Acai fruits (Euterpe precatoria) are rich in antioxidant anthocyanins. Acai consumption is believed to have many health benefits; however, relevant detailed scientific investigations are limited. The current study aimed to investigate an anthocyanin-rich extract from E. precatoria fruits (AE) with regard to its antioxidant and antiaging properties using the model organism Caenorhabditis elegans. AE can protect the worms against oxidative stress and can ameliorate accumulation of reactive oxygen species in vivo. The expression of stress-response genes, such as sod-3::GFP, was upregulated while hsp-16::GFP was down-regulated after AE treatment. Studies with DAF-16/FOXO mutants indicated that some of the antioxidant effects are mediated by this transcription factor. AE can modulate the development of age-related markers, such as pharyngeal pumping. Despite the apparent antioxidant activity, no lifespan-prolonging effect was observed.

BackgroundCell migration is involved in several pathological processes such as tumor invasion, neoangiogenesis and metastasis. Microtubules are needed in directional migration.MethodsTo investigate the effects of microtubule-binding agents (paclitaxel, vinblastine, colchicine, podophyllotoxin), benzophenanthridine alkaloids (sanguinarine, chelerythrine, chelidonine) and other anti-tumor drugs (homoharringtonine, doxorubicin) on cell migration, we performed the in vitro wound healing assay. The interactions between selected alkaloids and microtubules were studied via U2OS cells expressing microtubule-GFP markers.ResultsThe microtubule-binding natural products paclitaxel, vinblastine, colchicine and podophyllotoxin significantly altered microtubule dynamics in living cells and inhibited cell migration at concentrations below apparent cytotoxicity. The benzophenanthridine alkaloid sanguinarine, chelerythrine and chelidonine which affected microtubules in living cells, did not inhibit cell migration. Homoharringtonine (protein biosynthesis inhibitor) and doxorubicin significantly inhibited cell migration, however, they did not exert obvious effects on microtubules.ConclusionIn this study, we demonstrated that microtubule-binding agents are effective anti-migrating agents; moreover, homoharringtonine and doxorubicin can be referred as anti-migrating agents, but direct microtubule dynamics are not involved in their mode of action. Our study provides evidence that some alkaloids and other microtubule-binding natural products may be interesting candidates for the development of novel agents against metastasis.Electronic supplementary materialThe online version of this article (10.1186/s40360-018-0284-4) contains supplementary material, which is available to authorized users.

There is a need for consumers' education on reliable use of herbal medicines and herbal dietary supplements, in order to improve their awareness of the limits of herbal remedies safety and potential risks of their combination with drugs.

The essential oil compositions of the leaves of three related Myrtaceae species, namely Syzygium aqueum, Syzygium samarangense and Eugenia uniflora, were investigated using GLC/MS and GLC/FID. Altogether, 125 compounds were identified: α-Selinene (13.85%), β-caryophyllene (12.72%) and β-selinene constitute the most abundant constituents in S. aqueum. Germacrene D (21.62%) represents the major compound in S. samarangense whereas in E. uniflora, spathulenol (15.80%) represents the predominant component. Multivariate chemometric analyses were used to discriminate the essential oils using hierarchical cluster analysis (HCA) and principal component analysis (PCA) based on the chromatographic results. The antimicrobial activity of the popularly used E. uniflora essential oil was assessed using broth microdilution method against six Gram-positive, three Gram-negative bacteria and two fungi. The oil showed moderate antimicrobial activity against Bacillus licheniformis exhibiting MIC and MMC of 0.63 mg/ml. The cytotoxic activity of E. uniflora essential oil was investigated against Trypanosoma brucei brucei (T. b. brucei) and MCF-7 cancer cell line using MTT assay. It showed moderate activity against MCF-7 cells with an IC value of 76.40 μg/ml. On the other hand, T. brucei was highly susceptible to E. uniflora essential oil with IC of 11.20 μg/ml, and a selectivity index of 6.82.

Background: Multidrug resistance (MDR) can develop in cancer cells after treatment with anticancer drugs, mainly due to the overexpression of the ATP-binding cassette (ABC) transporters. We analyzed the ability of two pungent-tasting alkaloids—capsaicin and piperine from Capsicum frutescens and Piper nigrum, respectively—to reverse multidrug resistance in the cancer cell lines Caco-2 and CEM/ADR 5000, which overexpress P-glycoprotein (P-gp) and other ABC transporters. Methods: The MTT assay was first used to determine the cytotoxicity of doxorubicin, the alkaloids, and digitonin alone, and then their combinations. Furthermore, rhodamine (Rho) 123 and calcein-AM were used to detect the effects of alkaloids on the activity of P-gp. Results: Capsaicin and piperine synergistically enhanced the cytotoxicity of doxorubicin in Caco-2 and CEM/ADR 5000 cells. Furthermore, capsaicin and piperine increased the intracellular accumulation of the fluorescent P-glycoprotein (P-gp) substrates rhodamine and calcein and inhibited their efflux from the MDR cell lines. Conclusion: Our study has demonstrated that capsaicin and piperine are P-gp substrates and have potential chemosensitizing activity, which might be interesting for the development of novel modulators of multidrug resistance.