Impact of Portuguese propolis on keratinocyte proliferation, migration and ROS protection: Significance for applications in skin products

Abstract

Objective: Propolis has been used since antiquity, but recent reports of its biological properties hint that it could be employed as a topical pharmaceutical and cosmetic ingredient. This work aims to probe the action of Portuguese propolis extracts on skin cells, providing mechanistic insights into its mode of action and preliminarily assessing its applicability as a skin repair ingredient. Methods:The total phenolic content of propolis extracts was measured by the Folin Ciocalteu method. The cytotoxic effect of propolis extracts in human keratinocytes was determined and non-cytotoxic concentrations of the extracts were used to study the impact on collective cell migration, cell cycle and intracellular ROS levels.Results: o significant impact was observed in collective cell migration, but one of the extracts mildly increased G2 phase while reducing the % of sub-G1 at a noncytotoxic concentration. The two extracts with higher phenolic content strongly prevented intracellular cellular ROS accumulation upon exposure to TBHP. Collectively, these results indicate that the putative beneficial effects of propolis extracts in skin repair may not be attributable to induction of collective cell migration but could be partially ascribed to the protection from oxidative stress, which could act in synergy with its well-known antimicrobial activity. Conclusion:These data support the applicability of this material in topical and cosmetic formulations and further in vivo assays should be conducted to fully characterize its efficacy and safety.

Antimicrobial, Antibiofilm and Toxicological Assessment of Propolis

“…Furthermore, other studies performed in tumor epithelial and fibroblast cell lines have shown dose-response cytotoxicity with a half-maximal inhibitory concentration (IC50) of 0.04-0.16 mg/mL [20][21][22]. Additionally, propolis has shown healing properties by inducing the proliferation and migration of primary lineages of keratinocytes [23]. Therefore, we may suggest that this propolis ethanolic extract can be used without significant damage to fibroblasts and keratinocytes in concentrations below 1 mg/mL.…”

“…Besides their antibacterial and antibiofilm activities, propolis extracts have shown differential effect on the viability of several carcinoma and sarcoma cell lines being better tolerated by the latter [20][21][22]. The effect of propolis extracts on primary cell line viability, which are better models for normal epithelial and connective tissues, is less characterized; nevertheless, one study shows that the extracts are well-tolerated by a fibroblast lineage [20] and has shown to promote keratinocyte proliferation and migration [23], thus suggesting that it might be well-tolerated by animal tissues.…”

The Dietary Isothiocyanate Erucin Reduces Kidney Cell Motility by Disturbing Tubulin Polymerization

“…Intracellular ROS: The intracellular ROS levels were assessed by the dichloro-dihydro-fluorescein diacetate (DCFH-DA) method, based on the ROS-dependent oxidation of DCFH-DA to dichlorofluorescein according to Saraiva et al [31] Vero-E6 and 786-O cells were seeded in a black 96well plate with clear flat bottom, left to sit for 24 h at 37 °C, 5% CO 2 , and then exposed to vehicle or erucin (10, 50, and 80 μM). After a 22 h period, TBHP (1 mM) was added as the positive control, and the plate was left to incubate for another 2 h at 37 °C.…”