|
1
|
Shrum SA, Nukala U, Shrimali S, Pineda EN, Krager KJ, Thakkar S, Jones DE, Pathak R, Breen PJ, Aykin-Burns N, Compadre CM. Tocotrienols Provide Radioprotection to Multiple Organ Systems through Complementary Mechanisms of Antioxidant and Signaling Effects. Antioxidants (Basel) 2023; 12:1987. [PMID: 38001840 PMCID: PMC10668991 DOI: 10.3390/antiox12111987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 10/31/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Tocotrienols have powerful radioprotective properties in multiple organ systems and are promising candidates for development as clinically effective radiation countermeasures. To facilitate their development as clinical radiation countermeasures, it is crucial to understand the mechanisms behind their powerful multi-organ radioprotective properties. In this context, their antioxidant effects are recognized for directly preventing oxidative damage to cellular biomolecules from ionizing radiation. However, there is a growing body of evidence indicating that the radioprotective mechanism of action for tocotrienols extends beyond their antioxidant properties. This raises a new pharmacological paradigm that tocotrienols are uniquely efficacious radioprotectors due to a synergistic combination of antioxidant and other signaling effects. In this review, we have covered the wide range of multi-organ radioprotective effects observed for tocotrienols and the mechanisms underlying it. These radioprotective effects for tocotrienols can be characterized as (1) direct cytoprotective effects, characteristic of the classic antioxidant properties, and (2) other effects that modulate a wide array of critical signaling factors involved in radiation injury.
Collapse
Affiliation(s)
- Stephen A. Shrum
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Tocol Pharmaceuticals, LLC, Little Rock, AR 77205, USA
| | - Ujwani Nukala
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Joint Bioinformatics Graduate Program, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Shivangi Shrimali
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Joint Bioinformatics Graduate Program, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Edith Nathalie Pineda
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Joint Bioinformatics Graduate Program, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Kimberly J. Krager
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Shraddha Thakkar
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Darin E. Jones
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Rupak Pathak
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Philip J. Breen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Nukhet Aykin-Burns
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Cesar M. Compadre
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Tocol Pharmaceuticals, LLC, Little Rock, AR 77205, USA
| |
Collapse
|
|
2
|
Ishii K, Hido M, Sakamura M, Virgona N, Yano T. α-Tocotrienol and Redox-Silent Analogs of Vitamin E Enhances Bortezomib Sensitivity in Solid Cancer Cells through Modulation of NFE2L1. Int J Mol Sci 2023; 24:ijms24119382. [PMID: 37298331 DOI: 10.3390/ijms24119382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/23/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
Proteasome inhibitors (PIs) have emerged as an attractive novel cancer therapy. However, most solid cancers are seemingly resistant to PIs. The activation of transcription factor Nuclear factor erythroid 2 related factor-1 (NFE2L1) has been characterized as a potential resistance response to protect and restore proteasome activity in cancer cells. In this study, we demonstrated that α-Tocotrienol (T3) and redox-silent analogs of vitamin E (TOS, T3E) enhanced the sensitivity of bortezomib (BTZ), a proteasome inhibitor, in solid cancers through modulation of NFE2L1. In BTZ treatment, all of T3, TOS, and T3E inhibited an increase in the protein levels of NFE2L1, the expression levels of proteasome-related proteins, as well as the recovery of proteasome activity. Moreover, the combination of one of T3, TOS, or T3E and BTZ induced a significant decrease in cell viability in solid cancer cell lines. These findings suggested that the inactivation of NFE2L1 by T3, TOS, and T3E is essential to potentiate the cytotoxic effect of the proteasome inhibitor, BTZ, in solid cancers.
Collapse
Affiliation(s)
- Kyota Ishii
- Laboratory of Molecular Bromacology, Graduate School of Sports Health, Toyo University, Akabane City 115-8650, Japan
| | - Mayuko Hido
- Department of Food and Nutritional Sciences, Faculty of Food and Nutritional Sciences, Toyo University, Itakura 374-0193, Japan
| | - Misaki Sakamura
- Department of Food and Nutritional Sciences, Faculty of Food and Nutritional Sciences, Toyo University, Itakura 374-0193, Japan
| | - Nantiga Virgona
- Research Institute of Life Innovation, Toyo University, Akabane City 115-8650, Japan
| | - Tomohiro Yano
- Research Institute of Life Innovation, Toyo University, Akabane City 115-8650, Japan
| |
Collapse
|
|
3
|
Pang KL, Mai CW, Chin KY. Molecular Mechanism of Tocotrienol-Mediated Anticancer Properties: A Systematic Review of the Involvement of Endoplasmic Reticulum Stress and Unfolded Protein Response. Nutrients 2023; 15:nu15081854. [PMID: 37111076 PMCID: PMC10145773 DOI: 10.3390/nu15081854] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/08/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
BACKGROUND Tocotrienol, a type of vitamin E, is well known for its anti-cancer and other biological activities. This systematic review aims to summarize the involvement of endoplasmic reticulum stress (ERS) and subsequent unfolded protein response (UPR) as the underlying molecular mechanisms for the anticancer properties of tocotrienol. METHOD A comprehensive literature search was performed in March 2023 using the PubMed, Scopus, Web of Science, and EMBASE databases. In vitro, in vivo, and human studies were considered. RESULT A total of 840 articles were retrieved during the initial search, and 11 articles that fit the selection criteria were included for qualitative analysis. The current mechanistic findings are based solely on in vitro studies. Tocotrienol induces cancer cell growth arrest, autophagy, and cell death primarily through apoptosis but also through paraptosis-like cell death. Tocotrienol-rich fractions, including α-, γ- and δ-tocotrienols, induce ERS, as evidenced by upregulation of UPR markers and/or ERS-related apoptosis markers. Early endoplasmic reticulum calcium ion release, increased ceramide level, proteasomal inhibition, and upregulation of microRNA-190b were suggested to be essential in modulating tocotrienol-mediated ERS/UPR transduction. Nevertheless, the upstream molecular mechanism of tocotrienol-induced ERS is largely unknown. CONCLUSION ERS and UPR are essential in modulating tocotrienol-mediated anti-cancer effects. Further investigation is needed to elucidate the upstream molecular mechanism of tocotrienol-mediated ERS.
Collapse
Affiliation(s)
- Kok-Lun Pang
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia
- Newcastle University Medicine Malaysia, Iskandar Puteri 79200, Malaysia
| | - Chun-Wai Mai
- Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, UCSI University, Kuala Lumpur 56000, Malaysia
| | - Kok-Yong Chin
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia
| |
Collapse
|