Polyphenolic fraction of Lonicera caerulea L. fruits reduces oxidative stress and inflammatory markers induced by lipopolysaccharide in gingival fibroblasts

The most common oral diseases have a microbial aetiology. Pathogenic bacteria liberate a number of irritating agents including a lipopolysaccharide (LPS) that activates pro-inflammatory cytokines promoting increased activity of polymorphonucleocytes (PMN). Release of PMN-derived free radicals into an infected gingival area affects gums, periodontal ligaments and alveolar bone. Berries of Lonicera caerulea L (blue honeysuckle) are rich in phenolics, particularly phenolic acids, flavonoids and anthocyanins that have multiple biological activities in vitro and in vivo such as antiadherence, antioxidant and anti-inflammatory. Studies have shown that polyphenols suppress a number of LPS-induced signals and thus could be effective against gingivitis. Here we assessed effects of the polyphenolic fraction of L caerulea fruits (PFLC; containing 77% anthocyanins) on LPS-induced oxidative damage and inflammation in human gingival fibroblasts. Application of PFLC (10-50 mu g/ml) reduced reactive oxygen species (ROS) production, intracellular glutathione (GSH) depletion as well as lipid peroxidation in LPS-treated cells. PFLC treatment also inhibited LPS-induced up-regulation of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) and it suppressed expression of cyclooxygenase-2 (COX-2). The effects are presumably linked to its antioxidant and anti-inflammatory activities and suggest its use in attenuating the inflammatory process, including periodontal disease. (C) 2010 Elsevier Ltd. All rights reserved.