Study on antihepatocellular carcinoma effect of 6-shogaol and curcumin through network-based pharmacological and cellular assay.

Background: Hepatocellular carcinoma currently has the third highest mortality rate in the world. Patients with hepatocellular carcinoma are on the rise and at a younger age, but research into the pharmacological effects of cancer is mostly single-component, and natural plant products can have additive or synergistic effects that can better amplify the effects of intervention in cancer. Aim: To evaluate the synergistic therapeutic effects of 6-shogaol and curcumin against hepatocellular carcinoma line HepG2 cells. Methods: In this study, a network pharmacology approach was used to predict and validate the mol ecular targets and pathways of the hepatocellular carcinoma (HCC) of 6-shogaol and curcumin in combination and to investigate their mechanism of action. The results were also validated by cellular assays. HepG2 cells were treated with 6-shogaol and curcumin as well as the combination of the two. The combination index of 6-shogaol and curcumin in HepG2 cells was calculated using Compusyn software according to the Chou-Talalay equation. The synergistic anti-cancer effect was next investigated by MTT assay, apoptosis assay and cell cycle assay. The combined anti-hepatocellular carcinoma effect of the Ras-mediated PI3K/AKT and MAPK signalling pathways was analysed using protein blotting assays. Results: A network pharmacology-based screening identified 72 core targets of 6-curcumin and curcumin in hepatocellular carcinoma, and predicted that the main signalling pathway is the Ras signalling pathway. The anti-cancer effects of 6-shogaol and curcumin were validated in cell-based assays and the optimal synergistic concentrations of 5 µmoL/L for 6-shogaol and 30 µmoL/L for curcumin were determined. 6-shogaol and curcumin synergistically blocked the cell cycle in the G2/M phase and promoted apoptosis. Immunoblot analysis confirmed for the first time the combined action of both in down-regulating the Ras-mediated PI3K/AKT and MAPK signaling pathways. In addition, 6-shogaol and curcumin acting together downregulated Cyclin-B, CDK-1, Bcl-2, and upregulated BAX. Conclusion: 6-shogaol and curcumin act synergistically to alter the morphology of hepatocellular carcinoma cells, block the cell cycle in the G2/M phase, inhibit proliferation and division, and effectively promote late apoptosis. The combined action of these two components provides a theoretical basis for the further development of novel anti-liver cancer products.

6-Shogaol improves sorafenib efficacy in colorectal cancer cells by modulating its cellular accumulation and metabolism.

Carcinoma of the colon and rectum, also known as colorectal cancer, ranks as the third most frequently diagnosed malignancy globally. Sorafenib exhibits broad-spectrum antitumor activity against Raf, VEGF, and PDGF pathways in hepatocellular, thyroid, and renal cancers, but faces resistance in colorectal malignancies. 6-Shogaol, a prominent natural compound found in Zingiberaceae, exhibits antioxidant, anti-inflammatory, anticancer, and antiemetic properties. We investigated the influence of 6-shogaol on sorafenib's cytotoxic profile against colorectal cancer cell lines (HT-29, HCT-116, CaCo-2, and LS174T) through its effects on cellular accumulation and metabolism. Cytotoxicity was assessed using the sulpharodamine B assay, caspase-3 and c-PARP cleavage, cell cycle distribution analysis, and P-gp efflux activity. 6-Shogoal showed considerable cytotoxicity with decreased IC50 in colorectal cancer cell lines. Combining sorafenib and 6-shogaol increased c-PARP and pro-caspase-3 concentrations in HCT-116 cells compared to sorafenib alone. In combination, pro-caspase-3 concentrations were decreased in CaCo-2 cells compared to alone. Sorafenib combinations with 6-shogaol showed a significant drop in cell cycle distribution from 16.96±1.10 % to 9.16±1.85 %, respectively. At 100 µM, sorafenib and 6-shogaol showed potent and significant activity with intra-cellular rhodamine concentration on P-gp efflux activity in CRC cell lines. In conclusion, 6-shogaol substantially improved the cytotoxic profile of sorafenib by affecting its cellular uptake and metabolism. Future research should focus on dosage optimization and formulation and evaluate the efficacy and safety of the combination in animal models with colorectal cancer.

In silico and experimental potentials of 6-shogaol and meglumine antimoniate on Leishmania major: multiple synergistic combinations through modulation of biological properties.

Conventional therapeutic agents are no longer adequate against leishmaniasis. This complex condition continues to have a high mortality rate and public health impact. The present study aimed to explore an extensive array of experiments to monitor the biological activities of 6-shogaol, a major component of ginger, and meglumine antimoniate (MA or Glucantime®). The binding affinity of 6-shogaol and inducible nitric oxide synthase (iNOS), a major enzyme catalyzing nitric oxide (NO) from L-arginine was the source for the docking outline. The inhibitory effects of 6-shogaol, MA, and mixture were assessed using colorimetric and macrophage assays. Antioxidant activity was inferred by UV-visible spectrophotometry. Variably expressed genes were measured by quantifiable real-time polymerase chain reaction. Apoptotic and cell cycle profiles were analyzed by flow cytometry. Moreover, a DNA fragmentation assay was performed by electrophoresis and antioxidant metabolites include superoxide dismutase (SOD), catalase (CAT), and also nitric oxide (NO) by enzyme-linked immunosorbent assay. 6-shogaol and MA exhibited multiple synergistic mechanisms of action. These included a remarkable leishmanicidal effect, potent antioxidative activity, a high safety index, upregulation of M1 macrophages/Th1-associated cytokines (including, γ-interferon, interleukin-12p40, tumor necrotizing factor-alpha, and associated iNOS), significant cell division capture at the sub-G0/G1 phase, a high profile of apoptosis through DNA fragmentation of the nuclear components. In addition, the activity of NO was substantially elevated by treated intracellular amastigotes, while SOD and CAT activities were significantly diminished. This study is exclusive because no similar investigation has inclusively been conducted before. These comprehensive mechanistic actions form a logical foundation for additional advanced study.

Coadministration of 6-Shogaol and Levodopa Alleviates Parkinson's Disease-Related Pathology in Mice.

Parkinson's disease (PD) is a neurodegenerative disease caused by the death of dopaminergic neurons in the nigrostriatal pathway, leading to motor and non-motor dysfunctions, such as depression, olfactory dysfunction, and memory impairment. Although levodopa (L-dopa) has been the gold standard PD treatment for decades, it only relieves motor symptoms and has no effect on non-motor symptoms or disease progression. Prior studies have reported that 6-shogaol, the active ingredient in ginger, exerts a protective effect on dopaminergic neurons by suppressing neuroinflammation in PD mice. This study investigated whether cotreatment with 6-shogaol and L-dopa could attenuate both motor and non-motor symptoms and dopaminergic neuronal damage. Both 6-shogaol (20 mg/kg) and L-dopa (80 mg/kg) were orally administered to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/probenecid- induced PD model mice for 26 days. The experimental results showed that L-dopa alleviated motor symptoms, but had no significant effect on non-motor symptoms, loss of dopaminergic neuron, or neuroinflammation. However, when mice were treated with 6-shogaol alone or in combination L-dopa, an amelioration in both motor and non-motor symptoms such as depression-like behavior, olfactory dysfunction and memory impairment was observed. Moreover, 6-shogaol-only or co-treatment with 6-shogaol and L-dopa protected dopaminergic neurons in the striatum and reduced neuroinflammation in the striatum and substantia nigra. Overall, these results suggest that 6-shogaol can effectively complement L-dopa by improving non-motor dysfunction and restoring dopaminergic neurons via suppressing neuroinflammation.

Mechanistic exploration of 6-shogaol's preventive effects on azoxymethane and dextran sulfate sodium -induced colorectal cancer: involvement of cell proliferation, apoptosis, carcinoembryonic antigen, wingless-related integration site signaling, and oxido-inflammation.

Colorectal cancer (CRC) poses a significant global health burden, being the third most prevalent cancer and the second most significant contributor to cancer-related deaths worldwide. Preventive strategies are crucial to combat this rising incidence. 6-shogaol, derived from ginger, has shown promise in preventing and treating various cancers. This study investigated the preventive effects of 6-shogaol on azoxymethane (AOM) and dextran sulfate sodium (DSS)-induced CRC in mice. Forty male BALB/c mice were randomly divided into control, 6-shogaol, AOM + DSS, and 6-shogaol + AOM + DSS. Mice in the control group received corn oil for 16 weeks, while those in the 6-Shogaol group were administered 20 mg/kg of 6-shogaol for 16 weeks. The AOM + DSS group received a single intraperitoneal dose (ip) of 10 mg/kg of AOM, followed by three cycles of 2.5% DSS in drinking water. The 6-shogaol + AOM + DSS group received both 6-shogaol for 16 weeks and a single ip of 10 mg/kg of AOM, followed by three cycles of 2.5% DSS in drinking water. The AOM + DSS-treated mice exhibited reduced food consumption, colon weight, and colon length, along with increased tumor formation. Co-administration of 6-shogaol effectively reversed these changes, inhibiting CRC development. Histopathological analysis revealed protective effects of 6-shogaol against colonic insults and modulation of inflammatory responses. 6-shogaol significantly reduced Carcinoembryonic antigen and Kiel 67 levels, indicating inhibition of tumor cell proliferation. Mechanistically, 6-shogaol promoted apoptosis by upregulating protein 53 and caspase-3 expression, and it effectively restored the balance of the Wingless-related integration site signaling pathway by regulating ß-catenin and adenomatous polyposis coli levels. Moreover, 6-shogaol demonstrated anti-inflammatory effects, reducing myeloperoxidase, Tumor necrosis factor alpha, and cyclooxygenase-2 levels in AOM/DSS-treated mice. Additionally, 6-shogaol restored redox homeostasis by reducing lipid peroxidation and nitrosative stress and enhancing antioxidant enzyme activities. The findings suggest that 6-shogaol inhibits cell proliferation, induces apoptosis, regulates Wnt signaling, suppresses inflammation, and restores redox homeostasis, providing comprehensive insights into its potential therapeutic benefits for CRC.

Review of the anticancer properties of 6-shogaol: Mechanisms of action in cancer cells and future research opportunities.

Cancer is a major global health challenge that affects every nation and accounts for a large portion of the worldwide disease burden. Furthermore, cancer cases will rise significantly in the next few decades. The Food and Drug Administration has approved more than 600 drugs for treating diverse types of cancer. However, many conventional anticancer medications cause side effects, and drug resistance develops as the treatment proceeds with a concomitant impact on patients' quality of life. Thus, exploring natural products with antitumor properties and nontoxic action mechanisms is essential. Ginger (Zingiber officinale Roscoe) rhizome has a long history of use in traditional medicine, and it contains biologically active compounds, gingerols and shogaols. The main ginger shogaol is 6-shogaol, whose concentration dramatically increases during the processing of ginger, primarily due to the heat-induced conversion of 6-gingerol. Some studies have demonstrated that 6-shogaol possesses biological and pharmacological properties, such as antioxidant, anti-inflammatory, and anticancer activities. The mechanism of action of 6-shogaol as an anticancer drug includes induction of paraptosis, induction of apoptosis, increase in the production of reactive oxygen species, induction of autophagy, and the inhibition of AKT/mTOR signaling. Despite this knowledge, the mechanism of action of 6-shogaol is not fully understood, and the scientific data on its therapeutic dose, safety, and toxicity are not entirely described. This review article examines the potential of 6-shogaol as an anticancer drug, addressing the limitations of current medications; it covers 6-shogaol's attributes, mechanism of action in cancer cells, and opportunities for future research.

6-Shogaol alleviates high-fat diet induced hepatic steatosis through miR-3066-5p/Grem2 pathway.

The purpose of this study is to investigate the mechanism by which 6-shogaol ameliorates hepatic steatosis via miRNA-mRNA interaction analysis. C57BL/6 J mice were fed a high-fat diet (HFD) for 12 weeks, during which 6-shogaol was administered orally. The liver lipid level, liver function and oxidative damage in mice were evaluated. mRNA sequencing, miRNA sequencing, and RT-qPCR were employed to compare the expression profiles between the HFD group and the 6-shogaol-treated group. High-throughput sequencing was used to construct the mRNA and miRNA libraries. Target prediction and integration analysis identified eight potential miRNA-mRNA pairs involved in hepatic steatosis, which were subsequently validated in liver tissues and AML12 cells. The findings revealed that 6-shogaol modulates the miR-3066-5p/Grem2 pathway, thereby improving hepatic steatosis. This study provides new insights into the mechanisms through which 6-shogaol alleviates hepatic steatosis, establishing a foundation for future research on natural active compounds for the treatment of metabolic diseases.

Unraveling the interconversion pharmacokinetics and oral bioavailability of the major ginger constituents: [6]-gingerol, [6]-shogaol, and zingerone after single-dose administration in rats.

Background: The available in vitro evidences suggest the inherent instability and interconvertibility of [6]-gingerol and [6]-shogaol. However, limited data on their in vivo interconversion hinder understanding of their influence on the pharmacokinetic profiles. Purpose: This study presents the first comprehensive in vivo investigation aiming to determine the interconversion pharmacokinetics in rats, and elucidate the oral bioavailability, target distribution, biotransformation, and excretion profiles of the key ginger constituents, [6]-gingerol, [6]-shogaol, and zingerone. Methods: The pharmacokinetics was investigated through single intravenous (3 mg/kg) or oral (30 mg/kg) administration of [6]-gingerol, [6]-shogaol, or zingerone, followed by the determination of their tissue distribution after oral dosing (30 mg/kg). Intravenous pharmacokinetics was leveraged to evaluate the interconversion, circumventing potential confounders associated with the oral route. Results: All rats tolerated these compounds throughout the pharmacokinetic study. The parent compounds exhibited rapid but partial absorption, and extensive organ distribution with substantial biotransformation, thereby limiting the oral bioavailability of each compound to below 2% when administered as pure compounds. Conversion of [6]-gingerol to [6]-shogaol after intravenous administration, demonstrated a significantly larger clearance compared to the reverse conversion ([6]-shogaol to [6]-gingerol). The irreversible metabolic clearance for both compounds was significantly greater than their reversible bioconversions. Furthermore, [6]-gingerol underwent biotransformation to zingerone. Conjugated glucuronides were eliminated partly through renal excretion, with minimal fecal excretion. Conclusion: This in vivo investigation demonstrates the influence of interconversion on the disposition kinetics of [6]-gingerol, [6]-shogaol, and zingerone, as evidenced by the findings in the systemic circulation. The study further highlights the importance of considering this interconversion and tissue distribution when determining the administration dosage of ginger constituent combinations for therapeutic benefits and clinical applications.

Interactive Nutrient Process (INP) in a Generative AI of a New Drug-6-Shogaol as a Potential Case.

The dynamically evolving science of pharmacology requires AI technology to advance a new path for drug development. The author proposes generative AI for future drugs, identifying suitable drug molecules, uncharacteristically to previous generations of medicines, incorporating the wisdom, experience, and intuit of traditional materia medica and the respective traditional medicine practitioners. This paper describes the guiding principles of the new drug development, springing from the tradition and practice of Tibetan medicine, defined as the Interactive Nutrient Process (INP). The INP provides traditional knowledge and practitioner's experience, contextualizing and teaching the new drug therapy. An illustrative example of the outcome of the INP is a potential small molecule drug, 6-Shogaol and related shogaol derivatives, from ginger roots (Zingiber officinalis fam. Zingiberaceae) evaluated clinically for 12 months for biological markers of iron homeostasis in patients with the myelodysplastic syndromes (MDS). The study's preliminary results indicate that 6-Shogaol and related shogaols may improve iron homeostasis in low-risk/intermediate-1 MDS patients without objective or subjective side effects.

[6]-Shogaol Induces Apoptosis of Murine Bladder Cancer Cells.

BACKGROUND/AIMS: Bladder cancer is considered one of the most aggressive neoplasms due to its recurrence and progression profile, and even with the improvement in diagnosis and treatment methods, the mortality rate has not shown a declining trend in recent decades. From this perspective, the search and development of more effective and safer therapeutic alternatives are necessary. Phytochemicals are excellent sources of active principles with therapeutic potential. [6]-Shogaol is a phenolic compound extracted from the ginger rhizomes that has shown antitumor effects in a wide variety of cancer models. However, there is no record in the literature of studies reporting these effects in models of bladder cancer. Thus, this study aimed to investigate the in vitro cytotoxic and pro-apoptotic potential of [6]-Shogaol against murine bladder cancer urothelial cells (MB49). METHODS: The cytotoxic effects of [6]-Shogaol on cell viability (MTT method), cell morphology (light microscopy), alteration of proliferative processes (clonogenic assay), oxidative stress pathway (levels of reactive oxygen species) and the induction of apoptotic events (flow cytometry and high-resolution epifluorescence imaging) were evaluated in murine urothelial bladder cancer cell lines (MB49), relative to non-tumor murine fibroblasts (L929). RESULTS: The results showed that [6]-Shogaol was able to induce concentration-dependent cytotoxic effects, which compromised cell viability, exhibiting an inhibitory concentration of 50% of cells (IC50) of 146.8 µM for MB49 tumor cells and 236.0 µM for L929 non-tumor fibroblasts. In addition to inhibiting and altering the proliferative processes if colony formation, it presented pro-apoptotic activity identified through a quantitative analysis and the observation of apoptotic phenotypes, events apparently mediated by the induction of nuclear fragmentation. CONCLUSION: The data presented suggest that [6]-Shogaol has a higher concentration-dependent cytotoxic and apoptosis-inducing potential in MB49 cells than in L929 fibroblasts. These results may contribute to the development of therapeutic alternatives for bladder cancer.

Pterostilbene and 6-shogaol exhibit inhibitory effects on sunitinib resistance and motility by suppressing the RLIP76-initiated Ras/ERK and Akt/mTOR pathways in renal cancer cells.

Sunitinib (SUN) is the first-line targeted therapeutic drug for advanced renal cell carcinoma (RCC). However, SUN resistance is frequently observed to result in tumor metastasis, with a poor survival rate. Therefore, finding an effective and safe adjuvant to reduce drug resistance is important for RCC treatment. Pterostilbene (PTE) and 6-shogaol (6-S) are natural phytochemicals found in edible sources and have potential applications against various cancers. However, the biological mechanisms of PTE and 6-S in SUN-resistant RCC are still unclear. Accordingly, this study investigated the regulatory effects of PTE and 6-S on cell survival, drug resistance, and cell invasion in 786-O and SUN-resistant 786-O (786-O SUNR) cells, respectively. The results demonstrated that PTE and 6-S induced apoptosis in both cell lines by upregulating the Bax/Bcl-2 ratio. Additionally, PTE and 6-S increased SUN sensitivity by inhibiting the expression of the RLIP76 transport protein, reduced cell invasion and downregulated MMP expression in both 786-O and 786-O SUNR cells. Mechanistically, PTE, and 6-S significantly and dose-dependently suppressed the RLIP76-initiated Ras/ERK and Akt/mTOR pathways. In summary, PTE and 6-S induce apoptosis, enhance SUN sensitivity, and inhibit migration in both 786-O and 786-O SUNR cells. These novel findings demonstrate the potential of PTE and 6-S as target therapeutic adjuvants for RCC treatment.

Effect of microwave-assisted drying and extraction of 6-Shogaol from Zingiber officinale Roscoe.

Ginger (Zingiber officinale Roscoe, Zingeberaceae) is a medicinal plant widely used as food, spice, or flavoring agent worldwide. 6-Shogaol is a compound of prime interest in exhibiting anti-inflammatory, antioxidant and chemopreventive effects. The objective of the study is to investigate the effect of microwave-assisted drying (MAD) followed by microwave-assisted extraction (MAE) so as to produce 6-Shogaol enriched Ginger with improved therapeutic benefits. Various drying techniques viz. shade drying, tray drying, microwave-assisted drying and osmotic dehydration as a pretreatment were used for drying Ginger rhizomes. The dried rhizomes were extracted by conventional solvent extraction and microwave-assisted extraction techniques and tested for content of 6-Shogaol using the newly developed HPLC method whereas total flavonoid and polyphenol content were determined using the UV spectrophotometric method. Subjecting the microwave dried Ginger to microwave-assisted extraction for 45 min at constant power level of 284 W resulted in a significant rise in the extractability of 6-Shogaol (1.660 ± 0.018), total polyphenols (855.46 ± 5.33) and flavonoids (617.97 ± 6.40) compared to the conventional method of extraction. The proposed Ginger processing method of microwave drying followed by microwave extraction outperforms traditional methods in terms of speed, convenience, and performance thus can be scaled up to industrial levels.

6-Shogaol Ameliorates Liver Inflammation and Fibrosis in Mice on a Methionine- and Choline-Deficient Diet by Inhibiting Oxidative Stress, Cell Death, and Endoplasmic Reticulum Stress.

Non-alcoholic steatohepatitis (NASH) is becoming an increasingly serious global health threat, distinguished by hepatic lipid accumulation, inflammation, and fibrosis. There is a lack of approved pharmaceutical interventions for this disease, highlighting the urgent need for effective treatment. This study explores the hepatoprotective potential of 6-shogaol, a natural compound derived from ginger, in a methionine- and choline-deficient (MCD) dietary mouse model of NASH. Male C57BL/6J mice were subjected to the MCD diet for 4 weeks to induce NASH, with concurrent intraperitoneal administration of 6-shogaol (20 mg/kg) three times a week. While 6-shogaol did not impact body weight, liver weight, or hepatic lipid accumulation, it effectively mitigated liver injury, inflammation, and fibrosis in MCD diet-fed mice. Mechanistically, 6-shogaol inhibited lipid and DNA oxidation, restored hepatic glutathione levels, and regulated the expression of pro-oxidant and antioxidant enzymes. Furthermore, 6-shogaol inhibited apoptosis and necroptosis, as indicated by a decrease in TUNEL-stained cells and downregulation of apoptosis- and necroptosis-associated proteins. Additionally, 6-shogaol alleviated endoplasmic reticulum (ER) stress, as demonstrated by decreased expression of molecules associated with unfolded protein response pathways. These findings underscore the potential of 6-shogaol as a therapeutic intervention for NASH by targeting pathways related to oxidative stress, cell death, and ER stress.

6-Shogaol prevents benzo (A) pyrene-exposed lung carcinogenesis via modulating PRDX1-associated oxidative stress, inflammation, and proliferation in mouse models.

In this study, we have investigated the chemopreventive role of 6-shogaol (6-SGL) on benzopyrene (BaP) exposed lung carcinogenesis by modulating PRDX1-associated oxidative stress, inflammation, and proliferation in Swiss albino mouse models. Mice were exposed to BaP (50 mg/kg b.wt) orally twice a week for four consecutive weeks and maintained for 16 weeks, respectively. 6-SGL (30 mg/kg b.wt) were orally administered to mouse 1 h before BaP exposure for 16 weeks. After the experiment's termination, 6-SGL (30 mg/kg b.wt) prevented the loss in body weight, increased lung weight, and the total number of tumors in the mice. Moreover, we observed that 6-SGL treatment reverted the activity of BaP-induced lipid peroxidation and antioxidants in mice. Also, 6-SGL impeded the phosphorylation of MAPK family proteins such as Erk1, p38, and Jnk1 in BaP-exposed mice. PRDX1 is an essential antioxidant protein that scavenges toxic radicals and enhances several antioxidant proteins. Overexpression of PRDX1 substantially inhibits MAPKs, proliferation, and inflammation signaling axis. Hence, PRDX1 is thought to be a novel targeting protein for preventing BaP-induced lung cancer. In this study, we have obtained the 6-SGL treatment in a mouse model that reverted BaP-induced depletion of PRDX1 expression. Moreover, pretreatment of 6-SGL (30 mg/kg b.wt) significantly inhibited enhanced proinflammatory cytokines (TNF-α, IL-6, IL-ß1, IL-10) and proliferative markers (Cyclin-D1, Cyclin-D2, and PCNA) in BaP-exposed mice. The histopathological studies also confirmed that 6-SGL effectively protected the cells with less damage. Thus, the study demonstrated that 6-SGL could be a potential phytochemical and act as a chemopreventive agent in BaP-induced lung cancer by enhancing PRDX1 expression.

Corrigendum: 6-Shogaol inhibits oxidative stress-induced rat vascular smooth muscle cell apoptosis by regulating OXR1-p53 axis.

[This corrects the article DOI: 10.3389/fmolb.2022.808162.].

Involvement of the Spinal Serotonergic System in the Analgesic Effect of [6]-Shogaol in Oxaliplatin-Induced Neuropathic Pain in Mice.

Oxaliplatin is a chemotherapy drug that can induce severe acute neuropathy in patients within hours of treatment. In our previous study, 10 mg/kg [6]-shogaol (i.p.) significantly alleviated cold and mechanical allodynia induced by a 6 mg/kg oxaliplatin injection (i.p.); however, the precise serotonin-modulatory effect has not been investigated. In this study, we showed that intrathecal injections of NAN-190 (5-HT1A receptor antagonist, 1 µg) and MDL-72222 (5-HT3 receptor antagonist, 15 µg), but not ketanserin (5-HT2A receptor antagonist, 1 µg), significantly blocked the analgesic effect of [6]-shogaol (10 mg/kg, i.p.). Furthermore, the gene expression of the serotonin-synthesizing enzyme tryptophan hydroxylase 2 (TPH2) and serotonin levels in the spinal cord and serum were significantly downregulated (p < 0.0001 and p = 0.0002) and upregulated (p = 0.0298 and p = 0.0099) after oxaliplatin and [6]-shogaol administration, respectively. Moreover, both the gene and protein expression of the spinal serotonin receptors 5-HT1A and 5-HT3 significantly increased after [6]-shogaol injections (p < 0.0001). Finally, intrathecal injections of both receptor agonists (8-OH-DPAT; 5-HT1A receptor agonist, 10 µg and m-CPBG; 5-HT3 receptor agonist, 15 µg) mimicked the effects of [6]-shogaol in oxaliplatin-injected mice. Taken together, these results demonstrate that [6]-shogaol attenuates oxaliplatin-induced neuropathic pain by modulating the spinal serotoninergic system.

Anticancer perspective of 6-shogaol: anticancer properties, mechanism of action, synergism and delivery system.

Cancer is a malignant disease that has plagued human beings all the time, but the treatment effect of commonly used anticancer drugs in clinical practice is not ideal by reason of their drug tolerance and Strong adverse reactions to patients. Therefore, it is imperative to find effective and low-toxic anticancer drugs. Many research works have shown that natural products in Chinese herbal medicine have great anticancer potential, such as 6-shogaol, a monomer composition obtained from Chinese herbal ginger, which has been confirmed by numerous in vitro or vivo studies to be an excellent anti-cancer active substance. In addition, most notably, 6-shogaol has different selectivity for normal and cancer cells during treatment, which makes it valuable for further research and clinical development. Therefore, this review focus on the anti-cancer attributes, the mechanism and the regulation of related signaling pathways of 6-shogaol. In addition, its synergy with commonly used anticancer drugs, potential drug delivery systems and prospects for future research are discussed. This is the first review to comprehensively summarize the anti-cancer mechanism of 6-shogaol, hoping to provide a theoretical basis and guiding significance for future anti-cancer research and clinical development of 6-shogaol.

Targeting TRPV1 and TRPA1: A feasible strategy for natural herbal medicines to combat postoperative ileus.

Under physiological or pathological conditions, transient receptor potential (TRP) channel vanilloid type 1 (TRPV1) and TRP ankyrin 1 (TRPA1) possess the ability to detect a vast array of stimuli and execute diverse functions. Interestingly, increasing works have reported that activation of TRPV1 and TRPA1 could also be beneficial for ameliorating postoperative ileus (POI). Increasing research has revealed that the gastrointestinal (GI) tract is rich in TRPV1/TRPA1, which can be stimulated by capsaicin, allicin and other compounds. This activation stimulates a variety of neurotransmitters, leading to increased intestinal motility and providing protective effects against GI injury. POI is the most common emergent complication following abdominal and pelvic surgery, and is characterized by postoperative bowel dysfunction, pain, and inflammatory responses. It is noteworthy that natural herbs are gradually gaining recognition as a potential therapeutic option for POI due to the lack of effective pharmacological interventions. Therefore, the focus of this paper is on the TRPV1/TRPA1 channel, and an analysis and summary of the processes and mechanism by which natural herbs activate TRPV1/TRPA1 to enhance GI motility and relieve pain are provided, which will lay the foundation for the development of natural herb treatments for this disease.

6-Shogaol, an Active Component of Ginger, Inhibits p300 Histone Acetyltransferase Activity and Attenuates the Development of Pressure-Overload-Induced Heart Failure.

Hypertrophic stress-induced cardiac remodeling is a compensatory mechanism associated with cardiomyocyte hypertrophy and cardiac fibrosis. Continuation of this response eventually leads to heart failure. The histone acetyltransferase p300 plays an important role in the development of heart failure, and may be a target for heart failure therapy. The phenolic phytochemical 6-shogaol, a pungent component of raw ginger, has various bioactive effects; however, its effect on cardiovascular diseases has not been investigated. One micromolar of 6-shogaol suppressed phenylephrine (PE)-induced increases in cardiomyocyte hypertrophy in rat primary cultured cardiomyocytes. In rat primary cultured cardiac fibroblasts, 6-shogaol suppressed transforming growth factor-beta (TGF-ß)-induced increases in L-proline incorporation. It also blocked PE- and TGF-ß-induced increases in histone H3K9 acetylation in the same cells and in vitro. An in vitro p300-HAT assay revealed that 6-shogaol suppressed histone acetylation. The mice underwent transverse aortic constriction (TAC) surgery, and were administered 0.2 or 1 mg/kg of 6-shogaol daily for 8 weeks. 6-shogaol prevented TAC-induced systolic dysfunction and cardiac hypertrophy in a dose-dependent manner. Furthermore, it also significantly inhibited TAC-induced increases in histone H3K9 acetylation. These results suggest that 6-shogaol may ameliorate heart failure through a variety of mechanisms, including the inhibition of p300-HAT activity.

6-Shogaol, an Active Ingredient of Ginger, Improves Intestinal and Brain Abnormalities in Proteus Mirabilis-Induced Parkinson's Disease Mouse Model.

Parkinson's disease (PD) which has various pathological mechanisms, recently, it is attracting attention to the mechanism via microbiome-gut-brain axis. 6-Shogaol, a representative compound of ginger, have been known for improving PD phenotypes by reducing neuroinflammatory responses. In the present study, we investigated whether 6-shogaol and ginger attenuate degeneration induced by Proteus mirabilis (P. mirabilis) on the intestine and brain, simultaneously. C57BL/6J mice received P. mirabilis for 5 days. Ginger (300 mg/kg) and 6-shogaol (10 mg/kg) were treated by gavage feeding for 22 days including the period of P. mirabilis treatment. Results showed that 6-shogaol and ginger improved motor dysfunction and dopaminergic neuronal death induced by P. mirabilis treatment. In addition, they suppressed P. mirabilis-induced intestinal barrier disruption, pro-inflammatory signals such as toll-like receptor and TNF-α, and intestinal α-synuclein aggregation. Moreover, ginger and 6-shogaol significantly inhibited neuroinflammation and α-synuclein in the brain. Taken together, 6-shogaol and ginger have the potential to ameliorate PD-like motor behavior and degeneration of dopaminergic neurons induced by P. mirabilis in mice. Here, these findings are meaningful in that they provide the first experimental evidence that 6-shogaol might attenuate PD via regulating gut-brain axis.