Leishmanicidal activity of Morita-Baylis-Hillman adducts.

Leishmaniasis is a neglected disease that affects millions of people, mostly in developing countries. Although this disease has a high impact on public health, there are few drug options to treat the different leishmaniasis forms. Additionally, these current therapies have various adverse effects, including gastrointestinal disturbances, headache, pancreatitis, and hepatotoxicity. Thus, it is essential to develop new drug prototypes to treat leishmaniasis. Accordingly, the present study aimed to evaluate the leishmanicidal activity of Morita-Baylis-Hillman adducts and their O-acetylates, carboxylic acid derivatives, and acid and ester derivatives of 2-methyl-phenylpropanoids against Leishmania chagasi. Initially, we evaluated the cytotoxicity of 16 derivatives (1-16G) against J774A.1 macrophages. Eight derivatives (2G, 4G, 5G, 7G, 9G, 10G, 13G, and 15G) showed no cytotoxicity at up to the maximum concentration tested (100 µM). When evaluated for antileishmanial effect against promastigote forms, 1G, 6G, 8G, 10G, 11G, 13G, 14G, 15G, and 16G displayed significant toxicity compared to the control (0.1% DMSO). Additionally, the compounds 1G, 5G, 7G, 9G, 11G, 13G, 14G, and 16G reduced macrophage infection by amastigotes. Thus, we conclude that these derivatives have antileishmanial effects, particularly 1G, which showed activity against promastigotes and amastigotes, and low toxicity against macrophages.

Pigments from Antarctic bacteria and their biotechnological applications.

Pigments from microorganisms have triggered great interest in the market, mostly by their "natural" appeal, their favorable production conditions, in addition to the potential new chemical structures or naturally overproducing strains. They have been used in: food, feed, dairy, textile, pharmaceutical, and cosmetic industries. The high rate of pigment production in microorganisms recovered from Antarctica in response to selective pressures such as: high UV radiation, low temperatures, and freezing and thawing cycles makes this a unique biome which means that much of its biological heritage cannot be found elsewhere on the planet. This vast arsenal of pigmented molecules has different functions in bacteria and may exhibit different biotechnological activities, such as: extracellular sunscreens, photoprotective function, antimicrobial activity, biodegradability, etc. However, many challenges for the commercial use of these compounds have yet to be overcome, such as: the low stability of natural pigments in cosmetic formulations, the change in color when subjected to pH variations, the low yield and the high costs in their production. This review surveys the different types of natural pigments found in Antarctic bacteria, classifying them according to their chemical structure. Finally, we give an overview of the main pigments that are used commercially today.

Design and Synthesis In Silico Drug-like Prediction and Pharmacological Evaluation of Cyclopolymethylenic Homologous of LASSBio-1514.

Acylhydrazones are still an important framework to the design of new bioactive compounds. As treatment of chronic pain represents a clinical challenge, we decided to modify the structure of LASSBio-1514 (1), previously described as anti-inflammatory and analgesic prototype. Applying the homologation as a strategy for molecular modification, we designed a series of cyclopentyl- (2a-e), cyclobutyl- (3a-e), and cyclopropylacylhydrazones (4a-e) that were synthetized and evaluated in murine models of inflammation and pain. A comparison of their in silico physicochemical and drug-like profile was conducted, as well as their anti-inflammatory and analgesic effect. Compounds 4a (LASSBio-1755) and 4e (LASSBio-1757) displayed excellent in silico drug-like profiles and were identified as new analgesic lead-candidates in acute and chronic model of pain, through oral administration.

Semicarbazone derivatives as promising therapeutic alternatives in leishmaniasis.

In the present study, we investigated the in vitro and in vivo leishmanicidal activity of synthetic compounds, containing a semicarbazone scaffold as a peptide mimetic framework. The leishmanicidal effect against amastigotes of Leishmania amazonensis was also evaluated at concentration of 100 µM-0.01 nM. The derivatives 2e, 2f, 2g and 1g, beyond the standards miltefosine and pentamidine, significantly diminished the number of L. amazonensis amastigotes in macrophages. These derivatives were also active against amastigotes of L. braziliensis. As 2g presented potent leishmanicidal activity against the amastigotes of L. amazonensis in macrophages, we also investigated the in vivo leishmanicidal activity of this compound against L. amazonensis. Approximately 105L. amazonensis promastigotes were subcutaneously inoculated into the dermis of the right ear of BALB/c mice, which were subsequently treated with 2g (p.o. or i.p.), miltefosine (p.o.) or glucantime (i.p.) at 30 µmol/kg/day x 28 days. Thus, a similar reduction in the lesion size was observed after the administration of 2g through oral (63.7 ±â€¯10.1%) and intraperitoneal (61.8 ±â€¯3.7%) routes. A larger effect was observed after treatment with miltefosine (97.7 ±â€¯0.4%), and glucantime did not exhibit activity at the dose administered. With respect to the ear parasite load, 2g diminished the number of parasites by p.o. (30.5 ±â€¯5.1%) and i.p. (33.3 ±â€¯4.3%) administration. In addition, 2g induced in vitro apoptosis, autophagy and cell cycle alterations on L. amazonensis promastigotes. In summary, the derivative 2g might represent a lead candidate for antileishmanial drugs, as this compound displayed pronounced leishmanicidal activity.

Antinociceptive activity of Tibouchina pereirae, an endemic plant from the Brazilian semiarid region.

The anti-nociceptive activity of an extract of Tibouchina pereirae Aubl (AETP) was investigated using two models of chemically induced pain, viz. the acetic acid-induced writhing and the formalin test, respectively, with dipyrone and indomethacin as reference drugs, respectively. In the acetic acid-induced writhing test, AETP application (100 mg/kg) caused a significant reduction of writhing produced by acetic acid. In the formalin test, AETP reduced the formalin effects significantly only in the late phase. These findings thus indicate the involvement of AETP only in peripheral antinociceptive mechanisms. In addition, AETP exhibited good antioxidant activity (EC50 approx. 15 µg/mL) in the DPPH free radical scavenging assay.

Synthesis and evaluation of the anti-nociceptive and anti-inflammatory activity of 4-aminoquinoline derivatives.

In this paper, we describe the synthesis and pharmacological evaluation of a series of 4-aminoquinolines. The compounds were characterised and tested in models of pain and inflammation, using the writhing test with acetic acid, formalin test, peritonitis test by zymosan and arthritis test with Freund's adjuvant complete assay. The results revealed that all of the 4-aminoquinolines that were prepared promoted anti-nociceptive activity as well as acute and chronic anti-inflammatory effects, with marked activity in the derivates labelled with BAQ and 7-CF3-MAQ. After 7 days of treatment, 7-CF3-MAQ did not induce significant hepatotoxicity, gastrotoxicity or nephrotoxicity.

Antimicrobial Analysis of an Antiseptic Made from Ethanol Crude Extracts of P. granatum and E. uniflora in Wistar Rats against Staphylococcus aureus and Staphylococcus epidermidis.

INTRODUCTION: Surgical site infection remains a challenge for hospital infection control, especially when it relates to skin antisepsis in the surgical site. OBJECTIVE: To analyze the antimicrobial activity in vivo of an antiseptic from ethanol crude extracts of P. granatum and E. uniflora against Gram-positive and Gram-negative bacteria. METHODS: Agar drilling and minimal inhibitory tests were conducted for in vitro evaluation. In the in vivo bioassay were used Wistar rats and Staphylococcus aureus (ATCC 25923) and Staphylococcus epidermidis (ATCC 14990). Statistical analysis was performed through variance analysis and Scott-Knott cluster test at 5% probability and significance level. RESULTS: In the in vitro, ethanolic extracts of Punica granatum and Eugenia uniflora and their combination showed the best antimicrobial potential against S. epidermidis and S. aureus. In the in vivo bioassay against S. epidermidis, there was no statistically significant difference between the tested product and the patterns used after five minutes of applying the product. CONCLUSION: The results indicate that the originated product is an antiseptic alternative source against S. epidermidis compared to chlorhexidine gluconate. It is suggested that further researches are to be conducted in different concentrations of the test product, evaluating its effectiveness and operational costs.

Novel orally active analgesic and anti-inflammatory cyclohexyl-N-acylhydrazone derivatives.

The N-acylhydrazone (NAH) moiety is considered a privileged structure, being present in many compounds with diverse pharmacological activities. Among the activities attributed to NAH derivatives anti-inflammatory and analgesic ones are recurrent. As part of a research program aiming at the design of new analgesic and anti-inflammatory lead-candidates, a series of cyclohexyl-N-acylhydrazones 10-26 were structurally designed from molecular modification on the prototype LASSBio-294, representing a new class of cycloalkyl analogues. Compounds 10-26 and their conformationally restricted analogue 9 were synthetized and evaluated as analgesic and anti-inflammatory agents in classical pharmacologic protocols. The cyclohexyl-N-acylhydrazones 10-26 and the cyclohexenyl analogue 9 showed great anti-inflammatory and/or analgesic activities, but compound 13 stood out as a new prototype to treat acute and chronic painful states due to its important analgesic activity in a neuropathic pain model.

Assessment of mechanisms involved in antinociception produced by the alkaloid caulerpine.

In previous works we showed that oral administration of caulerpine, a bisindole alkaloid isolated from algae of the genus Caulerpa, produced antinociception when assessed in chemical and thermal models of nociception. In this study, we evaluated the possible mechanism of action of this alkaloid in mice, using the writhing test. The antinociceptive effect of caulerpine was not affected by intraperitoneal (i.p.) pretreatment of mice with naloxone, flumazenil, l-arginine or atropine, thus discounting the involvement of the opioid, GABAergic, l-arginine-nitric oxide and (muscarinic) cholinergic pathways, respectively. In contrast, i.p. pretreatment with yohimbine, an α2-adrenoceptor antagonist, or tropisetron, a 5-HT3 antagonist, significantly blocked caulerpine-induced antinociception. These results suggest that caulerpine exerts its antinociceptive effect in the writhing test via pathways involving α2-adrenoceptors and 5-HT3 receptors. In summary, this alkaloid could be of interest in the development of new dual-action analgesic drugs.

PI3K Signaling Pathways as a Molecular Target for Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) is the most common type of cancer that affects the central nervous system (CNS). It currently accounts for about 2% of diagnosed malignant tumors worldwide, with 296,000 new cases reported per year. The first-choice treatment consists of surgical resection, radiotherapy, and adjuvant chemotherapy, which increases patients' survival by 15 months. New clinical and pre-clinical research aims to improve this prognosis by proposing the search for new drugs that effectively eliminate cancer cells, circumventing problems such as resistance to treatment. One of the promising therapeutic strategies in the treatment of GBM is the inhibition of the phosphatidylinositol 3-kinase (PI3K) pathway, which is closely related to the process of tumor carcinogenesis. This review sought to address the main scientific studies of synthetic or natural drug prototypes that target specific therapy co-directed via the PI3K pathway, against human glioblastoma.

Spasmolytic effect of caulerpine involves blockade of Ca²âº influx on guinea pig ileum.

In this work, we investigated the spasmolytic effect of caulerpine, a bisindole alkaloid isolated from marine algae of the Caulerpa genus, on guinea pig ileum. Our findings indicated that caulerpine inhibited phasic contractions induced by carbachol (IC50 = 7.0 ± 1.9 × 10⁻5 M), histamine (IC50 = 1.3 ± 0.3 × 10⁻4 M) and serotonin (IC50 = 8.0 ± 1.4 × 10⁻5 M) in a non-selective manner. Furthermore, caulerpine concentration-dependently inhibited serotonin-induced cumulative contractions (pD'2 = 4.48 ± 0.08), shifting the curves to the right with Emax reduction and slope of 2.44 ± 0.21, suggesting a noncompetitive antagonism pseudo-irreversible. The alkaloid also relaxed the ileum pre-contracted by KCl (EC50 = 9.0 ± 0.9 × 10⁻5 M) and carbachol (EC50 = 4.6 ± 0.7 × 10⁻5 M) in a concentration-dependent manner. This effect was probably due to inhibition of Ca²âº influx through voltage-gated calcium channels (CaV), since caulerpine slightly inhibited the CaCl2-induced contractions in depolarizing medium without Ca²âº, shifting the curves to the right and with Emax reduction. According to these results, the spasmolytic effect of caulerpine on guinea pig ileum seems to involve inhibition of Ca²âº influx through CaV. However, other mechanisms are not discarded.

The antinociceptive and anti-inflammatory activities of Aspidosperma tomentosum (Apocynaceae).

We investigated the antinociceptive and anti-inflammatory activities of the crude ethanolic extract (CEE), its fractions, and the flavonoid isorhamnetin from Aspidosperma tomentosum using models of nociception and inflammation in mice. In the writhing test, the CEE and its fractions (except for soluble phase, CHCl3 100% and EtAcO 100%) at 100 mg/kg p.o. induced antinociceptive activity. Isorhamnetin (100 µ mol/kg, p.o.) was also active. In the hot plate test, only the treatment with the fractions Hex : CHCl3 50%, CHCl3 100%, and CHCl3 : MeOH 5% (100 mg/kg, p.o.) increased the latency time, reversed by the opioid antagonist naloxone. Fractions that were active in the hot plate test did not show catalepsy condition. It was observed that CEE, all fractions, and isorhamnetin reduced the formalin effects in the neurogenic phase. In the inflammatory phase, only CEE, isorhamnetin, and CHCl3 100% and CHCl3 : MeOH 5% fractions were active. CEE and all fractions, except for CHCl3 : MeOH 10% fraction, isorhamnetin, and soluble fraction were able to produce an antioedematogenic activity in the ear capsaicin-induced edema test. In the thioglycolate-induced peritonitis, only EtAcO 100% fraction was not active. The results demonstrate that A. tomentosum has antinociceptive and anti-inflammatory activities in animal models.

LQM10, a guanylhydrazone derivative, reduces nociceptive and inflammatory responses in mice.

In the present study, we examined the antinociceptive and anti-inflammatory activities of a guanylhydrazone derivative, (E)-(3,5-di-tert-butyl-4-hydroxybenzylidene)-2-guanylhydrazone hydrochloride (LQM10), in mice. The antinociceptive effect was determined by assessing behavioural responses in different pain models, while anti-inflammatory activity was examined in carrageenan-induced pleurisy. Intraperitoneal LQM10 administration reduced the acetic acid-induced nociceptive behaviour, a phenomenon that was unaltered by pretreatment with yohimbine, atropine, naloxone or glibenclamide. In the formalin assay, LQM10 reduced nociceptive behaviour only in the second phase, indicating an inhibitory effect on inflammatory pain. LQM10 did not alter the pain latency in the hot plate assay and did not impact the locomotor activity of mice in the rotarod assay. In the carrageenan-induced pleurisy assay, LQM10 treatment inhibited critical events involved in inflammatory responses, namely, leucocyte recruitment, plasma leakage and increased inflammatory mediators (tumour necrosis factor Like Properties of Chalchones and Flavonoid Derivatives [TNF]-α and interleukin [IL]-1ß) in the pleural exudate. Overall, these results indicate that LQM10 exhibits antinociceptive effects associated with peripheral mechanisms and anti-inflammatory activity mediated via a reduction in leucocyte migration and proinflammatory mediators, rendering this compound a promising candidate for treating pain and inflammatory process.

New immunodiagnostic methods for human tegumentary leishmaniasis in the last 10 years: Technological prospecting.

Leishmaniasis is a neglected disease and more than 1 billion people live in endemic areas with the risk of infection worldwide. Although it is an important epidemiological issue, the gold standard method of diagnosis requires invasive sample collection and is accompanied by a high level of sensitivity variation in results. The present study aims to conduct a patent prospection of immunodiagnostic methods for human tegumentary leishmaniasis in the last 10 years, focused on those with high sensitivity and specificity, and simple usability. We searched seven patent databases: The LENS, WIPO, EPO, USPTO, Patent Inspiration, Google patents, and INPI. Eleven patents were found that satisfy our search criteria, with six of them being registered in 2017. Most patents were registered in Brazil. The information obtained here covers the main characteristics of the immunodiagnostic methods evaluated. Moreover, our prospective study reveals the latest biotechnological advancements achieved in the immunodiagnosis of tegumentary leishmaniasis, especially in Brazil, which holds the majority of patents in this subject. However, no patent for immunodiagnostic methods was found in the last three years, which raises concerns about the present and future trends of leishmaniasis diagnosis.

Antinociceptive and anti-inflammatory activities of crude methanolic extract of red alga Bryothamnion triquetrum.

The marine environment is an extraordinary reservoir of bioactive natural products, many of which exhibit chemical and structural features not found in terrestrial natural products. In this regard, the aim of this study was to investigate the possible antinociceptive and anti-inflammatory activities of a crude methanolic extract of the red alga Bryothamnion triquetrum (BT-MeOH) in murine models. Groups of Swiss mice of both sexes (25-30 g) were used throughout the experiments. The potential antinociceptive of BT-MeOH was evaluated by means of the following tests: acetic acid-induced writhing, hot-plate test and glutamate- and formalin-induced nociception. The anti-inflammatory activity of BT-MeOH was investigated using the zymosan A-induced peritonitis test. The tests were conducted using 100 mg/kg (p.o.) BT-MeOH, 33.3 mg/kg (p.o.) dipyrone, 35.7 mg/kg (p.o.) indomethacin and 5.7 mg/kg (s.c.) morphine. The extract and all standard drugs were administered 40 min before the nociceptive/inflammatory stimulus. In the acetic acid-induced writhing test, BT-MeOH and dipyrone inhibited the nociceptive response by 55.9% (22.2 ± 2.0 writhings; p < 0.01) and 80.9% (9.6 ± 2.1 writhings; p < 0.01). In the hot-plate test, BT-MeOH did not increase the latency time of the animals in the time evaluated. In addition, BT-MeOH inhibited glutamate-induced nociception by 50.1%. While BT-MeOH did not inhibit the neurogenic phase in formalin-induced nociception, the inflammatory phase was inhibited by 53.1% (66.8 ± 14.2 s; p < 0.01). Indomethacin inhibited the inflammatory phase by 60.2% (56.8 ± 8.7 s; p < 0.01). In the zymosan-induced peritonitis test, BT-MeOH inhibited 55.6% (6.6 ± 0.2 × 10(6) leukocytes/mL; p < 0.01) of leukocyte migration, while indomethacin inhibited 78.1% (3.2 ± 0.1 × 10(6) leukocytes/mL; p < 0.01). Based on the results obtained in this study, we conclude that BT-MeOH has peripheral antinociceptive and anti-inflammatory activities. However, more studies need to be conducted to confirm these properties.

Design, synthesis, antinociceptive and anti-inflammatory activities of novel piroxicam analogues.

In this paper we report the design, synthesis, antinociceptive and anti-inflammatory activities of a series of benzothiazine N-acylhydrazones 14a­h, planned by structural modification of piroxicam (1), a non steroidal anti-inflammatory drug. Among the synthesized analogues, compounds 14f (LASSBio-1637) and 14g (LASSBio-1639) were identified as novel antinociceptive and anti-inflammatory prototypes, active by oral administration, acting by a mechanism of action that seems to be different from that of piroxicam, since they were inactive as an inhibitor of cyclooxygenase (COX-1 and COX-2) at concentrations of 10 mM.

Pre-clinical evaluation of LASSBio-1491: From in vitro pharmacokinetic study to in vivo leishmanicidal activity.

Leishmaniasis is a public health issue. It is among the top five parasitic illnesses worldwide and is one of the most neglected diseases. The current treatment disease includes limitations of toxicity, variable efficacy, high costs and inconvenient doses and treatment schedules. LASSBio-1736 was described as antileishmanial drug-candidate to cutaneous leishmaniasis, displaying plasma stability and with no preliminary signals of hepatic or renal toxicity. In this paper, we described the in vitro pharmacokinetic study of LASSBio-1491 (a less lipophilic isostere of LASSBio-1736) and it is in vitro and in vivo leishmanicidal activities. Our results demonstrated that LASSBio-1491 has high permeability, satisfactory aqueous solubility, long plasma and microsomal half-lives and low in vitro systemic clearance, suggesting a pharmacokinetic profile suitable for its use in a single daily dose. The antileishmanial effect of LASSBio-1491 was confirmed in vitro and in vivo. It exhibited no cytotoxic effect to mammalian cells and displayed good in -vivo effect against BALB/c mice infected with Leishmania major LV39 substrain, being 3 times more efficient than glucantime.

Obstacles to Glioblastoma Treatment Two Decades after Temozolomide.

Glioblastomas are considered the most common and aggressive primary brain tumor in adults, with an average of 15 months' survival rate. The treatment is surgery resection, followed by chemotherapy with temozolomide, and/or radiotherapy. Glioblastoma must have wild-type IDH gene and some characteristics, such as TERT promoter mutation, EGFR gene amplification, microvascular proliferation, among others. Glioblastomas have great heterogeneity at cellular and molecular levels, presenting distinct phenotypes and diversified molecular signatures in each tumor mass, making it difficult to define a specific therapeutic target. It is believed that the main responsibility for the emerge of these distinct patterns lies in subcellular populations of tumor stem cells, capable of tumor initiation and asymmetric division. Studies are now focused on understanding molecular mechanisms of chemoresistance, the tumor microenvironment, due to hypoxic and necrotic areas, cytoskeleton and extracellular matrix remodeling, and in controlling blood brain barrier permeabilization to improve drug delivery. Another promising therapeutic approach is the use of oncolytic viruses that are able to destroy specifically glioblastoma cells, preserving the neural tissue around the tumor. In this review, we summarize the main biological characteristics of glioblastoma and the cutting-edge therapeutic targets that are currently under study for promising new clinical trials.

LASSBio-596: a New Pre-clinical Candidate for Rheumatoid Arthritis?

Pain and inflammatory disorders are significant health problems because of prevalence and associated disabilities. In this context, LASSBio-596 is a hybrid compound able to modulate TNF-α and phosphodiesterases 4 and 5, exhibiting an anti-inflammatory effect in the pulmonary inflammatory model. Aiming at a better description of the activities of LASSBio-596, we initially conducted nociception tests (acetic acid-induced abdominal writhing, glutamate, and formalin-induced nociception and hot plate test) and later inflammatory tests (acute, peritonitis; and chronic, arthritis) that directed us to this last one. In the abdominal writhing test, there was a dose-dependent inhibition, whose response occurred at the maximum dose (50 mg/kg, p.o.), used in the subsequent tests. LASSBio-596 also inhibited nociception induced by chemical (glutamate by 31.9%; and formalin, in both phases, 1st phase: 25.7%; 2nd phase: 23.9%) and thermal agents (hotplate, by increased latency for pain at two different times). These effects were independent of the motor function, legitimated in rotarod. As there was a response in the inflammatory component of nociception, we performed the peritonitis test, in which migration was inhibited by LASSBio-596 by 39.9%. As the inflammatory process is present in autoimmune diseases, we also performed the arthritis test. LASSBio-596 reduced paw edema from the 15th day to the 21st day of treatment (no liver changes and with fewer paw injuries). In addition, LASSBio-596 decreased serum levels of TNF-α by 67.1%. These data demonstrated the antinociceptive effect of LASSBio-596 and reinforces its anti-inflammatory property (i.e., RA), amplifying the therapeutic potential of this molecule.

Can inflammasomes promote the pathophysiology of glioblastoma multiforme? A view about the potential of the anti-inflammasome therapy as pharmacological target.

Glioblastoma multiforme (GBM) is a malignant brain tumor with one of the worst general survivorship cases among the existing neoplasia. This aggressiveness is due to its complex molecular heterogeneity, immunohistochemistry and genetics. The current therapeutic approach brings little contribution to the improvement of the survival of the patients. Due to that, new forms of treatment have been explored, one of them being immunotherapy. In this aspect, the inflammasome pathway, which induces inflammation and immunosuppressive tumor response, contributing to the progression of the tumor, seems to be a new alternative to improve the treatment efficacy and the survival of the patients.