Mexican propolis: a source of antioxidants and anti-inflammatory compounds, and isolation of a novel chalcone and ε-caprolactone derivative

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The propolis produced by bees are used in alternative medicine for treating inflammation, and infections, presumably due to its antioxidant properties. In this context, five propolis fromMéxico were investigated to determine their inhibitory lipid peroxidation properties. The ethyl acetate extract from a red propolis from Chiapas State (4-EAEP) was the most potent (IC50 = 1.42±0.07 μg/mL) in the TBARS assay, and selected for further studies. This extract afforded two new compounds, epoxypinocembrin chalcone (6), and an ε-caprolactone derivative (10), as well as pinostrobin (1), izalpinin (2), cinnamic acid (3), pinocembrin (4), kaempherol (5), 3,3-dimethylallyl caffeate in mixture with isopent-3-enyl caffeate (7a + 7b), 3,4-dimethoxycinnamic acid (8), rhamnetin (9) and caffeic acid (11). The HPLC profile, anti-mycobacterial, and antioxidant properties of this extract was also determined. Most of the isolated compounds were also tested by inhibition of reactive oxygen species (ROS) in challenged mouse bone marrow-derived mast cells (BMMCs), and DPPH. Their anti-inflammatory activity was evaluated by TPA, and MPO (myeloperoxidase) activity by ear edema test in mice. The most potent compounds were 7a + 7b in the TBARS assay (IC50 = 0.49±0.06 μM), and 2 which restored the ROS baseline (3.5 μM). Our results indicate that 4-EAEP has anti-oxidant, and anti-inflammatory properties due to its active compounds, suggesting it has anti-allergy and anti-asthma potential. eng

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Human activities have changed and shaped landscape conditions of the Yucatán Peninsula for more than 4000 years. Several paleoecological studies showed the oldest pollen record of corn-based agriculture is from northern Belize, with an estimated age of 3300 BC. Several other studies report maize between 1500 and 3000 BC from northern Guatemala and the Mexican part of the Yucatán Peninsula. After 3500 cal yr BP several paleoecological studies showed a marked tendency to drier climatic conditions. In pollen records, increased drought is expressed as a reduced presence of fossil arboreal pollen. Pollen records with the presence of Zea mays also show other taxa, which are indicators of disturbance in different vegetation types. eng

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