Polyphenol Characterization of the Aqueous Extract from Hubertia ambavilla L. (Asteraceae) by HPLC-DAD-ESI-MSn and Assessment of Its Antioxidant Activity.

In this work, phytochemical components, and the antioxidant properties of an aqueous extract obtained from a medicinal plant Hubertia ambavilla, endemic to Reunion Island, were investigated. A total of 37 compounds were detected and identified by high-performance liquid chromatography (UHPLC) using a photodiode-array detector (DAD) coupled with electrospray ionization/mass spectrometry (ESI/MSn ). From calibration curves, the quantity of secondary metabolites in the aqueous extract was calculated. The mean amounts of phenols, flavonoids, and condensed tannins found were 158.38±1.20 mg GAE/g DE, 60.41±1.65 mg AE/g DE and 23.77±1.36 mg CE/g DE, respectively. The in vitro antioxidant properties of the Hubertia ambavilla plant were measured using three methods: DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging and ferric reducing antioxidant power. The results showed that crude aqueous extract of H. ambavilla had effective radical scavenging and reducing power in comparison with standard antioxidant compounds. In conclusion, the crude extract herein presented offers a natural alternative biosource of antioxidants with potential applications in food and health industries.

Docetaxel gold complex nanoflowers: A chemo-biological evaluation for their use as nanotherapeutics.

Docetaxel (DTX) is an anticancer treatment widely used in the clinic for the treatment of various human malignancies, including Non-Small-Cell Lung Cancer (NSCLC). Its low water solubility and systemic toxicity, however, negatively impact the clinical application of such drug. In order to improve DTX solubility in biological fluids and decrease its adverse effects in patients, the scientific community is currently focusing on developing drug delivery systems where DTX is the payload. In this context, the present study aims at presenting a step forward in the development of platforms based on gold complexes for multifunctional approaches (theragnostic tools) and stimuli-responsive therapies. Tetrachloroauric acid (HAuCl4) were complexed with the antitumor drug and dicarboxylic acid-terminated polyethylene-glycol (PEG) to form the nanometric complex named DTX-Au-PEG. Following reduction with sodium borohydride (NaBH4), the DTX-Au-PEG complex formed hybrid-metal nanoparticles (DTX IN PEG-AuNPs), where DTX was protected in the gold core embedded within the polymer chains. To achieve therapeutic targeting, DTX-Au-PEG complex and DTX IN PEG-AuNPs were chemical combined with the human anti-EGFR polyclonal antibody, which recognizes the hERG1 channel aberrantly expressed on the membrane of human lung cancer cells. The active targeting was demonstrated by various analytical techniques (Raman and UV-vis spectroscopies); whereas, in vitro experiments on tissue-mimetic, three-dimensional (3D) tumoroids grown at the Air-Liquid Interface (ALI) demonstrated that DTX encapsulation within a gold core strongly influenced the drug efficacy, with a significant increase of the DTX therapeutic index when AuNPs were specifically targeted against EGFR. Collectively, our study demonstrated that a drug delivery system based on Au (III)-DTX complexes constitutes an encouraging chemical approach to build Au (III) complexes into real chemotherapeutic drugs for cancer treatment.

Proof of concept of plasmonic thermal destruction of surface cancers by gold nanoparticles obtained by green chemistry.

A greener approach for the design of surface plasmon resonant gold nanoparticles has been obtained with a hydrosoluble fraction of an endemic asteraceae medicinal plant. This medicinal plant is originated from Indian Ocean and demonstrates its bioreducing activity in the design of stable green nanomedicine in aqueous media. This article describes the preclinical assessment of the efficacy of these novel nanocandidates on murine model by intratumoral and intravenous injections. It definitely demonstrates two key points in the treatment of cancer: 1) optimization of the tumor microenvironment targeting by specific ligands for a limited damage on healthy tissue, 2) the need to screen the specific irradiation dose (time, power) taking into account the type of tumor.