ABSTRACT
Background: Osteoarthritis (OA), the most prevalent form of arthritis, is a degenerative joint disease marked by the progressive deterioration of articular cartilage, leading to clinical manifestations such as joint pain. Objective: This study investigated the effects of Curcuma longa L. extract (CL) containing curcumin, demethoxycurcumin, and bisdemethoxycurcumin on monosodium iodoacetate (MIA)-induced OA rats. Design: Sprague-Dawley rats with MIA-induced OA received CL supplementation at doses of 5, 25, and 40 mg/kg body weight. Results: CL extract administration suppressed mineralisation parameters and morphological modifications and decreased arachidonate5-lipoxygenase and leukotriene B4 levels in articular cartilage. Additionally, it decreased serum prostaglandin E2, NO, and glycosaminoglycanlevels as well as the protein expression of phosphorylated inhibitor kappa B-alpha, phosphorylated p65, cyclooxygenase-2, and inducible nitric oxide synthase in the cartilage of MIA-injected rats. Furthermore, it also reduced matrix metalloproteinases and elevated SMAD family member 3 phosphorylation, tissue inhibitor of metalloproteinases, aggrecan, collagen type I, and collagen type II levels in the articular cartilage of MIA-induced OA rats. Conclusions: This study's findings suggest that CL supplementation helps prevent OA development and is an effective therapy for OA.
ABSTRACT
BACKGROUND/OBJECTIVES: Ultraviolet B (UVB) irradiation on skin can induce production of reactive oxygen species (ROS), which cause expression of matrix metalloproteinases (MMPs) and collagen degradation. Thus, chronic exposure of skin to UVB irradiation leads to histological changes consistent with aging, such as wrinkling, abnormal pigmentation, and loss of elasticity. We investigated the protective effect of the standardized green tea seed extract (GSE) on UVB-induced skin photoaging in hairless mice. MATERIALS/METHODS: Skin photoaging was induced by UVB irradiation on the back of Skh-1 hairless mice three times per week and UVB irradiation was performed for 10 weeks. Mice were divided into six groups; normal control, UVB irradiated control group, positive control (UVB + dietary supplement of vitamin C 100 mg/kg), GSE 10 mg/kg (UVB + dietary supplement of GSE 10 mg/kg), GSE 100 mg/kg (UVB + dietary supplement of GSE 100 mg/kg), and GSE 200 mg/kg (UVB + dietary supplement of GSE 200 mg/kg). RESULTS: The dietary supplement GSE attenuated UVB irradiation-induced wrinkle formation and the decrease in density of dermal collagen fiber. In addition, results of the antioxidant analysis showed that GSE induced a significant increase in antioxidant enzyme activity compared with the UVB irradiation control group. Dietary supplementation with GSE 200 mg/kg resulted in a significant decrease in expression of MMP-1, MMP-3, and MMP-9 and an increase in expression of TIMP and type-1 collagen. CONCLUSIONS: Findings of this study suggest that dietary supplement GSE could be useful in attenuation of UVB irradiation-induced skin photoaging and wrinkle formation due to regulation of antioxidant defense systems and MMPs expression.