Role of Vitamin E for Nonalcoholic Steatohepatitis in Patients With Type 2 Diabetes: A Randomized Controlled Trial

Bril F, Biernacki DM, Kalavalapalli S, Lomonaco R, Subbarayan SK, Lai J, Tio F, Suman A, Orsak BK, Hecht J, Cusi K

Diabetes Care. 2019 Aug;42(8):1481-1488. doi: 10.2337/dc19-0167. Epub 2019 May 21.

Abstract

OBJECTIVE:

While vitamin E has shown to improve nonalcoholic steatohepatitis (NASH) in patients without diabetes, information on patients with type 2 diabetes mellitus (T2DM) is lacking. The aim of this study was to determine whether vitamin E, alone or combined with pioglitazone, improves histology in patients with T2DM and NASH.

RESEARCH DESIGN AND METHODS:

This was a proof-of-concept, randomized, double-blind, placebo-controlled trial conducted from 2010 to 2016. Patients with T2DM and biopsy-proven NASH (n = 105) were randomized to vitamin E 400 IU b.i.d., vitamin E 400 IU b.i.d. plus pioglitazone 45 mg/day, or placebo. Eighty-six patients completed the 18-month study. The primary end point was a two-point reduction in the nonalcoholic fatty liver disease activity score from two different parameters, without worsening of fibrosis. Secondary outcomes were resolution of NASH without worsening of fibrosis, individual histological scores, and metabolic parameters.

RESULTS:

More patients on combination therapy achieved the primary outcome versus placebo (54% vs. 19%, P = 0.003) but not with vitamin E alone (31% vs. 19%, P = 0.26). Both groups showed improvements in resolution of NASH compared with placebo (combination group: 43% vs. 12%, P = 0.005; vitamin E alone: 33% vs. 12%, P = 0.04). While steatosis assessed by histology improved with combination therapy (P < 0.001) and vitamin E alone (P = 0.018), inflammation (P = 0.018) and ballooning (P = 0.022) only improved with combination therapy. No improvement in fibrosis was observed in any group.

CONCLUSIONS:

In this proof-of-concept study, combination therapy was better than placebo in improving liver histology in patients with NASH and T2DM. Vitamin E alone did not significantly change the primary histological outcome.

Hassan WN, Bin-Jaliah I, Haidara MA, Eid RA, Heidar EHA, Dallak M, Al-Ani B

Ultrastruct Pathol. 2019 Jun 9:1-9. doi: 10.1080/01913123.2019.1627446. [Epub ahead of print]

Abstract

We recently reported an animal model of osteoarthritis (OA) induced by a combination of the chondrocyte glycolysis inhibitor, monoiodoacetate (MIA) and the agent that induces diabetes mellitus, streptozotocin (STZ). Here we investigated the potential protective effect of the antioxidant and anti-inflammatory agent, vitamin E against MIA+STZ-induced OA. Therefore, rats were either injected once with MIA (2 mg/50 μL) + 65 mg/kg STZ before being sacrificed after 8 weeks (model group) or were treated immediately after MIA+STZ injections with vitamin E (600 mg/kg; thrice a week) before being sacrificed after 8 weeks (treatment group). Using scanning and transmission electron microscopy examinations, we observed in the model group a substantial damage to the articular cartilage of the knee joint as demonstrated by the destruction of the chondrocytes, territorial matrix, disrupted lacunae, collagen fibers, and profound chondrocyte ultrastructural alterations such as degenerated chondrocyte, irregular cytoplasmic membrane, damaged mitochondria and rough endoplasmic reticulum, vacuolated cytoplasm, presence of lipid droplets and different sizes of lysosomes, which were substantially but not completely protected by vitamin E. H&E stained sections of knee joint articular cartilage showed that MIA+STZ induced damage to the chondrocyte and territorial matrix. Vitamin E also significantly (p < .05) inhibited MIA+STZ-induced blood levels of the inflammatory biomarkers, tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) that are known to be modulated in OA and diabetes. We conclude that vitamin E protects against MIA+STZ-induced knee joints injuries in rats, which is associated with the inhibition of biomarkers of inflammation.

Afzali H, Jafari Kashi AH, Momen-Heravi M, Razzaghi R, Amirani E, Bahmani F, Gilasi HR, Asemi Z

Wound Repair Regen. 2019 Jan 28. doi: 10.1111/wrr.12701. [Epub ahead of print]

Abstract

This study was carried out to determine the effects of magnesium and vitamin E co-supplementation on wound healing and metabolic status in patients with diabetic foot ulcer (DFU). The current randomized, double-blind, placebo-controlled trial was conducted among 57 patients with grade 3 DFU. Participants were randomly divided into two groups to take either 250 mg magnesium oxide plus 400 IU vitamin E (n = 29) or placebo per day (n = 28) for 12 weeks. Compared with the placebo, taking magnesium plus vitamin E supplements reduced ulcer length (β [difference in the mean of outcomes measures between treatment groups] -0.56 cm; 95% CI, -0.92, -0.20; p = 0.003), width (β -0.35 cm; 95% CI, -0.64, -0.05; p = 0.02) and depth (β -0.18 cm; 95% CI, -0.33, -0.02; p = 0.02). In addition, co-supplementation led to a significant reduction in fasting plasma glucose (β -13.41 mg/dL; 95% CI, -20.96, -5.86; p = 0.001), insulin (β -1.45 μIU/ml; 95% CI, -2.37, -0.52; p = 0.003), insulin resistance (β -0.60; 95% CI, -0.99, -0.20; p = 0.003) and HbA1c (β -0.32%; 95% CI, -0.48, -0.16; p < 0.003), and a significant elevation in insulin sensitivity (β 0.007; 95% CI, 0.003, 0.01; p < 0.001) compared with the placebo. Additionally, compared with the placebo, taking magnesium plus vitamin E supplements decreased triglycerides (β -10.08 mg/dL; 95% CI, -19.70, -0.46; p = 0.04), LDL-cholesterol (β -5.88 mg/dL; 95% CI, -11.42, -0.34; p = 0.03), high sensitivity C-reactive protein (hs-CRP) (β -3.42 mg/L; 95% CI, -4.44, -2.41; p < 0.001) and malondialdehyde (MDA) (β -0.30 μmol/L; 95% CI, -0.45, -0.15; p < 0.001), and increased HDL-cholesterol (β 2.62 mg/dL; 95% CI, 0.60, 4.63; p = 0.01) and total antioxidant capacity (TAC) levels (β 53.61 mmol/L; 95% CI, 4.65, 102.57; p = 0.03). Overall, magnesium and vitamin E co-supplementation for 12 weeks to patients with DFU had beneficial effects on ulcer size, glycemic control, triglycerides, LDL- and HDL-cholesterol, hs-CRP, TAC, and MDA levels.

Zhao Y, Zhang W, Jia Q, Feng Z, Guo J, Han X, Liu Y, Shang H, Wang Y, Liu WJ

Front Physiol. 2019 Jan 21;9:1939. doi: 10.3389/fphys.2018.01939. eCollection 2018.

Abstract

It has been reported that autophagic stress, which is involved in many diseases, plays a key role in the development of diabetic nephropathy (DN). In this study, we investigated the effects of high dose vitamin E on renal tubular epithelial cells and autophagic stress-related mechanisms in diabetes condition. In diabetic rats, high dose vitamin E treatment significantly decreased the serum creatinine, urea nitrogen, urinary albumin and urinary protein, reduced the levels of LCN2, HAVCR1, LDH and 8-OHdG in urine, and attenuated the cellular apoptosis and interstitial fibrosis in renal cortex. In vitro, vitamin E could reduce the release of LCN2 and HAVCR1 and the protein levels of caspase 3 and TGF-β1, as well as improve the growth inhibition in cultured HK-2 cells after exposure to advanced glycation end products (AGEs). Also, LC3-II and SQSTM1-positive dots were significantly increased in the renal tubular epithelial cells of DN patients and diabetic rats, and in HK-2 cells after exposure to AGEs, which were markedly declined by vitamin E. In addition, we found that the autophagosome formation was not affected by AGEs, as assessed by the mRNA levels of LC3B, Beclin-1, and ATG7. However, AGEs blocked the lysosomal degradation of autophagosome, which was characterized by a decrease in the enzymatic activity of cathepsin B/cathepsin L and DQ-ovalbumin degradation in HK-2 cells, indicating that AGEs-induced accumulation of autophagic vacuoles was a sign of autophagic stress. Interestingly, vitamin Eexerted a protective effect on lysosomes to reduce the autophagic stress. Taken together, we conclude that autophagic stress may play an important part in the progression of DN, and alleviation of autophagic stress though improvement of lysosomal function provides a promising novel approach for treating DN.

Noguchi M, Yamawaki I, Takahashi S, Taguchi Y, Umeda M

J Oral Sci. 2018;60(4):579-587. doi: 10.2334/josnusd.17-0422.

Abstract

It is widely accepted that vitamin E (VE) acts as an antioxidant and is involved in various metabolic systems including the regulation of gene expression and inhibition of cell proliferation. The most predominant isoform of VE in the living body is α-tocopherol. However, the influence of α-tocopherol on bone marrow mesenchymal cells (BMMCs) in a background of type II diabetes mellitus (DM) has not been investigated. The focus of the present study was to clarify the effect of α-tocopherol on BMMCs derived from rats with type II DM and the underlying mechanisms involved. BMMCs were isolated from rats with type II DM. The BMMCs were either untreated or exposed to α-tocopherol at concentrations of 1.0, 10, and 100 μM, and the resulting effects of α-tocopherol on cell proliferation, H₂O₂ activity, and antioxidant and inflammatory cytokine production were examined. At 100 μM, α-tocopherol had no effect on cell proliferation, but H₂O₂ activity was significantly increased. At 10 μM, α-tocopherol increased the gene expression of IL-1β, and markedly promoted that of TNF-α. Expression of catalase in the presence of 100 μM α-tocopherol was lower than for the other concentrations. At a low concentration, α-tocopherol exerted good antioxidant and anti-inflammatory effects on BMMCs. The study suggests that maintaining α-tocopherol at a low concentration might promote the recovery of BMMCs from oxidative stress.

Dallak MA, Al-Ani B, El Karib AO, Abd Ellatif M, Eid RA, Al-Ani R, Mahmoud HM, Haidara MA

Arch Physiol Biochem. 2018 Nov 22:1-7. doi: 10.1080/13813455.2018.1538250. [Epub ahead of print]

Abstract

BACKGROUND:

We tested the hypothesis that vitamin E may protect against pre-diabetes-induced aortic injury (aortopathy), and exercise can augment the action of vitamin E.

MATERIAL AND METHODS:

Rats were either fed with a high fat and fructose diet (HFD) (model group) or a standard laboratory chow (control group) for 15 weeks before being sacrificed. The three protective groups were treated with vitamin E (HFD + Vit E), swimming exercises (HFD + Ex), and vitamin E plus swimming exercises (HFD + VitE + Ex), respectively.

RESULTS:

Aortopathy was developed in the model group as demonstrated by substantial tissue ultrastructural alterations, which were partially protected by vitamin E and effectively protected with vitamin E plus swim exercise. Also, swimming exercises significantly (p < .05) increased the modulatory effects of vitamin E on dyslipidemia, insulin resistance, blood pressure, oxidative stress, inflammation, leptin, and adiponectin, except coagulation and thrombosis.

CONCLUSIONS:

Swim exercise augments the protective effects of vitamin E in a pre-diabetic animal model.

Tan SMQ, Chiew Y, Ahmad B, Kadir KA

Nutrients. 2018 Sep 17;10(9). pii: E1315. doi: 10.3390/nu10091315.

Abstract

Tocotrienol-rich vitamin E from palm oil (Tocovid) has been shown to ameliorate diabetes through its superior antioxidant, antihyperglycemic, and anti-inflammatory properties in diabetic rats. This study aimed to investigate the effects of Tocovid on diabetic nephropathy in patients with type 2 diabetes. Baseline parameters of potential subjects such as HbA1c, blood pressure, Advanced Glycation Endproduct (AGE), soluble receptor for AGE (sRAGE), Nε-Carboxymethyllysine (Nε-CML), and Cystatin C were assessed for possible correlation with diabetic nephropathy. Only subjects with diabetic nephropathy or urine microalbuminuria-positive defined as Urine Albumin to Creatinine Ratio (UACR) >10 mg/mmol were recruited into a prospective, randomized, double-blinded, placebo-controlled trial. The intervention group (n = 22) received Tocovid 200 mg twice a day while the control group (n = 23) received placebo twice a day for 8 weeks. Changes in Hemoglobin A1c (HbA1c), blood pressure, serum biomarkers and renal parameters such as UACR, serum creatinine, and estimated Glomerular Filtration Rate (eGFR) were compared between the two groups. It was found that serum Nε-CML significantly correlated to the severity of microalbuminuria. For every 1 ng/mL increase in serum Nε-CML, the odds of diabetic nephropathy increased by 1.476 times. Tocovid, compared to placebo, significantly reduced serum creatinine but not eGFR, UACR, HbA1c, blood pressure, and serum biomarkers. In conclusion, serum Nε-CML is a potential biomarker for diabetic nephropathy. Treatment with Tocovid significantly reduced serum creatinine; therefore Tocovid may be a useful addition to the current treatment for diabetic nephropathy.

Wan Hasan WN, Chin KY, Jolly JJ, Abd Ghafar N, Soelaiman IN.

Endocr Metab Immune Disord Drug Targets. 2018 Apr 23. doi: 10.2174/1871530318666180423122409. [Epub ahead of print]

Abstract

BACKGROUND:

Osteoporosis is a silent skeletal disease characterized by low bone mass and destruction of skeletal microarchitecture, leading to an increased fracture risk. This occurs due to an imbalance in bone remodelling, whereby the rate of bone resorption is greater than bone formation. Mevalonate pathway, previously known to involve in cholesterol synthesis, is an important regulatory pathway for bone remodelling.

OBJECTIVE:

This review aimed to provide an overview of the relationship between mevalonate pathway and bone metabolism, as well as agents which act through this pathway to achieve their therapeutic potential.

DISCUSSION:

Mevalonate pathway produces farnesyl pyrophosphate and geranylgeranyl pyrophosphate essential in protein prenylation. An increase in protein prenylation favours bone resorption over bone formation. Non-nitrogen containing bisphosphonates inhibit farnesyl diphosphate synthase which produces farnesyl pyrophosphate. They are used as the first line therapy for osteoporosis. Statins, a well-known class of cholesterol-lowering agents, inhibit 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, the rate-determining enzyme in the mevalonate pathway. It was shown to increase bone mineral density and prevent fracture in humans. Tocotrienol is a group of vitamin E commonly found in palm oil, rice bran and annatto bean. It causes degradation of HMG-CoA reductase. Many studies demonstrated that tocotrienol prevented bone loss in animal studies but its efficacy has not been tested in humans.

CONCLUSION:

mevalonate pathway can be exploited to develop effective antiosteoporosis agents.

KEYWORDS:

bone; bone metabolism; mevalonate pathway; tocotrienol; vitamin E.

Lee H, Lim Y.

J Nutr Biochem. 2018 Mar 21;57:77-85. doi: 10.1016/j.jnutbio.2018.03.016. [Epub ahead of print]

Abstract

Chronic hyperglycemia induces impairment of muscle growth and development of diabetes mellitus (DM). Since skeletal muscle is the major site for disposal of ingested glucose, impaired glucose metabolism causes imbalance between protein synthesis and degradation which adversely affects physical mobility. In this study, we investigated the effect of tocotrienol-rich fraction (TRF) supplementation on skeletal muscle damage in diabetic mice. Diabetes was induced by a high-fat diet with streptozotocin (STZ) injection (100 mg/kg) in male C57BL/6J mice. After diabetes was induced (fasting blood glucose levels≥250 mg/dl), normal control (CON) and diabetic control (DMC) groups were administrated with olive oil, while TRF treatment groups were administrated with TRF (dissolved in olive oil) at low dose (100 mg/kg BW, LT) or high dose (300 mg/kg BW, HT) by oral gavage for 12 weeks. TRF supplementation ameliorated muscle atrophy, plasma insulin concentration and homeostatic model assessment estimated insulin resistance in diabetic mice. Moreover, TRF treatment up-regulated IRS-1 and Akt levels accompanied by increased translocation of GLUT4. Furthermore, TRF increased mitochondrial biogenesis by activating SIRT1, SIRT3 and AMPK in diabetic skeletal muscle. These changes were in part mechanistically explained by reduced levels of skeletal muscle proteins related to oxidative stress (4-hydroxynonenal, protein carbonyls, Nrf2 and HO-1), inflammation (NFkB, MCP-1, IL-6 and TNF-α), and apoptosis (Bax, Bcl₂ and caspase-3) in diabetic mice. Taken together, these results suggest that TRF might be useful as a beneficial nutraceutical to prevent skeletal muscle atrophy associated with diabetes by regulating insulin signaling via AMPK/SIRT1/PGC1α pathways in type 2 diabetic mice.

Dass AS, Narayana S, Venkatarathnamma PN

J Adv Pharm Technol Res. 2018 Jan-Mar;9(1):32-36. doi: 10.4103/japtr.JAPTR_309_17.

Abstract

Diabetes mellitus (DM) and its complications have been implicated in hyperglycemia-induced oxidative stress. Antioxidants can improve glycemic control, lipid profile, and cognitive functions. We assessed the effect of Vitamin E and omega 3 fatty acids (OFA) on the above parameters. One hundred patients with type 2 DM receiving metformin 500 mg and glimepiride 1 mg were randomized to receive add-on therapy of Vitamin E 400 mg or OFA once daily for 12 weeks and the third group served as control. Fasting blood sugar (FBS), postprandial blood sugar (PPBS), glycated hemoglobin (HbA1c), body mass index (BMI), waist-hip ratio (WHR), lipid profile, and mini-mental state examination were done at baseline and 12 weeks. Eighty-seven patients completed the study. A significant reduction in FBS, PPBS, and HbA1c was observed in all the three groups at 12 weeks. There was significant reduction in total cholesterol and triglycerides (TG) in patients receiving either of the antioxidants and also significant reduction in low-density lipoprotein in patients receiving OFA at 12 weeks compared to baseline. BMI and WHR were significantly increased in control group. Intergroup analysis showed that in patients receiving Vitamin E and OFA, the reduction of FBS, PPBS, and HbA1c were similar. The patients receiving OFA had significant reduction in TG compared to control. There was no significant effect on cognitive function. Vitamin E and OFA had beneficial effects on lipid profile and anthropometric measurements; however, the glycemic control was similar to the patients in control group.