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The hypoglycemic effect of methanol leaf extracts from Cecropia obtusifolia and C. peltata was evaluated in healthy mice. A significant decrease (p < 0.05) in plasma glucose levels was recorded 2 and 4 h after a single oral administration of methanol extracts (1 g/kg). This effect was correlated with the chlorogenic acid contents in both species; C. peltata, containing 19.84 +/- 1.64 mg of chlorogenic acid/g of dried leaves produced the highest decrease (D(alpha 2,60) = 20.18, p < 0.05) of plasma glucose levels (52.8%). The extracts of C. obtusifolia from Tabasco and Veracruz, showed similar hypoglycemic effects (33.3% and 35.7%, respectively) and chlorogenic acid contents (Tukey(0.05) = 1.8859) (13.3 +/- 3.2 mg/g and 13.1 +/- 1.6 mg/g, respectively). The hypoglycemic effect produced by different doses (0.1, 0.25, 0.50, 0.75 and 1 g/kg body wt, p.o.) of C. peltata showed a lineal relationship with chlorogenic acid content, reaching an ED(50) = 0.540 g/kg body wt for extract, and an ED(50) = 10.8 mg/kg body wt for chlorogenic acid. These results suggest that C. peltata is a better hypoglycemic agent than C. obtusifolia, and it could be considered for developing a phytomedicinal product to carry out clinical trials.

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The aerial parts of Ageratina pichinchensis are used in Mexican traditional medicine for the treatment of skin wounds. Recently, it was demonstrated that the aqueous extract of this plant reduced the time required to cicatrize a wound induced in the rat. The same extract showed a capability to induce overgrowth in normal fetal lung cells (MRC-5). The objective of the present study was isolating and identifying the active compounds in A. pichinchensis that are capable of inducing cellular overgrowth, as well as performing a preliminary evaluation of their anti-inflammatory and toxic effects. By means of bioguided chemical separation of an aqueous extract of A. pichinchensis, the most active compound capable of inducing cellular overgrowth was identified as 7-O-(β-D-glucopyranosyl)-galactin. In vivo inflammation induced with carrageenan in mice was significantly reduced by the aqueous extract of A. pichinchensis, reaching a decrease of up to 60.6 %. Acute (2 g/kg) and subchronic (1 g/kg for 28 days) oral administration of the aqueous extract of this plant did not affect hepatic function (through alanine aminotransferase and aspartate aminotransferase activity evaluation), while no alterations of the histologic samples of liver and kidney were evidenced.

The antidiabetic properties of Cecropia obtusifolia are attributed to chlorogenic acid (CGA) and isoorientin (ISO) phenolic compounds; both compounds possess hypoglycemic, hypolipidemic, and antioxidant properties. As a potential strategy for an adequate supply of authentic plant raw material, the aim of this study was to establish in vitro conditions for the development of cell suspension cultures that produce these bioactive compounds. Callus cultures of leaf explants from acclimatized tree and in vitro plantlets were set up using different auxin levels; treatments with 2,4-dichlorophenoxyacetic acid (2,4-D) and a-naphthalene acetic acid (NAA) to 8.92 lM with 6-benzylaminopurine (BAP) at 2.22 lM stimulate highest callus production. Seedling cotyledon, hypocotyl, leaf, and stem explants developed calli bearing roots with 2,4-D. With NAA, hypocotyl, cotyledon, and leaf explants developed morphogenic calli; 75% of stem explants formed calli, and the remaining calli developed shoots. Determined CGA concentrations in calli were similar to those detected in the leaves of wild trees, and ISO was not produced. Cell suspension cultures were established from leaf explants friable calli with 8.92 lM 2,4-D in combination with 2.22 lM BAP, employing 4 and 5% inocula in fresh weight; CGA levels were maintained and ISO was produced only at the end of logarithmic growth. On diminishing nitrate content in Murashige and Skoog (MS) medium to 8.0 mM, maximum cell biomasses diminished, CGA production is increased and twice with 16.0 and, instead of CGA production is tripled and quadrupled with 16.0 and 8.0 mM nitrates, respectively, and ISO synthesis was induced earlier and for a longer time period, increasing its levels at the end of culture. Two compounds with ultraviolet spectra similar to those of caffeic and ferulic acids were formed. Our results offer a protocol of cell suspension cultures for C. obtusifolia bioactive production and hypoglycemic property conservation.