RESUMO
Melanoma is the most aggressive type of skin cancer, with few therapeutic alternatives following metastasis development. In recent years, drug delivery-associated nanotechnology has shown promising targeted results with diminished adverse effects compared to conventional treatments. This study aimed to (1) examine the effects of plant-derived α-arbutin, a natural compound and (2) compare these findings with bioactively developed liposomes containing α-arbutin utilizing the B16-F10 murine melanoma cell line as a model. Liposomes were obtained through reversed-phase evaporation by applying a spray dryer to assess their stability. The following biologic assays were measured cytotoxicity/antiproliferative (MTT, Neutral Red, and dsDNA PicoGreen). In addition, the levels of melanin and purinergic enzymes were also measured. The production of reactive oxygen species (ROS) and nitric oxide (NO) was determined as a measure of oxidative state. Treatment with nano-liposome containing alpha-arbutin induced a significant 68.4% cytotoxicity, similar to the positive control, in the B16-F10 murine melanoma cell line at 72 hr. Further, arbutin and liposomes containing alpha-arbutin increased levels of ROS and nitrite formation at 72 hr at the highest concentration (100 and 300 µg/ml) of treatments. Arbutin and liposomes containing alpha-arbutin reduced melanin levels at all tested concentrations. In addition, arbutin and alpha-arbutin containing liposomes lowered nucleotides (AMP, ADP, and ATP) and nucleoside (adenosine) levels in melanoma cells. Evidence suggests that α-arbutin containing liposome can be considered as an alternative immunosuppressive agent stimulated in melanoma treatment.
Assuntos
Arbutina , Lipossomos , Melanoma Experimental , Animais , Camundongos , Arbutina/farmacologia , Linhagem Celular Tumoral , Melanoma Experimental/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismoRESUMO
Carbon-like materials from pyrolysis (<500°C) of agricultural leftovers (rice husks, eucalyptus sawdust and peach stones) were submitted to steam activation and the expected adsorbent properties evaluated by means of a chemical method (methylene blue) and physically characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and surface area (BET). Batch experiments were carried out to check the pH effect on the adsorption of methylene blue, by evaluating the respective equilibrium isotherms (Langmuir, Freundlich and Temkin). The steam-activated biocarbons showed significant adsorbent capacity, which increased along with pH. The best performance was achieved by the activated biocarbon from peach stones, which showed adsorptive properties similar to activated carbon market. The suitable detoxification efficiency of untreated broths with activated biocarbon, and an increase in the required fermentability, supports the potential use of these adsorptive bioproducts from agricultural leftovers. The profitable use of agricultural waste materials is actually a welcome strategy for consolidating the biorefinery concept as well as ensuring planetary sustainability. PRACTITIONER POINTS: Use of biomass residues for detoxification of fermentable broth. The activated biocarbons showed significant adsorbent capacity similar to activated carbon market. The results revealed the potential of the biomass residues as a promising source within bio-refineries.