Activation of Nrf2 target enzymes conferring protection against oxidative stress in PC12 cells by ginger principal constituent 6-shogaol

A novel hydroxytyrosol derivative HT-3 enhances antioxidant and neuroprotective activity through efficient molecular conjugation

Molecular conjugation is a promising strategy for drug development, which could enhance the efficacy, selectivity, and bioavailability of high-potency compounds through precise structural modifications. Our previous studies demonstrated that hydroxytyrosol (HT) provides excellent neuroprotection in PC12 cells, which is derived from olive oil, and now widely used as a natural food additive. In this study, we rationally designed and synthesized a string of HT derivations by coupling caffeic acid skeletons, and found that HT-3 exhibited the strongest antioxidant activity and superior neuroprotective efficacy via the Keap1/Nrf2/ARE pathway among the HT analogue. Additionally, nanoparticles of HT-3 (HT-3 NPs) were constructed for reducing toxicity and enhancing efficacy, which could enhance blood-brain barrier penetration, accelerate metabolism, and prolong brain retention in mice model of Parkinson's disease. This work would open a new avenue for further investigation of HT analogue.

Psoralen and Isopsoralen Activate Nuclear Factor Erythroid 2-Related Factor 2 Through Interaction With Kelch-Like ECH-Associated Protein 1

As natural furocoumarins, psoralen and its isomer isopsoralen are widely distributed in various fruits including Ficus carica L., vegetables including celery, and medicinal herbs including Psoralea corylifolia L. Although psoralen and isopsoralen have been used as dietary supplements because of their bioactivities such as antibacterial and anti-inflammatory properties; however, the potential mechanisms underlying the antioxidant activities of these two furocoumarins still need to be explored. Hence, the aims of this work were to examine the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) by psoralen and isopsoralen, as well as the binding interaction of Kelch-like ECH-associated protein 1 (Keap1) with these two furocoumarins. Interestingly, both psoralen and isopsoralen induced Nrf2 nuclear translocation in a dose-dependent manner in HEK293T cells. These two furanocoumarins also activated antioxidant response element (ARE)-driven luciferase activity. The mRNA expression of GCLM, HO-1, and NQO1 genes was significantly upregulated by treatment of HEK293T cells with psoralen and isopsoralen, respectively. Similarly, the expression of proteins can be promoted. Both psoralen and isopsoralen were located in the top of the central pocket of the Keap1 Kelch domain, suggesting that they were natural ligands of Keap1. In conclusion, both psoralen and isopsoralen activate Nrf2 through interaction with Keap1, thereby serving as natural antioxidants.

Combating Parkinson's disease with plant-derived polyphenols: Targeting oxidative stress and neuroinflammation

Parkinson's disease (PD) is a devastating neurodegenerative disorder predominantly affecting the elderly, characterized by the loss of dopaminergic neurons in the substantia nigra. Reactive oxygen species (ROS) generation plays a central role in the pathogenesis of PD and other neurodegenerative diseases. An imbalance between cellular antioxidant activity and ROS production leads to oxidative stress, contributing to disease progression. Dopamine metabolism, mitochondrial dysfunction, and neuroinflammation in dopaminergic neurons have been implicated in the pathogenesis of Parkinson's disease. Consequently, there is a pressing need for therapeutic interventions capable of scavenging ROS. Current pharmacological approaches, such as L-dihydroxyphenylalanine (levodopa or L-DOPA) and other drugs, provide symptomatic relief but are limited by severe side effects. Researchers worldwide have been exploring alternative compounds with less toxicity to address the multifaceted challenges associated with Parkinson's disease. In recent years, plant-derived polyphenolic compounds have gained significant attention as potential therapeutic agents. These compounds exhibit neuroprotective effects by targeting pathophysiological responses, including oxidative stress and neuroinflammation, in Parkinson's disease. The objective of this review is to summarize the current understanding of the neuroprotective effects of various polyphenols in Parkinson's disease, focusing on their antioxidant and anti-inflammatory properties, and to discuss their potential as therapeutic candidates. This review highlights the progress made in elucidating the molecular mechanisms of action of these polyphenols, identifying potential therapeutic targets, and optimizing their delivery and bioavailability. Well-designed clinical trials are necessary to establish the efficacy and safety of polyphenol-based interventions in the management of Parkinson's disease.

Effects of Ginger (Zingiber officinale) on the Hallmarks of Aging

Ginger (Zingiber officinale Roscoe) is broadly used as a traditional remedy and food ingredient, and numerous preclinical and clinical studies have demonstrated health benefits in a range of age-related disorders. Moreover, longevity-promoting effects have been demonstrated in several (preclinical) research models. With this work, we aimed to comprehensively review the reported effects of ginger and its bioactive constituents on the twelve established hallmarks of aging, with the ultimate goal of gaining a deeper understanding of the potential for future interventions in the area of longevity-extension and counteracting of aging-related diseases. The reviewed literature supports the favorable effects of ginger and some of its constituents on all twelve hallmarks of aging, with a particularly high number of animal research studies indicating counteraction of nutrient-sensing dysregulations, mitochondrial dysfunction, chronic inflammation, and dysbiosis. On this background, validation in human clinical trials is still insufficient or is entirely missing, with the exception of some studies indicating positive effects on deregulated nutrient-sensing, chronic inflammation, and dysbiosis. Thus, the existing body of literature clearly supports the potential of ginger to be further studied in clinical trials as a supplement for the promotion of both lifespan and health span.

Efficient Deep Model Ensemble Framework for Drug-Target Interaction Prediction

Accurate prediction of Drug-Target Interactions (DTI) is crucial for drug development. Current state-of-the-art deep learning methods have significantly advanced the field; however, these methods exhibit limitations in predictive performance and the propensity for false negatives. Therefore, we propose EADTN, a simple and efficient ensemble model. We have designed an innovative feature adaptation technique to automatically extract local weights of drugs and targets, and we utilize clustering-enhanced parameter fine-tuning to overcome the issue of false negatives, thereby enhancing its reliability in drug discovery. Based on EADTN, we also propose a Shapley value-based method for identifying key drug substructures, effectively enhancing the model's interpretability. Additionally, we utilized EADTN to reveal potential interactions between NQO1 targets and the drugs SIRT-IN-1 and LY2183240, which were subsequently validated through wet-lab experiments. Experimental evidence demonstrates that EADTN consistently outperforms existing best-performing models across various data sets, promising significant benefits in fields such as drug repositioning.

Hydroxygenkwanin exerts a neuroprotective effect by activating the Nrf2/ARE signaling pathway

High levels of reactive oxygen species (ROS) have been associated with the progression of neurodegenerative diseases such as Alzheimer's disease. The activation of the NFE2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway may restore the neuron's redox balance and provide a therapeutic impact. Hydroxygenkwanin (HGK), a dominant flavone from Genkwa Flos, has received expanding attention due to its medicinal activities. Our investigation results demonstrated the ability of HGK to protect the PC12 cells from oxidative damage caused by an excessive hydrogen peroxide load. HGK also showed the ability to upregulate a panel of endogenous antioxidant proteins. Further investigations have demonstrated that the neuroprotection mechanism of HGK is dependent on the activation of the Nrf2/ARE signaling pathway. Activating the Nrf2/ARE pathway by HGK reveals a novel mechanism for understanding the pharmacological functions of HGK. These findings suggest that HGK could be considered for further development as an oxidative stress-related neurological pathologies potential therapeutic drug.

An overview of 6-shogaol: new insights into its pharmacological properties and potential therapeutic activities

Ginger (Zingiber officinale Roscoe) has traditionally been used as a cooking spice and herbal medicine for treating nausea and vomiting. More recently, ginger was found to effectively reduce the risk of diseases such as gastroenteritis, migraine, gonarthritis, etc., due to its various bioactive compounds. 6-Shogaol, the pungent phenolic substance in ginger, is the most pharmacologically active among such compounds. The aim of the present study was to review the pharmacological characteristic of 6-shogaol, including the properties of anti-inflammatory, antioxidant and antitumour, and its corresponding molecular mechanism. With its multiple mechanisms, 6-shogaol is considered a beneficial natural compound, and therefore, this review will shed some light on the therapeutic role of 6-shogaol and provide a theoretical basis for the development and clinical application of 6-shogaol.

Ginger Bioactives: A Comprehensive Review of Health Benefits and Potential Food Applications

Ginger is an herbaceous and flowering plant renowned for its rhizome, which is widely employed as both a spice and an herb. Since ancient times, ginger has been consumed in folk medicine and traditional cuisines for its favorable health effects. Different in vitro and in vivo studies have disclosed the advantageous physiological aspects of ginger, primarily due to its antioxidant, anti-inflammatory, antimicrobial, and anti-carcinogenic properties. These health-promoting features are linked to the variety of bioactive compounds that are present in ginger. Following the advancement in consumer awareness and the industrial demand for organic antioxidants and functional ingredients, the application of ginger and its derivatives has been broadly investigated in a wide range of food products. The prominent features transmitted by ginger into different food areas are antioxidant and nutraceutical values (bakery); flavor, acceptability, and techno-functional characteristics (dairy); hedonic and antimicrobial properties (beverages); oxidative stability, tenderization, and sensorial attributes (meat); and shelf life and sensorial properties (film, coating, and packaging). This review is focused on providing a comprehensive overview of the tendencies in the application of ginger and its derivatives in the food industry and concurrently briefly discusses the beneficial aspects and processing of ginger.

6-Shogaol as a Novel Thioredoxin Reductase Inhibitor Induces Oxidative-Stress-Mediated Apoptosis in HeLa Cells

Inhibition of thioredoxin reductase (TrxR) is a crucial strategy for the discovery of antineoplastic drugs. 6-Shogaol (6-S), a primary bioactive compound in ginger, has high anticancer activity. However, its potential mechanism of action has not been thoroughly investigated. In this study, we demonstrated for the first time that 6-S, a novel TrxR inhibitor, promoted oxidative-stress-mediated apoptosis in HeLa cells. The other two constituents of ginger, 6-gingerol (6-G) and 6-dehydrogingerduone (6-DG), have a similar structure to 6-S but fail to kill HeLa cells at low concentrations. 6-Shogaol specifically inhibits purified TrxR1 activity by targeting selenocysteine residues. It also induced apoptosis and was more cytotoxic to HeLa cells than normal cells. The molecular mechanism of 6-S-mediated apoptosis involves TrxR inhibition, followed by an outburst of reactive oxygen species (ROS) production. Furthermore, TrxR knockdown enhanced the cytotoxic sensitivity of 6-S cells, highlighting the physiological significance of targeting TrxR by 6-S. Our findings show that targeting TrxR by 6-S reveals a new mechanism underlying the biological activity of 6-S and provides meaningful insights into its action in cancer therapeutics.

The effect of zingiber officinale on prooxidant-antioxidant balance and glycemic control in diabetic patients with ESRD undergoing hemodialysis: a double-blind randomized control trial

BACKGROUND

Diabetes management in hemodialysis patients with end-stage renal disease needs precision to avoid complications. The study aimed to investigate the effect of ginger supplementation on prooxidant-antioxidant balance, glycemic management, and renal function in diabetic hemodialysis patients.

TRIAL DESIGN AND METHODS

Forty-four patients were randomly allocated to either the ginger or the placebo group in this randomized, double blind, placebo-controlled study. Patients in the ginger group received 2000 mg/d ginger for eight weeks, whereas those in the placebo group received equivalent placebos. After a 12- to 14-h fast, serum levels of fasting blood glucose (FBG), insulin, urea, creatinine, and prooxidant-antioxidant balance (PAB) were measured at baseline and at the end of the study. The homeostatic model evaluation of insulin resistance was used to determine insulin resistance (HOMA-IR).

RESULTS

Serum levels of FBG (p = 0.001), HOMA-IR (p = 0.001), and urea (p = 0.017) were considerably lower in the ginger group compared to baseline, and the difference was significant when compared to the placebo group (p < 0.05). Moreover, ginger supplementation decreased serum levels of creatinine (p = 0.034) and PAB (p = 0.013) within the group, but the effect was insignificant between groups (p > 0.05). On the other hand, insulin levels did not vary significantly across and among the groups (p > 0.05).

CONCLUSION

In summary, this study indicated that in diabetic hemodialysis patients, ginger could result to lower blood glucose levels, enhanced insulin sensitivity, and lower serum urea levels. Further studies with a more extended intervention period and various doses and forms of ginger are needed.

TRIAL REGISTRATION

IRCT20191109045382N2. (06/07/2020), Retrospectively registered, https://www.irct.ir/trial/48467.

Characterization of tangeretin as an activator of nuclear factor erythroid 2-related factor 2/antioxidant response element pathway in HEK293T cells

Numerous studies have reported that tangeretin is a polymethoxylated flavone with a variety of biological activates, but little research has been done on the antioxidant mechanism of tangeretin. Hence, we investigated the effect of tangeretin on the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway and its potential molecular mechanisms by in vitro and in silico research. The results of molecular docking suggested that tangeretin bound at the top of the central pore of Kelch-like ECH-associated protein 1 (Keap1) Kelch domain, and the hydrophobic and hydrogen bond interactions contributed to their stable binding. Herein, the regulation of Nrf2-ARE pathway by tangeretin was explored in the human embryonic kidney cell line HEK293T, which is relatively easy to be transfected. Upon binding to tangeretin, Nrf2 translocated to the nucleus of HEK293T cells, which in turn activated the Nrf2-ARE pathway. Luciferase reporter gene analysis showed that tangeretin significantly induced ARE-mediated transcriptional activation. Real-time PCR and Western blot assays showed that tangeretin induced the gene and protein expressions of Nrf2-mediated targets, including heme oxygenase 1 (HO-1), nicotinamide adenine dinucleotide phosphate (NADPH) quinone dehydrogenase 1 (NQO1), and glutamate-cysteine ligase (GCLM). In addition, tangeretin could effectively scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. In summary, tangeretin may be a potential antioxidant via activating the Nrf2-ARE pathway.

Effect of Ginger on Inflammatory Diseases

Ulcerative colitis, Crohn's disease, rheumatoid arthritis, psoriasis, and lupus erythematosus are some of common inflammatory diseases. These affections are highly disabling and share signals such as inflammatory sequences and immune dysregulation. The use of foods with anti-inflammatory properties such as ginger (Zingiber officinale Roscoe) could improve the quality of life of these patients. Ginger is a plant widely used and known by its bioactive compounds. There is enough evidence to prove that ginger possesses multiple biological activities, especially antioxidant and anti-inflammatory capacities. In this review, we summarize the current knowledge about the bioactive compounds of ginger and their role in the inflammatory process and its signaling pathways. We can conclude that the compounds 6-shoagol, zingerone, and 8-shoagol display promising results in human and animal models, reducing some of the main symptoms of some inflammatory diseases such as arthritis. For lupus, 6-gingerol demonstrated a protective attenuating neutrophil extracellular trap release in response to phosphodiesterase inhibition. Ginger decreases NF-kβ in psoriasis, and its short-term administration may be an alternative coadjuvant treatment. Ginger may exert a function of supplementation and protection against cancer. Furthermore, when receiving chemotherapy, ginger may reduce some symptoms of treatment (e.g., nausea).

Synergistic Anti-Inflammatory Activity of Ginger and Turmeric Extracts in Inhibiting Lipopolysaccharide and Interferon-γ-Induced Proinflammatory Mediators

This study aims to investigate the combined anti-inflammatory activity of ginger and turmeric extracts. By comparing the activities of individual and combined extracts in lipopolysaccharide and interferon-γ-induced murine RAW 264.7 cells, we demonstrated that ginger-turmeric combination was optimal at a specific ratio (5:2, w/w) in inhibiting nitric oxide, tumour necrosis factor and interleukin 6 with synergistic interaction (combination index < 1). The synergistic inhibitory effect on TNF was confirmed in human monocyte THP-1 cells. Ginger-turmeric combination (5:2, w/w) also upregulated nuclear factor erythroid 2−related factor 2 activity and heme oxygenase-1 protein expression. Additionally, 6-shogaol, 8-shogaol, 10-shogaol and curcumin were the leading compounds in reducing major proinflammatory mediators and cytokines, and a simplified compound combination of 6-s, 10-s and curcumin showed the greatest potency in reducing LPS-induced NO production. Our study provides scientific evidence in support of the combined use of ginger and turmeric to alleviate inflammatory processes.

Potential Role of Ginger (Zingiber officinale Roscoe) in the Prevention of Neurodegenerative Diseases

Ginger is composed of multiple bioactive compounds, including 6-gingerol, 6-shogaol, 10-gingerol, gingerdiones, gingerdiols, paradols, 6-dehydrogingerols, 5-acetoxy-6-gingerol, 3,5-diacetoxy-6-gingerdiol, and 12-gingerol, that contribute to its recognized biological activities. Among them, the major active compounds are 6-shogaol and 6-gingerol. Scientific evidence supports the beneficial properties of ginger, including antioxidant and anti-inflammatory capacities and in contrast, a specific and less studied bioactivity is the possible neuroprotective effect. The increase in life expectancy has raised the incidence of neurodegenerative diseases (NDs), which present common neuropathological features as increased oxidative stress, neuroinflammation and protein misfolding. The structure-activity relationships of ginger phytochemicals show that ginger can be a candidate to treat NDs by targeting different ligand sites. Its bioactive compounds may improve neurological symptoms and pathological conditions by modulating cell death or cell survival signaling molecules. The cognitive enhancing effects of ginger might be partly explained via alteration of both the monoamine and the cholinergic systems in various brain areas. Moreover, ginger decreases the production of inflammatory related factors. The aim of the present review is to summarize the effects of ginger in the prevention of major neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and multiple sclerosis.

Current Status and Future Perspectives on Therapeutic Potential of Apigenin: Focus on Metabolic-Syndrome-Dependent Organ Dysfunction

Metabolic syndrome and its associated disorders such as obesity, insulin resistance, atherosclerosis and type 2 diabetes mellitus are globally prevalent. Different molecules showing therapeutic potential are currently available for the management of metabolic syndrome, although their efficacy has often been compromised by their poor bioavailability and side effects. Studies have been carried out on medicinal plant extracts for the treatment and prevention of metabolic syndrome. In this regard, isolated pure compounds have shown promising efficacy for the management of metabolic syndrome, both in preclinical and clinical settings. Apigenin, a natural bioactive flavonoid widely present in medicinal plants, functional foods, vegetables and fruits, exerts protective effects in models of neurological disorders and cardiovascular diseases and most of these effects are attributed to its antioxidant action. Various preclinical and clinical studies carried out so far show a protective effect of apigenin against metabolic syndrome. Herein, we provide a comprehensive review on both in vitro and in vivo evidence related to the promising antioxidant role of apigenin in cardioprotection, neuroprotection and renoprotection, and to its beneficial action in metabolic-syndrome-dependent organ dysfunction. We also provide evidence on the potential of apigenin in the prevention and/or treatment of metabolic syndrome, analysing the potential and limitation of its therapeutic use.

Effects of Zingiber officinale extract supplementation on metabolic and genotoxic parameters in diet-induced obesity in mice

Obesity is an epidemic associated with many diseases. The nutraceutical Zingiber officinale (ZO) is a potential treatment for obesity; however, the molecular effects are unknown. Swiss male mice were fed a high-fat diet (59 % energy from fat) for 16 weeks to generate a diet-induced obesity (DIO) model and then divided into the following groups: standard diet + vehicle; standard diet + ZO; DIO + vehicle and DIO + ZO. Those in the ZO groups were supplemented with 400 mg/kg per d of ZO extract (oral administration) for 35 d. The animals were euthanised, and blood, quadriceps, epididymal fat pad and hepatic tissue were collected. DIO induced insulin resistance, proinflammatory cytokines, oxidative stress and DNA damage in different tissues. Treatment with ZO improved insulin sensitivity as well as decreased serum TAG, without changes in body weight or adiposity index. TNF-α and IL-1β levels were lower in the liver and quadriceps in the DIO + ZO group compared with the DIO group. ZO treatment reduced the reactive species and oxidative damage to proteins, lipids and DNA in blood and liver in obese animals. The endogenous antioxidant activity was higher in the quadriceps of DIO + ZO. These results in the rat model of DIO may indicate ZO as an adjuvant on obesity treatment.

Effects of ginger supplementation on biomarkers of oxidative stress: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The present systematic review and meta-analysis were conducted to investigate the effects of ginger on biomarkers of oxidative stress such as glutathione peroxidase (GPx), malondialdehyde (MDA), and total antioxidant capacity (TAC) this meta-analysis was performed.

METHODS

Five databases were searched from inception to May 2020 using relevant keywords. Results were reported as bias-corrected standardized mean difference (Hedges' g) with 95 % confidence intervals (CI) using random-effects models.

RESULTS

Eleven RCTs were included. Ginger resulted in significantly increased on GPx (Hedges' g: 1.93, 95 % CI: 0.20 to 3.66, P = 0.029) and significant reduction in MDA (Hedges' g: -1.45, 95 % CI: -2.31 to -0.59, P = 0.001), but no significant change in TAC (Hedges' g: 0.42, 95 % CI: -0.03 to 0.88, P = 0.069). Greater reduction in MDA was detected in trials using ≤1 g ginger, lasted <12 weeks, participants aged ≥30 years old, among both gender and were conducted sample size ≤40. TAC was increased by administered high doses of ginger, lasted ≥12 weeks, mean age ≥30, sample size >40, and both gender and female.

CONCLUSION

Overall, this meta-analysis demonstrated ginger supplementation decreased MDA and increased GPx but the results showed no significant alterations in TAC activities.

Protective Effects of 6-Shogaol, an Active Compound of Ginger, in a Murine Model of Cisplatin-Induced Acute Kidney Injury

Acute kidney injury (AKI) is a dose-limiting side effect of cisplatin therapy in cancer patients. However, effective therapies for cisplatin-induced AKI are not available. Oxidative stress, tubular cell death, and inflammation are known to be the major pathological processes of the disease. 6-Shogaol is a major component of ginger and exhibits anti-oxidative and anti-inflammatory effects. Accumulating evidence suggest that 6-shogaol may serve as a potential therapeutic agent for various inflammatory diseases. However, whether 6-shogaol exerts a protective effect on cisplatin-induced renal side effect has not yet been determined. The aim of this study was to evaluate the effect of 6-shogaol on cisplatin-induced AKI and to investigate its underlying mechanisms. An administration of 6-shogaol after cisplatin treatment ameliorated renal dysfunction and tubular injury, as shown by a reduction in serum levels of creatinine and blood urea nitrogen and an improvement in histological abnormalities. Mechanistically, 6-shogaol attenuated cisplatin-induced oxidative stress and modulated the renal expression of prooxidant and antioxidant enzymes. Apoptosis and necroptosis induced by cisplatin were also suppressed by 6-shogaol. Moreover, 6-shogaol inhibited cisplatin-induced cytokine production and immune cell infiltration. These results suggest that 6-shogaol exhibits therapeutic effects against cisplatin-induced AKI via the suppression of oxidative stress, tubular cell death, and inflammation.

Nephroprotective activity of Aframomum melegueta seeds extract against diclofenac-induced acute kidney injury: A mechanistic study

ETHNOPHARMACOLOGICAL RELEVANCE

In Africa, Aframomum species have been traditionally used to treat illnesses such as inflammation, hypertension, diarrhea, stomachache and fever. Moreover, Aframomum melegueta seed extracts (AMSE) are used in traditional medicine to relieve stomachaches and inflammatory diseases.

AIM

Chronic administration of diclofenac (DIC) has been reported to cause acute kidney injury (AKI), which is a serious health condition. The nephroprotective effect of AMSE is yet to be elucidated. Accordingly, this study aims to investigate the phytoconstituents of standardized AMSE, evaluate its nephroprotective effects against DIC-induced AKI in rats, and elaborate its underlying molecular mechanisms.

MATERIALS AND METHODS

The quantitative estimation of major AMSE constituents and profiling of its secondary metabolites were conducted via RP-HPLC and LC-ESI/Triple TOF/MS, respectively. Next, DIC (50 mg/kg)-induced AKI was achieved in Sprague-Dawley rats and DIC-challenged rats were administered AMSE (100 and 200 mg/kg) orally. All treatments were administered for five consecutive days. Blood samples were collected and the sera were used for estimating creatinine, urea and, kidney injury molecule (KIM)-1 levels. Kidney specimens were histopathologically assessed and immunohistochemically examined for c-Myc expression. A portion of the kidney tissue was homogenized and examined for levels of oxidative stress markers (MDA and GSH). Heme oxygenase (HO)-1, TNF-α, IL-6, Bax, Bcl2 and caspase-3 renal levels were quantified by ELISA. Moreover, the protein expression levels of NF-ҡB p65 was quantified using Western blot analysis, whereas mRNA expression levels of AMPK, SIRT-1, nuclear factor erythroid-2-related factor (Nrf2) and STAT3 were detected using qRT-PCR in the remaining kidney tissues.

RESULTS

Standardized AMSE was shown to primarily contain 6-gingerol, 6-shogaol and 6-paradol among the 73 compounds that were detected via LC-ESI/Triple TOF/MS including phenolic acids, hydroxyphenylalkanes, diarylheptanoids and fatty acids. Relative to DIC-intoxicated rats, AMSE modulated serum creatinine, urea, KIM-1, renal MDA, TNF-α, IL-6, Bax, and caspase-3 levels. AMSE has also improved renal tissue architecture, enhanced GSH and HO-1 levels, and upregulated renal Nrf2, AMPK, and SIRT-1 mRNA expression levels. Furthermore, AMSE suppressed NF-ҡB p65 protein and STAT3 mRNA expression, and further reduced c-Myc immunohistochemical expression in renal tissues. Overall, our findings revealed that AMSE counteracted DIC-induced AKI via its antioxidant, anti-inflammatory, and antiapoptotic activities. Moreover, AMSE activated Nrf2/HO1 and AMPK/SIRT1, and inhibited NF-ҡB/STAT3 signaling pathways. Therefore, AMSE is a promising agent for inhibiting DIC-induced nephrotoxicity.

Natural Molecules Targeting Thioredoxin System and Their Therapeutic Potential

Significance: Thioredoxin (Trx) and thioredoxin reductase are two core members of the Trx system. The system bridges the gap between the universal reducing equivalent NADPH and various biological molecules and plays an essential role in maintaining cellular redox homeostasis and regulating multiple cellular redox signaling pathways. Recent Advance: In recent years, the Trx system has been well documented as an important regulator of many diseases, especially tumorigenesis. Thus, the development of potential therapeutic molecules targeting the system is of great significance for disease treatment. Critical Issues: We herein first discuss the physiological functions of the Trx system and the role that the Trx system plays in various diseases. Then, we focus on the introduction of natural small molecules with potential therapeutic applications, especially the anticancer activity, and review their mechanisms of pharmacological actions via interfering with the Trx system. Finally, we further discuss several natural molecules that harbor therapeutic potential and have entered different clinical trials. Future Directions: Further studies on the functions of the Trx system in multiple diseases will not only improve our understanding of the pathogenesis of many human disorders but also help develop novel therapeutic strategies against these diseases. Antioxid. Redox Signal. 34, 1083-1107.

A recent update on the multifaceted health benefits associated with ginger and its bioactive components

Due to recent lifestyle shifts and health discernments among consumers, synthetic drugs are facing the challenge of controlling disease development and progression. Various medicinal plants and their constituents are recognized for their imminent role in disease management via modulation of biological activities. At present, research scholars have diverted their attention on natural bioactive entities with health-boosting perception to combat the lifestyle-related disarrays. In particular, Zingiber officinale is a medicinal herb that has been commonly used in food and pharmaceutical products. Its detailed chemical composition and high value-added active components have been extensively studied. In this review, we have summarized the pharmacological potential of this well-endowed chemo preventive agent. It was revealed that its functionalities are attributed to several inherent chemical constituents, including 6-gingerol, 8-gingerol, 10-gingerol, 6-shogaol, 6-hydroshogaol, and oleoresin, which were established through many studies (in vitro, in vivo, and cell lines). In this review, we also focused on the therapeutic effects of ginger and its constituents for their effective antioxidant properties. Their consumption may reduce or delay the progression of related diseases, such as cancer, diabetes, and obesity, via modulation of genetic and metabolic activities. The updated data could elucidate the relationship of the extraction processes with the constituents and biological manifestations. We have collated the current knowledge (including the latest clinical data) about the bioactive compounds and bioactivities of ginger. Their detailed mechanisms, which can lay foundation for their food and medical applications are also discussed.

Is 6-Shogaol an Effective Phytochemical for Patients With Lower-risk Myelodysplastic Syndrome? A Narrative Review

Myelodysplastic syndrome (MDS) evolves due to genomic instability, dysregulated signaling pathways, and overproduction of inflammatory markers. Reactive oxygen species contribute to the inflammatory response, which causes gene damage, cellular remodeling, and fibrosis. MDS can be a debilitating condition, and management options in patients with MDS aim to improve cytopenias, delay disease progression, and enhance quality of life. High serum ferritin levels, a source of iron for reactive oxygen species production, correlate with a higher risk of progression to acute myeloid leukemia, and iron overload is compounded by blood transfusions given to improve anemia. 6-shogaol is a natural phenolic compound formed when ginger is exposed to heat and/or acidic conditions, and it has been shown to possess anti-tumor activity against leukemia cell lines and antioxidant effects. This narrative review assessed the potential benefits of this phytochemical in lower-risk MDS patients through examining the current evidence on the pharmacological and therapeutic properties of ginger and 6-shogaol.

A hybrid systems biology and systems pharmacology investigation of Zingerone's effects on reconstructed human epidermal tissues

Background

As individuals live longer, elderly populations can be expected to face issues. This pattern urges researchers to investigate the aging concept further to produce successful anti-aging agents. In the current study, the effects of Zingerone (a natural compound) on epidermal tissues were analyzed using a bioinformatics approach.

Methods

For this purpose, we chose the GEO dataset GSE133338 to carry out the systems biology and systems pharmacology approaches, ranging from identifying the differentially expressed genes to analyzing the gene ontology, determining similar structures of Zingerone and their features (i.e., anti-oxidant, anti-inflammatory, and skin disorders), constructing the gene-chemicals network, analyzing gene-disease relationships, and validating significant genes through the evidence presented in the literature.

Results

The post-processing of the microarray dataset identified thirteen essential genes among control and Zingerone-treated samples. The procedure revealed various structurally similar chemical and herbal compounds with possible skin-related effects. Additionally, we studied the relationships of differentially expressed genes with skin-related diseases and validated their direct connections with skin disorders the evidence available in the literature. Also, the analysis of the microarray profiling dataset revealed the critical role of interleukins as a part of the cytokines family on skin aging progress.

Conclusions

Zingerone, and potentially any constituents of Zingerone (e.g., their similar compound scan functionality), can be used as therapeutic agents in managing skin disorders such as skin aging. However, the beneficial effects of Zingerone should be assessed in other models (i.e., human or animal) in future studies.

Nrf2: a dark horse in Alzheimer's disease treatment

Alzheimer's disease (AD), an age-dependent neurodegenerative disorder, is the main cause of dementia. Common hallmarks of AD include the amyloid β-peptide (Aβ) aggregation, high levels of hyperphosphorylated tau protein (p-tau) and failure in redox homeostasis. To date, all proposed drugs affecting Aβ and/or p-tau have been failed in clinical trials. A decline in the expression of the transcription factor Nrf2 (nuclear factor-erythroid 2-p45 derived factor 2) and its driven genes (NQO1, HO-1, and GCLC), and alteration of the Nrf2-related pathways have been observed in AD brains. Nrf2 plays a critical role in maintaining cellular redox homeostasis and regulating inflammation response. Nrf2 activation also provides cytoprotection against increasing pathologies including neurodegenerative diseases. These lines of evidence imply that Nrf2 activation may be a novel AD treatment option. Interestingly, recent studies have also demonstrated that Nrf2 interferes with several key pathogenic processes in AD including Aβ and p-tau pathways. The current review aims to provide insights into the role of Nrf2 in AD. Also, we discuss the progress and challenges regarding the Nrf2 activators for AD treatment.

Generation of potent Nrf2 activators via tuning the electrophilicity and steric hindrance of vinyl sulfones for neuroprotection

Oxidative stress is constantly involved in the etiopathogenesis of an ever-widening range of neurodegenerative diseases. As a consequence, effective repression of cellular oxidative stress to a redox homeostatic condition is a promising and feasible strategy to treat, or at least retard the progression of, such disorders. Nrf2, a primary orchestrator of cellular antioxidant response machine, is responsible for detoxifying and compensating for deleterious oxidative stress via transcriptional activation of a diverse array of antioxidant biomolecules. In the framework of our persistent interest in disclosing small molecules that interfere with cellular redox-regulating machinery, we report herein the synthesis, optimization, and biological assessment of 47 vinyl sulfone scaffold-bearing small molecules, most of which exhibit robust neuroprotective effect against H₂O₂-mediated lesions to PC12 cells. After initial screening, the most potent neuroprotective compounds 9b and 9c with marginal cytotoxicity were selected for the follow-up studies. Our results demonstrate that their neuroprotective effects are attributed to the up-regulation of a panel of antioxidant genes and corresponding gene products. Further mechanistic studies indicate that Nrf2 is indispensable for the cellular performances of 9b and 9c, arising from the fact that silence of Nrf2 gene drastically nullifies their protective action. Taken together, 9b and 9c discovered in this work merit further development as neuroprotective candidates for the treatment of oxidative stress-mediated pathological conditions.

A Mechanistic Evaluation of Antioxidant Nutraceuticals on Their Potential against Age-Associated Neurodegenerative Diseases

Nutraceuticals have been extensively studied worldwide due to its neuroprotective effects in in vivo and in vitro studies, attributed by the antioxidative properties. Alzheimer (AD) and Parkinson disease (PD) are the two main neurodegenerative disorders that are discussed in this review. Both AD and PD share the similar involvement of oxidative stress in their pathophysiology. Nutraceuticals exert their antioxidative effects via direct scavenging of free radicals, prevent damage to biomolecules, indirectly stimulate the endogenous antioxidative enzymes and gene expressions, inhibit activation of pro-oxidant enzymes, and chelate metals. In addition, nutraceuticals can act as modulators of pro-survival, pro-apoptotic, and inflammatory signaling pathways. They have been shown to be effective particularly in preclinical stages, due to their multiple mechanisms of action in attenuating oxidative stress underlying AD and PD. Natural antioxidants from food sources and natural products such as resveratrol, curcumin, green tea polyphenols, and vitamin E are promising therapeutic agents in oxidative stress-mediated neurodegenerative disease as they have fewer adverse effects, more tolerable, cheaper, and sustainable for long term consumption.

6-Shogaol, an active ingredient of ginger, inhibits osteoclastogenesis and alveolar bone resorption in ligature-induced periodontitis in mice

BACKGROUND

Periodontitis is an inflammatory disease of the tissues surrounding teeth that causes destruction of connective tissues. During the progress of periodontitis, osteoclasts are solely accountable for the resorption of alveolar bones that leads to the loss of teeth if not properly treated. Thus, the development of effective anti-resorptive therapies will greatly benefit the treatment of periodontitis patients. In the present study, we suggest an inhibitory effect of 6-shogaol, an ingredient of ginger, on osteoclast differentiation and bone resorption.

METHODS

Mouse bone marrow cells were cultured in the presence of macrophage-colony stimulating factor and receptor activator of nuclear factor-κB ligand (RANKL) to investigate the effect of 6-shogaol on osteoclast differentiation and intracellular signaling pathways. 6-shogaol significantly reduced osteoclast differentiation, actin ring formation, and resorption. In the presence of 6-shogaol, osteoclast signaling including the RANKL-induced activation of mitogen-activated protein kinases, Ca2+ oscillation, generation of reactive oxygen species, and nuclear factor of activated T-cells, cytoplasmic 1 nuclear translocation was significantly inhibited in vitro. Furthermore, a ligature-induced periodontitis model in mice was used to determine the role of 6-shogaol in vivo.

RESULTS

The administration of 6-shogaol prevented osteoclastogenesis and alveolar bone resorption induced by ligature. Furthermore, the ligature-induced number of macrophages and neutrophils as well as the expression of interleukin-1β and tumor necrosis factor-α were considerably lower in the periodontal tissues following shogaol injection.

CONCLUSION

These results confirm the anti-osteoclastogenic effect of 6-shogaol and suggest the possibility of application as an anti-resorptive strategy in periodontitis.

The role of natural products in revealing NRF2 function

Covering: up to 2020The transcription factor NRF2 is one of the body's major defense mechanisms, driving transcription of >300 antioxidant response element (ARE)-regulated genes that are involved in many critical cellular processes including redox regulation, proteostasis, xenobiotic detoxification, and primary metabolism. The transcription factor NRF2 and natural products have an intimately entwined history, as the discovery of NRF2 and much of its rich biology were revealed using natural products both intentionally and unintentionally. In addition, in the last decade a more sinister aspect of NRF2 biology has been revealed. NRF2 is normally present at very low cellular levels and only activated when needed, however, it has been recently revealed that chronic, high levels of NRF2 can lead to diseases such as diabetes and cancer, and may play a role in other diseases. Again, this "dark side" of NRF2 was revealed and studied largely using a natural product, the quassinoid, brusatol. In the present review, we provide an overview of NRF2 structure and function to orient the general reader, we will discuss the history of NRF2 and NRF2-activating compounds and the biology these have revealed, and we will delve into the dark side of NRF2 and contemporary issues related to the dark side biology and the role of natural products in dissecting this biology.

Zingiber Officinale Roscoe Prevents Cellular Senescence of Myoblasts in Culture and Promotes Muscle Regeneration

Background

Ageing resulted in a progressive loss of muscle mass and strength. Increased oxidative stress in ageing affects the capacity of the myoblast to differentiate leading to impairment of muscle regeneration. Zingiber officinale Roscoe (ginger) has potential benefits in reversing muscle ageing due to its antioxidant property. This study aimed to determine the effect of ginger in the prevention of cellular senescence and promotion of muscle regeneration.

Methods

Myoblast cells were cultured into young and senescent state before treated with different concentrations of ginger standardised extracts containing different concentrations of 6-gingerol and 6-shogaol. Analysis on cellular morphology and myogenic purity was carried out besides determination of SA-β-galactosidase expression and cell cycle profile. Myoblast differentiation was quantitated by determining the fusion index, maturation index, and myotube size.

Results

Treatment with ginger extracts resulted in improvement of cellular morphology of senescent myoblasts which resembled the morphology of young myoblasts. Our results also showed that ginger treatment caused a significant reduction in SA-β-galactosidase expression on senescent myoblasts indicating prevention of cellular senescence, while cell cycle analysis showed a significant increase in the percentage of cells in the G₀/G₁ phase and reduction in the S-phase cells. Increased myoblast regenerative capacity was observed as shown by the increased number of nuclei per myotube, fusion index, and maturation index.

Conclusions

Ginger extracts exerted their potency in promoting muscle regeneration as indicated by prevention of cellular senescence and promotion of myoblast regenerative capacity.

Synthesis of Dithiolethiones and Identification of Potential Neuroprotective Agents via Activation of Nrf2-Driven Antioxidant Enzymes

Oxidative stress is implicated in the pathogenesis of a wide variety of neurodegenerative disorders, and accordingly, dietary supplement of exogenous antioxidants or/and upregulation of the endogenous antioxidant defense system are promising for therapeutic intervention or chemoprevention of neurodegenerative diseases. Nrf2, a master regulator of the cellular antioxidant machinery, cardinally participates in the transcription of cytoprotective genes against oxidative/electrophilic stresses. Herein, we report the synthesis of 59 structurally diverse dithiolethiones and evaluation of their neuroprotection against 6-hydroxydopamine- or H₂O₂-induced oxidative damages in PC12 cells, a neuron-like rat pheochromocytoma cell line. Initial screening identified compounds 10 and 11 having low cytotoxicity but conferring remarkable protection on PC12 cells from oxidative-mediated damages. Further studies demonstrated that both compounds upregulated a battery of antioxidant genes as well as corresponding genes' products. Significantly, silence of Nrf2 expression abolishes cytoprotection of 10 and 11, indicating targeting Nrf2 activation is pivotal for their cellular functions. Taken together, the two lead compounds discovered here with potent neuroprotective functions against oxidative stress via Nrf2 activation merit further development as therapeutic or chemopreventive candidates for neurodegenerative disorders.

Ginger extract ameliorates bisphenol A (BPA)-induced disruption in thyroid hormones synthesis and metabolism: Involvement of Nrf-2/HO-1 pathway

Environmental exposure to BPA is alarming because of the potential health threats for example those concerning the thyroid glands which may show signs of oxidative stress. This original study aimed to investigate the possible antioxidant protective effects of ginger extract (GE) against BPA-induced thyroid injury in male rats, focusing on its effect on Nrf-2/HO-1 signaling and thyroid hormone synthesis regulating genes. The cascade of events in thyroid injury induced by chronic exposure to BPA (200 mg/kg b.w/day for 35 days) involved a preliminary overproduction of ROS followed by significant (p ≤ 0.05) depletion of reduced glutathione (GSH) levels and superoxide dismutase (SOD) activity as well as significant increases of malondialdehyde (MDA) contents, myeloperoxidase (MPO) activity and inducible nitric oxide synthase (iNOS) gene expression. These actions consequently down-regulate the Nrf-2/HO-I signaling which eventually resulting in the DNA fragmentation within the thyroid tissues. Moreover, BPA administration caused a reduction of thyroid iodide uptake evidenced by significant inhibitions (p ≤ 0.05) of sodium-iodide symporter (NIS), thyroid peroxidase (TPO) and thyroid-stimulating hormone receptor (TSHR) mRNA expressions within the thyroid glands. A subsequent significant decreased serum levels of T3 and T4 accompanied by a significantly increased serum TSH level were also detected. These findings were confirmed by the severe pathological changes detected in the thyroid tissue of BPA treated rats. These biochemical and histological alterations were significantly alleviated with ginger administration (250 mg/kg b.w/day for 35 days) plus BPA. In conclusion, ginger extract is a potent antioxidant that can effectively protect against BPA-induced thyroid oxidative damage by activating the Nrf-2/HO-1 gene expressions and enhancing the thyroid hormones synthesis. This is the first study to show the contribution of Nrf-2/HO-1 pathway to the protective effect of ginger extract against BPA-induced thyroid oxidative damage and thyroid hormonal disruption.

Development of small molecule inhibitors targeting NLRP3 inflammasome pathway for inflammatory diseases

NLRP3 (Nod-like receptor protein 3) belongs to the NOD-like receptor family, which is activated by pathogen and damage-associated signals to form a multimeric protein complex, known as the NLRP3 inflammasome. NLRP3 inflammasome activation leads to release of proinflammatory cytokines IL-1β and IL-18, thus inducing pyroptosis, a programmed cell death mechanism. Dysregulation of the NLRP3 inflammasome pathway is closely related to the development of many human diseases, such as neuroinflammation, metabolic inflammation, and immune inflammation. Emerging studies have suggested NLRP3 inflammasome as a potential drug-target for inflammatory diseases. Several small molecules have recently been identified to target the NLRP3 inflammasome pathway directly or indirectly and alleviate related disease pathology. This review summarizes recent evolving landscape of small molecule inhibitor development targeting the NLRP3 inflammasome pathway.

Ginger (Zingiber officinale Roscoe) in the Prevention of Ageing and Degenerative Diseases: Review of Current Evidence

Currently, the age of the population is increasing as a result of increased life expectancy. Ageing is defined as the progressive loss of physiological integrity, which can be characterized by functional impairment and high vulnerability to various types of diseases, such as diabetes, hypertension, Alzheimer's disease (AD), Parkinson's disease (PD), and atherosclerosis. Numerous studies have reported that the presence of oxidative stress and inflammation contributes to the development of these diseases. In general, oxidative stress could induce proinflammatory cytokines and reduce cellular antioxidant capacity. Increased oxidative stress levels beyond the production of antioxidant agents cause oxidative damage to biological molecules, including DNA, protein, and carbohydrates, which affects normal cell signalling, cell growth, differentiation, and apoptosis and leads to disease pathogenesis. Since oxidative stress and inflammation contribute to these diseases, ginger (Zingiber officinale Roscoe) is one of the potential herbs that can be used to reduce the level of oxidative stress and inflammation. Ginger consists of two major active components, 6-gingerol and 6-shogaol, which are essential for preventing oxidative stress and inflammation. Thus, this paper will review the effects of ginger on ageing and degenerative diseases, including AD, PD, type 2 diabetes mellitus (DM), hypertension, and osteoarthritis.

6-shogaol, a active constiuents of ginger prevents UVB radiation mediated inflammation and oxidative stress through modulating NrF2 signaling in human epidermal keratinocytes (HaCaT cells)

Disclosure of ultraviolet (UV) radiation is the key feature from environment to cause redness of the skin, inflammation, photoaging and skin cancer. 6-Shogaol, a spicy compound secluded from ginger, which shows anti-inflammatory effects. Present study was demonstrated the role of 6-Shogaol on UVB induced oxidative stress and photoaging signaling in human epidermal keratinocytes (HaCaT cells). In this study, UVB-irratiation (180 mJ/cm2) significantly elevated the intracellular ROS levels, depletion of antioxidants resulted in apoptotic HaCaT cells. MAPKs signaling are concerned in oxidative stress; these signaling events are measured as differentiation. We found that 6-shogaol prevents over expression of MAPKs (ERK1, JNK1 & p38), in disclosure of UVB in HaCaT cells. Moreover, 6-shogaol infringed Bax and Bcl-2 in which 20 μg 6-shogaol influenced apoptosis in HaCaT cells by investigating augmented appearance of Bax and condensed appearance of Bcl-2 in contrast to control HaCaT cells. These results suggest that 6-shogaol could be a successful healing agent provides fortification against UVB-induced provocative and oxidative skin reimbursement.

Lipoamide Ameliorates Oxidative Stress via Induction of Nrf2/ARE Signaling Pathway in PC12 Cells

The mechanisms underlying neurodegenerative diseases are not fully understood yet. However, an increasing amount of evidence has suggested that these disorders are related to oxidative stress. We reported herein that lipoamide (LM), a neutral amide derivative of lipoic acid (LA), could resist oxidative stress-mediated neuronal cell damage. LM is more potent than LA in alleviating hydrogen peroxide- or 6-hydroxydopamine-induced PC12 cell injury. Our results reveal that LM promotes the nuclear accumulation of NFE2-related factor 2 (Nrf2), following with the activation of expression of Nrf2-governed antioxidant and detoxifying enzymes. Notably, silencing Nrf2 gene annuls the protection of LM, which demonstrates that Nrf2 is engaged in this cytoprotection. Our findings suggest that LM might be used as a potential therapeutic candidate for oxidative stress-related neurological disorders.

Bioactive Compounds and Bioactivities of Ginger (Zingiber officinale Roscoe)

Ginger (Zingiber officinale Roscoe) is a common and widely used spice. It is rich in various chemical constituents, including phenolic compounds, terpenes, polysaccharides, lipids, organic acids, and raw fibers. The health benefits of ginger are mainly attributed to its phenolic compounds, such as gingerols and shogaols. Accumulated investigations have demonstrated that ginger possesses multiple biological activities, including antioxidant, anti-inflammatory, antimicrobial, anticancer, neuroprotective, cardiovascular protective, respiratory protective, antiobesity, antidiabetic, antinausea, and antiemetic activities. In this review, we summarize current knowledge about the bioactive compounds and bioactivities of ginger, and the mechanisms of action are also discussed. We hope that this updated review paper will attract more attention to ginger and its further applications, including its potential to be developed into functional foods or nutraceuticals for the prevention and management of chronic diseases.

Neuroprotection of mangiferin against oxidative damage via arousing Nrf2 signaling pathway in PC12 cells

Accumulating evidence demonstrates that oxidative stress is involved in the pathogenesis and progression of neurodegeneration. As NF-E2-related factor 2 (Nrf2) plays a crucial role in maintaining cellular redox homeostasis, small molecules with the ability in activation of Nrf2 pathway are promising neuroprotective agents. Mangiferin (Mg) is a xanthone glucoside extracted from mangoes and papayas, and has been reported to possess multiple pharmacological activities. In this study, we investigated neuroprotective effects of Mg in the neuron-like rat pheochromocytoma cell line (PC12 cells). Mg scavenges different kinds of free radicals in vitro and attenuates hydrogen peroxide- or 6-hydroxydopamine-induced cell death. After treatment with Mg, a range of antioxidant genes governed by Nrf2 were upregulated, and the expressions and activities of these gene products were also elevated. Moreover, knockdown of Nrf2 antagonized the protective effect of Mg, indicating that Nrf2 is an essential factor in this cytoprotective process. In summary, our study demonstrates that Mg is a potent antioxidant that can provide neuroprotection against oxidative stress-mediated damage of PC12 cells. © 2019 BioFactors, 45(3):381-392, 2019.

Depletion of protein thiols and the accumulation of oxidized thioredoxin in Parkinsonism disclosed by a red-emitting and environment-sensitive probe

Protein sulfhydryl groups play a vital role in maintaining cellular redox homeostasis and protein functions and have attracted increasing interests for the selective detection of protein thiols over low-molecular-weight thiols (LMWTs).

Ameliorative and protective effects of ginger and its main constituents against natural, chemical and radiation-induced toxicities: A comprehensive review

Fatal unintentional poisoning is widespread upon human exposure to toxic agents such as pesticides, heavy metals, environmental pollutants, bacterial and fungal toxins or even some medications and cosmetic products. In this regards, the application of the natural dietary agents as antidotes has engrossed a substantial attention. One of the ancient known traditional medicines and spices with an arsenal of metabolites of several reported health benefits is ginger. This extended literature review serves to demonstrate the protective effects and mechanisms of ginger and its phytochemicals against natural, chemical and radiation-induced toxicities. Collected data obtained from the in-vivo and in-vitro experimental studies in this overview detail the designation of the protective effects to ginger's antioxidant, anti-inflammatory, and anti-apoptotic properties. Ginger's armoury of phytochemicals exerted its protective function via different mechanisms and cell signalling pathways, including Nrf2/ARE, MAPK, NF-ƙB, Wnt/β-catenin, TGF-β1/Smad3, and ERK/CREB. The outcomes of this review could encourage further clinical trials of ginger applications in radiotherapy and chemotherapy regime for cancer treatments or its implementation to counteract the chemical toxicity induced by industrial pollutants, alcohol, smoking or administered drugs.

Ginger (Zingiber officinale Roscoe) for the treatment and prevention of necrotizing enterocolitis

ETHNOPHARMACOLOGICAL RELEVANCE

Necrotizing enterocolitis (NEC) is the most important gastrointestinal emergency affecting especially preterm infants and causes severe morbidities and mortality. However, there is no cure. Oxidant stress, inflammation, apoptosis, as well as prematurity are believed to responsible in the pathogenesis of the disease. Ginger and its compounds have anti-inflammatory, antimicrobial, anti-oxidant properties and immunomodulatory, cytoprotective/regenerative actions.

AIM OF THE STUDY

This study aimed to evaluate the beneficial effects of ginger on the intestinal damage in an experimental rat model of NEC.

MATERIALS AND METHODS

Thirty newborn Wistar rats were divided into three groups: NEC, NEC + ginger and control in this experimental study. NEC was induced by injection of intraperitoneal lipopolysaccharide, feeding with enteral formula, hypoxia-hyperoxia and cold stress exposure. The pups in the NEC + ginger group were orally administered ginger at a dose of 1000 mg/kg/day. Proximal colon and ileum were excised. Histopathological, immunohistochemical (TUNEL for apoptosis, caspase 3 and 8) and biochemical assays including xanthine oxidase (XO), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malonaldehyde (MDA) and myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α), interleukin1β (IL-1β), and interleukin 6 (IL-6) activity were evaluated.

RESULTS

Compared with the NEC group, the rat pups in the NEC + ginger group had better clinical disease scores and weight gain (p < 0.05). Macroscopic evaluation, Histopathologic and apoptosis assessment (TUNEL, caspase 3 and 8) releaved that severity of intestinal damage were significantly lower in the NEC + ginger group (p < 0.05). The levels of TNF-α, IL-1β and IL-6 in the ginger treated group were significantly decreased (P < 0.05). The GSH-Px and SOD levels of the ginger treated group were significantly preserved in the NEC + ginger group (p < 0.05). The tissue XO, MDA and MPO levels of the NEC + ginger group were significantly lower than those in the NEC group (P < 0.05).

CONCLUSION

Ginger therapy efficiently ameliorated the severity of intestinal damage in NEC and may be a promising treatment option.

Sulforaphane protects granulosa cells against oxidative stress via activation of NRF2-ARE pathway

Sulforaphane (SFN) has been considered as an indirect antioxidant and potential inducer of the Nrf2-ARE pathway. This study was conducted to investigate the protective role of SFN against oxidative stress in bovine granulosa cells (GCs). GCs were collected from antral follicles (4-8 mm) and cultured according to the experimental design where group 1 = control, group 2 = treated with SFN, group 3 = treated with hydrogen peroxide (H₂O₂), group 4 = pretreated with SFN and then with H₂O₂ (protective) and group 5 = treated with H₂O₂ followed by SFN treatment (rescuing). Results showed that SFN pretreatment significantly increases cell viability and reduces cytotoxicity in GCs under oxidative stress. Following H₂O₂ exposure, expression of NRF2 was found to be significantly increased (p < 0.05) in SFN-pretreated cells, while no significant differences were observed between group 3 and group 5, although the expression was significantly increased compared to the control group. Moreover, the relative abundance of the NRF2 downstream target antioxidant genes (CAT, PRDX1, SOD1 and TXN1) were higher (fold change ranged from 7 to 14, p < 0.05) in sulforaphane pretreated GCs. Low level of ROS and lipid accumulation and higher mitochondrial activity were observed in GCs pretreated with SFN, whereas no such changes were observed in GCs treated with SFN after exposure to oxidative stress (group 5). Thus, we suggest that SFN pretreatment effectively protects GCs against oxidative damage through the activation of the NRF2-ARE pathway, whereas addition of SFN during oxidative insult failed to rescue GCs.

Piceatannol attenuates behavioral disorder and neurological deficits in aging mice via activating the Nrf2 pathway

Aging is a complex process that is accompanied by neurological damage. Chronic injection of d-galactose (d-gal) can accelerate the aging process similar to natural aging and is commonly used to build an aging model to investigate aging. In the present study, the effects of piceatannol on d-gal-induced aging in mice were evaluated. Piceatannol treatment showed an observable anti-aging effect. Results obtained in vivo showed that piceatannol retained spontaneous motor activity and enhanced spatial learning and memory abilities in mice in which aging was induced by d-gal. Morphometric analysis displayed that piceatannol prevented d-gal-induced neuronal loss, increased the number of Nissl bodies, and promoted cell proliferation in the hippocampus and cortex. Piceatannol also significantly decreased the level of MDA and elevated SOD and CAT activity in the hippocampal and cortical tissues. Furthermore, western blotting results revealed that piceatannol treatment noticeably reversed the suppression of Nrf2 nuclear translocation and increased the expressions of HO-1 and NOQ1 in mice with aging induced by d-gal. Furthermore, piceatannol activated the Nrf2 pathway in natural aging mice, whereas treatment with the Nrf2 inhibitor brusatol reversed the increased expressions of Nrf2, HO-1, and NOQ1. In conclusion, treatment with piceatannol ameliorates behavioral disorder and brain injury in an aging mouse model; this suggests that piceatannol is a promising pharmaceutical candidate for the treatment of age-associated diseases.

Occurrence, biological activity and metabolism of 6-shogaol

As one of the main bioactive compounds of dried ginger, 6-shogaol has been widely used to alleviate many ailments. It is also a major pungent flavor component, and its precursor prior to dehydration is 6-gingerol, which is reported to be responsible for the pungent flavor and biological activity of fresh ginger. Structurally, gingerols including 6-gingerol have a β-hydroxyl ketone moiety and is liable to dehydrate to generate an α,β-unsaturated ketone under heat and/or acidic conditions. The conjugation of the α,β-unsaturated ketone skeleton in the chemical structure of 6-shogaol explicates its higher potency and efficacy than 6-gingerol in terms of antioxidant, anti-inflammatory, anticancer, antiemetic and other bioactivities. Research on the health benefits of 6-shogaol has been conducted and results have been reported recently; however, scientific data are scattered due to a lack of systematic collection. In addition, action mechanisms of the preventive and/or therapeutic actions of 6-shogaol remain obscurely non-collective. Herein, we review the preparations, biological activity and mechanisms, and metabolism of 6-shogaol as well as the properties of 6-shogaol metabolites.

Comparison of Inhibitory Capacities of 6-, 8- and 10-Gingerols/Shogaols on the Canonical NLRP3 Inflammasome-Mediated IL-1β Secretion

Endogenous noninfectious substances that mediate the nucleotide oligomerization domain (NOD)-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation and interleukin (IL)-1β secretion causes inappropriate sterile inflammation and is implicated in the pathogenesis of several chronic diseases, such as type 2 diabetes mellitus, gout, atherosclerosis and Alzheimer’s disease. Consequently, dietary phytochemicals exhibiting capacities to suppress canonical NLRP3 inflammasome-mediated IL-1β secretion can be a reliable supplement to prevent such diseases. The purpose of this study was to investigate and compare the inhibitory effects of ginger phytochemicals, including 6-, 8- and 10-gingerols/shogaols on the canonical NLRP3 inflammasome-mediated IL-1β secretion in THP-1 macrophages with ordered stimulations of lipopolysaccharide (LPS) and adenosine 5′-triphosphate (ATP). At 20 μM, the 10-gingerol and all the shogaols significantly inhibited canonical IL-1β secretion. The shogaols had a more potent inhibitory capacity than that of corresponding gingerols. Increase of alkyl chain length impacted negatively the inhibitory activity of shogaols. Additionally, these effective ginger phytochemicals not only inhibited the LPS-primed expression of pro-IL-1β and NLRP3, but also decreased ATP-activated caspase-1. The results demonstrated that ginger phytochemicals, especially the most potent, 6-shogaol, might be promising for developing as an inhibitor of the canonical NLRP3 inflammasome-mediated IL-1β secretion and further applied in prevention of NLRP3 inflammasome-associated diseases.

Pharmacotherapeutic potential of ginger and its compounds in age-related neurological disorders

Age-related neurological disorders (ANDs), including neurodegenerative diseases, are multifactorial disorders with a risk that increases with aging. ANDs are generally characterized by common neuropathological conditions of the central nervous system, such as oxidative stress, neuroinflammation, and protein misfolding. Recently, efforts have been made to overcome ANDs because of the increase in age-dependent prevalence. Ginger, the rhizome of Zingiber officinale Roscoe, is a popular food spice and has a long history of use in traditional medicine for treating various disease symptoms. The structure-activity relationships of ginger phytochemicals show that ginger can be used to treat ANDs by targeting different ligand sites. This review shows that ginger and its constituents, such as 6-gingerol, 6-shogaol, 6-paradol, zingerone, and dehydrozingerone, are effective for ameliorating the neurological symptoms and pathological conditions of ANDs through by modulating cell death or cell survival signaling molecules. From this review, we conclude that the active ingredients in ginger have therapeutic potential in ANDs.