Investigation of the curative effects of palm vitamin E tocotrienols on autoimmune arthritis disease in vivo

Zaida Zainal,Huzwah Khaza’Ai,Sui Kiat Chang,Ammu Kutty Radhakrishnan,Afiqah Abdul Rahim

doi:10.1038/s41598-019-53424-7

Abstract

The tocotrienol-rich fraction (TRF) from palm oil contains vitamin E, which possesses potent antioxidant and anti-inflammatory activities. Rheumatoid arthritis (RA) is a chronic joint inflammatory disease characterised by severe joint pain, cartilage destruction, and bone erosion owing to the effects of various pro-inflammatory mediators and cytokines. Here, we investigated the therapeutic effects of TRF in a rat model of collagen-induced arthritis (CIA). Arthritis was induced by a single intradermal injection of collagen type II in Dark Agouti (DA) rats. Rats were then treated with or without TRF by oral gavage from day 28 after the first collagen injection. Arthritic rats supplemented with TRF showed decreased articular index scores, ankle circumferences, paw volumes, and radiographic scores when compared with untreated rats. The untreated arthritic rats showed higher plasma C-reactive protein levels (p < 0.05) and production of pro-inflammatory cytokines than arthritic rats fed TRF. Moreover, there was a marked reduction in the severity of histopathological changes observed in arthritic rats treated with TRF compared with that in untreated arthritic rats. Overall, the results show that TRF had beneficial effects in this rat model of RA.

Highlights

The tocotrienol-rich fraction (TRF) from palm oil contains vitamin E, which possesses potent antioxidant and anti-inflammatory activities
The body weights of arthritic rats supplemented with TRF increased steadily starting from day 21 (Fig. 1)
Our results showed that oral TRF supplementation attenuated the development of progressive joint destruction in rats with collagen-induced arthritis (CIA)

Summary

Introduction

The tocotrienol-rich fraction (TRF) from palm oil contains vitamin E, which possesses potent antioxidant and anti-inflammatory activities. The aetiology of RA is unclear, growing evidence suggests that most of the pathological features observed in the joints of patients with RA are related to the effects of various pro-inflammatory cytokines, such as tumour necrosis factor-α (TNF-α), interleukin (IL)-1α, and IL-1β6 These cytokines play key roles in modulating inflammatory responses in affected joints[7]. Many of the MMPs have been reported to play key roles in cartilage destruction, which is often observed in RA These MMPs are Resources Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South generally produced by activated macrophages and fibroblasts in response to pro-inflammatory cytokines, such as IL-1β and TNF-α13. In this study, we aimed to investigate the therapeutic effects of supplementation with palm TRF to reduce inflammation in the joints of rats with collagen-induced arthritis (CIA) and decrease the levels of pro-inflammatory mediators in the plasma

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Discussion

Conclusion