Anti-Helicobacter pylori Activity of Artemisia ludoviciana subsp. mexicana and Two of Its Bioactive Components, Estafiatin and Eupatilin.

Artemisia ludoviciana subsp. mexicana has been traditionally used for the treatment of digestive ailments such as gastritis, whose main etiological agent is Helicobacter pylori. In a previous screening study, the aqueous extract exhibited a good in vitro anti-H. pylori activity. With the aim of determining the efficacy of this species as a treatment for H. pylori related diseases and finding bioactive compounds, its aqueous extract was subjected to solvent partitioning and the fractions obtained were tested for their in vitro anti-H. pylori effect, as well as for their in vivo gastroprotective and anti-inflammatory activities. The aqueous extract showed a MIC = 250 µg/mL. No acute toxicity was induced in mice. A gastroprotection of 69.8 ± 3.8%, as well as anti-inflammatory effects of 47.6 ± 12.4% and 38.8 ± 10.2% (by oral and topical administration, respectively), were attained. Estafiatin and eupatilin were isolated and exhibited anti-H. pylori activity with MBCs of 15.6 and 31.2 µg/mL, respectively. The finding that A. ludoviciana aqueous extract has significant anti-H. pylori, gastroprotective and anti-inflammatory activities is a relevant contribution to the ethnopharmacological knowledge of this species. This work is the first report about the in vivo gastroprotective activity of A. ludoviciana and the anti-H. pylori activity of eupatilin and estafiatin.

Bioactive Dimeric Acylphloroglucinols from the Mexican Fern Elaphoglossum paleaceum.

Two new prenylated acylphloroglucinols, paleacenins A (1) and B (2), were isolated from the rhizome n-hexane and chloroform extracts of the fern Elaphoglossum paleaceum. Both compounds were found to possess the same geranylated filicinic acid moiety but have a different phloroglucinol ring substituent. Their structures were determined using 1H and 13C NMR spectroscopic, HRMS, and ECD analysis. The plant extracts and purified compounds were assayed for inhibition of monoamine oxidase (MAO) activity, and the n-hexane and chloroform extracts displayed 25.0% and 26.5% inhibition of MAO-A, respectively, as well as 42.5% and 23.7% inhibition of MAO-B, respectively. Compounds 1 and 2 exhibited IC50 values of 31.0 (1.3) µM for MAO-A and 4.7 (4.4) µM for MAO-B. Paleacenin A (1) showed a higher selective index (SI) toward MAO-B (SIMAO-B/MAO-A 0.1), and paleacenin B (2) exhibited selectivity to MAO-A (SIMAO-B/MAO-A, 3.5). The extracts showed cytotoxicity against a panel of prostate, cervix, breast, and colon cancer cell lines (IC50 values between 1.7 and 10.6 µg/mL); the pure compounds were more active against the prostate, cervix, and colon cancer cell lines. Paleacenins A (1) and B (2), with IC50 values of 46 and 41 µM, respectively, inhibited nitric oxide production by the RAW264.7 murine macrophage model.