Antioxidant Effects of Glutathione and IGF in a Hyperglycaemic Cell Culture Model of Fibroblasts: Some Actions of Advanced Glycaemic end Products (AGE) and Nicotine

Abstract

The aim of this investigation was to establish potential oxidative effects of glucose, advanced glycation end products (AGE) and nicotine (N) in a fibroblast cell culture model using the anti-oxidants glutathione (G) and insulin like growth factor (IGF). Assays of androgen metabolites were used as biomarkers of healing in this context. Confluent monolayer cultures of human gingival fibroblasts were established in 24 well multiwell plates and incubated in Eagle's MEM for 24h using two radiolabelled androgen substrates 14C-testosterone/14C-4-androstenedione. The established effective concentrations of G1000, glutathione and AGE were used alone and in combination with nicotine and insulin-like growth factor. The medium was then solvent extracted for steroid metabolites, evaporated to dryness and subjected to thin layer chromatography in a benzene acetone solvent system 4:1 v/v for separation of formed metabolites. The metabolites were quantified, using a radioisotope scanner. Significant reduction in the yields of DHT in response to G1000, AGE and nicotine (n=6; p <0.003) were overcome by glutathione (n=6; p <0.002). The stimulatory effect of IGF when combined with AGE was further enhanced by the antioxidant effect of glutathione (n=6; p <0.003). Glucose, AGE and nicotine had a significant inhibitory effect on the yields of the androgen biomarker DHT, overcome by the antioxidant glutathione and IGF, suggestive of an oxidant role for the former agents and an anti-oxidant one for the latter. These agents affected yields of androgen metabolites, biomarkers of oxidative stress and repair, with potential implications on healing in uncontrolled diabetic smokers.

Evidence supporting antioxidant action of adipose-derived stem cells: Protection of human dermal fibroblasts from oxidative stress

“…For example, IGF protected fibroblasts and intestinal epithelial cells, and HGF have a protective effect on retinal pigment epithelium in oxidative injury [10][11][12]. Also, FGF, PEDF and IL-6 reduce the epithelial cell death induced by hydrogen peroxide [14,24].…”

“…Although there are few reports involving the antioxidant action of stem cells, some evidences support a protective effect of cytokines on the epithelial cells during oxidative injury. For example, insulin like growth factor (IGF) reportedly protects fibroblasts and intestinal epithelial cells from free radicals [10,11]. HGF has a protective effect on retinal pigment epithelium in oxidative stress induced by glutathione depletion [12].…”

Anabolic Actions of the Regenerative Agent Enamel Matrix Derivative (EMD) in Oral Periosteal Fibroblasts and MG 63 Osteoblasts, Modulation by Nicotine and Glutathione in a Redox Environment

“…The optimal effective concentration of G was established at 3 µg/mL (G3). Similar optimal effective concentrations of N and G were established in fibroblast cultures in our previous work [29,43]. The optimal effective concentration of enamel matrix derivative (E) was established using serial concentrations of 15, 30, 45, 60 and 75 µg/mL in MG63 osteoblasts with MEM and radiolabeled 14C-testosterone (T) as substrate.…”

Diagnostic Value of Acute Phase Proteins in Periodontal, Psychosomatic and Cardiometabolic Diseases: Response to Treatment

“…The pathogenesis and progression of periodontal disease is escalated by advanced glycaemic end products AGE (Takeda et al 2006), receptor for AGE (RAGE) which is highly expressed in periodontal tissues and AGE/RAGE interactions in uncontrolled diabetics. Using a diabetogenic cell culture model of well characterized osteoblasts, it has been demonstrated that the oxidative effects of AGE and nicotine were overcome by the antioxidant glutathione (Rahman & Soory 2006). Preliminary studies in pro-oxidant cultures of oral periosteal fibroblasts and well characterized osteoblasts demonstrated that co-enzyme Q10, phytoestrogens and the antioxidant Pycnogenol derived from pine bark, attenuated oxidative stress induced by nicotine in this model (Figuero-Ruiz et al 2006); indicating a possible role for these antioxidants in the adjunctive therapy of inflammatory diseases characterized by a pro-oxidant profile.…”