Gamma-tocotrienol Synergistically Promotes the Anti-proliferative and Pro-apoptotic Effects of Etoposide on Breast Cancer Cell Lines

Maya Idriss, Maria Younes, Sonia Abou Najem, Mohammad Hassan Hodroj, Rajaa Fakhoury, Sandra Rizk

Curr Mol Pharmacol . 2022 Jan 31. doi: 10.2174/1874467215666220131095611. Online ahead of print.


Background: Breast Cancer is one of the most commonly diagnosed cancers worldwide and a major cause of death among women. Although chemotherapeutic agents remain the keystones in cancer therapy, significant side effects have failed to provide a safe and tolerable treatment for cancer patients. Dietary antioxidant vitamins were extensively investigated over the past years and their relevance in cancer chemotherapy remains to be elucidated.

Objective: In the current study, we aimed to investigate the anti-proliferative and apoptotic effects of combining γ-tocotrienol, a member of the vitamin E family, with the chemotherapeutic drug etoposide in MCF-7 and MDA-MB-231 breast cancer cell lines.

Methods: The antiproliferative effect of etoposide combined with γ-tocotrienol was measured using MTS viability reagent. The pro-apoptotic effect was elucidated through Cell Death ELISA and dual Annexin V/PI staining followed by flow cytometric analysis.

Results: Our results showed that etoposide significantly decreased the cell growth of both cell lines with MDA-MB-231 cells being more sensitive to etoposide treatment than MCF-7. Moreover, the simultaneous treatment of both breast cancer cell lines with low doses of γ-tocotrienol and etoposide induced a synergistic antiproliferative effect (CI<1). Furthermore, the combination therapy significantly increased the percentage of total apoptotic cells in the MDA-MB-231 cell line and the degree of DNA fragmentation as compared to treatment with either compound alone.

Conclusion: In conclusion, our results provide evidence for the profound anti-tumorigenic effect of combined etoposide and γ-tocotrienol in the breast cancer cell lines.

Read More

Expression Profiling of Selected Immune Genes and Trabecular Microarchitecture in Breast Cancer Skeletal Metastases Model: Effect of α-Tocopherol Acetate Supplementation

Riadh Badraoui, Mohd Saeed, Nouha Bouali, Walid S Hamadou, Salem Elkahoui, Mohammad J Alam, Arif J Siddiqui, Mohd Adnan, Mongi Saoudi, Tarek Rebai

Calcif Tissue Int . 2022 Jan 6. doi: 10.1007/s00223-021-00931-3. Online ahead of print.


Breast cancer bone metastases (BCBM) result in serious skeletal morbidity. Although there have been important advances in cancer treatment methods such as surgery and chemotherapy, the complementary treatments, such as α-tocopherol acetate (ATA), still remain of key role via complementary and/or synergistic effects. The aim of this work was to study immune response in a rat model of BCBM due to Walker 256/B cells inoculation and the effect of ATA alone. Compared to the control group (CTRL), rat injected with Walker 256/B cells (5 × 104) in the medullar cavity (W256 group) showed osteolytic damages with marked tumor osteolysis of both cancellous and trabecular bone as assessed by X-ray radiology, micro-computed tomography, and histology. Rats inoculated with Walker 256/B cells and treated with ATA (45 mg/kg BW, W256ATA group) presented marked less tumor osteolysis, less disturbance of Tb.Th and Tb.Sp associated with conversion of rods into plates, and increased structure model index and trabecular pattern factor (Tb.Pf). Elsewhere, 3D frequency distributions of Tb.Th and Tb.Sp were highly disturbed in metastatic W256 rats. Overexpression of some genes commonly associated with cancer and metastatic proliferation: COX-2, TNF-α, and pro-inflammatory interleukins 1 and 6 was outlined. ATA alleviated most of the Walker 256/B cells-induced microarchitectural changes in the target parameters without turning back to normal levels. Likewise, it alleviates the BCSM-induced overexpression of COX-2, TNF-α, IL-1, and IL-6. In silico approach showed that ATA bound these proteins with high affinities, which satisfactory explain its beneficial effects. In conclusion, BCBM is associated with bone microarchitectural disorders and an immune response characterized by an overexpression of some key role genes in cancer proliferation and invasion. ATA exerted favorable effects on trabecular bone distribution and morphology, which may involve the COX-2, TNF-α, and ILs pathways.

Read More

Effects of Vitamin E on Doxorubicin Cytotoxicity in Human Breast Cancer Cells in Vitro

Mohadeseh Ahmadi, Akbar Hedayatizadeh-Omran, Reza Alizadeh-Navaei, Majid Saeedi, Ehsan Zaboli, Omolbanin Amjadi, Hamidreza Kelidari, Zahra Besharat

Asian Pac J Cancer Prev . 2022 Jan 1;23(1):201-205. doi: 10.31557/APJCP.2022.23.1.201.


Objective: This study aimed to evaluate in vitro synergistic anticancer effect of doxorubicin combined with Vitamin E.

Methods: The MTT assay was utilized to assess the cytotoxicity of Vitamin E and vitamin E combined with doxorubicin and vital activities of SKBR3, MDA-MB-231, and HFF cells over a 24-hour incubation period. In addition, the antioxidant properties of these interventions and the decrease of reactive oxygen species (ROS) content caused by the treatment were evaluated.

Results: The antiproliferative effect of doxorubicin increased significantly in combination with vitamin E (Doxcorobicin 2µM vs. Vitamin E 120µM, P=0.000). Despite reducing cell ROS content due to vitamin E treatment, the combination of vitamin E and doxorubicin showed no significant synergistic effect (Doxcorobicin 2µM vs. Vitamin E 120µM, P=0.998).

Conclusion: This study indicated that the doxorubicin-vitamin E treatment reduced the viability of breast cancer cells with the minimum side effects on normal cells. In addition, the high dosage of vitamin E intensified the cytotoxicity of doxorubicin.

Read More

Gamma-tocotrienol modifies methylation of HOXA10, IRF4 and RORα genes in CD4 + T-lymphocytes: Evidence from a syngeneic mouse model of breast cancer

Ammu K Radhakrishnan, Jeya Seela Anandha Rao, Shonia Subramaniam, Premdass Ramdas

Curr Res Immunol . 2021 Oct 9;2:169-174. doi: 10.1016/j.crimmu.2021.10.001. eCollection 2021


DNA methylation plays a crucial role in polarising naïve lymphocytes towards their various sub-populations to fight against many immune challenges including establishment of tumour. Gamma-tocotrienol (γT3) is a natural form of vitamin E, reported to possess anticancer and immunomodulatory effects. This study reports the anticancer effects of γT3 through modulation of DNA methylation in several genes in CD4+ T-lymphocytes using a syngeneic mouse model of breast cancer. Female BALB/c mice were fed with γT3 or vehicle (soy oil) for two-weeks via oral gavage before they were inoculated with 4T1 mouse mammary cancer cells. Supplementation continued until the mice were sacrificed. At autopsy, blood was collected via cardiac puncture and CD4+ T-cells were isolated for DNA extraction. The DNA was analysed using the EpiTech Methyl II mouse T-helper cell differentiation PCR array. γT3 supplementation reduced tumour growth in the tumour-induced animals and modulated host immune system by inducing changes in DNA methylation patterns of the HOXA10IRF4 and RORα genes, which are involved in differentiation and clonal expansion of CD4+ T-cells. Results suggest that γT3 may enhance cell-mediated immune response in mice with breast cancer by inducing changes in DNA methylation pattern.

Read more

Tocotrienols as an Anti-Breast Cancer Agent

Madison Trujillo, Anupreet Kharbanda, Christa Corley, Pilar Simmons, Antiño R Allen

Antioxidants (Basel) . 2021 Aug 29;10(9):1383. doi: 10.3390/antiox10091383.


In the past few years, breast cancer has become the most prevalent type of cancer. The majority of patients receive combinatorial chemotherapy treatments, which may result in increased risk of developing drug resistance, a reduced quality of life, and substantial side effects. Treatment modalities that could lessen the physical toll of standard treatments or act in synergy with chemotherapeutic treatments would benefit women worldwide. Research into tocotrienols has thus far demonstrated their potential to be such an agent, with tocotrienols surpassing the pharmacological potential of tocopherols. Further research using in vitro and preclinical breast cancer models to support clinical trials is needed. This review uses bibliometric analysis to highlight this gap in research and summarizes the current and future landscape of tocotrienols as an anti-breast cancer agent.

Read More

Reduced infiltration of T-regulatory cells in tumours from mice fed daily with gamma-tocotrienol supplementation

Shonia Subramaniam, Jeya Seela Anandha Rao, Premdass Ramdas, Mei Han Ng, Methil Kannan Kutty, Kanga Rani Selvaduray, Ammu Kutty Radhakrishnan

Clin Exp Immunol . 2021 Jul 31. doi: 10.1111/cei.13650. Online ahead of print.


Gamma-tocotrienol (γT3) is an analogue of vitamin E with beneficial effects on the immune system, including immune-modulatory properties. This study reports the immune-modulatory effects of daily supplementation of γT3 on host T-helper (Th) and T-regulatory (Treg) populations in a syngeneic mouse model of breast cancer. Female BALB/c mice were fed with either γT3 or vehicle (soy oil) for 2-weeks via oral gavage before they were inoculated with syngeneic 4T1 mouse mammary cancer cells (4T1 cells). Supplementation continued until the mice were sacrificed. Mice (n=6) were sacrificed at specified time-points for various analysis (blood leucocyte, cytokine production, and immunohistochemistry). Tumour volume was measured once every seven days. Gene expression studies were carried out on tumour-specific T-lymphocytes isolated from splenic cultures. Supplementation with γT3 increased CD4+ (p<0.05), CD8+ (p<0.05) T-cells and natural killer cells (p<0.05) but suppressed Treg cells (p<0.05) in peripheral blood when compared to animals fed with the vehicle. Higher interferon-gamma (IFNγ) and lower transforming growth factor-beta (TGF-ꞵ) levels were noted in the γT3 fed mice. Immunohistochemistry findings revealed higher infiltration of CD4+ cells, increased expression of interleukin-12 receptor-beta-2 (IL-12ꞵ2R), interleukin-24 (IL-24) and reduced expression of cells that express the forkhead box P3 (FoxP3) in tumours from the γT3 fed animals. Gene expression studies showed the downregulation of seven prominent genes in splenic CD4+ T-cells isolated from γT3-fed mice. Supplementation with γT3 from palm oil-induced T-cell dependent cell-mediated immune responses and suppressed Treg cells in the tumour microenvironment in a syngeneic mouse model of BC.

Read More

Role of Vitamin E in Selected Malignant Neoplasms in Women

Anna Markowska, Michał Antoszczak, Janina Markowska, Adam Huczyński

Nutr Cancer . 2021 Jul 19;1-8. doi: 10.1080/01635581.2021.1952626. Online ahead of print.


Vitamin E, which is actually a mixture of eight isoforms (four tocopherols and four tocotrienols), is a powerful antioxidant that protects polyunsaturated fatty acids against oxidation and has the ability to break the chain lipid peroxidation, which is used in the treatment of heart disease, atherosclerosis, muscle disorders or infertility among men. Studies in-vitro show that one of the effects of tocopherol is the reduction of cancer stem cell activity which is connected to poor clinical course. In the scientific literature, reports on the participation of vitamin E not only in protection against the mutagenic effects of reactive oxygen species, but also in its anti-angiogenic activity and the ability to inhibit the invasion and metastasis of neoplastic cells are increasingly common. In this context, the role of vitamin E in preventing the neoplastic process and selected malignant neoplasms among women seems to be of particular interest. In this article, we present the results of research on the potential anticancer effects of vitamin E in the fight against breast, cervical, endometrial and ovarian cancer.

Read More

Evaluating Anticancer and Immunomodulatory Effects of Spirulina (Arthrospira) platensis and Gamma-Tocotrienol Supplementation in a Syngeneic Mouse Model of Breast Cancer

Hemavathy Subramaiam, Wan-Loy Chu, Ammu Kutty Radhakrishnan, Srikumar Chakravarthi, Kanga Rani Selvaduray, Yih-Yih Kok

Nutrients . 2021 Jul 6;13(7):2320. doi: 10.3390/nu13072320.


Nutrition can modulate host immune responses as well as promote anticancer effects. In this study, two nutritional supplements, namely gamma-tocotrienol (γT3) and Spirulina, were evaluated for their immune-enhancing and anticancer effects in a syngeneic mouse model of breast cancer (BC). Five-week-old female BALB/c mice were fed Spirulina, γT3, or a combination of Spirulina and γT3 (Spirulina + γT3) for 56 days. The mice were inoculated with 4T1 cells into their mammary fat pad on day 28 to induce BC. The animals were culled on day 56 for various analyses. A significant reduction (p < 0.05) in tumor volume was only observed on day 37 and 49 in animals fed with the combination of γT3 + Spirulina. There was a marked increase (p < 0.05) of CD4/CD127+ T-cells and decrease (p < 0.05) of T-regulatory cells in peripheral blood from mice fed with either γT3 or Spirulina. The breast tissue of the combined group showed abundant areas of necrosis, but did not prevent metastasis to the liver. Although there was a significant increase (p < 0.05) of MIG-6 and Cadherin 13 expression in tumors from γT3-fed animals, there were no significant (p > 0.05) differences in the expression of MIG-6, Cadherin 13, BIRC5, and Serpine1 upon combined feeding. This showed that combined γT3 + Spirulina treatment did not show any synergistic anticancer effects in this study model.

Read More

γ-Tocotrienol reverses multidrug resistance of breast cancer cells through the regulation of the γ-Tocotrienol-NF-κB-P-gp axis

Yuedi Ding, Jun Fan, Zhenqiang Fan, Kai Zhang

J Steroid Biochem Mol Biol . 2021 May;209:105835. doi: 10.1016/j.jsbmb.2021.105835. Epub 2021 Feb 5.


The problem of multidrug resistance (MDR) presents a major obstacle in the chemotherapy of cancer. The MDR phenotype is often linked to the overexpression of ATP-binding cassette (ABC) transporters, that pumps out and decreased intracellular drug accumulation. γ-Tocotrienol, an unsaturated tocopherol belonging to the vitamin E family, has been shown to reverse the MDR of MCF-7/Adr cell. To reveal the role of γ-tocotrienol-NF-κB-P-gp axis in the reversal process, the expression level of mdr1/P-gp was determined by real-time PCR and western blot, while NF-κB activity was detected by immunofluorescence and NF-κB transcriptional activity reporter assay. Besides, mdr1 promoter activity and P-gp transport capacity were measured with the effect of γ-tocotrienol and NF-κB agonist/antagonist. Results showed that γ-tocotrienol effectively inhibited the expression levels of mdr1 mRNA and P-gp protein. It is demonstrated that γ-tocotrienol also suppressed mdr1 promoter activity and the efflux activity of P-gp. In addition, the activation of NF-κB signaling pathway and the transcriptional activity of NF-κB were both reduced by γ-tocotrienol. Evidences also showed that the NF-κB pathway is really involved in the regulation of the expression and function of mdr1/P-gp. Taken together, we confirmed that γ-tocotrienol reversed the MDR of MCF-7/Adr through the signaling pathway of NF-κB and P-gp.

Read More

Tuning mPEG-PLA/vitamin E-TPGS-based Mixed Micelles for Combined Celecoxib/Honokiol Therapy for Breast Cancer

Jiahui Sun, Jing Li, Qi Liu, Min Jiang, Mengjia Yang, Siwen Zhan, Tong Qiu, Kaiyong He, Xueqiong Zhang

Eur J Pharm Sci . 2020 Apr 15;146:105277. doi: 10.1016/j.ejps.2020.105277. Epub 2020 Feb 24.


This study aimed to develop, evaluate, and optimize the mPEG-PLA/vitamin E-TPGS mixed micelle drug delivery system to encapsulate celecoxib (CXB) and honokiol (HNK) for intravenous treatment of breast cancer. To this end, we formulated CXB-loaded mPEG-PLA/vitamin E-TPGS (PV-CXB) and HNK-loaded mPEG-PLA/vitamin E-TPGS (PV-HNK) mixed micelles and analyzed their characteristics. The 4T1 cell line was used for cytotoxicity determination and cellular uptake experiments, and for establishing a 4T1-bearing mouse model for histopathology, immunofluorescence, terminal deoxynucleotidyl transferase-mediated nick end labeling, and Western blot analysis. The synergistic effects of PV-CXB and PV-HNK combination therapy were investigated in vitro and in vivo using the coefficient of drug interaction values. The mean size of PV-CXB and PV-HNK prepared with optimal formulation was approximately 50 nm, with a spherical shape. PV-CXB and PV-HNK combination therapy exhibited cytotoxicity in 4T1 cells in vitro. However, the toxicity of PV-CXB and PV-HNK combination therapy was not apparent in normal tissues (heart, liver, spleen, lung, and kidney) in vivo and reduced the expression of collagen fibers in tumor tissues. Moreover, the combination therapy reduced the expression of tumor growth biomarkers (Foxp3, CD4, Gr-1, CD11b, CD31, Ki67, FoxM1, and VEGF). In addition, the tumor cell apoptosis rate reached 45.71 ± 0.62%. The combined treatment with PV-CXB and PV-HNK showed synergistic effect both in vitro and in vivo. Thus, the PV-CXB and PV-HNK drug delivery system could be used as a potential combination therapy for breast cancer .

Read More