Valorization of Arnica montana Wastes after Extraction of the Ethanol Tincture: Application in Polymer-Based Matrices

Abstract

The waste solids remaining after the ethanolic extraction of arnica were proposed as raw material for the recovery of the remaining phenolic fraction. Greener processes based on intensification extraction, with microwave (MHG) and ultrasound (UAE) assistance and pressurized hot water extraction under subcritical conditions (AH), were studied. The entire process provided approximately 28% of phenolics for the sequence when MHG was used, 22% in the sequence where AH was employed, and the extracts showed up to 60% the ABTS radical scavenging capacity of Trolox. However, the cytotoxic effects on the cell growth of tumoral cells were only moderate. Therefore, considering a possible external topical application, extracts containing selected arnica extracts were further used to develop polymer-based gelled matrices formulated with either chitosan or polyvinyl alcohol. Rheological testing indicated that all proposed matrices exhibited relatively high mechanical features, even better than those determined with matrices prepared with their counterpart commercial arnica tinctures. Overall, the shear-thinning behavior of gelled matrices loaded with arnica extracts obtained by MHG or AH stages was enhanced compared to those containing ethanolic extracts, whereas the viscoelastic features became smoother for polymeric matrices incorporated with arnica extracts recovered at the highest MHG irradiation powers or at the highest set point temperatures of AH treatments.

Nitrogen Fertilization and Solvents as Factors Modifying the Antioxidant and Anticancer Potential of Arnica montana L. Flower Head Extracts

“…Antioxidants derived from medicinal plants have been increasingly investigated for their various health benefits [ 67 ]. The antioxidant potential of arnica flower heads has been studied with the use of numerous chemical assays and their very high antioxidant activity has been demonstrated [ 19 , 42 , 68 ]. The present study confirmed this finding.…”

“…Žitek et al [ 24 ] reported apoptotic activity of A. montana flower head extracts against melanoma WM-266–4 cells. In turn, Flórez-Fernández et al [ 68 ] showed cytotoxic properties against colorectal cancer HCT-116 and pancreatic adenocarcinoma PSN1 cells. It was clearly shown in the present study that NF determined the quality of the studied extracts and, in consequence, their anticancer activity in the case of all the analyzed cell lines.…”

Stages of Development and Solvents Determine the Anticancer Potential of Mountain Arnica (Arnica montana L.) Inflorescence Extracts

“…can be determined via the propagule type during introduction [9], soil quality [7,9], soil and foliar fertilization [3,18], morphological features, and plant organs [23,24], and may be responsible for the biological activity of plant material [23][24][25][26][27]. There are reports available in the literature on the apoptotic activity of mountain arnica extracts against melanoma WM-266-4 cells [4] and cytotoxic properties against colorectal cancer HCT-116 cells [43]. The present study has shown that the stage of plant development, the solvent type, and their interactions can modify the chemical composition of extracts and their antitumor activity against human carcinoma (HeLa), colon (HT29), and colon metastatic SW620 cell lines.…”