Advances in Pharmacological Activities and Chemical Composition of Propolis Produced in Americas

Propolis is a resinous material produced by bees from the selective collection of plant exudates that are subsequently mixed with beeswax and salivary bee secretions. Propolis has been used in folk medicine, and certainly, several studies have validated its biological properties. The chemical composition and pharmacological activities of propolis collected through North (including Central America and Caribbean) and South America have been studied in the last years, and several papers have reported differences and similarities among the analysed geographical samples. Propolis has been classified according to its aspect and plant source; however, the ecological diversity present along the Americas provides a plethora of botanical resins. Herein, we summarize and discuss most of the studies performed at present on this profitable product for apiculture, attempting to compare the bioactivity, phytochemical diversity and botanical sources of honeybee propolis produced in Americas

Apoptotic induction by pinobanksin and some of its ester derivatives from Sonoran propolis in a B-cell lymphoma cell line

Propolis is a resinous substance produced by honeybees (Apis mellifera) from the selective collection of exudates and bud secretions from several plants. In previous works, we reported the antiproliferative activity of Sonoran propolis (SP) on cancer cells; in addition we suggested the induction of apoptosis after treatment with SP due to the presence of morphological changes and a characteristic DNA fragmentation pattern. Herein, in this study we demonstrated that the antiproliferative effect of SP is induced through apoptosis in a B-cell lymphoma cancer cell line, M12.C3.F6, by an annexin V-FITC/Propidium iodide double labeling. This apoptotic effect of SP resulted to be mediated by modulations in the loss of mitochondrial membrane potential (ΔΨm) and through activation of caspases signaling pathway (3, 8 and 9). Afterward, in order to characterize the chemical constituents of SP that induce apoptosis in cancer cells, an HPLC-PDA-ESI-MS/MS method followed by a preparative isolation procedure and NMR spectroscopy analysis have been used. Eighteen flavonoids, commonly described in propolis from temperate regions, were characterized. Chrysin, pinocembrin, pinobanksin and its ester derivatives are the main constituents of SP and some of them have never been reported in SP. In addition, two esters of pinobanksin (8 and 13) are described by first time in propolis samples in general. The antiproliferative activity on M12.C3.F6 cells through apoptosis induction was exhibited by pinobanksin (4), pinobanksin-3-O-propanoate (14), pinobanksin-3-O-butyrate (16), pinobanksin-3-O-pentanoate (17), and the already reported galangin (11), chrysin (9) and CAPE. To our knowledge this is the first report of bioactivity of pinobanksin and some of its ester derivatives as apoptosis inducers. Further studies are needed to advance in the understanding of the molecular basis of apoptosis induction by SP and its constituents, as well as the structure–activity relationship of them

Modulatory effects of propolis samples from Latin America (Brazil, Cuba and Mexico) on cytokine production by human monocytes

Propolis has been used in folk medicine in different regions of the world including Latin America. Propolis is a resinous mixture of substances collected by honey bees from several botanical sources, and its composition contains a rich chemical variety, depending on the geographical area and plant sources. Our aim was to compare the modulatory effect of propolis samples from three different countries of Latin America (Brazil, Cuba and Mexico) on pro- and anti-inflammatory cytokine production (tumor necrosis factor (TNF)-α and interleukin (IL)-10, respectively) by human monocytes. Cells were incubated with propolis for 18 h at 37°C. Cell viability was assessed by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide method, and cytokine production was determined by ELISA. All samples did not affect monocyte viability. Brazilian propolis stimulated both TNF-α and IL-10 production by monocytes. Cuban propolis stimulated TNF-α and inhibited IL-10 production, while Mexican sample exerted the opposite effect, inhibiting TNF-α and stimulating IL-10 production. The major compounds found in Brazilian, Cuban and Mexican propolis samples were artepillin C, isoflavonoids and pinocembrin, respectively. Brazilian, Cuban and Mexican propolis contained different components that may exert pro- and anti-inflammatory activity depending on concentration, what may provide a novel approach to the development of immunomodulatory drugs containing propolis

Arabinoxylan-Based Particles: In Vitro Antioxidant Capacity and Cytotoxicity on a Human Colon Cell Line

Background and objectives: Arabinoxylans (AX) can gel and exhibit antioxidant capacity. Previous studies have demonstrated the potential application of AX microspheres as colon-targeted drug carriers. However, the cytotoxicity of AX gels has not been investigated so far. Therefore, the aim of the present study was to prepare AX-based particles (AXM) by coaxial electrospraying method and to investigate their antioxidant potential and cytotoxicity on human colon cells. Materials and Methods: The gelation of AX was studied by monitoring the storage (G′) and loss (G′′) moduli. The morphology of AXM was evaluated using optical and scanning electron microscopy (SEM). The in vitro antioxidant activity of AX before and after gelation was measured using the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods. In addition, the effect of AX and AXM on the proliferation of human colon cells (CCD 841 CoN) was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: The final G′ and G′′ values for AX gels were 293 and 0.31 Pa, respectively. AXM presented spherical shape and rough surface with a three-dimensional and porous network. The swelling ratio and mesh size of AXM were 35 g water/g AX and 27 nm, respectively. Gelation decreased the antioxidant activity of AX by 61–64 %. AX and AXM did not affect proliferation or show any toxic effect on the normal human colon cell line CCD 841 CoN. Conclusion: The results indicate that AXM could be promising biocompatible materials with antioxidant activity

Plant origin authentication of Sonoran Desert propolis: an antiproliferative propolis from a semi-arid region

The main chemical composition of Sonoran propolis (SP), as well as its antiproliferative activity on cancer cells through apoptosis induction, has been reported. The chemical constitution of SP remained qualitatively similar throughout the year, whereas the antiproliferative effect on cancer cells exhibited significant differences amongst seasonal samples. The main goal of this study was to provide phytochemical and pharmacological evidence for the botanical source of SP and its antiproliferative constituents. A chemical comparative analysis of SP and plant resins of species found in the surrounding areas of the beehives was carried out by HPLC-UV-DAD, as well as by 1H NMR experiments. The antiproliferative activity on cancerous (M12.C3.F6, HeLa, A549, PC-3) and normal cell lines (L-929; ARPE-19) was assessed through MTT assays. Here, the main polyphenolic profile of SP resulted to be qualitatively similar to Populus fremontii resins (PFR). However, the antiproliferative activity of PFR on cancer cells did not consistently match that exhibited by SP throughout the year. Additionally, SP induced morphological modifications on treated cells characterised by elongation, similar to those induced by colchicine, and different to those observed with PFR treatment. These results suggest that P. fremontii is the main botanical source of SP along the year. Nevertheless, the antiproliferative constituents of SP that induce that characteristic morphological elongation on treated cells are not obtained from PFR. Moreover, the presence of kaempferol-3-methyl-ether in SP could point Ambrosia ambrosioides as a secondary plant source. In conclusion, SP is a bioactive poplar-type propolis from semi-arid zones, in which chemical compounds derived from other semi-arid plant sources than poplar contribute to its antiproliferative activity