Suppression of colorectal cancer cell growth by combined treatment of 6-gingerol and γ-tocotrienol via alteration of multiple signalling pathways

Therapeutic potential of tocotrienols as chemosensitizers in cancer therapy

Chemoresistance is the adaptation of cancer cells against therapeutic agents. When exhibited by cancer cells, chemoresistance helps them to avoid apoptosis, cause relapse, and metastasize, making it challenging for chemotherapeutic agents to treat cancer. Various strategies like dosage modification of drugs, nanoparticle-based delivery of chemotherapeutics, antibody-drug conjugates, and so on are being used to target and reverse chemoresistance, one among such is combination therapy. It uses the combination of two or more therapeutic agents to reverse multidrug resistance and improve the effects of chemotherapy. Phytochemicals are known to exhibit chemosensitizing properties and are found to be effective against various cancers. Tocotrienols (T3) and tocopherols (T) are natural bioactive analogs of vitamin E, which exhibit important medicinal value and potential curative properties apart from serving as an antioxidant and nutrient supplement. Notably, T3 exhibits a variety of pharmacological activities like anticancer, anti-inflammatory, antiproliferative, and so on. The chemosensitizing property of tocotrienol is exhibited by modulating several signaling pathways and molecular targets involved in cancer cell survival, proliferation, invasion, migration, and metastasis like NF-κB, STATs, Akt/mTOR, Bax/Bcl-2, Wnt/β-catenin, and many more. T3 sensitizes cancer cells to chemotherapeutic drugs including cisplatin, doxorubicin, and paclitaxel increasing drug concentration and cytotoxicity. Discussed herewith are the chemosensitizing properties of tocotrienols on various cancer cell types when combined with various drugs and biological molecules.

Insights into the Anticancer Mechanisms Modulated by Gamma and Delta Tocotrienols in Colorectal Cancers

Colorectal cancer (CRC) is a growing concern all over the world. There has been a concerted effort to identify natural bioactive compounds that can be used to prevent or overcome this condition. Tocotrienols (T3s) are a naturally occurring form of vitamin E known for various therapeutic effects, such as anticancer, antioxidant, neuroprotective, and anti-inflammatory activities. The literature evidence suggests that two T3 analogues, ie, gamma (γ)- and delta (δ)-T3, can modulate cancers via several cancer-related signaling pathways. The aim of this review was to compile and analyze the existing literature on the diverse anticancer mechanisms of γT3 and δT3 exhibited in CRC cells, to showcase the anticancer potential of T3s. Medline was searched for research articles on anticancer effects of γT3 and δT3 in CRC published in the past 2 decades. A total of 38 articles (26 cell-based, 9 animal studies, 2 randomized clinical trials, and 1 scoping review) that report anticancer effects of γT3 and δT3 in CRC were identified. The findings reported in those articles indicate that γT3 and δT3 inhibit the proliferation of CRC cells, induce cell cycle arrest and apoptosis, suppress metastasis, and produce synergistic anticancer effects when combined with well-established anticancer agents. There is preliminary evidence that shows that T3s affect telomerase functions and support anticancer immune responses. γT3 and δT3 have the potential for development as anticancer agents.

Molecular Insights in the Anticancer Activity of Natural Tocotrienols: Targeting Mitochondrial Metabolism and Cellular Redox Homeostasis

The role of mitochondria as the electric engine of cells is well established. Over the past two decades, accumulating evidence has pointed out that, despite the presence of a highly active glycolytic pathway (Warburg effect), a functional and even upregulated mitochondrial respiration occurs in cancer cells to meet the need of high energy and the biosynthetic demand to sustain their anabolic growth. Mitochondria are also the primary source of intracellular ROS. Cancer cells maintain moderate levels of ROS to promote tumorigenesis, metastasis, and drug resistance; indeed, once the cytotoxicity threshold is exceeded, ROS trigger oxidative damage, ultimately leading to cell death. Based on this, mitochondrial metabolic functions and ROS generation are considered attractive targets of synthetic and natural anticancer compounds. Tocotrienols (TTs), specifically the δ- and γ-TT isoforms, are vitamin E-derived biomolecules widely shown to possess striking anticancer properties since they regulate several intracellular molecular pathways. Herein, we provide for the first time an overview of the mitochondrial metabolic reprogramming and redox homeostasis perturbation occurring in cancer cells, highlighting their involvement in the anticancer properties of TTs. This evidence sheds light on the use of these natural compounds as a promising preventive or therapeutic approach for novel anticancer strategies.

Exploring the Chemopreventive Potential of Artemisia annua Methanolic Extract in Colorectal Cancer Induced by Azoxymethane in Mice

Background/Objectives: Colorectal cancer (CRC) remains a major global health burden, necessitating innovative preventive approaches. Artemisia annua (A. annua), known for its extensive pharmacological properties, has shown potential in cancer therapy. This study investigates the chemopreventive efficacy of methanolic extract of A. annua (MEA) in an azoxymethane (AOM)-induced murine model of CRC, with a focus on its antioxidant, biomarker modulation, and pro-apoptotic activities. Methods: MEA was obtained via cold solvent extraction, yielding 39%, and demonstrated potent in vitro cytotoxicity against HCT116 and RKO colon cancer cell lines, with IC50 values of 20 µg/mL and 15 µg/mL, respectively. Swiss albino mice were treated with MEA beginning two weeks before AOM induction, with treatment continuing for 21 weeks. Survival was monitored for 40 weeks. Key outcomes included serum biomarker levels (ADA, GGT, CD73, LDH), antioxidant enzyme activities (SOD, CAT, GPx1, MDA), reactive oxygen species (ROS) modulation, apoptosis induction, and histopathological evaluation. Results: MEA significantly improved survival rates, reduced AOM-induced weight loss, and modulated cancer biomarkers, with marked reductions in ADA, GGT, CD73, and LDH levels. Antioxidant defenses were restored, as evidenced by increased SOD, CAT, and GPx1 activities and decreased MDA levels. ROS levels were significantly reduced, and apoptosis in colonic cells was effectively induced. Histopathological analysis revealed substantial mitigation of CRC-associated morphological abnormalities. Conclusions: MEA exhibits robust chemopreventive properties, demonstrating its potential to reduce oxidative stress, modulate key biomarkers, and induce apoptosis in CRC. These findings position MEA as a promising natural candidate for CRC prevention and therapy, warranting further exploration for clinical application.

Ginger Root Bioactive Compounds Specifically Inhibits Growth of Colon Cancer Cells in Culture

Objective

Colon cancer is affluent among many people, and having cancer greatly impacts the lives of many. Ginger is a common food, particularly in Asian cuisine. However, the health benefits of ginger as a whole food and 6-gingerol, its bioactive compound in prevention of colon cancer have not been fully addressed. This experiment investigated effects of ginger juice and 6-gingerol on colon cancer cell growth and death.

Methods

Fresh ginger roots were homogenized for juice preparation. Total phenolic contents of ginger juice were measured using Folin-C assay. Colon cancer SW480 cells and normal colon epithelial cells CCD-18Co were treated with ginger juice and/or 6-gingerol. Cell metabolic activity was assessed by MTT assay. Cell apoptosis and cell cycle arrest were accessed by immunoblotting. Data were analyzed by 2-way ANOVA with a Tukey post-hoc test and statistical significance was set at P < .05.

Results

The results showed that ginger juice selectively inhibited SW480 cell growth at 25 µL/mL for 40 hours. High doses of ginger juice (at 50 and 100 µL/mL for 40 hours) inhibited the growth of both cell types. This was independent of caspase-3 activation. Six-gingerol specifically inhibited SW480 cell growth starting at 0.5 µmoL/L (P < .01). More than 1 µmoL/L 6-gingerol did not give more power to inhibit SW480 cell growth. The results also showed that CCD-18Co cell growth rates were not changed after 6-gingerol treatments (up to 10 µmoL/L, P > .1). Immunoblotting results revealed that the elevation of Myt1 levels and decreases in CDK1, p21 Wafl/Cip1 and pSer642-Wee1 only occurred in SW480 but not CCD-18Co cells when treated with 1 and/or 2.5 µmoL/L 6-gingerol for 40 hours.

Conclusion

6-gingerol can specifically inhibit SW480 cancer cells without killing normal CCd-18Co cells, through cell cycle arrest. Ginger juice can selectively inhibit colon cancer cell growth in a narrow window at ~25 µL/mL.

Research progress of ginger in the treatment of gastrointestinal tumors

Cancer seriously endangers human health. Gastrointestinal cancer is the most common and major malignant tumor, and its morbidity and mortality are gradually increasing. Although there are effective treatments such as radiotherapy and chemotherapy for gastrointestinal tumors, they are often accompanied by serious side effects. According to the traditional Chinese medicine and food homology theory, many materials are both food and medicine. Moreover, food is just as capable of preventing and treating diseases as medicine. Medicine and food homologous herbs not only have excellent pharmacological effects and activities but also have few side effects. As a typical medicinal herb with both medicinal and edible uses, some components of ginger have been shown to have good efficacy and safety against cancer. A mass of evidence has also shown that ginger has anti-tumor effects on digestive tract cancers (such as gastric cancer, colorectal cancer, liver cancer, laryngeal cancer, and pancreatic cancer) through a variety of pathways. The aim of this study is to investigate the mechanisms of action of the main components of ginger and their potential clinical applications in treating gastrointestinal tumors.

Metabonomic profiling of clubroot-susceptible and clubroot-resistant radish and the assessment of disease-resistant metabolites

Plasmodiophora brassicae causes a serious threat to cruciferous plants including radish (Raphanus sativus L.). Knowledge on the pathogenic regularity and molecular mechanism of P. brassicae and radish is limited, especially on the metabolism level. In the present study, clubroot-susceptible and clubroot-resistant cultivars were inoculated with P. brassicae Race 4, root hairs initial infection of resting spores (10⁷ CFU/mL) at 24 h post-inoculation and root galls symptom arising at cortex splitting stage were identified on both cultivars. Root samples of cortex splitting stage of two cultivars were collected and used for untargeted metabonomic analysis. We demonstrated changes in metabolite regulation and pathways during the cortex splitting stage of diseased roots between clubroot-susceptible and clubroot-resistant cultivars using untargeted metabonomic analysis. We identified a larger number of differentially regulated metabolites and heavier metabolite profile changes in the susceptible cultivar than in the resistant counterpart. The metabolites that were differentially regulated in both cultivars were mostly lipids and lipid-like molecules. Significantly regulated metabolites and pathways according to the P value and variable important in projection score were identified. Moreover, four compounds, including ethyl α-D-thioglucopyranoside, imipenem, ginsenoside Rg1, and 6-gingerol, were selected, and their anti-P. brassicae ability and effects on seedling growth were verified on the susceptible cultivar. Except for ethyl α-D-thioglucopyranoside, the remaining could inhibit clubroot development of varing degree. The use of 5 mg/L ginsenoside Rg1 + 5 mg/L 6-gingerol resulted in the lowest disease incidence and disease index among all treatments and enhanced seedling growth. The regulation of pathways or metabolites of carbapenem and ginsenoside was further explored. The results provide a preliminary understanding of the interaction between radish and P. brassicae at the metabolism level, as well as the development of measures for preventing clubroot.

Phytochemicals in cancer and their effect on the PI3K/AKT-mediated cellular signalling

Protein kinases belong to the largest family of enzymes controlling every aspect of cellular activity including gene expression, cell division, differentiation and metabolism. They are part of major intracellular signalling pathways. Hence, it is not surprising that they are involved in the development of major diseases such as cardiovascular disorders, diabetes, dementia and, most importantly, cancer when they undergo mutations, modifications and unbalanced expression. This review will explore the possibility to draw a connection between the application of natural phytochemicals and the treatment of cancer. We have chosen to focus on the PI3K/AKT cellular signalling pathway which has been shown to be a major target by natural compounds in cell cultures and animal models.

Radioiodinated Ginger Compounds (6-gingerol and 6-shogaol) and Incorporation Assays on Breast Cancer Cells

BACKGROUND

6-Gingerol (6G) and 6-Shogaol (6S) are the main active components of ginger. 6-Gingerol is known for its anti-metastatic and anti-invasive pharmacological activities on cancer cells, besides, 6-Shogaol also inhibits breast cancer cell invasion.

OBJECTIVE

In this study, radioiodination (131I) of 6G and 6S was aimed. Additionally, it is aimed to monitor their incorporation behavior on breast cancer cell lines.

METHODS

6-Gingerol was isolated from the fresh ginger-roots extract, additionally, dehydrated to obtain 6-Shogaol. 6G and 6S were radioiodinated using iodogen method. Quality control studies of radioiodinated ginger compounds (6G and 6S) were performed by thin layer radio-chromatography. In vitro studies of radioiodinated ginger compounds on MCF-7 and MDA-MB-231 cells were performed with incorporation assays.

RESULTS

6-Gingerol and 6-Shogaol were radioiodinated (131I-6G and 131I-6S) in high yields over 95%. 131I-6S demonstrated higher incorporation values than 131I-6G on MDA-MB-231 cells. Incorporation behavior of 131I-6G and 131I-6S was similar to MCF-7 cells.

CONCLUSION

It has been observed that ginger compounds were radioiodinated successfully and 131I-6S have a noteworthy incorporation on MDA-MB-231 cells which is a known breast carcinoma cell line with highly invasive characteristics.