Preconditioning with mono and polyunsaturated fatty acids and low-intensity electrical stimulation. Effects on skin repair in rats

Abstract

PURPOSE: To evaluate the effects of preconditioning with oils mixes containing ω3/ω6/ω9 associated with micro-currents on skin repair in rats. METHODS: One-hundred and eight Wistar rats randomized into G-1, G-2 and G-3 groups were treated with saline (0.9%), mix 1 (corn+soybean oils) and mix 2 (olive+canola+flaxseed oils), respectively, in a single dose (0.01ml/g) by gavage. Next, each group was subdivided into sham and stimulated subgroups. Pulsed-wave microcurrents (0.5 µA, 0.5 Hz) were applied to stimulated subgroups for 20 min. One hour later anesthetized rats were subjected to surgery. A dorsal incision (6 cm long) was carried out and closed with interrupted nylon sutures. Samples (1cm2) were harvested from the mid-portion of the incision on the 7, 14, 21 post-operative (P.O.) days. Variables were analyzed using Mann-Whitney/Dunn tests Significance level was set to 5 % (p<0.05). RESULTS: Micro-currents promoted increase of exudate and reduction of epithelialization on day 7 in G1 rats. Mixes 1/2 reduced vascularization on 7/14th days P.O. Both 1/2 mixes reduced fibrosis on day 14. Preconditioning with mix 1 led to increased expression of NF-kB on the 7th day. CONCLUSION: Preconditioning with microcurrents has pro-inflammatory effects while oil mixes 1 and 2 decrease fibrosis and vascularization in the proliferative phase of cicatrization.