Anti-Inflammatory Potential of Seasonal Sonoran Propolis Extracts and Some of Their Main Constituents.

Biological properties of Sonoran propolis (SP) are influenced by harvest time. Caborca propolis showed cellular protective capacity against reactive oxygen species, which might be implicated in anti-inflammatory effects. However, the anti-inflammatory activity of SP has not been investigated so far. This study investigated the anti-inflammatory activity of previously characterized seasonal SP extracts (SPE) and some of their main constituents (SPC). The anti-inflammatory activity of SPE and SPC was evaluated by measuring nitric oxide (NO) production, protein denaturation inhibition, heat-induced hemolysis inhibition, and hypotonicity-induced hemolysis inhibition. SPE from spring, autumn, and winter showed a higher cytotoxic effect on RAW 264.7 cells (IC50: 26.6 to 30.2 µg/mL) compared with summer extract (IC50: 49.4 µg/mL). SPE from spring reduced the NO secretion to basal levels at the lowest concentration tested (5 µg/mL). SPE inhibited the protein denaturation by 79% to 100%, and autumn showed the highest inhibitory activity. SPE stabilized erythrocyte membrane against heat-induced and hypotonicity-induced hemolysis in a concentration-dependent manner. Results indicate that the flavonoids chrysin, galangin, and pinocembrin could contribute to the anti-inflammatory activity of SPE and that the harvest time influences such a property. This study presents evidence of SPE pharmacological potential and some of their constituents.

Biosynthesis of Silver Nanoparticles Using Seasonal Samples of Sonoran Desert Propolis: Evaluation of Its Antibacterial Activity against Clinical Isolates of Multi-Drug Resistant Bacteria.

Multi-drug resistant (MDR) bacteria have gained importance as a health problem worldwide, and novel antibacterial agents are needed to combat them. Silver nanoparticles (AgNPs) have been studied as a potent antimicrobial agent, capable of countering MDR bacteria; nevertheless, their conventional synthesis methods can produce cytotoxicity and environmental hazards. Biosynthesis of silver nanoparticles has emerged as an alternative to reduce the cytotoxic and environmental problems derived from their chemical synthesis, using natural products as a reducing and stabilizing agent. Sonoran Desert propolis (SP) is a poplar-type propolis rich in polyphenolic compounds with remarkable biological activities, such as being antioxidant, antiproliferative, and antimicrobial, and is a suitable candidate for synthesis of AgNPs. In this study, we synthesized AgNPs using SP methanolic extract (SP-AgNPs) and evaluated the reduction capacity of their seasonal samples and main chemical constituents. Their cytotoxicity against mammalian cell lines and antibacterial activity against multi-drug resistant bacteria were assessed. Quercetin and galangin showed the best-reduction capacity for synthesizing AgNPs, as well as the seasonal sample from winter (SPw-AgNPs). The SPw-AgNPs had a mean size of around 16.5 ± 5.3 nm, were stable in different culture media, and the presence of propolis constituents was confirmed by FT-IR and HPLC assays. The SPw-AgNPs were non-cytotoxic to ARPE-19 and HeLa cell lines and presented remarkable antibacterial and antibiofilm activity against multi-drug resistant clinical isolates, with E. coli 34 and ATCC 25922 being the most susceptible (MBC = 25 µg/mL), followed by E. coli 2, 29, 37 and PNG (MBC = 50 µg/mL), and finally E. coli 37 and S. aureus ATCC 25923 (MBC = 100 µg/mL). These results demonstrated the efficacy of SP as a reducing and stabilizing agent for synthesis of AgNPs and their capacity as an antibacterial agent.

Seasonality Modulates the Cellular Antioxidant Activity and Antiproliferative Effect of Sonoran Desert Propolis.

The main chemical composition and pharmacological potential of propolis from arid and semi-arid regions of the Sonoran Desert have been previously reported. Caborca propolis (CP), from an arid zone of the Sonoran Desert, has shown a polyphenolic profile that suggests a mixed plant origin, presenting poplar-type markers, as well as a 6-methoxylated flavonoid, xanthomicrol, characteristic of Asteraceae plants. In addition, CP has shown significant antioxidant properties and antiproliferative activity on cancer cells. In this study, we analyzed the influence of collection time on the chemical constitution, antiproliferative activity and protective capacity of CP against reactive oxygen species (ROS), by using HPLC-UV-diode array detection (DAD) analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-Dimethyltetrazoliumbromide (MTT) and 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assays, as well as cellular antioxidant activity (CAA) assay on murine B-cell lymphoma M12.C3.F6 cells. HPLC-UV-DAD analyses of seasonally collected CP (one-year period) revealed quantitative differences among the most abundant CP constituents: pinocembrin, galangin, chrysin and pinobanksin-3-O-acetate. Though all seasonal samples of CP induced an antiproliferative effect in M12.C3.F6 cells, CP from autumn showed the highest inhibitory activity (IC50: 5.9 ± 0.6 µg/mL). The DPPH assay pointed out that CP collected in autumn presented the highest antioxidant potential (IC50: 58.8 ± 6.7 µg/mL), followed by winter (65.7 ± 12.2 µg/mL) and spring (67.0 ± 7.5 µg/mL); meanwhile, the summer sample showed a lesser antioxidant capacity (IC50: 98.7 ± 2.5 µg/mL). The CAA assay demonstrated that CP induced a significant protective effect against ROS production elicited by H2O2 in M12.C3.F6 cells. Pretreatment of M12.C3.F6 cells with CP from spring and autumn (25 and 50 µg/mL for 1 h) showed the highest reduction in intracellular ROS induced by H2O2 (1 and 5 mM). These results indicate that the antiproliferative effect and cellular antioxidant activity of CP are modulated by quantitative fluctuations in its polyphenolic profile due to its collection time.

Compuestos bioactivos, actividad antioxidante y perfil de ácidos grasos en aceite de semilla de Mezquite (Prosopis spp) / Bioactive Compounds, Antioxidant Activity and Profile of Fatty Acids in Mesquite Seed Oil (Prosopis spp)

La medicina tradicional y estudios realizados a diferentes especies del género Prosopis, del desierto sonorense, indican que es una fuente para la cualificación de compuestos bioactivos, con poder antioxidante y ácidos grasos (linoleico y linolénico) de la semilla. La actividad biológica, es atribuible a alcaloides, flavonoides, terpenos y compuestos fenólicos, para lo cual, se realizó el perfil fitoquímico en los extractos acuoso, etanólico, hexanico y clorofórmico (mediante técnicas colorimétricas), actividad antioxidante (método: 1,1-difenil-2-picrilhidrazil (DPPH)), fenoles totales (utilizando el reactivo de Folin-Ciocalteau) y perfil de ácidos grasos (cromatografía de gases) de la semilla de Prosopis spp. La extracción del aceite se realizó mediante Soxhlet. Se encontraron saponinas en todos los extractos, mientras que, en el etanólico, hexanico y clorofórmico, terpenos y esteroles. En el extracto etanólico se encontraron quinonas y en el acuoso aminoácidos libres. El valor más alto de la actividad antioxidante de EC50 fue de 3.272,41 ± 5,97, para el extracto etanólico, indicando su potencial como antioxidante. El contenido de fenoles totales, fue hexano> etanol > cloroformo> acuoso (81,95; 119,83; 125,18 y 127,57 mg equivalentes de ácido gálico/g de extracto seco). Los ácidos grasos en mayor proporción fueron los insaturados con 71,41 % (ácido linoleico: 42,68 %; oleico: 28.73 %) y ácidos grasos saturados: ácido palmítico (13.42 %) y estérico (4,73 %). Se concluye que este tipo de extractos presentan metabolitos importantes para la dieta, presentan actividad antioxidante y ácidos grasos esenciales para el organismo(AU)

Traditional medicine and studies with different species of the Prosopis genus, from the Sonoran Desert, is a source for the qualification of bioactive compounds, with antioxidant power and fatty acids (linoleic and linolenic) of the seed. The biological activity is attributable to alkaloids, flavonoids, terpenes and phenolic compounds, for which, the phytochemical profile was performed in the aqueous, ethanolic, hexane and chloroform extracts (using colorimetric techniques), antioxidant activity (method: 1,1-diphenyl-2-picrilhidrazil (DPPH)), total phenols (using the Folin-Ciocalteau reagent) and fatty acid profile (gas chromatography). The oil was extracted using Soxhlet. Saponins were found in all extracts, while, in ethanolic, hexanic and chloroform, terpenes and sterols. In the ethanolic extract quinones were found and in the aqueous free amino acids. The highest value of the antioxidant activity of EC50 was 3,272.41 ± 5.97, for the ethanolic extract, indicating its potential as an antioxidant. The total phenolic content was hexane> ethanol> chloroform> aqueous (81.95, 119.83, 125.18 and 127.57 mg equivalent of gallic acid / g of dry extract). The fatty acids in greater proportion were unsaturated with 71.41 % (linoleic acid: 42.68 %; oleic: 28.73 %) and saturated fatty acids: palmitic acid (13.42 %) and stearic (4.73 %). It is concluded that this type of extracts have important metabolites for the diet, have antioxidant activity and essential fatty acids for the body(AU)

Effect of Ultrasound-Treated Arabinoxylans on the Oxidative Stability of Soybean Oil.

Arabinoxylans (AX) are polysaccharides with antioxidant activity and emulsifying properties, which make them an attractive alternative for its potential application as a natural antioxidant in oils. Therefore, this work aimed to investigate the effect of ultrasonic treatment of AX on their antioxidant capacity and its ability to improve the oxidative stability of soybean oil. For this purpose, AX were exposed to ultrasonic treatment at 25% (100 W, AX-1) and 50% (200 W, AX-2) power and an operating frequency of 20 KHz during 15 min, and their macromolecular properties (weight average molecular weight (Mw), polydispersity index and intrinsic viscosity) were evaluated. The antioxidant capacity of AX was determined by the DPPH assay and Rancimat test. Results showed that ultrasonic treatment did not affect the molecular identity of the polysaccharide but modified its Mw distribution. AX-1 showed the highest antioxidant activity (75% inhibition) at 533 µg/mL by the DPPH method compared to AX and AX-2. AX at 0.25% (w/v) and AX-1 at 0.01% (w/v) exerted the highest protective effects on oxidative stability of soybean oil with induction periods of 7.69 and 5.54 h, respectively. The results indicate that AX could be a good alternative for the potential application as a natural antioxidant in oils.