Antiprotozoal Sesquiterpene Pyridine Alkaloids from <i>Maytenus ilicifolia</i>

As part of a bioprospecting program aimed at the discovery of antiprotozoal agents from the Brazilian flora, two new sesquiterpene pyridine alkaloids, ilicifoliunines A (<b>1</b>) and B (<b>2</b>), along with the known alkaloids aquifoliunine E-I (<b>3</b>) and mayteine (<b>4</b>), were isolated from the root bark of <i>Maytenus ilicifolia</i>. The structures of <b>1</b> and <b>2</b> were established on the basis of spectroscopic data interpretation. Alkaloid <b>3</b> displayed potent in vitro antiprotozoal activity against <i>Leishmania chagasi</i> and <i>Trypanosoma cruzi</i>, with IC₅₀ values of 1.4 and 41.9 μM, respectively, as well as low cytotoxicity against murine peritoneal macrophages (IC₅₀ of 1.8 mM)

Immunomodulatory effect of crude leaf extract of <i>Piper fuligineum</i> on LPS-stimulated human monocytes.

<p>The results of the controls (medium and ketoprofin, unstimulated and LPS stimulated) were used in the analyses for all extract evaluated. Data are expressed as median ± SEM (pg/mL). ANOVA with Bonferroni post-test; p < 0.05; *: significantly different from placebo treatment, #: significantly different from ketoprofen treatment.</p

Immunomodulatory effect of crude leaf extract of <i>Piper gaudichaudianum</i> on LPS-stimulated human monocytes.

<p>The results of the controls (medium and ketoprofin, unstimulated and LPS stimulated) were used in the analyses for all extract evaluated. Data are expressed as median ± SEM (pg/mL). ANOVA with Bonferroni post-test; p < 0.05; *: significantly different from placebo treatment, #: significantly different from ketoprofen treatment.</p

Immunomodulatory effect of crude leaf extract of <i>Piper arboreum</i> on LPS-stimulated human monocytes.

<p>The results of the controls (medium and ketoprofin, unstimulated and LPS stimulated) were used in the analyses for all extract evaluated. Data are expressed as median ± SEM (pg/mL). ANOVA with Bonferroni post-test; p < 0.05; *: significantly different from placebo treatment, #: significantly different from ketoprofen treatment.</p

Immunomodulatory effect of crude leaf extract of <i>Peperomia obtusifolia</i> on LPS-stimulated human monocytes.

<p>The results of the controls (medium and ketoprofin, unstimulated and LPS stimulated) were used in the analyses for all extract evaluated. Data are expressed as median ± SEM (pg/mL). ANOVA with Bonferroni post-test; p < 0.05; *: significantly different from placebo treatment, #: significantly different from ketoprofen treatment.</p

Immunomodulatory effect of crude leaf extract of <i>Piper umbellata</i> on LPS-stimulated human monocytes.

<p>The results of the controls (medium and ketoprofin, unstimulated and LPS stimulated) were used in the analyses for all extract evaluated. Data are expressed as median ± SEM (pg/mL). ANOVA with Bonferroni post-test; p < 0.05; *: significantly different from placebo treatment, #: significantly different from ketoprofen treatment.</p