Effect of Blueberry Supplementation on a Diet-Induced Rat Model of Prediabetes-Focus on Hepatic Lipid Deposition, Endoplasmic Stress Response and Autophagy.

Blueberries, red fruits enriched in polyphenols and fibers, are envisaged as a promising nutraceutical intervention in a plethora of metabolic diseases. Prediabetes, an intermediate state between normal glucose tolerance and type 2 diabetes, fuels the development of complications, including hepatic steatosis. In previous work, we have demonstrated that blueberry juice (BJ) supplementation benefits glycemic control and lipid profile, which was accompanied by an amelioration of hepatic mitochondrial bioenergetics. The purpose of this study is to clarify the impact of long-term BJ nutraceutical intervention on cellular mechanisms that govern hepatic lipid homeostasis, namely autophagy and endoplasmic reticulum (ER) stress, in a rat model of prediabetes. Two groups of male Wistar rats, 8-weeks old, were fed a prediabetes-inducing high-fat diet (HFD) and one group was fed a control diet (CD). From the timepoint where the prediabetic phenotype was achieved (week 16) until the end of the study (week 24), one of the HFD-fed groups was daily orally supplemented with 25 g/kg body weight (BW) of BJ (HFD + BJ). BW, caloric intake, glucose tolerance and insulin sensitivity were monitored throughout the study. The serum and hepatic lipid contents were quantified. Liver and interscapular brown and epidydimal white adipose tissue depots (iBAT and eWAT) were collected for histological analysis and to assess thermogenesis, ER stress and autophagy markers. The gut microbiota composition and the short-chain fatty acids (SCFAs) content were determined in colon fecal samples. BJ supplementation positively impacted glycemic control but was unable to prevent obesity and adiposity. BJ-treated animals presented a reduction in fecal SCFAs, increased markers of arrested iBAT thermogenesis and energy expenditure, together with an aggravation of HFD-induced lipotoxicity and hepatic steatosis, which were accompanied by the inhibition of autophagy and ER stress responses in the liver. In conclusion, despite the improvement of glucose tolerance, BJ supplementation promoted a major impact on lipid management mechanisms at liver and AT levels in prediabetic animals, which might affect disease course.

Synergism Between Essential Oils and Evaluation of Their Activities with a Focus on Malassezia furfur Control.

Seborrheic dermatitis is a chronic inflammatory disease caused by Malassezia yeast species that affects the regions of the body where the sebaceous glands are present. The combined use of different essential oils (EOs) can increase their spectrum of action. Thus, the present study aimed to evaluate the action of EOs alone and in combination with each other on M. furfur, in planktonic and biofilm form, and their anti-inflammatory and mutagenic potential, in addition to the effects on the viability of cells lines. Of the 40 evaluated EOs, 22 showed activity against M. furfur at 0.5 - 2.0 mg/mL concentrations. Among the most active species, a blend of essential oils (BEOs) composed of Cymbopogon martini (Roxb.) Will. Watson (MIC = 0.5 mg/mL) and Mentha × piperita L. (MIC = 1.0 mg/mL) was selected, which showed a synergistic effect against yeast when evaluated through the checkerboard assay. The fungicidal activity was maintained by the addition of anti-inflammatory oil from Varronia curassavica Jacq. to BEOs. The BEOs also showed activity in the inhibition of biofilm formation and in the eradication of the biofilm formed by M. furfur, being superior to the action of fluconazole. Furthermore, it did not show mutagenic potential and did not interfere with the cell viability of both evaluated cell lines (HaCaT and BMDMs). TNF-α levels were reduced only by C. martini; however, this property was maintained when evaluating BEOs. BEOs had no effect on IL-8 levels. Thus, the BEOs may be indicated for alternative treatments against seborrheic dermatitis.

Preliminary Assays towards Melanoma Cells Using Phototherapy with Gold-Based Nanomaterials.

Cancer like melanoma is a complex disease, for which standard therapies have significant adverse side effects that in most cases are ineffective and highly unspecific. Thus, a new paradigm has come with the need of achieving alternative (less invasive) and effective therapies. In this work, biocompatible gold nanoparticles (GNPs) coated with hyaluronic acid and oleic acid were prepared and characterized in terms of size, morphology and cytotoxicity in the presence of Saccharomyces cerevisiae, and two cell lines, the keratinocytes (healthy skin cells, HaCat) and the melanoma cells (B16F10). Results showed that these GNPs absorb within the near-infrared region (750-1400 nm), in the optical therapeutic window (from 650 to 1300 nm), in contrast to other commercial gold nanoparticles, which enables light to penetrate into deep skin layers. A laser emitting in this region was applied and its effect also analyzed. The coated GNPs showed a spherical morphology with a mean size of 297 nm without cytotoxic effects towards yeast and tested cell lines. Nevertheless, after laser irradiation, a reduction of 20% in B16F10 cell line viability was observed. In summary, this work appears to be a promising strategy for the treatment of non-metastatic melanoma or other superficial tumors.

Probing deep tissues with laser-induced thermotherapy using near-infrared light.

Optically tunable gold nanoparticles have been widely used in research with near-infrared light as a means to enhance laser-induced thermal therapy since it capitalizes on nanoparticles' plasmonic heating properties. There have been several studies published on numerical models replicating this therapy in such conditions. However, there are several limitations on some of the models which can render the model unfaithful to therapy simulations. In this paper, two techniques of simulating laser-induced thermal therapy with a high-absorbing localized region of interest inside a phantom are compared. To validate these models, we conducted an experiment of an agar-agar phantom with an inclusion reproducing it with both models. The phantom was optically characterized by absorption and total attenuation. The first model is based on the macroperspective solution of the radiative transfer equation given by the diffusion equation, which is then coupled with the Pennes bioheat equation to obtain the temperature. The second is a Monte Carlo model that considers a stochastic solution of the same equation and is also considered as input to the Pennes bioheat transfer equation which is then computed. The Monte Carlo is in good agreement with the experimental data having an average percentage difference of 4.5% and a correlation factor of 0.98, while the diffusion method comparison with experimental data is 61% and 0.95 respectively. The optical characterization of the phantom and its inclusion were also validated indirectly since the Monte Carlo, which used those parameters, was also validated. While knowing the temperature in all points inside a body during photothermal therapy is important, one has to be mindful of the model which fits the conditions and properties. There are several reasons to justify the discrepancy of the diffusion method: low-scattering conditions, absorption, and reduced scattering are comparable. The error bars that are normally associated when characterizing an optical phantom can justify also a part of that uncertainty. For low-size tumors in depth, one may have to increase the light dosage in photothermal therapies to have a more effective treatment.

Bioproduction of gold nanoparticles for photothermal therapy.

BACKGROUND: Photothermal response of plasmonic nanomaterials can be utilized for a number of therapeutic applications such as the ablation of solid tumors. METHODS & RESULTS: Gold nanoparticles were prepared using different methods. After optimization, we applied an aqueous plant extract as the reducing and capping agent of gold and maximized the near-infrared absorption (650-900 nm). Resultant nanoparticles showed good biocompatibility when tested in vitro in human keratinocytes and yeast Saccharomyces cerevisiae. Gold nanoparticles were easily activated by controlled temperature with an ultrasonic water bath and application of a pulsed laser. CONCLUSION: These gold nanoparticles can be synthesized with reproducibility, modified with seemingly limitless chemical functional groups, with adequate controlled optical properties for laser phototherapy of tumors and targeted drug delivery.

Gut Bacteria Products Prevent AKI Induced by Ischemia-Reperfusion.

Short-chain fatty acids (SCFAs) are fermentation end products produced by the intestinal microbiota and have anti-inflammatory and histone deacetylase-inhibiting properties. Recently, a dual relationship between the intestine and kidneys has been unraveled. Therefore, we evaluated the role of SCFA in an AKI model in which the inflammatory process has a detrimental role. We observed that therapy with the three main SCFAs (acetate, propionate, and butyrate) improved renal dysfunction caused by injury. This protection was associated with low levels of local and systemic inflammation, oxidative cellular stress, cell infiltration/activation, and apoptosis. However, it was also associated with an increase in autophagy. Moreover, SCFAs inhibited histone deacetylase activity and modulated the expression levels of enzymes involved in chromatin modification. In vitro analyses showed that SCFAs modulated the inflammatory process, decreasing the maturation of dendritic cells and inhibiting the capacity of these cells to induce CD4(+) and CD8(+) T cell proliferation. Furthermore, SCFAs ameliorated the effects of hypoxia in kidney epithelial cells by improving mitochondrial biogenesis. Notably, mice treated with acetate-producing bacteria also had better outcomes after AKI. Thus, we demonstrate that SCFAs improve organ function and viability after an injury through modulation of the inflammatory process, most likely via epigenetic modification.

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon.

Artemisinin is the active antimalarial compound obtained from the leaves of Artemisia annua L. Artemisinin, and its semi-synthetic derivatives, are the main drugs used to treat multi-drug-resistant Plasmodium falciparum (one of the human malaria parasite species). The in vitro susceptibility of P. falciparum K1 and 3d7 strains and field isolates from the state of Amazonas, Brazil, to A. annua infusions (5 g dry leaves in 1 L of boiling water) and the drug standards chloroquine, quinine and artemisinin were evaluated. The A. annua used was cultivated in three Amazon ecosystems (várzea, terra preta de índio and terra firme) and in the city of Paulínia, state of São Paulo, Brazil. Artemisinin levels in the A. annua leaves used were 0.90-1.13% (m/m). The concentration of artemisinin in the infusions was 40-46 mg/L. Field P. falciparum isolates were resistant to chloroquine and sensitive to quinine and artemisinin. The average 50% inhibition concentration values for A. annua infusions against field isolates were 0.11-0.14 µL/mL (these infusions exhibited artemisinin concentrations of 4.7-5.6 ng/mL) and were active in vitro against P. falciparum due to their artemisinin concentration. No synergistic effect was observed for artemisinin in the infusions.

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

Artemisinin is the active antimalarial compound obtained from the leaves of Artemisia annua L. Artemisinin, and its semi-synthetic derivatives, are the main drugs used to treat multi-drug-resistant Plasmodium falciparum (one of the human malaria parasite species). The in vitro susceptibility of P. falciparum K1 and 3d7 strains and field isolates from the state of Amazonas, Brazil, to A. annua infusions (5 g dry leaves in 1 L of boiling water) and the drug standards chloroquine, quinine and artemisinin were evaluated. The A. annua used was cultivated in three Amazon ecosystems (várzea, terra preta de índio and terra firme) and in the city of Paulínia, state of São Paulo, Brazil. Artemisinin levels in the A. annua leaves used were 0.90-1.13% (m/m). The concentration of artemisinin in the infusions was 40-46 mg/L. Field P. falciparum isolates were resistant to chloroquine and sensitive to quinine and artemisinin. The average 50% inhibition concentration values for A. annua infusions against field isolates were 0.11-0.14 μL/mL (these infusions exhibited artemisinin concentrations of 4.7-5.6 ng/mL) and were active in vitro against P. falciparum due to their artemisinin concentration. No synergistic effect was observed for artemisinin in the infusions.

In vivo and in vitro antimalarial activity of 4-nerolidylcatechol.

4-Nerolidylcatechol (4-NC) isolated from Piper peltatum L. (Piperaceae) was evaluated for in vitro antiplasmodial activity against Plasmodium falciparum (cultures of both standard CQR (K1) and CQS (3D7) strains and two Amazonian field isolates) and for in vivo antimalarial activity using the Plasmodium berghei-murine model. 4-NC exhibits significant in vitro and moderate in vivo antiplasmodial activity. 4-NC administered orally and subcutaneously at doses of 200, 400 and 600 mg/kg/day suppressed the growth of P. berghei by up to 63% after four daily treatments (days 1-4). Also, 4-NC exhibited important in vitro antiplasmodial activity against both standard and field P. falciparum strains in which 50% inhibition of parasite growth (IC(50) ) was produced at concentrations of 0.05-2.11 µg/mL and depended upon the parasite strain. Interestingly, healthy (non-infected) mice that received 4-NC orally presented (denatured) blood plasma which exhibited significant in vitro activity against P. falciparum. This is evidence that mouse metabolism allows 4-NC or active metabolites to enter the blood. Further chemical and pharmacological studies are necessary to confirm the potential of 4-NC as a new antimalarial prototype.

Biological activity of neosergeolide and isobrucein B (and two semi-synthetic derivatives) isolated from the Amazonian medicinal plant Picrolemma sprucei (Simaroubaceae).

In the present study, in vitro techniques were used to investigate a range of biological activities of known natural quassinoids isobrucein B (1) and neosergeolide (2), known semi-synthetic derivative 1,12-diacetylisobrucein B (3), and a new semi-synthetic derivative, 12-acetylneosergeolide (4). These compounds were evaluated for general toxicity toward the brine shrimp species Artemia franciscana, cytotoxicity toward human tumour cells, larvicidal activity toward the dengue fever mosquito vector Aedes aegypti, haemolytic activity in mouse erythrocytes and antimalarial activity against the human malaria parasite Plasmodium falciparum. Compounds 1 and 2 exhibited the greatest cytotoxicity against all the tumor cells tested (IC50 = 5-27 microg/L) and against multidrug-resistant P. falciparum K1 strain (IC50 = 1.0-4.0 g/L) and 3 was only cytotoxic toward the leukaemia HL-60 strain (IC50 = 11.8 microg/L). Quassinoids 1 and 2 (LC50 = 3.2-4.4 mg/L) displayed greater lethality than derivative 4 (LC50 = 75.0 mg/L) toward A. aegypti larvae, while derivative 3 was inactive. These results suggest a novel application for these natural quassinoids as larvicides. The toxicity toward A. franciscana could be correlated with the activity in several biological models, a finding that is in agreement with the literature. Importantly, none of the studied compounds exhibited in vitro haemolytic activity, suggesting specificity of the observed cytotoxic effects. This study reveals the biological potential of quassinoids 1 and 2 and to a lesser extent their semi-synthetic derivatives for their in vitro antimalarial and cytotoxic activities.

Biological activity of neosergeolide and isobrucein B (and two semi-synthetic derivatives) isolated from the Amazonian medicinal plant Picrolemma sprucei (Simaroubaceae)

In the present study, in vitro techniques were used to investigate a range of biological activities of known natural quassinoids isobrucein B (1) and neosergeolide (2), known semi-synthetic derivative 1,12-diacetylisobrucein B (3), and a new semi-synthetic derivative, 12-acetylneosergeolide (4). These compounds were evaluated for general toxicity toward the brine shrimp species Artemia franciscana, cytotoxicity toward human tumour cells, larvicidal activity toward the dengue fever mosquito vector Aedes aegypti, haemolytic activity in mouse erythrocytes and antimalarial activity against the human malaria parasite Plasmodium falciparum. Compounds 1 and 2 exhibited the greatest cytotoxicity against all the tumor cells tested (IC50 = 5-27 µg/L) and against multidrug-resistant P. falciparum K1 strain (IC50 = 1.0-4.0 g/L) and 3 was only cytotoxic toward the leukaemia HL-60 strain (IC50 = 11.8 µg/L). Quassinoids 1 and 2 (LC50 = 3.2-4.4 mg/L) displayed greater lethality than derivative 4 (LC50 = 75.0 mg/L) toward A. aegypti larvae, while derivative 3 was inactive. These results suggest a novel application for these natural quassinoids as larvicides. The toxicity toward A. franciscana could be correlated with the activity in several biological models, a finding that is in agreement with the literature. Importantly, none of the studied compounds exhibited in vitro haemolytic activity, suggesting specificity of the observed cytotoxic effects. This study reveals the biological potential of quassinoids 1 and 2 and to a lesser extent their semi-synthetic derivatives for their in vitro antimalarial and cytotoxic activities.

New antimalarial and cytotoxic 4-nerolidylcatechol derivatives.

4-Nerolidylcatechol (1) was isolated from cultivated Pothomorphe peltata root on a multigram scale using straight-forward solvent extraction-column chromatography. New semi-synthetic derivatives of 1 were prepared and tested in vitro against multidrug-resistant Plasmodium falciparum K1 strain. Mono-O-methyl, mono-O-benzyl, O,O-dibenzyl and O,O-dibenzoyl derivatives 2-8 exhibited IC(50) in the 0.67-22.52 microM range. Mono-O-methyl ethers 6 and 7 inhibited the in vitro growth of human tumor cell lines HCT-8 (colon carcinoma), SF-295 (central nervous system), LH-60 (human myeloblastic leukemia) and MDA/MB-435 (melanoma). In general, derivatives 2-8 are more stable to light, air and pH at ambient temperatures than their labile, natural precursor 1. These derivatives provide leads for the development of a novel class of antimalarial drugs with enhanced chemical and pharmacological properties.

In vitro inhibition of Plasmodium falciparum by substances isolated from Amazonian antimalarial plants.

In the present study, a quassinoid, neosergeolide, isolated from the roots and stems of Picrolemma sprucei (Simaroubaceae), the indole alkaloids ellipticine and aspidocarpine, isolated from the bark of Aspidosperma vargasii and A. desmanthum (Apocynaceae), respectively, and 4-nerolidylcatechol, isolated from the roots of Pothomorphe peltata (Piperaceae), all presented significant in vitro inhibition (more active than quinine and chloroquine) of the multi-drug resistant K1 strain of Plasmodium falciparum. Neosergeolide presented activity in the nanomolar range. This is the first report on the antimalarial activity of these known, natural compounds. This is also the first report on the isolation of aspidocarpine from A. desmanthum. These compounds are good candidates for pre-clinical tests as novel lead structures with the aim of finding new antimalarial prototypes and lend support to the traditional use of the plants from which these compounds are derived.

In vitro inhibition of Plasmodium falciparum by substances isolated from Amazonian antimalarial plants

In the present study, a quassinoid, neosergeolide, isolated from the roots and stems of Picrolemma sprucei (Simaroubaceae), the indole alkaloids ellipticine and aspidocarpine, isolated from the bark of Aspidosperma vargasii and A. desmanthum (Apocynaceae), respectively, and 4-nerolidylcatechol, isolated from the roots of Pothomorphe peltata (Piperaceae), all presented significant in vitro inhibition (more active than quinine and chloroquine) of the multi-drug resistant K1 strain of Plasmodium falciparum. Neosergeolide presented activity in the nanomolar range. This is the first report on the antimalarial activity of these known, natural compounds. This is also the first report on the isolation of aspidocarpine from A. desmanthum. These compounds are good candidates for pre-clinical tests as novel lead structures with the aim of finding new antimalarial prototypes and lend support to the traditional use of the plants from which these compounds are derived.