxidative Damage of Arsenic in Rat

Arsenic (As) is a widespread environmental contaminant present around the world in both organic and inorganic forms. Oxidative stress is postulated as the main mechanism for As-induced toxicity. This study was planned to examine the protective effect of acetyl-L-carnitine (ALC) on As-induced oxidative damage in male rats. Animals were randomly divided into four groups of control (saline), sodium arsenite (NaAsO2, 20 mg/kg), ALC (300 mg/kg), and NaAsO2 plus ALC. Animals were dosed orally for 28 successive days. Blood and tissue samples including kidney, brain, liver, heart, and lung were collected on the 28th day and evaluated for oxidative damage and histological changes. NaAsO2 exposure caused a significant lipid peroxidation as evidenced by elevation in thiobarbituric acid-reactive substances (TBARS). The activity of antioxidant enzymes such as glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), as well as sulfhydryl group content (SH group) was significantly suppressed in various organs following NaAsO2 treatment (P < 0.05). Furthermore, NaAsO2 administration increased serum values of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and bilirubin. Our findings revealed that co-administration of ALC and NaAsO2 significantly suppressed the oxidative damage induced by NaAsO2. Tissue histological studies have confirmed the biochemical findings and provided evidence for the beneficial role of ALC. The results concluded that ALC attenuated NaAsO2-induced toxicity, and this protective effect may result from the ability of ALC in maintaining oxidant-antioxidant balance.

Prevention of cardiac dysfunction, kidney fibrosis and lipid metabolic alterations in l-NAME hypertensive rats by sinapic acid--Role of HMG-CoA reductase

The present study was designed to evaluate the effect of sinapic acid, a bioactive phenolic acid on high blood pressure associated cardiac dysfunction, kidney fibrosis and lipid alterations in N(ω)-nitro-l-arginine methyl ester hydrochloride (l-NAME) induced hypertensive rats. Sinapic acid was administered to rats orally at a dosage of 40 mg/kg everyday for a period of 4 weeks. Sinapic acid treatment significantly decreased mean arterial pressure, left ventricular end diastolic pressure, organ weights (liver and kidney), lipid peroxidation products in tissues (liver and kidney), activities of hepatic marker enzymes and the levels of renal function markers in serum of l-NAME rats. Sinapic acid treatment also significantly increased the level of plasma nitric oxide metabolites, and enzymatic and non-enzymatic antioxidants in tissues of l-NAME rats. Tissue damage was assessed by histopathological examination. Alterations in plasma angiotensin-converting enzyme activity, level of plasma lipoproteins and tissue lipids were corrected by sinapic acid treatment in l-NAME rats. Sinapic acid treatment significantly decreased the activity of 3-hydroxy-3-methylglutaryl-Coenzyme A (HMG-CoA) reductase in plasma and liver, whereas the activity of lecithin cholesterol acyl transferase was significantly increased in the plasma of hypertensive rats. Docking result showed the interaction between sinapic acid and HMG-CoA reductase. Sinapic acid has shown best ligand binding energy of -5.5 kcal/M. Moreover, in chick embryo model, sinapic acid improved vessel density on chorioallantoic membrane. These results of the present study concludes that sinapic acid acts as a protective agent against hypertension associated cardiac dysfunction, kidney fibrosis and lipid alterations.

Sinapic Acid and Its Derivatives as Medicine in Oxidative Stress-Induced Diseases and Aging

Sinapic acid (3,5-dimethoxy-4-hydroxycinnamic acid) is an orally bioavailable phytochemical, extensively found in spices, citrus and berry fruits, vegetables, cereals, and oilseed crops and is known to exhibit antioxidant, anti-inflammatory, anticancer, antimutagenic, antiglycemic, neuroprotective, and antibacterial activities. The literature reveals that sinapic acid is a bioactive phenolic acid and has the potential to attenuate various chemically induced toxicities. This minireview is an effort to summarize the available literature about pharmacokinetic, therapeutic, and protective potential of this versatile molecule in health related areas.

New Polyphenols Identified in Artemisiae abrotani herba Extract

Artemisia abrotanum L. (“southernwood”) belongs to the Artemisia genus and it is used in traditional medicine for the treatment of a variety of illnesses. Scarce data is available on the chemical composition of this medicinal plant, most research being focused on the quantitative and qualitative analyses of its essential oil. Our aim was to investigate the content and profile of polyphenols, flavonoids and hydroxycinnamic derivatives present in the Artemisiae abrotani herba extract. We conducted LC/MS analysis and we screened for 19 polyphenols, flavonoids and hydroxycinnamic derivatives. We determined the total content of these compounds and we screened for antioxidant activity. Most polyphenol acids, hydroxycinnamic derivatives and flavonoids were identified and quantified for the first time in this study. We found an original polyphenol distribution profile with high concentration of sinapic acid, rutin, quercetol, ferulic acid and patuletin. We measured the antioxidant activity, the ethanolic extract presenting a modest radical scavenging activity. The value of this study consists in its novelty as it adds new data on the chemical composition of A. abrotanum L. and it opens novel perspectives for medical and nutritional applications of this plant.

Effects of nanoparticle-encapsulated curcumin on arsenic-induced liver toxicity in rats

We investigated the therapeutic effectiveness of the nanoparticle-encapsulated curcumin (CUR-NP) against sodium arsenite-induced hepatic oxidative damage in rats. The CUR-NP prepared by emulsion technique was spherical in shape with an encapsulation efficiency of 86.5%. The particle size ranged between 120 and 140 nm with the mean particle size being 130.8 nm. Rats were divided into five groups of six each. Group 1 served as control. Group 2 rats were exposed to sodium arsenite (25 ppm) daily through drinking water for 42 days. Groups 3, 4, and 5 were treated with arsenic as in group 2, however, they were administered, empty nanoparticles, curcumin (100 mg/kg bw) and CUR-NP (100 mg/kg bw), respectively, by oral gavage during the last 14 days of arsenic exposure. Arsenic increased the activities of serum alanine aminotransferase and aspartate aminotransferase and caused histological alterations in liver indicating hepatotoxicity. Arsenic increased lipid peroxidation, depleted reduced glutathione and decreased the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase in liver. All these effects of arsenic were attenuated with both curcumin and CUR-NP. However, the magnitude of amelioration was more pronounced with CUR-NP. The results indicate that curcumin given in nano-encapsulated form caused better amelioration than free curcumin. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 628-637, 2015.

The neuroprotective potential of sinapic acid in the 6-hydroxydopamine-induced hemi-parkinsonian rat

Parkinson's disease (PD) is a neurodegenerative movement disorder due to selective loss of dopaminergic neurons of mesencephalic substantia nigra pars compacta (SNC) with debilitating motor symptoms. Current treatments for PD afford symptomatic relief with no prevention of disease progression. Due to the antioxidant and neuroprotective potential of sinapic acid, this study was conducted to evaluate whether this agent could be of benefit in an experimental model of early PD in rat. Unilateral intrastriatal 6-hydroxydopamine (6-OHDA)-lesioned rats were pretreated p.o. with sinapic acid at doses of 10 or 20 mg/kg. One week after surgery, apomorphine caused significant contralateral rotations, a significant reduction in the number of Nissl-stained and tyrosine hydroxylase (TH)-positive neurons and a significant increase of iron reactivity on the left side of SNC. Meanwhile, malondialdehyde (MDA) and nitrite levels in midbrain homogenate significantly increased and activity of superoxide dismutase (SOD) significantly reduced in the 6-OHDA-lesioned group. In addition, sinapic acid at a dose of 20 mg/kg significantly improved turning behavior, prevented loss of SNC dopaminergic neurons, lowered iron reactivity, and attenuated level of MDA and nitrite. These results indicate the neuroprotective potential of sinapic acid against 6-OHDA neurotoxicity that is partially due to the attenuation of oxidative stress and possibly lowering nigral iron level.

Sinapic acid prevents hypertension and cardiovascular remodeling in pharmacological model of nitric oxide inhibited rats

Objectives

Hypertensive heart disease is a constellation of abnormalities that includes cardiac fibrosis in response to elevated blood pressure, systolic and diastolic dysfunction. The present study was undertaken to examine the effect of sinapic acid on high blood pressure and cardiovascular remodeling.

Methods

An experimental hypertensive animal model was induced by L-NAME intake on rats. Sinapic acid (SA) was orally administered at a dose of 10, 20 and 40 mg/kg body weight (b.w.). Blood pressure was measured by tail cuff plethysmography system. Cardiac and vascular function was evaluated by Langendorff isolated heart system and organ bath studies, respectively. Fibrotic remodeling of heart and aorta was assessed by histopathologic analyses. Oxidative stress was measured by biochemical assays. mRNA and protein expressions were assessed by RT-qPCR and western blot, respectively. In order to confirm the protective role of SA on endothelial cells through its antioxidant property, we have utilized the in vitro model of H₂O₂-induced oxidative stress in EA.hy926 endothelial cells.

Results

Rats with hypertension showed elevated blood pressure, declined myocardial performance associated with myocardial hypertrophy and fibrosis, diminished vascular response, nitric oxide (NO) metabolites level, elevated markers of oxidative stress (TBARS, LOOH), ACE activity, depleted antioxidant system (SOD, CAT, GPx, reduced GSH), aberrant expression of TGF-β, β-MHC, eNOS mRNAs and eNOS protein. Remarkably, SA attenuated high blood pressure, myocardial, vascular dysfunction, cardiac fibrosis, oxidative stress and ACE activity. Level of NO metabolites, antioxidant system, and altered gene expression were also repaired by SA treatment. Results of in vitro study showed that, SA protects endothelial cells from oxidative stress and enhance the production of NO in a concentration dependent manner.

Conclusions

Taken together, these results suggest that SA may have beneficial role in the treatment of hypertensive heart disease by attenuating fibrosis and oxidative stress through its antioxidant potential.

Effect of ionizing radiation on liver protein oxidation and metabolic function in C57BL/6J mice

PURPOSE

Protein oxidation in response to radiation results in DNA damage, endoplasmic reticulum stress/unfolded protein response, cell cycle arrest, cell death and senescence. The liver, a relatively radiosensitive organ, undergoes measurable alterations in metabolic functions following irradiation. Accordingly, we investigated radiation-induced changes in liver metabolism and alterations in protein oxidation.

MATERIALS AND METHODS

C57BL/6 mice were sham irradiated or exposed to 8.5 Gy (60)Co (0.6 Gy/min) total body irradiation. Metabolites and metabolic enzymes in the blood and liver tissue were analyzed. Two-dimensional gel electrophoresis and OxyBlot™ were used to detect carbonylated proteins that were then identified by peptide mass fingerprinting.

RESULTS

Analysis of serum metabolites revealed elevated glucose, bilirubin, lactate dehydrogenase (LDH), high-density lipoprotein, and aspartate aminotransferase within 24-72 h post irradiation. Liver tissue LDH and alkaline phosphatase activities were elevated 24-72 h post irradiation. OxyBlotting revealed that the hepatic proteome contains baseline protein carbonylation. Radiation exposure increased carbonylation of specific liver proteins including carbonic anhydrase 1, α-enolase, and regucalcin.

CONCLUSIONS

8.5 Gy irradiation resulted in distinct metabolic alterations in hepatic functions. Coincident with these changes, radiation induced the carbonylation of specific liver enzymes. The oxidation of liver enzymes may underlie some radiation-induced alterations in hepatic function.

Arsenite-induced changes in hepatic protein abundance in cynomolgus monkeys (Macaca fascicularis)

Arsenic is an environmental pollutant, and its liver toxicity has long been recognized. The effect of arsenic on liver protein expression was analyzed using a proteomic approach in monkeys. Monkeys were orally administered sodium arsenite (SA) for 28 days. As shown by 2D-PAGE in combination with MS, the expression levels of 16 proteins were quantitatively changed in SA-treated monkey livers compared to control-treated monkey livers. Specifically, the levels of two proteins, mortalin and tubulin beta chain, were increased, and 14 were decreased, including plastin-3, cystathionine-beta-synthase, selenium-binding protein 1, annexin A6, alpha-enolase, phosphoenolpyruvate carboxykinase-M, erlin-2, and arginase-1. In view of their functional roles, differential expression of these proteins may contribute to arsenic-induced liver toxicity, including cell death and carcinogenesis. Among the 16 identified proteins, four were selected for validation by Western blot and immunohistochemistry. Additional Western blot analyses indicated arsenic-induced dysregulation of oxidative stress related, genotoxicity-related, and glucose metabolism related proteins in livers from SA-treated animals. Many changes in the abundance of toxicity-related proteins were also demonstrated in SA-treated human hepatoma cells. These data on the arsenic-induced regulation of proteins with critical roles may help elucidate the specific mechanisms underlying arsenic-induced liver toxicity.

Phenolic profiling in the pulp and peel of nine plantain cultivars (Musa sp.)

The present study investigated the phenolic profiles of the pulp and peel of nine plantain cultivars and compared them to those of two dessert bananas of commercial interest (Grand Nain and Gros Michel), alongside a newly created hybrid, resistant to black sigatoka disease (F568). Identification and quantification of phenolic compounds were performed by means of HPLC-ESI-HR-MS and HPLC-DAD. Hydroxycinnamic acids, particularly ferulic acid-hexoside with 4.4-85.1 μg/g of dry weight, dominated in the plantain pulp and showed a large diversity among cultivars. Flavonol glycosides were predominant in plantain peels, rutin (242.2-618.7 μg/g of dry weight) being the most abundant. A principal component analysis on the whole data revealed that the phenolic profiles of the hybrid, the dessert bananas and the pure plantains differed from each other. Plantain pulps and peels appeared as good sources of phenolics, which could be involved in the health benefits associated with their current applications.

Chemopreventive effect of sinapic acid on 1,2-dimethylhydrazine-induced experimental rat colon carcinogenesis

Sinapic acid (SA) is a naturally occurring phenolic acid found in various herbal plants which is attributed with numerous pharmacological properties. This study was aimed to investigate the chemopreventive effect of SA on 1,2-dimethylhydrazine (DMH)-induced rat colon carcinogenesis. Rats were treated with DMH injections (20 mg kg(-1) bodyweight (b.w.) subcutaneously once a week for the first 4 consecutive weeks and SA (20, 40 and 80 mg kg(-1) b.w.) post orally for 16 weeks. At the end of the 16-week experimental period, all the rats were killed, and the tissues were evaluated biochemically. Our results reveal that DMH alone treatment decreased the levels/activities of lipid peroxidation by-products such as thiobarbituric acid reactive substances, conjugated dienes and antioxidants such as superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and reduced glutathione in the intestine and colonic tissues which were reversed on supplementation with SA. Moreover, the activities of drug-metabolizing enzymes of phase I (cytochrome P450 and P4502E1) were enhanced and those of phase II (glutathione-S-transferase, DT-diaphorase and uridine diphosphate glucuronosyl transferase) were diminished in the liver and colonic mucosa of DMH alone-treated rats and were reversed on supplementation with SA. All the above changes were supported by the histopathological observations of the rat liver and colon. These findings suggest that SA at the dose of 40 mg kg(-1) b.w. was the most effective dose against DMH-induced colon carcinogenesis, and thus, SA could be used as a potential chemopreventive agent.

Binary solvent extraction system and extraction time effects on phenolic antioxidants from kenaf seeds (Hibiscus cannabinus L.) extracted by a pulsed ultrasonic-assisted extraction

The aim of this study was to determine the best parameter for extracting phenolic-enriched kenaf (Hibiscus cannabinus L.) seeds by a pulsed ultrasonic-assisted extraction. The antioxidant activities of ultrasonic-assisted kenaf seed extracts (KSE) were determined by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay, β-carotene bleaching inhibition assay, and ferric reducing antioxidant power (FRAP) assay. Total phenolic content (TPC) and total flavonoid content (TFC) evaluations were carried out to determine the phenolic and flavonoid contents in KSE. The KSE from the best extraction parameter was then subjected to high performance liquid chromatography (HPLC) to quantify the phenolic compounds. The optimised extraction condition employed 80% ethanol for 15 min, with the highest values determined for the DPPH, ABTS, and FRAP assay. KSE contained mainly tannic acid (2302.20 mg/100 g extract) and sinapic acid (1198.22 mg/100 g extract), which can be used as alternative antioxidants in the food industry.

Protective effect of edible marine algae, Laminaria japonica and Porphyra haitanensis, on subchronic toxicity in rats induced by inorganic arsenic

Arsenic, a potent environmental toxic agent, causes various hazardous effects on human health. This study was performed to evaluate the protective effects of edible marine algae, Laminaria japonica and Porphyra haitanensis, on subchronic stress of rats induced by arsenic trioxide (As2O3). The co-treatment of marine algae could slightly increase the growth rates of body weights compared to the As2O3-treated group. The marine algae application restored liver and renal function by preventing the increment in the activities of alanine transaminase and alkaline phosphatase, and the levels of total protein, blood urea nitrogen, and creatinine. The increase in the contents of total cholesterol, triglyceride, and low density lipoprotein cholesterol, and decrease in the contents of high density lipoprotein cholesterol were observed in algae co-treated groups which indicated that marine algae could reverse the abnormal lipid metabolisms induced by arsenic. Moreover, these algae could protect the rats from lipid peroxidation by restoring the depletion of superoxide dismutase and glutathione peroxidase activities and sulfhydryl group contents, and lowering the enhanced malondialdehyde contents. Therefore, evidences indicate that L. japonica and P. haitanensis can serve as an effective regimen for treating arsenic poisoning.