Poly-є-caprolactone based formulations for drug delivery and tissue engineering: A review

Reactive oxygen species (ROS) are a class of highly reactive molecules derived from the metabolism of oxygen. ROS, including superoxide radicals, hydroxyl radical and hydrogen peroxide molecules are often generated as by products of biological reactions or from exogenous factors. There is extensive evidence to involve ROS in the development of degenerative diseases. Evidence suggests that compounds especially from natural sources are capable of providing protection against free radicals. This has attracted a great deal of research interest in natural antioxidants. It is necessary to Screen out medicinal plants for their antioxidant potential. Therefore an attempt has been made to review different in vitro models for estimating antioxidant properties of natural products from medicinal plants. All the models are described along with the different standards that can be used for estimation. In the end, a large number of plants showing in vitro antioxidant activity are listed but in vivostudies are lacking. 

	 

	Key words: Antioxidant assay, in vitro models, antioxidant medicinal plants.

In vitro models for antioxidant activity evaluation and some medicinal plants possessing antioxidant properties: An overview

http://www.pnei-it.com/1/upload/bioactive_compounds_from_natural_resources_against_skin_aging.pdf

Bioactive compounds from natural resources against skin aging.

A review of microencapsulation methods for food antioxidants: Principles, advantages, drawbacks and applications.

Skin whitening products are commercially available for cosmetic purposes in order to obtain a lighter skin appearance. They are also utilized for clinical treatment of pigmentary disorders such as melasma or postinflammatory hyperpigmentation. Whitening agents act at various levels of melanin production in the skin. Many of them are known as competitive inhibitors of tyrosinase, the key enzyme in melanogenesis. Others inhibit the maturation of this enzyme or the transport of pigment granules (melanosomes) from melanocytes to surrounding keratinocytes. In this review we present an overview of (natural) whitening products that may decrease skin pigmentation by their interference with the pigmentary processes.

https://www.mdpi.com/1422-0067/10/12/5326/pdf?view=inline

The Hunt for Natural Skin Whitening Agents

To develop a new whitening agent for cosmetics from natural products, Angelica dahurica was selected for its inhibitory effect on melanogenesis in B16 melanoma cells. From the mechanism study, it was clarified that the ethanolic extracts of this plant showed the suppression of tyrosinase synthesis but no inhibition of tyrosinase activity. In order to find the active constituents from this plant, the ethanol extracts were chromatographed repeatedly with silica gel. Two coumarin compounds were isolated from A. dahurica. Their structures were identified by physicochemical and spectral data such as UV, IR, NMR, and MS. It was shown that the active substance was isoimperatorin (10-[(3-methyl-2-butenyl)oxy]-7H-furo[3,2-g][1] benzopyran-7-one) and imperatorin (9-[(3-methyl-2-butenyl)oxy]-7H-furo[3,2-g][1] benzopyran-7-one). They significantly inhibited tyrosinase synthesis in B16 melanoma cells. To elucidate the action mechanism of the active compounds of A. dahurica, we investigated the changes in the mRNA level of tyrosinase using the RT-PCR technique. As a result, the mRNA level of tyrosinase was markedly reduced by active compounds of A. dahurica. From these results, we suggest that these extracts might be useful as a new whitening agent in cosmetics, but the in vitro findings must be verified in in vivo skin-lightening studies.

New cosmetic agents for skin whitening from Angelica dahurica

Antioxidative and acute antiinflammatory effects of Torreya grandis.

Rosmarinic acid (RA) has a number of interesting biological activities, e.g. anti-viral, anti-bacterial, anti-inflammatory and antioxidant. The antioxidant activity of RA is stronger than that of vitamin E. Despite its strong antioxidant activity, it was limited to use in cosmetics because of the low water solubility, discolouration and chemical instability. The purpose of this study was to prepare RA-loaded polycaprolactone (PCL) microspheres using emulsion solvent evaporation method and characterize them with different surfactants used in the formation process. Finally, long-term stability of RA was evaluated in the cosmetic formulation. As a result, PCL microspheres were found to be spherical in shape, with zwitterionic surfactant-PCL particles being the smallest size distribution and highest entrapment efficiency of RA. Emulsions containing RA-loaded PCL microspheres showed a better long-term stability of the RA compared with those containing only RA. These results suggest that RA may be stably and efficiently encapsulated into polycaprolactone microspheres.

Microencapsulation of rosmarinic acid using polycaprolactone and various surfactants.

Antioxidative and acute anti-inflammatory effects of Campsis grandiflora flower.

Flavonoids and related compounds exhibit a wide range of useful pharmacological properties but present challenges related to their stability and solubility in commonly available solvents. In this study, polymethyl methacrylate (PMMA) microcapsules were prepared using a novel polyol-in-oil-in-polyol (P/O/P) emulsion solvent evaporation method as a means of stabilizing the flavonoids, using quercetin as a model flavonoid drug. The morphology of the microcapsules was evaluated using a scanning electron microscope, revealing a spherical shape with a smooth surface. The cross-section image of the PMMA microcapsules prepared with an amphiphilic polymer in the inner polyol phase showed that the microcapsule was filled with several submicron microspheres. The mean diameter varied from 1.03+/-0.12 microm to 2.39+/-0.42 microm, and the encapsulation efficiency ranged from 12.7% to 26.9%. When free quercetin was stored at 42 degrees C, the residual quercetin content gradually decreased to 18% over 28 days as a result of oxidation. However, when encapsulated in PMMA microcapsules with an amphiphilic polymer in the inner polyol phase, the residual quercetin content decreased to just 82%. In-vitro release studies indicated a sustained release pattern throughout the 36-h study. The release kinetics of the microcapsules with an amphiphilic polymer followed a diffusion-controlled mechanism and the microcapsule without amphiphilic polymer followed an anomalous diffusion behaviour. This study suggests that the novel P/O/P emulsion solvent evaporation method can be applied to the encapsulation of flavonoids.

Preparation and characterization of quercetin-loaded polymethyl methacrylate microcapsules using a polyol-in-oil-in-polyol emulsion solvent evaporation method.

Hyeong-Bae Pyo

Papers

New cosmetic agents for skin whitening from Angelica dahurica

Antioxidative and acute antiinflammatory effects of Torreya grandis.

Microencapsulation of rosmarinic acid using polycaprolactone and various surfactants.

Antioxidative and acute anti-inflammatory effects of Campsis grandiflora flower.

Preparation and characterization of quercetin-loaded polymethyl methacrylate microcapsules using a polyol-in-oil-in-polyol emulsion solvent evaporation method.