Rosa canina - Rose hip pharmacological ingredients and molecular mechanics counteracting osteoarthritis - A systematic review

Background: The successful use of rose hip for the treatment of osteoarthritis is well documented. Several randomized placebo controlled double-blind studies, as mono or combination therapy, have demonstrated treatment efficacy as well as excellent tolerability. Purpose: This review focuses on the molecular mechanism underlying the clinical effects of rose hip in osteoarthritis (OA). Methods: The database Medline was screened - using the search term Rosa canina or rose hip - for publications on pharmacological or mechanistic studies with relevance to OA; in addition for findings on pharmacologically active constituents as well as clinical studies. The screening results were complemented by following-up on cited literature. Results: In particular, 24 pharmacological studies on Rosa canina or preparations thereof were considered relevant. Potent antioxidant radical scavenging effects are well documented for numerous rose hip constituents besides Vitamin C. Furthermore, anti-inflammatory activities include the reduction of pro-inflammatory cytokines and chemokines, reduction of NF-kB signaling, inhibition of pro-inflammatory enzymes, including COX1/2, 5-LOX and iNOS, reduction of C-reactive protein levels, reduction of chemotaxis and chemoluminescence of PMNs, and an inhibition of pro-inflammatory metalloproteases. Conclusion: The antioxidant and anti-inflammatory effects of Rosa canina match its clinical action - especially considering new findings on the pharmacological disease pattern of OA. The entirety of several compounds including phenolics, terpenoids, galactolipids, carotenoids, fruit acids and fatty oils can be considered responsible for the observed pharmacological and clinical effects. Further research is needed to eludicate how and in which manner single rose hip compounds interact with their molecular pharmacological targets.