Employing photoacoustic spectroscopy in the evaluation of the skin permeation profile of emulsion containing antioxidant phenolic-rich extract of Melochia arenosa.
CONTEXT
Oxidative stress is an important factor modulating skin alterations. Melochia arenosa Benth. (Malvaceae) is a Brazilian plant with antimicrobial activity and antioxidant potential.


OBJECTIVE
The objective of this study is to develop a topical formulation containing antioxidant phenolic-rich extract of M. arenosa and to evaluate its skin permeation profile.


MATERIALS AND METHODS
Response surface methodology was used to maximize the total phenolic (TP) content of the extract and its antioxidant activity was evaluated by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and respiratory burst methods. An emulsion containing 1% optimized extract (OE) was developed and employed photoacoustic spectroscopy (PAS) for the determination of its skin permeation profile. The morphology of the skin was studied in histological sections stained with hematoxylin-eosin.


RESULTS AND DISCUSSION
The optimum conditions predicted for the major extractive efficiency of the phenolics with 100% ethanol led extraction time 101 h and plant:solvent proportion 1:13.5 (w/v). OE presented TP = 724.6 ± 8.2 mg GAE/g extract and scavenging capacity of DPPH (IC50 value = 11.43 ± 0.14 µg/mL) and ABTS radicals (IC50 value = 35.42 ± 0.48 µg/mL). The production of ROS by neutrophils after stimulation with phorbol miristate acetate was lower when the OE was present in the reaction medium, endorsing its high antioxidant capacity. The data obtained by PAS indicated that the OE present in the emulsion has permeated and was distributed in the whole skin. No histopathological alterations were observed in the histological analysis.


CONCLUSION
The formulation developed is a promising tool for skin care and could prevent the damage caused by oxidative stress.
['Tunin|Luana Magri|LM|', 'Borghi|Fernanda Belincanta|FB|', 'Nogueira|Ana Claudia|AC|', 'Higachi|Luciana|L|', 'Barbosa|Décio Sabbatini|DS|', 'Baesso|Mauro Luciano|ML|', 'Hernandes|Luzmarina|L|', 'Diniz|Andréa|A|', 'Truiti|Maria da Conceição Torrado|Mda C|']
D000279:Administration, Cutaneous D000818:Animals D000975:Antioxidants D004655:Emulsions D006801:Humans D008297:Male D019660:Malvaceae D009504:Neutrophils D010539:Permeability D010636:Phenols D061088:Photoacoustic Techniques D008517:Phytotherapy D035261:Plant Components, Aerial D010936:Plant Extracts D010946:Plants, Medicinal D017208:Rats, Wistar D017382:Reactive Oxygen Species D016897:Respiratory Burst D012867:Skin D012869:Skin Absorption D013057:Spectrum Analysis D013997:Time Factors
oxidative stress skin care Central composite design skin penetration