Effect of combining Zingiber officinale and Juglans regia extracts on Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis: antibiofilm action and low toxicity.

Objective was evaluated the therapeutic effect of Juglans regia (J) and Zingiber officinale (Z) extracts, alone or associated (Z75% + J25%, Z50% + J50% and Z25% + J75%) applied on planktonic cultures and biofilms of Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus, as well as analyzing the cytotoxic effects of plant extracts on mouse macrophages (Raw 264-7). Broth microdilution assay was performed (M7-A6 - CLSI). Anti-biofilm activities and cytotoxicity on Raw 264-7 were studied using MTT assay and scanning electron microscopy. ANOVA with post-hoc Tukey HSD applied for parametric data and Kruskal-Wallis with Conover-Iman test, for non-parametric (p<0.05). On P. acnes biofilm, Z50% + J50% reduced 46.9% in 5 min and Z25% + J75% reduced 74.1% in 24hs. On S. aureus, Z75% + J25% reduced 23.1% in 5 min Z25% +J75% reduced 79.4% in 24hs. On S. epidermidis, Z75% + J25% reduced 74.6% in 5 min and 82.05% in 24 h. The treatments on macrophages for 24 h promoted a maximum reduction by 14,5% for groups of extracts associations. On multispecies biofilm, Z75%+J25% reduced 84.3% in 24 h. In conclusion association of glycolic extracts provided therapeutic effect, demonstrated antimicrobial activity and low cytotoxicity.