Essential oil of Pterodon polygalaeflorus Benth attenuates nociception in mice

Essential oils (EO) are volatile liquids responsible for the aroma of plants. Pterodon polygalaeflorus seeds have received widespread use in folk medicine for the treatment of inflammatory diseases. For this reason and because Pterodon polygalaeflorus seeds have great EO content, which is frequently pharmacologically active, the present study aimed to evaluate the antinociceptive effect of EO from Pterodon polygalaeflorus (EOPPgfl) and its acute toxic effects. The EEOPPgfl sample, which was extracted by steam distillation of the seeds, had a yield of 2.4% of the seeds weight and had, as major constituents, beta-elemene (48.19%), trans-caryophyllene (19.51%), and epi-bicyclosesquiphellandrene (12.24%). The EOPPgfl sample showed mild acute toxicity and its calculated median lethal dose (LD₅₀) was 3.38 g/kg. EOPPgfl (20–60 mg/kg) showed antinociceptive activity as evidenced by several tests and inhibited writhing induced by acetic acid. The maximum effect was obtained with the 30 mg/kg dose and at 60 min after its administration. EOPPgfl also decreased formalin-induced nociception, as verified by the inhibition of the first and second phase of the formalin test. At 30 mg/kg, EOPPgfl also decreased thermally stimulated nociception. Nociception may be related to inflammatory and antiedematogenic activity and at doses ranging 10–100 mg/kg, EOPPgfl blocked dextran- and carrageenan-induced edema. The results demonstrated that EOPPgfl presented, at doses approximately 100 times smaller than LD₅₀, an antinociceptive effect that probably was due to anti-inflammatory activities.

Flavonoid-enriched fraction from Echinodorus macrophyllus aqueous extract exhibits high in-vitro and in-vivo anti-inflammatory activity

Objectives

Echinodorus macrophyllus (Kunth) Micheli (Alismataceae) is popularly used as an infusion to treat inflammatory diseases. This work fractionated the aqueous extract of E. macrophyllus (AEEm) to improve its anti-inflammatory effects.

Methods

Aqueous extract of E. macrophyllus was fractionated by Sephadex LH-20 and analysed by HPLC-DAD. Anti-inflammatory action was evaluated, in vivo, by air pouch model (total leucocyte, protein and leukotriene B4 (LTB4)), and, in vitro, by neutrophil migration (transwell assay) and its Mac1 expression (flow cytometry), and RAW 264.7 nitric oxide (NO) production (Griess reaction).

Key findings

Fr20 reduced total leucocyte at 2.5 mg/kg (29.7%) while ethanolic extract of E. macrophyllus (EAEm) increased it (94.0%). Fr20 showed higher (P < 0.05) inhibition (89.8%) of LTB4 in exudate than EAEm (75.0%). Fr20 and EAEm decreased exudate protein and inflammatory infiltrate in pouch tissues, in-vitro neutrophil migration, and NO production. Otherwise, Fr40 did not reduce leucocytes and exudate protein (until 50 mg/kg) nor tissue inflammation, and increased in-vitro NO production. The inhibition of neutrophil migration by EAEm, but not Fr20, was dependent on reduced Mac-1 expression.

Conclusions

The fractionation of AEEm provided a more potent anti-inflammatory fraction containing flavonoids (Fr20) that reduces the migration of neutrophils and LTB4 release, probably contributing to its mechanism of action.

Anti-Colon Cancer Effects of 6-Shogaol Through G2/M Cell Cycle Arrest by p53/p21-cdc2/cdc25A Crosstalk

Chemopreventive agents can be identified from botanicals. Recently, there has been strong support for the potential of 6-shogaol, a natural compound from dietary ginger (Zingiber officinale), in cancer chemoprevention. However, whether 6-shogaol inhibits the growth of colorectal tumors in vivo remains unknown, and the underlying anticancer mechanisms have not been well characterized. In this work, we observed that 6-shogaol (15 mg/kg) significantly inhibited colorectal tumor growth in a xenograft mouse model. We show that 6-shogaol inhibited HCT-116 and SW-480 cell proliferation with IC50 of 7.5 and 10 μM, respectively. Growth of HCT-116 cells was arrested at the G2/M phase of the cell cycle, primarily mediated by the up-regulation of p53, the CDK inhibitor p21(waf1/cip1) and GADD45α, and by the down-regulation of cdc2 and cdc25A. Using p53(-/-) and p53(+/+) HCT-116 cells, we confirmed that p53/p21 was the main pathway that contributed to the G2/M cell cycle arrest by 6-shogaol. 6-Shogaol induced apoptosis, mainly through the mitochondrial pathway, and the bcl-2 family might act as a key regulator. Our results demonstrated that 6-shogaol induces cancer cell death by inducing G2/M cell cycle arrest and apoptosis. 6-Shogaol could be an active natural product in colon cancer chemoprevention.