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Sadikan MZ, Abdul Nasir NA, Bakar NS, Iezhitsa I, Agarwal R. Tocotrienol-rich fraction reduces retinal inflammation and angiogenesis in rats with streptozotocin-induced diabetes. BMC Complement Med Ther 2023; 23:179. [PMID: 37268913 DOI: 10.1186/s12906-023-04005-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 05/20/2023] [Indexed: 06/04/2023] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is the second commonest microvascular complication of diabetes mellitus. It is characterized by chronic inflammation and angiogenesis. Palm oil-derived tocotrienol-rich fraction (TRF), a substance with anti-inflammatory and anti-angiogenic properties, may provide protection against DR development. Therefore, in this study, we investigated the effect of TRF on retinal vascular and morphological changes in diabetic rats. The effects of TRF on the retinal expression of inflammatory and angiogenic markers were also studied in the streptozotocin (STZ)-induced diabetic rats. METHODS Male Sprague Dawley rats weighing 200-250 g were grouped into normal rats (N) and diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (55 mg/kg body weight) whereas N similarly received citrate buffer. STZ-injected rats with blood glucose of more than 20 mmol/L were considered diabetic and were divided into vehicle-treated (DV) and TRF-treated (DT) groups. N and DV received vehicle, whereas DT received TRF (100 mg/kg body weight) via oral gavage once daily for 12 weeks. Fundus images were captured at week 0 (baseline), week 6 and week 12 post-STZ induction to estimate vascular diameters. At the end of experimental period, rats were euthanized, and retinal tissues were collected for morphometric analysis and measurement of NFκB, phospho-NFκB (Ser536), HIF-1α using immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA). Retinal inflammatory and angiogenic cytokines expression were measured by ELISA and real-time quantitative PCR. RESULTS TRF preserved the retinal layer thickness (GCL, IPL, INL and OR; p < 0.05) and retinal venous diameter (p < 0.001). TRF also lowered the retinal NFκB activation (p < 0.05) as well as expressions of IL-1β, IL-6, TNF-α, IFN-γ, iNOS and MCP-1 (p < 0.05) compared to vehicle-treated diabetic rats. Moreover, TRF also reduced retinal expression of VEGF (p < 0.001), IGF-1 (p < 0.001) and HIF-1α (p < 0.05) compared to vehicle-treated rats with diabetes. CONCLUSION Oral TRF provided protection against retinal inflammation and angiogenesis in rats with STZ-induced diabetes by suppressing the expression of the markers of retinal inflammation and angiogenesis.
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Affiliation(s)
- Muhammad Zulfiqah Sadikan
- Department of Pharmacology, Faculty of Medicine, Manipal University College Malaysia (MUCM), Bukit Baru, 75150, Melaka, Malaysia
- Centre for Neuroscience Research (NeuRon), Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh Campus, 47000, Sungai Buloh, Selangor, Malaysia
| | - Nurul Alimah Abdul Nasir
- Centre for Neuroscience Research (NeuRon), Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh Campus, 47000, Sungai Buloh, Selangor, Malaysia.
| | - Nor Salmah Bakar
- Department of Pathology, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh Campus, 47000, Sungai Buloh, Selangor, Malaysia
| | - Igor Iezhitsa
- School of Medicine, International Medical University, Bukit Jalil, 57000, Kuala Lumpur, Malaysia
- Department of Pharmacology and Bioinformatics, Volgograd State Medical University, Pavshikh Bortsov sq. 1, Volgograd, 400131, Russia
| | - Renu Agarwal
- School of Medicine, International Medical University, Bukit Jalil, 57000, Kuala Lumpur, Malaysia
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Abdul Ghani NA, Abdul Nasir NA, Lambuk L, Sadikan MZ, Agarwal R, Ramli N. The effect of palm oil-derived tocotrienol-rich fraction in preserving normal retinal vascular diameter in streptozotocin-induced diabetic rats. Graefes Arch Clin Exp Ophthalmol 2023; 261:1587-1596. [PMID: 36622408 DOI: 10.1007/s00417-022-05965-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/30/2022] [Accepted: 12/27/2022] [Indexed: 01/10/2023] Open
Abstract
PURPOSE Angiogenesis in diabetic retinopathy (DR) is associated with increased retinal expression of angiopoietin-2 (Ang-2) and protein kinase C (PKC). Tocotrienol-rich fraction (TRF) has been shown to reduce the expression vascular endothelial growth factor (VEGF) in several experimental models. However, its effect against other angiogenic markers such as Ang-2 and PKC in rat model of diabetes remains unknown. Therefore, we investigated the effect of TRF on the retinal vascular changes and Ang-2 and PKC expressions in rats with streptozotocin (STZ)-induced DR. METHODS Sprague-Dawley rats were divided into normal control rats (N) which received vehicle, and diabetic rats which either received vehicle (DV) or 100 mg/kg of TRF (DT). Diabetes was induced with intraperitoneal injection of STZ (60 mg/kg body weight). Treatments were given orally, once daily, for 12 weeks after confirmation of hyperglycaemia. Fundus photographs were captured at baseline, 6- and 12-week post-STZ injection and average diameter of retinal veins and arteries were measured. At 12-week post-STZ injection, rats were euthanised, and retinae were collected for measurement of Ang-2 and PKC gene and protein expressions. RESULTS Retinal venous and arterial diameters were significantly greater in DV compared to DT at week 12 post-STZ injection (p < 0.001 and < 0.05, respectively). The vessel diameter measurements in DT were comparable to N and this effect of TRF was associated with significantly lower Ang-2 and PKC gene and protein expressions compared to DV. CONCLUSION Oral TRF reduces the expression of retinal angiogenic markers and preserves the retinal vascular diameter of rats with STZ-induced DR.
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Affiliation(s)
- Nurliyana Ain Abdul Ghani
- Department of Ophthalmology, Faculty of Medicine, University Malaya Eye Research Centre, University of Malaya, Kuala Lumpur, Malaysia.,Department of Ophthalmology, Faculty of Medicine, Universiti Teknologi MARA, Selangor, Malaysia
| | - Nurul Alimah Abdul Nasir
- Centre for Neuroscience Research, Faculty of Medicine, Universiti Teknologi MARA, Selangor, Malaysia.
| | - Lidawani Lambuk
- Centre for Neuroscience Research, Faculty of Medicine, Universiti Teknologi MARA, Selangor, Malaysia
| | - Muhammad Zulfiqah Sadikan
- Centre for Neuroscience Research, Faculty of Medicine, Universiti Teknologi MARA, Selangor, Malaysia.,Department of Pharmacology, Faculty of Medicine, Manipal University College Malaysia (MUCM), Bukit Baru, 75150, Melaka, Malaysia
| | - Renu Agarwal
- School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Norlina Ramli
- Department of Ophthalmology, Faculty of Medicine, University Malaya Eye Research Centre, University of Malaya, Kuala Lumpur, Malaysia
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Teo CWL, Png SJY, Ung YW, Yap WN. Therapeutic effects of intranasal tocotrienol-rich fraction on rhinitis symptoms in platelet-activating factor induced allergic rhinitis. Allergy Asthma Clin Immunol 2022; 18:52. [PMID: 35698169 PMCID: PMC9195334 DOI: 10.1186/s13223-022-00695-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 05/30/2022] [Indexed: 12/22/2022] Open
Abstract
Background Platelet-activating factor (PAF) has been suggested to be a potent inflammatory mediator in Allergic rhinitis (AR) pathogenesis. Vitamin E, an essential nutrient that comprises tocopherol and tocotrienol, is known as a potential therapeutic agent for airway allergic inflammation. This study aimed to investigate the beneficial effects of intranasal Tocotrienol-rich fraction (TRF) on PAF-induced AR in a rat model. Methods Sprague Dawley rats were randomly assigned into 3 groups: Control, PAF-induced AR and PAF-induced AR with TRF treatment. To induce AR, 50 μl of 16 μg/ml PAF was nasally instilled into each nostril. From day 1 to 7 after AR induction, 10 μl of 16 μg/μl TRF was delivered intranasally to the TRF treatment group. Complete upper skulls were collected for histopathological evaluation on day 8. Results The average severity scores of AR were significantly higher in the PAF-induced AR rats compared to both control and PAF-induced AR with TRF treatment. The histologic examination of the nasal structures showed moderate degree of inflammation and polymorphonuclear cells infiltration in the lamina propria, mucosa damage and vascular congestion in the PAF-induced AR rats. TRF was able to ameliorate the AR symptoms by restoring the nasal structures back to normal. H&E staining demonstrated a statistically significant benefit upon TRF treatment, where minimal degree of inflammation, and a reduction in the infiltration of polymorphonuclear cells, mucosa damage and vascular congestion were observed. Conclusion TRF exhibited symptomatic relief action in AR potentially due to its antioxidant, anti-inflammatory and anti-allergic properties.
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Affiliation(s)
- Cheryl Wei Ling Teo
- Research and Development Department, Davos Life Science, 3 Biopolis Drive, #04-19, Synapse, 138623, Singapore, Singapore. .,Research and Development Department, KL-Kepong Oleomas (KLK Oleo), Level 8, Menara KLK, No 1, Jalan PJU 7/6, Mutiara Damansara, 47810, Petaling Jaya, Selangor, Malaysia.
| | - Stephanie Jia Ying Png
- School of Biological Sciences, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore, Singapore
| | - Yee Wei Ung
- Research and Development Department, KL-Kepong Oleomas (KLK Oleo), Level 8, Menara KLK, No 1, Jalan PJU 7/6, Mutiara Damansara, 47810, Petaling Jaya, Selangor, Malaysia
| | - Wei Ney Yap
- Research and Development Department, Davos Life Science, 3 Biopolis Drive, #04-19, Synapse, 138623, Singapore, Singapore.,Research and Development Department, KL-Kepong Oleomas (KLK Oleo), Level 8, Menara KLK, No 1, Jalan PJU 7/6, Mutiara Damansara, 47810, Petaling Jaya, Selangor, Malaysia
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Irandoost P, Mesri Alamdari N, Saidpour A, Shidfar F, Farsi F, Asghari Jafarabadi M, Alivand MR, Vafa M. The effect of royal jelly and tocotrienol-rich fraction along with calorie restriction on hypothalamic endoplasmic reticulum stress and adipose tissue inflammation in diet-induced obese rats. BMC Res Notes 2020; 13:409. [PMID: 32867829 PMCID: PMC7460780 DOI: 10.1186/s13104-020-05258-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 08/26/2020] [Indexed: 03/20/2023] Open
Abstract
Objectives Endoplasmic reticulum (ER) stress causes adipose tissue dysfunction and chronic inflammation in obesity. Royal jelly (RJ) and tocotrienol-rich fraction (TRF) are reported to ameliorate inflammation. However, the improving effects of RJ and TRF on inflammation from ER stress modulating view have not been assessed so far. Hence, we investigated the effect of RJ and TRF on ER stress and some adipose tissue-derived inflammatory markers in the high-fat diet (HFD)-induced obesity. Wistar obese rats randomly allocated into 5 groups: HFD, calorie restriction diet (CRD), RJ + CRD, TRF + CRD, RJ + TRF + CRD. After 8-week intervention, adipose tissues and hypothalamus were dissected and serum was collected. Results RJ reduced glucose-regulated protein-78 (GRP78) expression as ER stress indicator in WAT and hypothalamus compared to CRD. Besides, RJ diminished the expression of inflammatory markers in white adipose tissue (WAT) and also decreased the serum concentration of them. TRF reduced inflammatory markers in the serum without remarkable effects on ER stress. Overall, RJ has protective effect against adipose tissue dysfunction and inflammation then suggested as a therapeutic approach to reduce some obesity-related complications. The impact of TRF in this regard is lower than RJ and limited to systemic inflammation improvement without remarkable changes in adipose tissue inflammation.
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Affiliation(s)
- Pardis Irandoost
- Student Research Committee, Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Naimeh Mesri Alamdari
- Student Research Committee, Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Atoosa Saidpour
- National Nutrition and Food Technology Research Institute, Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Farzad Shidfar
- Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.,Colorectal Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Farnaz Farsi
- Colorectal Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Asghari Jafarabadi
- Road Traffic Injury Prevention Research Center, School of Health, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Reza Alivand
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammadreza Vafa
- Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
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Khor SC, Mohd Yusof YA, Wan Ngah WZ, Makpol S. Tocotrienol-rich fraction prevents cellular aging by modulating cell proliferation signaling pathways. Clin Ter 2017; 166:e81-90. [PMID: 25945449 DOI: 10.7417/ct.2015.1825] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE Vitamin E has been suggested as nutritional intervention for the prevention of degenerative and age-related diseases. In this study, we aimed to elucidate the underlying mechanism of tocotrienol-rich fraction (TRF) in delaying cellular aging by targeting the proliferation signaling pathways in human diploid fibroblasts (HDFs). MATERIALS AND METHODS Tocotrienol-rich fraction was used to treat different stages of cellular aging of primary human diploid fibroblasts viz. young (passage 6), pre-senescent (passage 15) and senescent (passage 30). Several selected targets involved in the downstream of PI3K/AKT and RAF/MEK/ERK pathways were compared in total RNA and protein. RESULTS Different transcriptional profiles were observed in young, pre-senescent and senescent HDFs, in which cellular aging increased AKT, FOXO3, CDKN1A and RSK1 mRNA expression level, but decreased ELK1, FOS and SIRT1 mRNA expression level. With tocotrienol-rich fraction treatment, gene expression of AKT, FOXO3, ERK and RSK1 mRNA was decreased in senescent cells, but not in young cells. The three down-regulated mRNA in cellular aging, ELK1, FOS and SIRT1, were increased with tocotrienol-rich fraction treatment. Expression of FOXO3 and P21Cip1 proteins showed up-regulation in senescent cells but tocotrienol-rich fraction only decreased P21Cip1 protein expression in senescent cells. CONCLUSIONS Tocotrienol-rich fraction exerts gene modulating properties that might be responsible in promoting cell cycle progression during cellular aging.
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Affiliation(s)
- S C Khor
- Department of Biochemistry, Level 17, Pre-Clinical Building, Universiti Kebangsaan Malaysia Medical Center, Jalan Yaacob Latif, Bandar Tun Razak, Cheras, 56000 Kuala Lumpur, Malaysia
| | - Y A Mohd Yusof
- Department of Biochemistry, Level 17, Pre-Clinical Building, Universiti Kebangsaan Malaysia Medical Center, Jalan Yaacob Latif, Bandar Tun Razak, Cheras, 56000 Kuala Lumpur, Malaysia
| | - W Z Wan Ngah
- Department of Biochemistry, Level 17, Pre-Clinical Building, Universiti Kebangsaan Malaysia Medical Center, Jalan Yaacob Latif, Bandar Tun Razak, Cheras, 56000 Kuala Lumpur, Malaysia
| | - S Makpol
- Department of Biochemistry, Level 17, Pre-Clinical Building, Universiti Kebangsaan Malaysia Medical Center, Jalan Yaacob Latif, Bandar Tun Razak, Cheras, 56000 Kuala Lumpur, Malaysia
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Durani LW, Jaafar F, Tan JK, Tajul Arifin K, Mohd Yusof YA, Wan Ngah WZ, Makpol S. Targeting genes in insulin-associated signalling pathway, DNA damage, cell proliferation and cell differentiation pathways by tocotrienol-rich fraction in preventing cellular senescence of human diploid fibroblasts. Clin Ter 2016; 166:e365-73. [PMID: 26794818 DOI: 10.7417/t.2015.1902] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVES Tocotrienols have been known for their antioxidant properties besides their roles in cellular signalling, gene expression, immune response and apoptosis. This study aimed to determine the molecular mechanism of tocotrienol-rich fraction (TRF) in preventing cellular senescence of human diploid fibroblasts (HDFs) by targeting the genes in senescence-associated signalling pathways. MATERIALS AND METHODS Real time quantitative PCR (qRT-PCR) was utilized to evaluate the expression of genes involved in these pathways. RESULTS Our findings showed that SOD1 and CCS-1 were significantly down-regulated in pre-senescent cells while CCS-1 and PRDX6 were up-regulated in senescent cells (p<0.05). Treatment with TRF significantly down-regulated SOD1 in pre-senescent and senescent HDFs, up-regulated SOD2 in senescent cells, CAT in young HDFs, GPX1 in young and pre-senescent HDFs, and CCS-1 in young, pre-senescent and senescent HDFs (p<0.05). TRF treatment also caused up-regulation of FOXO3A in all age groups of cells (p<0.05). The expression of TP53, PAK2 and CDKN2A was significantly increased in senescent HDFs and treatment with TRF significantly down-regulated TP53 in senescent cells (p<0.05). MAPK14 was significantly up-regulated (p<0.05) in senescent HDFs while no changes was observed on the expression of JUN. TRF treatment, however, down-regulated MAPK14 in young and senescent cells and up-regulated JUN in young and pre-senescent HDFs (p<0.05). CONCLUSIONS TRF modulated the expression of genes involved in senescence-associated signalling pathways during replicative senescence of HDFs.
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Affiliation(s)
- L W Durani
- Department of Biochemistry, Faculty of Medicine, Level 17, Preclinical Building, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
| | - F Jaafar
- Department of Biochemistry, Faculty of Medicine, Level 17, Preclinical Building, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
| | - J K Tan
- Department of Biochemistry, Faculty of Medicine, Level 17, Preclinical Building, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
| | - K Tajul Arifin
- Department of Biochemistry, Faculty of Medicine, Level 17, Preclinical Building, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
| | - Y A Mohd Yusof
- Department of Biochemistry, Faculty of Medicine, Level 17, Preclinical Building, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
| | - W Z Wan Ngah
- Department of Biochemistry, Faculty of Medicine, Level 17, Preclinical Building, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
| | - S Makpol
- Department of Biochemistry, Faculty of Medicine, Level 17, Preclinical Building, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
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