Protective effects of syringic acid against acetaminophen-induced hepatic damage in albino rats

Nutraceutical Properties of Syringic Acid in Civilization Diseases-Review

Civilization diseases account for a worldwide health issue. They result from daily behavioral, environmental, and genetic factors. One of the most significant opportunities to prevent and alleviate the occurrence of these diseases is a diet rich in antioxidants like polyphenols. This review paper is concentrated on syringic acid (SA), one of the representative compounds of phenolic acids subgroups. There are many in vitro and in vivo studies on SA that assess its pivotal effects on oxidative stress and inflammation parameters. It is effective on metabolic risk factors as well, including hyperglycemia, high blood pressure, and hyperlipidemia. SA is one of the prominent polyphenolic compounds that may help address health issues related to civilization diseases.

In Vitro Bioaccessibility Assessment of Phenolic Compounds from Encapsulated Grape Pomace Extract by Ionic Gelation

Grape pomace is a by-product of winemaking characterized by a rich chemical composition from which phenolics stand out. Phenolics are health-promoting agents, and their beneficial effects depend on their bioaccessibility, which is influenced by gastrointestinal digestion. The effect of encapsulating phenol-rich grape pomace extract (PRE) with sodium alginate (SA), a mixture of SA with gelatin (SA-GEL), and SA with chitosan (SA-CHIT) on the bioaccessibility index (BI) of phenolics during simulated digestion in vitro was studied. A total of 27 individual phenolic compounds (IPCs) were quantified by UHPLC. The addition of a second coating to SA improved the encapsulation efficiency (EE), and the highest EE was obtained for SA-CHIT microbeads (56.25%). Encapsulation affected the physicochemical properties (size, shape and texture, morphology, crystallinity) of the produced microbeads, which influenced the delivery of phenolics to the intestine and their BI. Thus, SA-GEL microbeads had the largest size parameters, as confirmed by scanning electron microscopy (SEM), and the highest BI for total phenolic compounds and IPCs (gallic acid, 3,4-dihydroxybenzoic acid and o-coumaric acid, epicatechin, and gallocatechin gallate) ranged from 96.20 to 1011.3%. The results suggest that encapsulated PRE has great potential to be used as a functional ingredient in products for oral administration.

Syringic acid demonstrates an anti-inflammatory effect via modulation of the NF-κB-iNOS-COX-2 and JAK-STAT signaling pathways in methyl cellosolve-induced hepato-testicular inflammation in rats

Syringic acid (SACI) is an emerging nutraceutical and antioxidant used in modern Chinese medicine. It has potential neuroprotective, anti-hyperglycemic, and anti-angiogenic properties. Methyl cellosolve (MCEL) has been reported to induce tissue inflammation in the testis, kidney, liver, and lung. This study aimed to investigate the effect and probable mechanism of action of SACI on MCEL-induced hepatic and testicular inflammation in male rats. Compared to the control group, administration of MCEL to rats significantly increased the levels of IL-6, TNF-α, iNOS, COX-2, and NF-κB in the liver and testis. Additionally, the total mRNA expressions of JAK1 (in the liver only), STAT1, and SOCS1 were significantly increased in both the liver and testis, while testicular JAK1 total mRNA levels were significantly decreased. The expression of PIAS1 protein was significantly higher in the liver and testis. Treatments with SACI at 25 (except liver iNOS), 50, and 75 mg/kg significantly decreased the levels of IL-6, TNF-α, iNOS, COX-2, and NF-κB compared to the control group. Furthermore, the total mRNA expressions of JAK1 and SOCS1 in the liver were significantly reduced by all doses of SACI investigated, while the total mRNA levels of liver and testis STAT1 were significantly reduced by 25 and 50 mg/kg of SACI only. In the testis, the mRNA level of SOCS1 was significantly reduced by all doses of SACI compared to MCEL only. Additionally, SACI (at 75 mg/kg) significantly reduced PIAS1 protein expression in the liver, while in the testis, SACI at all investigated doses significantly reduced the expression of PIAS1. In conclusion, SACI demonstrated a hepatic and testicular anti-inflammatory effect by inhibiting the MCEL-induced activation of the NF-κB and JAK-STAT signaling pathways in rats.

Syringic acid demonstrates better anti-apoptotic, anti-inflammatory and antioxidative effects than ascorbic acid via maintenance of the endogenous antioxidants and downregulation of pro-inflammatory and apoptotic markers in DMN-induced hepatotoxicity in rats

Dimethyl nitrosamine (DMN) is a known hepatotoxin, carcinogen, and mutagen. This study is therefore carried out to investigate the therapeutic effects of syringic acid (SYRA) and ascorbic acid (ASCA) in DMN-induced hepatic injury in rats. Following DMN administrations, malondialdehyde (MDA), nitric oxide (NO) and reduced glutathione (GSH) as well as activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) were significantly increased. Also significantly increased were levels of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Following treatment with SYRA and ASCA, the activities of ALT, AST, GPx, CAT and SOD, as well as MDA, GSH, TNF-α, IL-1β, and NFkB levels were significantly reduced. Overall, both treatments were effective, but SYRA had a better therapeutic effect than ASCA. Therefore, this promising potential of SYRA can be taken advantage of in the treatment of DMN-induced hepatic injury.

Acetaminophen induced hepatotoxicity: An overview of the promising protective effects of natural products and herbal formulations

BACKGROUND

The liver plays an important role in regulating the metabolic processes and is the most frequently targeted organ by toxic chemicals. Acetaminophen (APAP) is a well-known anti-allergic, anti-pyretic, non-steroidal anti-inflammatory drug (NSAID), which upon overdose leads to hepatotoxicity, the major adverse event of this over-the-counter drug.

PURPOSE

APAP overdose induced acute liver injury is the second most common cause that often requires liver transplantation worldwide, for which N-acetyl cysteine is the only synthetic drug clinically approved as an antidote. So, it was felt that there is a need for the novel therapeutic approach for the treatment of liver diseases with less adverse effects. This review provides detailed analysis of the different plant extracts; phytochemicals and herbal formulations for the amelioration of APAP-induced liver injury.

METHOD

The data was collected using different online resources including PubMed, ScienceDirect, Google Scholar, Springer, and Web of Science using keywords given below.

RESULTS

Over the past decades various reports have revealed that plant-based approaches may be a better treatment choice for the APAP-induced hepatotoxicity in pre-clinical experimental conditions. Moreover, herbal compounds provide several advantages over the synthetic drugs with fewer side effects, easy availability and less cost for the treatment of life-threatening diseases.

CONCLUSION

The current review summarizes the hepatoprotective effects and therapeutic mechanisms of various plant extracts, active phytoconstituents and herbal formulations with potential application against APAP induced hepatotoxicity as the numbers of hepatoprotective natural products are more without clinical relativity. Further, pre-clinical pharmacological research will contribute to the designing of natural products as medicines with encouraging prospects for clinical application.

Syringic Acid Ameliorates Cardiac, Hepatic, Renal and Neuronal Damage Induced by Chronic Hyperglycaemia in Wistar Rats: A Behavioural, Biochemical and Histological Analysis

This study investigated the effects of syringic acid (SA) on renal, cardiac, hepatic, and neuronal diabetic complications in streptozotocin-induced neonatal (nSTZ) diabetic rats. STZ (110 mg/kg i.p) was injected into Wistar rat neonates as a split dose (second and third postnatal day). Diabetes mellitus was diagnosed in adults by measuring fasting blood glucose levels, urine volume, and food and water intake. The treatment of SA (25 mg/kg, 50 mg/kg p.o) was given from the 8th to 18th postnatal week. To assess the development of diabetic complications and the effect of therapy, biochemical indicators in serum and behavioural parameters were recorded at specific intervals during the study period. SA (25 mg/kg, 50 mg/kg p.o) treatment reduced hyperglycaemia, polydipsia, polyphagia, polyuria, relative organ weight, cardiac hypertrophic indices, inflammatory markers, cell injury markers, glycated haemoglobin, histopathological score, and oxidative stress, and increased Na/K ATPase activity. These findings suggest that SA might significantly alleviate diabetic complications and/or renal, neuronal, cardiac, and hepatic damage in nSTZ diabetic rats.

Syringic acid and silymarin concurrent administration inhibits sodium valproate-induced liver injury in rats

Sodium valproate (SV) is a well-known anti-epileptic drug, also used to control convulsions, bipolar disorders and migraines. SV has been shown to induce liver toxicity in clinical subjects. Syringic acid (SA), a natural polyphenolic compound has potential antioxidant, anti-inflammatory and several beneficial effects. Therefore, in this study, we evaluated hepatoprotective effect of SA against SV-induced liver injury in rats. Wistar rats were treated with SV orally at a dose of 500 mg/kg, once daily, for 14 days. Another three groups of rats were administered with SV and concurrently treated with SA (40 and 80 mg/kg) and silymarin (SIL) (100 mg/kg) for 14 days. SV administration for 14 days caused significant (p < .001) elevation of liver transaminases and ALP in serum. Liver MDA level was significantly (p < .001) increased with a concomitant decrease (p < .001) in enzymic antioxidants activities in SV administered rats. SV administration also caused the upregulation of proinflammatory markers such as tumor necrosis factor α, c-Jun N-terminal kinase, nuclear factor kappa B, cyclooxygenase-2 and Interleukin 6 expressions in liver tissue. Histopathological studies also revealed the presence of inflammatory cell infiltration and hepatocellular necrosis upon SV administration. At both doses, concurrent administration of SA and SIL significantly (p < .001) inhibited the liver transaminase activities in serum, oxidative stress, and proinflammatory markers expression in liver tissue. Our current results suggest that SA can be a promising herbal drug that can inhibit SV-induced hepatotoxicity when administered together due its potential anti-inflammatory effects.

Syringic and ascorbic acids prevent NDMA-induced pulmonary fibrogenesis, inflammation, apoptosis, and oxidative stress through the regulation of PI3K-Akt/PKB-mTOR-PTEN signaling pathway

Idiopathic lung fibrosis (ILF) is a severe and life threatening lung disorder that is characterized by scarring of lung tissue, leading to thickening and stiffening of affected areas. This study looked at the role played by PI3K-Akt/PKB-mToR signaling pathway in the pathogenesis of N-Nitrosodimethylamine (NDMA)-induced lung fibrotic injury, and the effects of syringic acid (SYR) and ascorbic acid (ASC) treatments in male Wistar rats. Pulmonary fibrosis was induced by intraperitoneal injection of 10 mg/kg NDMA once daily, thrice (consecutively) a week for four weeks, and this condition was treated daily with SYR (50 mg/kg) and ASC (100 mg/kg) acids orally for four weeks. Fibrogenesis, following NDMA administration was marked by a significant increase in collagen-1 and α-SMA levels, while oxidative stress was marked by a significant decrease in GSH level, GST, GPx, CAT, and SOD activities. Also, NDMA significantly increased lung Bax, p53, caspase-3, TNF-α, IL-1β, NFkB, and decreased Bcl-2, mdm2, cyclin D1 and Nrf-2 levels. Looking at the PI3K-Akt-mTOR signaling pathway, NDMA administration significantly activated lung PI3K, Akt, and mTOR, and deactivated PTEN, FoxO1 and TSC2. Treatments with SYR and ASC significantly reduced oxidative stress by restoring the antioxidant systems via Nrf2 activation, decreased the levels of inflammatory markers through inhibition of NFkB, downregulated p53, Bax, and caspase-3 via up-regulation of mdm2 and cyclin D1. SYR and ASC also regulated the PI3K-Akt-mTOR signaling pathway via the deactivation of PI3K, Akt, and mTOR, and up-regulation of PTEN, FoxO1 and TSC2. Overall, SYR and ASC modulate the PI3K-Akt-mTOR signaling pathway via inhibition of oxidative stress, inflammation and apoptosis in NDMA-induced lung fibrosis.

Protective Effect of Phoenix dactylifera L. Seeds against Paracetamol-Induced Hepatotoxicity in Rats: A Comparison with Vitamin C

Phoenix dactylifera L. (date palm) seeds have been mentioned in the Moroccan pharmacopoeia as efficient remedies against a wide range of diseases including hepatic and gastrointestinal disorders and countless infections. The current work was performed to assess the phenolic profile and hepatoprotective potential of two date seed varieties, locally known as Jihl and Majhoul, aqueous extracts against paracetamol- (PCM-) driven liver toxicity in 42 Wistar rats. The polyphenol profile was built by means of an HPLC analysis. Hepatic damage was provoked by exposing rats to PCM at a dose of 1.5 g/kg once a week. Besides PCM, Jihl and Majhoul date seed extracts (200 and 400 mg/kg) were administered orally in a day-to-day routine. Our findings showed that among the examined polyphenol compounds, p-coumaric acid, quercetin, caffeic acid, and rutin were the most abundant phytochemicals. Date pits significantly (p < 0.001) stabilized the PCM-driven alterations in liver function parameters (AST, ALT, ALP, LDH, total protein, direct bilirubin, and total bilirubin). Moreover, Phoenix dactylifera pits enhanced considerably (p < 0.001) the activities of antioxidant enzymes (SOD, CAT, and GPx) as well as the level of reduced glutathione (GSH). The established hepatoprotective effect may be due to the date seeds antioxidant effect and their ability to trap free radicals. The main outcomes of the present study could validate the traditional use of these date seeds to manage various health conditions.

Syringic acid, a novel thyroid hormone receptor-β agonist, ameliorates propylthiouracil-induced thyroid toxicity in rats

The aim of this study was to evaluate the potential of syringic acid (SA) against propylthiouracil (PTU)-induced hypothyroidism in rats. SA at a prestandardized dose, 50 mg/kg/day, was orally administered to PTU-induced hypothyroid rats for 30 days, and alterations in the levels of serum triiodothyronine (T₃ ), thyroxine (T₄ ), thyrotropin (TSH), alanine transaminase (ALT), and aspartate transaminase (AST); tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6); total cholesterol (CHOL) and triglycerides (TG); hepatic lipid peroxidation (LPO) and antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione content), as well as histological changes in liver and thyroid were examined. The molecular interactions of the ligand, SA, with thyroid-related protein targets, such as human thyroid hormone receptor β (hTRβ), and thyroid peroxidase (TPO) protein, were studied using molecular docking. Whereas in hypothyroid animals, T₄ , T₃ , and antioxidants were decreased, there was an increase in TSH, TNF-α, IL-6, ALT, AST, and hepatic LPO; administration of SA in PTU-induced animals reversed all these indices to near normal levels. SA also improved the histological features of liver and thyroid gland. Our study clearly demonstrates SA as a novel thyroid agonist for augmenting the thyroid functions in rats. Molecular docking analysis reveals that SA possesses good binding affinity toward both the targets, hTRβ and TPO. Through this approach, for the first time we provide the evidence for SA as a novel thyroid agonist and suggest a receptor-mediated mechanism for its thyroid stimulatory potential.

Hepatoprotective effect of Moringa oleifera leaves aquatic extract against lead acetate-induced liver injury in male Wistar rats

Current research was performed to explore the hepatoprotective potential of Moringa oleifera leaves extract on lead acetate-induced hepatic injury. Twenty-four male Wistar rats were divided equally into 4 groups. The first group was control, while the second, third, and fourth groups were given 200 mg/kg aqueous Moringa extract only, 100 mg/kg lead only, and 100 mg/kg lead plus 200 mg/kg aqueous Moringa leaves extract, respectively, via oral gavage for 4 weeks. Weight gain and feed efficiency ratio were recorded. Serum lipid profiles, liver enzyme activities, and proteins beside hepatic superoxide dismutase activity, reduced glutathione, tumor necrosis factor alpha (TNF-α), and deoxyribonucleic acid fragmentation were assessed. Liver histopathological examination and nuclear factor kappa B (NF-kB) immunohistochemistry were performed. Administration of lead lowered (P < 0.05) weight gain, feed efficiency ratio, and perturbed lipid profile than control. Lead increased liver enzyme activities and TNF-α, while reduced serum proteins and hepatic antioxidant markers compared to control. Lead aggravated hepatic DNA fragmentation beside the presence of histopathological lesions. Co-administration of aqueous Moringa extract with lead significantly alleviated lead-induced adverse effects. The administration of aqueous Moringa extract with its antioxidant significantly restored the lead perturbations through reduction of oxidative stress-induced DNA damage via amelioration of NF-kB and TNF-α which kept hepatocyte integrity and reduced serum hepatic enzyme activities.

A supramolecular adduct of tegafur and syringic acid: the first tegafur-nutraceutical cocrystal with perfected in vitro and in vivo characteristics as well as synergized anticancer activities

The in vitro and in vivo properties as well as synergistic antitumor activities of the first tegafur-nutraceutical cocrystal are reported.

Dynamics of the Cellular Metabolism of Leptosperin Found in Manuka Honey

Leptosperin (methyl syringate β-d-gentiobioside) is abundantly found in manuka honey, which is widely used because of its antibacterial and possible anti-inflammatory activities. The aim of this study was to examine the molecular mechanism underlying the metabolism of leptosperin. Five phytochemicals (leptosperin, methyl syringate (MSYR), glucuronate conjugate of MSYR (MSYR-GA), sulfonate conjugate of MSYR (MSYR-S), and syringic acid (SYR)) were separately incubated with HepG2 and Caco-2 cells. After incubation, we found that the concentration of MSYR decreased, whereas the concentrations of SYR, MSYR-GA, and MSYR-S increased. By profiling with inhibitors and carboxylesterases (CES1, 2), we found that the conversion from MSYR to SYR was mediated by CES1. Lipopolysaccharide-stimulated RAW264.7 cells restored MSYR-GA to MSYR possibly by the secreted β-glucuronidase. All of the mice administered with leptosperin, MSYR, or manuka honey showed higher MSYR (13.84 ± 11.51, 14.29 ± 9.19, or 6.66 ± 2.30 nM) and SYR (1.85 ± 0.66, 6.01 ± 1.20, or 8.16 ± 3.10 nM) levels in the plasma compared with that of the vehicle controls (3.33 ± 1.45 (MSYR) and 1.85 ± 0.66 (SYR) nM). The findings of our study indicate that the unique metabolic pathways of these compounds may account for possible functionalities of manuka honey.

Acceleration of wound healing activity with syringic acid in streptozotocin induced diabetic rats

Impaired wound healing is a serious concern of uncontrolled hyperglycemia that can lead to gangrene, and even death. There is an urgent need to look for better alternative therapy because of the undesirable side effects of currently available synthetic drugs in the market. Syringic acid (SA) is a natural phenolic compound abundantly available in edible fruits and plants. In this study, wound healing activities of 2.5% and 5.0% SA were evaluated in type 2 diabetic rats using incisional wound model. SA-treated diabetic wounds showed faster rate of wound closure and epithelization with enhanced contents of hydroxyproline and protein compared to diabetic wounds. SA effectively prevents alterations in blood glucose levels, serum insulin and dyslipidemia in diabetic wound rats. The SA-treated diabetic wounds after 14 days of treatment demonstrated inhibition of pro-inflammatory response (NF-κB p65, TNF-α, IL-1β, IL-8 and IL-2) with improvement in anti-inflammatory response (IL-10), inhibited the elevated oxidative stress and decreased the concentrations of matrix metalloproteinases (MMP-2, -8 and -9) and increased the concentrations of TIMP-1 & TIMP- 2. Furthermore, the diabetic wounds were presented with an increase in expression of CD 31 and 68, growth factors (TGF-β1, collagen-I and α-SMA and VEGF) with significant improvement in collagen deposition, re-epithelialization and complete skin structure as revealed by histological analysis after treatment of diabetic wounds with SA for 14 days. Hence, the results of this study designate that SA significantly improves wound healing in diabetic rats and could be used as a potential therapy for treatment of diabetic wounds.

Syringic acid triggers reactive oxygen species–mediated cytotoxicity in HepG2 cells

Hepatocellular carcinoma is the second most common cause of cancer death in the world and its incidence has dramatically increased worldwide in the past two decades. Syringic acid (SA) has been studied for its hepatoprotective, anti-inflammatory, immunomodulatory, free radical scavenging, and antioxidant activities. We aimed to evaluate the cytotoxic effect of SA against human hepatoma HepG2 cell line. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. HepG2 cells were treated with SA at concentration ranges of 25, 50, and 100 µM for 24 h. Reactive oxygen species (ROS) expression was investigated by dichlorofluorescein staining assay. Morphological changes of SA-treated HepG2 cells were evaluated by acridine orange (AO) and ethidium bromide (EB) dual staining. Apoptotic marker gene expressions were evaluated by qPCR. SA treatment caused significant cytotoxicity and liberation of ROS in HepG2 cells. AO and EB staining showed membrane blebbing and distortion in SA-treated cells. Apoptotic markers such as caspases 3 and 9, cytochrome c, Apaf-1, Bax, and p53 gene expressions were significantly increased upon SA treatment indicating the possibility of apoptosis induction in HepG2 cells. This treatment also caused significant downregulation of Bcl-2 gene expression. SA has a cytotoxic effect on human HepG2 cell line, and this might be a promising agent in anticancer research.

Attenuation of high glucose induced apoptotic and inflammatory signaling pathways in RIN-m5F pancreatic β cell lines by Hibiscus rosa sinensis L. petals and its phytoconstituents

ETHNOPHARMACOLOGICAL RELEVANCE

Hibiscus rosa sinensis petals possess wide range of pharmacological properties, with remarkable nutritional values. Diabetes is one of the most devastating diseases affecting the world today. A few side effects associated with the use of insulin and oral hypoglycemic agents prompted us to search new bioactive principles from antidiabetic plants used in traditional medicine.

AIM OF THE STUDY

The anti-diabetic therapeutic potential of the flavonoids rich ethyl acetate fraction of Hibiscus rosa sinensis petals (EHRS) was evaluated.

MATERIALS AND METHODS

High glucose (25 mM) induced apoptotic model of diabetes in RIN-m5F pancreatic β-cells was used for the study.

RESULTS

EHRS elevated the release of insulin in pancreatic cells and modulated apoptotic signaling cascades. It significantly reduced NF-κB nuclear translocation, thereby down-regulated the expressions of major inflammatory cytokines and up-regulated expressions of pancreatic β-cell functional genes such as, foxO-1, Ucn-3, Pdx-1, MafA and Nkx6.1. On comparison with its constituent phytochemicals, superior protective effect shown by EHRS may be due to the additive action of these phytoconstituents.

CONCLUSIONS

Results of the present study suggest hibiscus petals as a natural source and functional food of potential therapeutics to protect pancreatic β-cells in experimental diabetes mellitus.

Therapeutic Potential of Plants and Plant Derived Phytochemicals against Acetaminophen-Induced Liver Injury

Acetaminophen (APAP), which is also known as paracetamol or N-acetyl-p-aminophenol is a safe and potent drug for fever, pain and inflammation when used at its normal therapeutic doses. It is available as over-the-counter drug and used by all the age groups. The overdose results in acute liver failure that often requires liver transplantation. Current clinical therapy for APAP-induced liver toxicity is the administration of N-acetyl-cysteine (NAC), a sulphydryl compound an approved drug which acts by replenishing cellular glutathione (GSH) stores in the liver. Over the past five decades, several studies indicate that the safety and efficacy of herbal extracts or plant derived compounds that are used either as monotherapy or as an adjunct therapy along with conventional medicines for hepatotoxicity have shown favorable responses. Phytochemicals mitigate necrotic cell death and protect against APAP-induced liver toxicityby restoring cellular antioxidant defense system, limiting oxidative stress and subsequently protecting mitochondrial dysfunction and inflammation. Recent experimental evidences indicat that these phytochemicals also regulate differential gene expression to modulate various cellular pathways that are implicated in cellular protection. Therefore, in this review, we highlight the role of the phytochemicals, which are shown to be efficacious in clinically relevant APAP-induced hepatotoxicity experimental models. In this review, we have made comprehensive attempt to delineate the molecular mechanism and the cellular targets that are modulated by the phytochemicals to mediate the cytoprotective effect against APAP-induced hepatotoxicity. In this review, we have also defined the challenges and scope of phytochemicals to be developed as drugs to target APAP-induced hepatotoxicity.

Syringic acid may attenuate the oral mucosal carcinogenesis via improving cell surface glycoconjugation and modifying cytokeratin expression

Syringic acid (SRA) is an excellent anti-oxidant and anti-cancer property in various in vitro and in vivo studies. In the present study was modifying effect of SRA on 7,12-dimethylbenz(a)anthracene (DMBA) induced cell surface glycoconjugates (GCs) abnormalities in the plasma and buccal mucosa of golden Syrian hamster buccal pouch carcinogenesis (HBPCs). Topical application of DMBA three times a week for 10 weeks on the buccal pouches of the hamsters resulted in well developed squamous cell carcinoma. GCs status was assessed biochemically, histological and immunoexpression pattern of cytokeratin (CK) in the buccal mucosa of the DMBA treated hamsters. Elevated levels of GCs and CK expression were observed in DMBA alone treated hamsters. Oral pre-administration of SRA (50 mg/kg bw) positively modulates the GCs levels and CK expressions to near normal. The present findings suggested that SRA can protect cell surface GCs and CK expression during DMBA induced HBPCs.

Syringic acid (SA) ‒ A Review of Its Occurrence, Biosynthesis, Pharmacological and Industrial Importance

The use of phytochemicals in control of human diseases have been considerable public and scientific interest in current days. Syringic acid (SA), a phenolic compound often found in fruits and vegetables and which is synthesized via shikimic acid pathway in plants. It shows a wide range of therapeutic applications in prevention of diabetes, CVDs, cancer, cerebral ischemia; as well as it possess anti-oxidant, antimicrobial, anti-inflammatory, antiendotoxic, neuro and hepatoprotective activities. It has an effective free radical scavenger and alleviates the oxidative stress markers. The therapeutic property of SA is attributed by the presence of methoxy groups onto the aromatic ring at positions 3 and 5. The strong antioxidant activity of SA may confer its beneficial effects for human health. SA has the potential to modulate enzyme activity, protein dynamics and diverse transcription factors involved in diabetes, inflammation, cancer and angiogenesis. In vivo experimental data and histopathological studies on SA activity has delineated its possible therapeutic mechanisms. Besides usage in biomedical field, SA has greater industrial applications in bioremediation, photocatalytic ozonation, and laccase based catalysis. The present review deals about SA natural sources, biosynthesis, bioavailability, biomedical applications (in vivo and in vito. The review addresses basic information about molecular mechanisms, therapeutic and industrial potential of SA.

Association of antioxidant nutraceuticals and acetaminophen (paracetamol): Friend or foe?

Acetaminophen (paracetamol or APAP) is an analgesic and antipyretic drug that can induce oxidative stress-mediated hepatotoxicity at high doses. Several studies reported that antioxidant nutraceuticals, in particular phenolic phytochemicals from dietary food, spices, herbs and algae have hepatoprotective effects. Others, however, suggested that they may negatively impact the metabolism, efficacy and toxicity of APAP. The aim of this review is to discuss the pros and consofthe association of antioxidant nutraceuticals and APAP by reviewing the in vivo evidence, with particular reference to APAP pharmacokinetics and hepatotoxicity. Results from the murine models of APAP-induced hepatotoxicity showed amelioration of liver damage with nutraceuticals coadministration, as well as reductions in tissue markers of oxidative stress, and serum levels of hepatic enzymes, bilirubin, cholesterol, triglycerides and inflammatory cytokines. On the other hand, both increased and decreased APAP plasma levels have been reported, depending on the nutraceutical type and route of administration. For example, studies showed that repeated administration of flavonoids causes down-regulation of cytochrome P450 enzymes and up-regulation of uridine diphosphate glucuronosyltransferases (UGT). Moreover, nutraceuticals can alter the levels of APAP metabolites, such as mercapturate glucuronide, sulfate and cysteine conjugates. Overall, the reviewed in vivo studies indicate that interactions between APAP and nutraceuticals or plant foods exist. However, the majority of data come from animal models with doses of phytochemicals far from dietary ones. Human studies should investigate gene-diet interactions, as well as ethnic variability in order to clarify the pros and cons of co-administering antioxidant nutraceuticals and APAP.

Anti-steatotic and anti-inflammatory roles of syringic acid in high-fat diet-induced obese mice

This study examined the effects of syringic acid (SA) on obese diet-induced hepatic dysfunction.

4-Hydroxy-3,5-dimethoxy-N-{4-[(5-methyl-1,2-oxazol-3-yl)sulfamoyl]phenyl}benzamide methanol monosolvate

The title compound, C₁₉H₁₉N₃O₇S·CH₃OH, was synthesized from syringic acid and sulfamethoxazole. The benzene rings make a dihedral angle of 41.8 (1)° and the isoxazole ring is twisted by 74.3 (1)° from the central benzene ring. The crystal packing features O—H⋯O and O—H⋯N hydrogen bonds in which the hy­droxy groups from the main mol­ecule and methanol solvent mol­ecules serve as donor groups.