Curcumin and tetrahydrocurcumin both prevent osteoarthritis symptoms and decrease the expressions of pro-inflammatory cytokines in estrogen-deficient rats.

Sunmin Park,La Ra Lee,Ji Hyun Seo,Suna Kang

doi:10.1186/s12263-016-0520-4

Abstract

BackgroundMenopausal symptoms are associated with inflammation. Curcumin is a well-known anti-inflammatory bioactive compound from turmeric whereas tetrahydrocurcumin (THC) is a major metabolite of curcumin that may have different efficacies. However, they have not been studied for anti-menopausal symptoms and anti-osteoarthritis effects. We compared the efficacies of curcumin and THC for preventing postmenopausal and osteoarthritis symptoms in ovariectomized (OVX) obese rats with monoiodoacetate (MIA) injections into the right knee to generate a similar pathology as osteoarthritis.MethodsOVX rats were provided a 45 % fat diet containing either (1) 0.4 % curcumin (curcumin), (2) 0.4 % THC, (3) 30 μg/kg body weight 17β-estradiol + 0.4 % dextrin (positive control), (4) 0.4 % dextrin (placebo; control), or (5) 0.4 % dextrin with no MIA injection (normal control) for 4 weeks. At the beginning of the fifth week, OVX rats were given articular injections of MIA or normal-control saline into the right knee and the assigned diets were provided for an additional 3 weeks.ResultsCurcumin and THC had similar efficacies for skin tail temperature in OVX rats whereas THC, but not curcumin, prevented glucose intolerance, which might be involved in exacerbating osteoarthritis. Both protected against osteoarthritis symptoms and pain-related behaviors better than 17β-estradiol treatment in estrogen-deficient rats. Curcumin and THC prevented the deterioration of articular cartilage compared to control. They also maintained lean body mass and lowered fat mass as much as 17β-estradiol treatment. The improvement in osteoarthritis symptoms was associated with decreased gene expressions of matrix metalloproteinase (MMP)3 and MMP13 and tumor necrosis factor-α, interleukin (IL)1β, and IL6 in the articular cartilage.ConclusionsTHC and curcumin are effective for treating postmenopausal and osteoarthritis symptoms in OVX rats with MIA-induced osteoarthritis-like symptoms and may have potential as interventions for menopausal and osteoarthritic symptoms in humans.

Highlights

IntroductionCurcumin is a well-known antiinflammatory bioactive compound from turmeric whereas tetrahydrocurcumin (THC) is a major metabolite of curcumin that may have different efficacies
OVX rats had lower uterine weight and serum 17β-estradiol levels, and they were both normalized by 17β-estradiol treatment, but not by curcumin and THC (Table 1)
The modulation of fat mass by curcumin and THC is not due to Glucose metabolism Control and normal-control rats both had mildly impaired glucose intolerance due to the high-fat diets, as evidenced by homeostasis model assessment estimate of insulin resistance (HOMA-IR) which is a reliable predictor of insulin resistance in rats (Cacho et al 2008)

Summary

Introduction

Curcumin is a well-known antiinflammatory bioactive compound from turmeric whereas tetrahydrocurcumin (THC) is a major metabolite of curcumin that may have different efficacies. They have not been studied for anti-menopausal symptoms and anti-osteoarthritis effects. OA is a leading cause of physical disability, and its incidence is rising due to increasing obesity and an aging population (Johnson and Hunter 2014). Both are associated with systemic inflammation (Greene and Loeser 2015).

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