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

Glycosylation of 6-gingerol and unusual spontaneous deglucosylation of two novel intermediates to form 6-shogaol-4'-O-β-glucoside by bacterial glycosyltransferase

6-Gingerol is a major phenolic compound within ginger (Zingiber officinale), often used in healthcare; however, its lower bioavailability is partly due to its poor solubility. Four bacterial glycosyltransferases (GTs) were tested to glycosylate 6-gingerol into soluble gingerol glucosides. BsUGT489 was a suitable GT to biotransform 6-gingerol into five significant products, which could be identified via nucleic magnetic resonance and mass spectrometry as 6-gingerol-4',5-O-β-diglucoside (1), 6-gingerol-4'-O-β-glucoside (2), 6-gingerol-5-O-β-glucoside (3), 6-shogaol-4'-O-β-glucoside (4), and 6-shogaol (5). The enzyme kinetics of BsUGT489 showed substrate inhibition toward 6-gingerol for producing two glucosides. The kinetic parameters were determined as KM (110 µM), kcat (862 min-1), and KI (571 µM) for the production of 6-gingerol-4'-O-β-glucoside (2) and KM (104 µM), kcat (889 min-1), and KI (545 µM) for the production of 6-gingerol-5-O-β-glucoside (3). The aqueous solubility of the three 6-gingerol glucosides, compound (1) to (3), was greatly improved. However, 6-shogaol-4'-O-β-glucoside (4) was found to be a product biotransformed from 6-shogaol (5). This study first confirmed that the glucose moiety at the C-5 position of both 6-gingerol-4',5-O-β-diglucoside (1) and 6-gingerol-5-O-β-glucoside (3) caused spontaneous deglucosylation through β-elimination to form 6-shogaol-4'-O-β-glucoside (4) and 6-shogaol (5), respectively. Moreover, the GTs could glycosylate 6-shogaol to form 6-shogaol-4'-O-β-glucoside (4). The assays showed 6-shogaol-4'-O-β-glucoside (4) had higher anti-inflammatory activity (IC50 value of 10.3 ± 0.2 µM) than 6-gingerol. The 6-gingerol-5-O-β-glucoside (3) possessed 346-fold higher solubility than 6-shogaol, in which the highly soluble glucoside is a potential prodrug of 6-shogaol via spontaneous deglucosylation. This unusual deglucosylation plays a vital role in influencing the anti-inflammatory activity.

IMPORTANCE

Both 6-gingerols and 6-shogaol possess multiple bioactivities. However, their poor solubility limits their application. The present study used bacterial GTs to catalyze the glycosylation of 6-gingerol, and the resulting gingerol glycosides were found to be new compounds with improved solubility and anti-inflammatory activity. In addition, two of the 6-gingerol glucosides were found to undergo spontaneous deglucosylation to form 6-shogaol or 6-shogaol glucosides. The unique spontaneous deglucosylation property of the new 6-gingerol glucosides makes them a good candidate for the prodrug of 6-shogaol.

Zingiber officinale promotes autophagy and apoptosis in human oral cancer through the C/EBP homologous protein

The rhizome of Zingiber officinale (Z. officinale), commonly known as ginger, has been characterized as a potential drug candidate due to its antitumor effects. However, the chemotherapeutic effect of ginger on human oral cancer remains poorly understood. In this study, we examined the effects of an ethanol extract of Z. officinale rhizomes (ZOE) on oral cancer and identified the components responsible for its pharmacological activity. ZOE exerts its inhibitory activity in oral cancer by inducing both autophagy and apoptosis simultaneously. Mechanistically, ZOE-induced autophagy and apoptosis in oral cancer are attributed to the reactive oxygen species (ROS)-mediated endoplasmic reticulum stress response. Additionally, we identified two active components of ZOE, 1-dehydro-6-gingerdione and 8-shogaol, which were sufficient to stimulate autophagy initiation and apoptosis induction by enhancing CHOP expression. These results suggest that ZOE and its two active components induce ROS generation, upregulate CHOP, initiate autophagy and apoptosis, and hold promising therapeutics against human oral cancer.

Green Synthesis and Characterization of Ginger-Derived Silver Nanoparticles and Evaluation of Their Antioxidant, Antibacterial, and Anticancer Activities

The efficacy, targeting ability, and biocompatibility of plant-based nanoparticles can be exploited in fields such as agriculture and medicine. This study highlights the use of plant-based ginger nanoparticles as an effective and promising strategy against cancer and for the treatment and prevention of bacterial infections and related disorders. Ginger is a well-known spice with significant medicinal value due to its phytochemical constituents including gingerols, shogaols, zingerones, and paradols. The silver nanoparticles (AgNPs) derived from ginger extracts could be an important non-toxic and eco-friendly nanomaterial for widespread use in medicine. In this study, AgNPs were biosynthesized using an ethanolic extract of ginger rhizome and their phytochemical, antioxidant, antibacterial, and cytotoxic properties were evaluated. UV-visible spectral analysis confirmed the formation of spherical AgNPs. FTIR analysis revealed that the NPs were associated with various functional biomolecules that were associated with the NPs during stabilization. The particle size and SEM analyses revealed that the AgNPs were in the size range of 80-100 nm, with a polydispersity index (PDI) of 0.510, and a zeta potential of -17.1 mV. The purity and crystalline nature of the AgNPs were confirmed by X-ray diffraction analysis. The simple and repeatable phyto-fabrication method reported here may be used for scaling up for large-scale production of ginger-derived NPs. A phytochemical analysis of the ginger extract revealed the presence of alkaloids, glycosides, flavonoids, phenolics, tannins, saponins, and terpenoids, which can serve as active biocatalysts and natural stabilizers of metallic NPs. The ginger extracts at low concentrations demonstrated promising cytotoxicity against Vero cell lines with a 50% reduction in cell viability at 0.6-6 μg/mL. When evaluated for biological activity, the AgNPs exhibited significant antioxidant and antibacterial activity on several Gram-positive and Gram-negative bacterial species, including Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus. This suggests that the AgNPs may be used against multi-drug-resistant bacteria. Ginger-derived AgNPs have a considerable potential for use in the development of broad-spectrum antimicrobial and anticancer medications, and an optimistic perspective for their use in medicine and pharmaceutical industry.

Preventing Cancer by Inhibiting Ornithine Decarboxylase: A Comparative Perspective on Synthetic vs. Natural Drugs

This perspective delves into the investigation of synthetic and naturally occurring inhibitors, their patterns of inhibition, and the effectiveness of newly utilized natural compounds as inhibitors targeting the Ornithine decarboxylase enzyme. This enzyme is known to target the MYC oncogene, thereby establishing a connection between polyamine metabolism and oncogenesis in both normal and cancerous cells. ODC activation and heightened polyamine activity are associated with tumor development in numerous cancers and fluctuations in ODC protein levels exert a profound influence on cellular activity for inhibition or suppressing tumor cells. This perspective outlines efforts to develop novel drugs, evaluate natural compounds, and identify promising inhibitors to address gaps in cancer prevention, highlighting the potential of newly designed synthetic moieties and natural flavonoids as alternatives. It also discusses natural compounds with potential as enhanced inhibitors.

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.