Affiliation:
1. Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
2. Department of
Chemistry, University of Florence, Sesto Fiorentino, Florence, Italy
Abstract
Background:
Reactive oxygen species (ROS) production and oxidative stress may be responsible
for the onset of several chronic diseases. Usnic acid (UA) is a natural secondary metabolite of
lichens with several healthful bioactivities, including antioxidant properties. However, UA is a hydrophobic
compound known for its hepatic toxicity. These aspects limit its therapeutic applications. To
overcome these drawbacks and improve the pharmacological use of hydrophobic compounds, nanotechnology
is widely used. Therefore, the incorporation of UA into appropriate nanocarriers could enhance
the bioactivity of UA by increasing its solubility.
Objective:
The aim of this work was to improve the solubility of UA and its bioactivity in the absence
of cytotoxicity.
Methods:
In this study, UA loaded liposomes (UA-LP) were developed. The formulations were chemically
and physically characterized, and an in vitro release study was performed. Free UA and UA-LP
were tested on RAW 264.7 murine macrophages in terms of cytotoxicity, intracellular ROS production,
and NO release in the absence or presence of pro-oxidant LPS stimulus.
Results:
UA-LP showed excellent physical and chemical stability during storage and improved solubility
of UA. UA-LP showed an antioxidant effect in the absence of cytotoxicity compared with free UA
on LPS-exposed macrophages.
Conclusion:
For the first time, liposomal formulation improved the beneficial action of UA in terms of
solubility and antioxidant activity.
Publisher
Bentham Science Publishers Ltd.