Antidepressant-like effect of riparin I and riparin II against CUMS-induced neuroinflammation via astrocytes and microglia modulation in mice.

Depression is a common mood disorder and many patients do not respond to conventional pharmacotherapy or experience a variety of adverse effects. This work proposed that riparin I (RIP I) and riparin II (RIP II) present neuroprotective effects through modulation of astrocytes and microglia, resulting in the reversal of depressive-like behaviors. To verify our hypothesis and clarify the pathways underlying the effect of RIP I and RIP II on neuroinflammation, we used the chronic unpredictable mild stress (CUMS) depression model in mice. Male Swiss mice were exposed to stressors for 28 days. From 15 th to the 22 nd day, the animals received RIP I or RIP II (50 mg/kg) or fluoxetine (FLU, 10 mg/kg) or vehicle, by gavage. On the 29 th day, behavioral tests were performed. Expressions of microglia (ionized calcium-binding adaptor molecule-1 - Iba-1) and astrocyte (glial fibrillary acidic protein - GFAP) markers and levels of cytokines tumor necrosis factor alfa (TNF-α) and interleukin 1 beta (IL-1ß) were measured in the hippocampus. CUMS induced depressive-like behaviors and cognitive impairment, high TNF-α and IL-1ß levels, decreased GFAP, and increased Iba-1 expressions. RIP I and RIP II reversed these alterations. These results contribute to the understanding the mechanisms underlying the antidepressant effect of RIP I and RIP II, which may be related to neuroinflammatory suppression.

Evaluation of naphthoquinones identified the acetylated isolapachol as a potent and selective antiplasmodium agent.

This study reports on the design, synthesis and antiparasitic activity of three new semi-synthetic naphthoquinones structurally related to the naturally-occurring lapachol and lapachone. Of the compounds tested, 3-(3-methylbut-1-en-1-yl)-1,4-dioxo-1,4-dihydronaphthalen-2-yl acetate (1) was the most active against Plasmodium falciparum among both natural and semi-synthetic naphthoquinones, showing potent and selective activity. Compound 1 was able to reduce the in vitro parasite burden, in vitro parasite cell cycle, as well as the blood parasitemia in Plasmodium berghei-infected mice. More importantly, infection reduction under compound 1-treatment was achieved without exhibiting mouse genotoxicity. Regarding the molecular mechanism of action, this compound inhibited the hemozoin crystal formation in P. falciparum treated cells, and this was further confirmed by observing that it inhibits the ß-hematin polymerization process similarly to chloroquine. Interestingly, this compound did not affect either mitochondria structure or cause DNA fragmentation in parasite treated cells. In conclusion, we identified a semi-synthetic antimalarial naphthoquinone closely related to isolapachol, which had stronger antimalarial activity than lapachol.

3,6-Dimethoxy-6″,6″-Dimethyl-(7,8,2″,3″)-Chromeneflavone, a Flavonoid Isolated from Lonchocarpus Araripensis Benth. (Fabaceae), Reduces Nociceptive Behaviour in Mice.

Lonchocarpus araripensis Benth. is largely distributed in the northeast region of Brazil. It is popularly known as 'sucupira'. Recent studies have shown that some species of Lonchocarpus have interesting pharmacological activities. In this study, we evaluated the antinociceptive effect of a flavone isolated from L. araripensis. The chemical examination resulted in the isolation of 3,6-dimethoxy-6″,6″-dimethyl-(7,8,2″,3″)-chromeneflavone (DDF). The structure of the compound was established by spectral analysis. Antinociceptive activity of DDF was evaluated by measuring nociception by acetic acid, formalin and hot plate tests. The rota rod test was used to evaluate motor coordination. The results demonstrated that DDF was able to prevent acetic-acid-writhing-induced nociception (p < 0.001) in mice. Furthermore, DDF produced a significant reduction of the nociceptive behaviour at the early and late phases of paw licking in the formalin test. Also, DDF produced an inhibition of the nociceptive behaviour during a hot-plate test. No alteration in motor coordination was observed. These results confirm the hypothesis that DDF reduces the nociceptive behaviour in mice, probably through central mechanisms, but without compromising the motor coordination of animals.

Warifteine, a bisbenzylisoquinoline alkaloid, induces relaxation by activating potassium channels in vascular myocytes.

The present study used functional and electrophysiological approaches to investigate the mechanisms by which warifteine, a bisbenzylisoquinoline alkaloid isolated from Cissampelos sympodialis Eichl., causes vasorelaxation of the rat thoracic aorta. Warifteine (1 pmol/L-10 µmol/L) induced concentration-dependent relaxation (pD(2) = 9.40 ± 0.06; n = 5) of endothelium-intact aortic rings precontracted with noradrenaline (10-100 µmol/L). The relaxation effects were not attenuated by removal of the endothelium. Warifteine also induced the relaxation of prostaglandin F(2α) (1-10 mmol/L)-precontracted rings (pD(2) = 9.2 ± 0.2; n = 8). In contrast, the relaxant activity of warifteine was nearly abolished in high K(+) (80 mmol/L)-precontracted aortic rings. In preparations incubated with 20 mmol/L KCl or with the K(+) channel blockers tetraethylammonium (1, 3 and 5 mmol/L), iberiotoxin (20 nmol/L), 4-aminopyridine (1 mmol/L) or glibenclamide (10 µmol/L), the vasorelaxant activity of warifteine was markedly reduced. However, BaCl(2) (1 mmol/L) had no effect on the relaxant effects of warifteine. In vascular myocytes, warifteine (100 nmol/L) significantly increased whole-cell K(+) currents (at 70 mV). Under nominally Ca(2+) -free conditions, warifteine did not reduce extracellular Ca(2+) -induced contractions in rings precontracted with high K(+) or noradrenaline (100 µmol/L). Together, the results of the present study indicate that warifteine induces potent concentration-dependent relaxation in the rat aorta via an endothelium-independent mechanism that involves the activation of K(+) channels.

Neolignan Licarin A presents effect against Leishmania (Leishmania) major associated with immunomodulation in vitro.

Leishmaniasis' treatment is based mostly on pentavalent antimonials or amphotericin B long-term administration, expensive drugs associated with severe side effects. Considering these aforementioned, the search for alternative effective and safe leishmaniasis treatments is a necessity. This work evaluated a neolignan, licarin A anti-leishmanial activity chemically synthesized by our study group. It was observed that licarin A effectively inhibited Leishmania (Leishmania) major promastigotes (IC50 of 9.59 ± 0.94 µg/mL) growth, by inducing in these parasites genomic DNA fragmentation in a typical death pattern by apoptosis. Additionally, the neolignan proved to be even more active against intracellular amastigotes of the parasite (EC50 of 4.71 ± 0.29 µg/mL), and significantly more effective than meglumine antimoniate (EC50 of 216.2 ± 76.7 µg/mL) used as reference drug. The antiamastigote activity is associated with an immunomodulatory activity, since treatment with licarin A of the infected macrophages induced a decrease in the interleukin (IL)-6 and IL-10 production. This study demonstrates for the first time the antileishmanial activity of licarin A and suggests that the compound may be a promising in the development of a new leishmanicidal agent.

Synthesis, structure-activity relationships (SAR) and in silico studies of coumarin derivatives with antifungal activity.

The increased incidence of opportunistic fungal infections, associated with greater resistance to the antifungal drugs currently in use has highlighted the need for new solutions. In this study twenty four coumarin derivatives were screened in vitro for antifungal activity against strains of Aspergillus. Some of the compounds exhibited significant antifungal activity with MICs values ranging between 16 and 32 µg/mL. The structure-activity relationships (SAR) study demonstrated that O-substitutions are essential for antifungal activity. It also showed that the presence of a short aliphatic chain and/or electron withdrawing groups (NO(2) and/or acetate) favor activity. These findings were confirmed using density functional theory (DFT), when calculating the LUMO density. In Principal Component Analysis (PCA), two significant principal components (PCs) explained more than 60% of the total variance. The best Partial Least Squares Regression (PLS) model showed an r2 of 0.86 and q2(cv) of 0.64 corroborating the SAR observations as well as demonstrating a greater probe N1 interaction for active compounds. Descriptors generated by TIP correlogram demonstrated the importance of the molecular shape for antifungal activity.

Morphological and physiological changes in Leishmania promastigotes induced by yangambin, a lignan obtained from Ocotea duckei.

We have previously demonstrated that yangambin, a lignan obtained from Ocotea duckei Vattimo (Lauraceae), shows antileishmanial activity against promastigote forms of Leishmania chagasi and Leishmania amazonensis. The aim of this study was to determine the in vitro effects of yangambin against these parasites using electron and confocal microscopy. L. chagasi and L. amazonensis promastigotes were incubated respectively with 50 µg/mL and 65 µg/mL of pure yangambin and stained with acridine orange. Treated-parasites showed significant alterations in fluorescence emission pattern and cell morphology when compared with control cells, including the appearance of abnormal round-shaped cells, loss of cell motility, nuclear pyknosis, cytoplasm acidification and increased number of acidic vesicular organelles (AVOs), suggesting important physiological changes. Ultrastructural analysis of treated-promatigotes showed characteristics of cell death by apoptosis as well as by autophagy. The presence of parasites exhibiting multiples nuclei suggests that yangambin may also affect the microtubule dynamic in both Leishmania species. Taken together our results show that yangambin is a promising agent against Leishmania.

Vasorelaxation, induced by Dictyota pulchella (Dictyotaceae), a brown alga, is mediated via inhibition of calcium influx in rats.

This study aimed to investigate the cardiovascular effects elicited by Dictyota pulchella, a brown alga, using in vivo and in vitro approaches. In normotensive conscious rats, CH(2)Cl(2)/MeOH Extract (CME, 5, 10, 20 and 40 mg/kg) from Dictyota pulchella produced dose-dependent hypotension (-4 ± 1; -8 ± 2; -53 ± 8 and -63 ± 3 mmHg) and bradycardia (-8 ± 6; -17 ± 11; -257 ± 36 and -285 ± 27 b.p.m.). In addition, CME and Hexane/EtOAc Phase (HEP) (0.01-300 µg/mL) from Dictyota pulchella induced a concentration-dependent relaxation in phenylephrine (Phe, 1 µM)-pre-contracted mesenteric artery rings. The vasorelaxant effect was not modified by the removal of the vascular endothelium or pre-incubation with KCl (20 mM), tetraethylammonium (TEA, 3 mM) or tromboxane A(2) agonist U-46619 (100 nM). Furthermore, CME and HEP reversed CaCl(2)-induced vascular contractions. These results suggest that both CME and HEP act on the voltage-operated calcium channel in order to produce vasorelaxation. In addition, CME induced vasodilatation after the vessels have been pre-contracted with L-type Ca(2+) channel agonist (Bay K 8644, 200 nM). Taken together, our data show that CME induces hypotension and bradycardia in vivo and that both CME and HEP induce endothelium-independent vasodilatation in vitro that seems to involve the inhibition of the Ca(2+) influx through blockade of voltage-operated calcium channels.

Tropane alkaloids from Erythroxylum caatingae Plowman.

Three tropane alkaloids, 1-3, were isolated from Erythroxylum caatingae, i.e., 6ß-benzoyloxy-3α-[(4-hydroxy-3,5-dimethoxybenzoyl)oxy]tropane (1), a new tropane alkaloid, along with the known alkaloids 3α,6ß-dibenzoyloxytropane (2) and 6ß-benzoyloxy-3α-[(3,4,5-trimethoxybenzoyl)oxy]tropane (catuabine B; 3). Their structures were determined by 2D- ((1) H and (13) C) NMR. By LC/ESI-MS/MS analysis of the fractions of alkaloids 1-3, it was possible to detect five more alkaloids, 4-8, two of these, 4 and 8, possibly being new natural products. X-Ray crystallography of the chloride derivate of 1, i.e., 6ß-benzoyloxy-3α-(4-hydroxy-3,5-dimethoxybenzoyloxy)tropane hydrochloride (1a) confirmed the structure of 1. Cytotoxicity was tested against the cell lines HEp-2, NCI-H292, and KB for the MeOH extract and alkaloid 3, and antitumor activity was tested against Sarcoma 180 only for the MeOH extract.

Bioactivities from marine algae of the genus Gracilaria.

Seaweeds are an important source of bioactive metabolites for the pharmaceutical industry in drug development. Many of these compounds are used to treat diseases like cancer, acquired immune-deficiency syndrome (AIDS), inflammation, pain, arthritis, as well as viral, bacterial, and fungal infections. This paper offers a survey of the literature for Gracilaria algae extracts with biological activity, and identifies avenues for future research. Nineteen species of this genus that were tested for antibacterial, antiviral, antifungal, antihypertensive, cytotoxic, spermicidal, embriotoxic, and anti-inflammatory activities are cited from the 121 references consulted.

Inhibitory effect of the alkaloid warifteine purified from Cissampelos sympodialis on B lymphocyte function in vitro and in vivo.

The aqueous fraction of the ethanolic extract of the plant CISSAMPELOS SYMPODIALIS (Menispermaceae) was previously described to inhibit B cell function. The alkaloid warifteine is the major component of this extract. In the present study we investigated the effect of warifteine on B lymphocyte function and characterized its mechanism of action. Purified splenic murine B lymphocytes were stimulated with either Toll-like receptor (TLR) ligands (LPS, Pam (3)Cys and CpG oligodeoxynucleotides) or anti-IgM antibody and the effect of warifteine on B cell response was investigated. Warifteine inhibited both the proliferative response and immunoglobulin (Ig) secretion induced by these stimuli. Kinetics studies demonstrated that warifteine blocked B cell function even when added after 24 h of a 72 h culture. The inhibitory effect of warifteine was also detected in cultures activated by phorbol myristate acetate and calcium ionophore. We investigated the signal transduction pathways blocked by warifteine. It did not modify the total protein phosphorylation pattern in LPS and anti-IgM-stimulated B cell cultures. It did, however, decrease the rise in intracellular calcium levels, the phosphorylation of the mitogen activated protein kinase (MAPK) ERK and the intranuclear levels of the transcription factor NFkappaB. Warifteine also induced an increase in cAMP and its effect on LPS-induced proliferation was mimicked by the control adenyl cyclase activator forskolin. IN VIVO Ig production induced by the TI-2 antigen TNP-ficoll was also inhibited by warifteine. Taking together, our data suggest that warifteine is a potent inhibitor of B cell response both IN VITRO and IN VIVO and that this effect may be due to the induction of increased intracellular cAMP levels, suggesting that this substance may be useful as a modulator of B cell function.

Tropane alkaloids from Erythroxylum genus: distribution and compilation of 13C-NMR spectral data.

Erythroxylum, the most representative genus of the Erythroxylaceae family, presents tropane alkaloids as main constituents. This class of compounds greatly contributes to the chemotaxonomic characterization of plants of this genus, and it has important medical uses and shows toxic effects. This review describes 186 tropane alkaloids in the 35 species of Erythroxylum distributed worldwide. In addition, a compilation of their (13)C-NMR spectral data is presented.

Biological and physical approaches on the role of piplartine (piperlongumine) in cancer.

Chronic inflammation provides a favorable microenvironment for tumorigenesis, which opens opportunities for targeting cancer development and progression. Piplartine (PL) is a biologically active alkaloid from long peppers that exhibits anti-inflammatory and antitumor activity. In the present study, we investigated the physical and chemical interactions of PL with anti-inflammatory compounds and their effects on cell proliferation and migration and on the gene expression of inflammatory mediators. Molecular docking data and physicochemical analysis suggested that PL shows potential interactions with a peptide of annexin A1 (ANXA1), an endogenous anti-inflammatory mediator with therapeutic potential in cancer. Treatment of neoplastic cells with PL alone or with annexin A1 mimic peptide reduced cell proliferation and viability and modulated the expression of MCP-1 chemokine, IL-8 cytokine and genes involved in inflammatory processes. The results also suggested an inhibitory effect of PL on tubulin expression. In addition, PL apparently had no influence on cell migration and invasion at the concentration tested. Considering the role of inflammation in the context of promoting tumor initiation, the present study shows the potential of piplartine as a therapeutic immunomodulator for cancer prevention and progression.

Betulinic Acid Exerts Cytoprotective Activity on Zika Virus-Infected Neural Progenitor Cells.

Zika virus (ZIKV), a member of the Flaviviridae family, was brought into the spotlight due to its widespread and increased pathogenicity, including Guillain-Barré syndrome and microcephaly. Neural progenitor cells (NPCs), which are multipotent cells capable of differentiating into the major neural phenotypes, are very susceptible to ZIKV infection. Given the complications of ZIKV infection and potential harm to public health, effective treatment options are urgently needed. Betulinic acid (BA), an abundant terpenoid of the lupane group, displays several biological activities, including neuroprotective effects. Here we demonstrate that Sox2+ NPCs, which are highly susceptible to ZIKV when compared to their neuronal counterparts, are protected against ZIKV-induced cell death when treated with BA. Similarly, the population of Sox2+ and Casp3+ NPCs found in ZIKV-infected cerebral organoids was significantly higher in the presence of BA than in untreated controls. Moreover, well-preserved structures were found in BA-treated organoids in contrast to ZIKV-infected controls. Bioinformatics analysis indicated Akt pathway activation by BA treatment. This was confirmed by phosphorylated Akt analysis, both in BA-treated NPCs and brain organoids, as shown by immunoblotting and immunofluorescence analyses, respectively. Taken together, these data suggest a neuroprotective role of BA in ZIKV-infected NPCs.

(S)-reticuline induces vasorelaxation through the blockade of L-type Ca(2+) channels.

In Brazil, various species of the genus Ocotea are used in folk medicine for treating several diseases. The chemical characterization of this plant showed the presence of alkaloids belonging to the benzyltetrahydroisoquinoline family, the major component of which is (S)-reticuline. The present study investigated whether (S)-reticuline exerts an inhibitory effect on smooth muscle L-type Ca(2+) channels. Tension measurements and patch clamp techniques were utilized to study the effects of (S)-reticuline. Whole-cell Ca(2+) currents were measured using the A7r5 smooth muscle cell line. (S)-reticuline antagonized CaCl(2)- and KCl-induced contractions and elicited vasorelaxation. It also reduced the voltage-activated peak amplitude of I (Ca,L) in a concentration-dependent manner. (S)-reticuline did not change the characteristics of current density vs. voltage relationship. (S)-reticuline shifted leftwards the steady-state inactivation curve of I (Ca,L). The application of dibutyryl cyclic adenosine monophosphate to the cell decreased the amplitude of Ca(2+) currents. In cells pretreated with forskolin, an adenylate cyclase activator, the addition of (S)-reticuline caused further inhibition of the Ca(2+) currents suggesting an additive effect. The results obtained show that (S)-reticuline elicits vasorelaxation probably due to the blockade of the L-type voltage-dependent Ca(2+) current in rat aorta. The reported effect may contribute to the potential cardioprotective efficacy of (S)-reticuline.

Phenylethanoid and lignan glycosides from polar extracts of Lantana, a genus of verbenaceous plants widely used in traditional herbal therapies.

Many references to the use of Lantana spp. can be found in the ethnopharmacological literature from locations around the globe. This study was focused on examining constituents from the polar extracts of Lantana radula Sw. and Lantana canescens Kunth, for which no prior chemical investigations had been reported. A new phenylethanoid glycoside, raduloside, and lignan glycoside, radulignan, were identified along with the known compounds alyssonoside, arenarioside, calceolarioside E, isonuomioside, samioside, and verbascoside.

Ecdysteroids from Vitex species: distribution and compilation of their 13C-NMR spectral data.

Iridoids and ecdysteroids are found in some genera of the family Verbenaceae. In such cases, they are used as chemotaxonomic markers for the difficult task of taxonomic identification by using morphological characteristics of plants belonging to this family. The present work describes the distribution of ecdysteroids in plants from the genus Vitex from a review of previous work on seventeen Vitex species. In addition, (13)C-NMR data of the main ecdysteroids found in this genus are described. This study attempted to summarize previous research on ecdysteroids distribution in Vitex species with the addition of (13)C-NMR analysis to further refine the characterization of these compounds in the Verbenaceae family.

Structure and spasmolytic activity relationships of monoterpene analogues found in many aromatic plants.

Rotundifolone, a monoterpene isolated from the essential oil of the leaves of Mentha x villosa, is a constituent of several essential oils and known to have spasmolytic activity. The present study aimed to investigate the correlation between structure and spasmolytic activity of rotundifolone and its analogues in ileum isolated from guinea-pig. Five of the seven tested analogues were found to have a spasmolytic effect more potent than rotundifolone itself, except for pulegone and (+)-limonene. The comparison between rotundifolone and limonene oxide showed that the absence of the keto group did not decrease the relaxant effect. Comparison of the spasmolytic activity between rotundifolone and (+)-pulegone showed that the absence of the epoxy group did not decrease the relaxation of the ileum. Carvone epoxide was found to be significantly more potent than rotundifolone. The monoterpene (-)-carvone produced ileum relaxation and was more potent than its enantiomer (+)-carvone. (+)-Limonene and pulegone oxide showed a similar effect. The study showed that the functional groups and their position at the ring of rotundifolone contributed to the relaxation activity of the ileum. The absence of the oxygenated molecular structure is not a critical requirement for the molecule to be bioactive.

Inactivation of Spoilage Yeasts by Mentha spicata L. and M. × villosa Huds. Essential Oils in Cashew, Guava, Mango, and Pineapple Juices.

This study evaluated the efficacy of the essential oil from Mentha spicata L. (MSEO) and M. × villosa Huds. (MVEO) to inactivate Candida albicans, C. tropicalis, Pichia anomala and Saccharomyces cerevisiae in Sabouraud dextrose broth and cashew, guava, mango, and pineapple juices during 72 h of refrigerated storage. The effects of the incorporation of an anti-yeast effective dose of MSEO on some physicochemical and sensory characteristics of juices were evaluated. The incorporation of 3.75 µL/mL MSEO or 15 µL/mL MVEO caused a ≥5-log reductions in counts of C. albicans, P. anomala, and S. cerevisiae in Sabouraud dextrose broth. In cashew and guava juices, 1.875 µL/mL MSEO or 15 µL/mL MVEO caused ≥5-log reductions in counts of P. anomala and S. cerevisiae. In pineapple juice, 3.75 µL/mL MSEO caused ≥5-log reductions in counts of P. anomala and S. cerevisiae; 15 µL/mL MVEO caused ≥5-log reductions in counts of S. cerevisiae in mango juice. The incorporation of 1.875 µL/mL MSEO did not affect the physicochemical parameters of juices and did not induce negative impacts to cause their possible sensory rejection. These results show the potential of MSEO and MVEO, primarily MSEO, to comprise strategies to control spoilage yeasts in fruit juices.

A new coumarin derivative, 4-acetatecoumarin, with antifungal activity and association study against Aspergillus spp.

Fungal infections have become a concern for health professionals, and the emergence of resistant strains has been reported for all known classes of antifungal drugs. Among the fungi causing disease, we highlight those that belong to the genus Aspergillus. For these reasons, the search for new antifungals is important. This study examines the effects of a coumarin derivative, 4-acetatecoumarin (Cou-UMB16) both alone and together with antifungal drugs, and its mode of action against Aspergillus spp. Cou-UMB16 was tested to evaluate its effects on mycelia growth, and germination of Aspergillus spp. fungal conidia. We investigated its possible action on cell walls, on the cell membrane, and also the capacity of this coumarin derivative to enhance the activity of antifungal drugs. Our results suggest that Cou-UMB16 inhibits Aspergillus spp. virulence factors (mycelia growth and germination of conidia) and affects the structure of the fungal cell wall. When applying Cou-UMB16 in combination with azoles, both synergistic and additive effects were observed. This study concludes that Cou-UMB16 inhibits mycelial growth and spore germination, and that the activity is due to its action on the fungal cell wall, and that Cou-UMB16 could act as an antifungal modifier.