Pleonotoquinones, Cytotoxic Oxepinenaphthoquinones from Pleonotoma jasminifolia.

Two unusual naphthoquinones, named here as pleonotoquinones A (1) and B (2), were isolated along with two known anthraquinones (3 and 4) via chromatographic separations of an ethyl acetate extract of the roots of Pleonotoma jasminifolia. Compounds 1 and 2 are the first examples of quinones bearing a 2-methyloxepine moiety. The compounds were isolated with the aid of mass spectrometry and molecular networking, and their structures were resolved using 1D and 2D NMR and HRESIMS data. The isolated compounds were evaluated for their antiproliferative activity against human cancer cell lines, and compounds 1 and 2 displayed cytotoxicity against human colon cancer HCT116 cells (IC50 = 2.6 µM for compound 1 and IC50 = 4.3 µM for compound 2) and human liver cancer HepG2 cells (IC50 = 1.9 µM for compound 1 and IC50 = 6.4 µM for compound 2).

Paradoxical activation of oncogenic signaling as a cancer treatment strategy.

Cancer homeostasis depends on a balance between activated oncogenic pathways driving tumorigenesis and engagement of stress-response programs that counteract the inherent toxicity of such aberrant signaling. While inhibition of oncogenic signaling pathways has been explored extensively, there is increasing evidence that overactivation of the same pathways can also disrupt cancer homeostasis and cause lethality. We show here that inhibition of Protein Phosphatase 2A (PP2A) hyperactivates multiple oncogenic pathways and engages stress responses in colon cancer cells. Genetic and compound screens identify combined inhibition of PP2A and WEE1 as synergistic in multiple cancer models by collapsing DNA replication and triggering premature mitosis followed by cell death. This combination also suppressed the growth of patient-derived tumors in vivo. Remarkably, acquired resistance to this drug combination suppressed the ability of colon cancer cells to form tumors in vivo. Our data suggest that paradoxical activation of oncogenic signaling can result in tumor suppressive resistance.

Mass Spectrometry-Based Investigation of Sugarcane Exposed to Five Different Pesticides.

The use of agrochemicals has become a standard practice worldwide to ensure the productivity and quality of sugarcane crops. This study aimed to analyze the metabolic changes in sugarcane culms treated with five different nematicides. The experimental design was randomized in blocks, and agro-industrial and biometric variables were evaluated. The samples were extracted and then analyzed using LC-MS, LC-MS/MS, and LC-HRMS. The data obtained were submitted to statistical methods (PCA and PLS). Fragmentation patterns, retention time, and UV absorptions of the main features were analyzed. The plantations treated with carbosulfan (T4) obtained higher agricultural productivity and total recoverable sugar (TRS), while the use of benfuracarb (T3) was associated with lower growth and lower TRS. Statistical analysis revealed the contribution of the features at m/z 353 and m/z 515, assigned as chlorogenic acids, which discriminated the groups. The MS profile also supported the occurrence of flavonoids (C-glycosides and O-glycosides) in the samples.

New Pregnane Glycosides from Mandevilla dardanoi and Their Anti-Inflammatory Activity.

Mandevilla Lindl. is an important genus of the Apocynaceae family, not only as ornamental plants but also for its medicinal uses. In Brazil, Mandevilla species are indicated to treat asthma and skin infections, their anti-inflammatory potential and wound healing properties are also reported in the literature. Concerning their chemical composition, this group of plants is a conspicuous producer of pregnane glycosides. Mandevilla dardanoi is an endemic species from the Brazilian semiarid region not studied by any phytochemical methods. In view of the medicinal potential of Mandevilla species, this study aimed to isolate new pregnane glycosides from M. dardanoi. To achieve this main goal, modern chromatography techniques were employed. Five new pregnane glycosides, dardanols A-E, were isolated from the roots of M. dardanoi by HPLC. Their structures were determined using extensive 1D and 2D-NMR and mass spectrometry (MSn and HRESIMS) data. The cytotoxicity and the anti-inflammatory potential of these compounds were evaluated. The first was evaluated by measuring proinflammatory cytokines and nitric oxide production by stimulated macrophages. Dardanols were able to inhibit the production of nitric oxide and reduce IL-1ß and TNF-α. The current work demonstrates the chemodiversity of Brazilian semiarid species and contributes to amplifying knowledge about the biological potential of the Mandevilla genus.

Antitumor and antiangiogenic effects of Tonantzitlolone B, an uncommon diterpene from Stillingia loranthacea.

Natural products have played a pivotal role for the discovery of anticancer drugs. Tonantzitlolones are flexibilan-type diterpenes rare in nature; therefore, few reports have shown antiviral and cytotoxic activities. This study aimed to investigate the in vivo antitumor action of Tonantzitlolone B (TNZ-B) and its toxicity. Toxicity was evaluated in mice (acute and micronucleus assays). Antitumor activity of TNZ-B (1.5 or 3 mg/kg intraperitoneally - i.p.) was assessed in Ehrlich ascites carcinoma model. Angiogenesis and reactive oxygen species (ROS) and nitric oxide (NO) production were also investigated, in addition to toxicological effects after 7-day treatment. The LD50 (lethal dose 50%) was estimated at around 25 mg/kg (i.p.), and no genotoxicity was recorded. TNZ-B reduced the Ehrlich tumor's volume and total viable cancer cell count (p < 0.001 for both). Additionally, TNZ-B reduced peritumoral microvessel density (p < 0.01), suggesting antiangiogenic action. Moreover, a decrease was observed on ROS (p < 0.05) and nitric oxide (p < 0.001) levels. No significant clinical findings were observed in the analysis of biochemical, hematological, and histological (liver and kidney) parameters. In conclusion, TNZ-B exerts antitumor and antiangiogenic effects by reducing ROS and NO levels and has weak in vivo dose-repeated toxicity. These data contribute to elucidate the antitumor action of TNZ-B and point the way for further studies with this natural compound as an anticancer drug.

Autophagy buffers Ras-induced genotoxic stress enabling malignant transformation in keratinocytes primed by human papillomavirus.

Malignant transformation involves an orchestrated rearrangement of cell cycle regulation mechanisms that must balance autonomic mitogenic impulses and deleterious oncogenic stress. Human papillomavirus (HPV) infection is highly prevalent in populations around the globe, whereas the incidence of cervical cancer is 0.15%. Since HPV infection primes cervical keratinocytes to undergo malignant transformation, we can assume that the balance between transforming mitogenic signals and oncogenic stress is rarely attained. We showed that highly transforming mitogenic signals triggered by HRasG12V activity in E6E7-HPV-keratinocytes generate strong replication and oxidative stresses. These stresses are counteracted by autophagy induction that buffers the rapid increase of ROS that is the main cause of genotoxic stress promoted by the oncoprotein. As a result, autophagy creates a narrow window of opportunity for malignant keratinocytes to emerge. This work shows that autophagy is crucial to allow the transition of E6E7 keratinocytes from an immortalized to a malignant state caused by HRasG12V.

Dereplication and quantification of the ethanol extract of Miconia albicans (Melastomaceae) by HPLC-DAD-ESI-/MS/MS, and assessment of its anti-hyperalgesic and anti-inflammatory profiles in a mice arthritis-like model: Evidence for involvement of TNF-α, IL-1ß and IL-6.

ETHNOPHARMACOLOGICAL RELEVANCE: Miconia albicans (Sw) Triana (Melastomataceae), a medicinal plant widely used by practitioners of folk medicine in the northeast of Brazil, has been used to treat chronic inflammatory disorders, such as rheumatoid arthritis (RA) and other joint conditions. Oddly, there is little research on the species. AIM OF THE STUDY: We aimed to evaluate the anti-arthritic and anti-inflammatory profile of the ethanolic leaf extract of M. albicans (EEMA), as well as to perform dereplication and quantification by HPLC-DAD-ESI-/MS/MS. MATERIALS AND METHODS: The compounds present in the extracts were identified by HPLC-DAD-ESI-MS/MS. The possible anti-inflammatory effect of EEMA (50 and 100 mg/kg, p.o) was evaluated using the pleurisy model induced by carrageenan and its action on IL-1ß and TNF-α levels was also evaluated. The RA model was induced through the intra-articular injection of complete Freund's adjuvant (CFA). RESULTS: HPLC-DAD-ESI-MS/MS analysis identified 23 compounds, with glycoside flavonoids mainly derived from quercetin, and rutin being the main compounds. EEMA significantly reduced (p < 0.001) leukocyte migration in the pleurisy model and reduced TNF-α and IL-1ß levels in pleural lavage (p < 0.001). In the CFA animal model, EEMA significantly reduced the nociceptive and hyperalgesic behaviors demonstrated by the rearing test (p < 0.01 or p < 0.05) and decreased mechanical hyperalgesia (p < 0.001). EEMA produced a significant improvement in mobility in the open-field test (only at the higher dose, p < 0.05). EEMA significantly (p < 0.01) increased hindpaw grip strength. The diameter of CFA-induced ipsilateral knee edema was significantly reduced (p < 0.001) by EEMA, which was related to reduced levels of IL-6 and TNF-α in the joint knee (p < 0.01). No indication of hepatic injury after chronic treatment was found. CONCLUSION: Taken together, these results contribute to the chemical and pharmacological knowledge of M. albicans and demonstrated that this medicinal plant appears to be able to mitigate deleterious symptoms of RA, which supports its use in folk medicine.

Bioactive Compounds from the Aerial Parts of Evolvulus linarioides.

Three new caryophyllane-type sesquiterpenoids, linariophyllenes A-C (1-3), two new hamamelitol derivatives, linaritols A (4) and B (5), two new chromones, linariosides A (6) and B (7), and three known chromones, cnidimol C (8), monnieriside A (9), and undulatoside A (10), were identified from the aerial parts of Evolvulus linarioides. The structures of these compounds were elucidated by NMR, MS, and IR data. The absolute configurations of compounds 1-5 and 7 were established via electronic circular dichroism data. The anti-inflammatory potential of compounds 1-5 and 7-10 was evaluated by determining their ability to inhibit the production of nitric oxide (NO) and proinflammatory cytokine IL-1ß by stimulated J774 macrophages. Compounds tested at noncytotoxic concentrations inhibited NO production by macrophages, exhibiting IC50 values between 17.8 and 66.2 µM, and inhibited IL-1ß production by stimulated macrophages by 72.7-96.2%.

Fibroblast Growth Factor 2 lethally sensitizes cancer cells to stress-targeted therapeutic inhibitors.

In malignant transformation, cellular stress-response pathways are dynamically mobilized to counterbalance oncogenic activity, keeping cancer cells viable. Therapeutic disruption of this vulnerable homeostasis might change the outcome of many human cancers, particularly those for which no effective therapy is available. Here, we report the use of fibroblast growth factor 2 (FGF2) to demonstrate that further mitogenic activation disrupts cellular homeostasis and strongly sensitizes cancer cells to stress-targeted therapeutic inhibitors. We show that FGF2 enhanced replication and proteotoxic stresses in a K-Ras-driven murine cancer cell model, and combinations of FGF2 and proteasome or DNA damage response-checkpoint inhibitors triggered cell death. CRISPR/Cas9-mediated K-Ras depletion suppressed the malignant phenotype and prevented these synergic toxicities in these murine cells. Moreover, in a panel of human Ewing's sarcoma family tumor cells, sublethal concentrations of bortezomib (proteasome inhibitor) or VE-821 (ATR inhibitor) induced cell death when combined with FGF2. Sustained MAPK-ERK1/2 overactivation induced by FGF2 appears to underlie these synthetic lethalities, as late pharmacological inhibition of this pathway restored cell homeostasis and prevented these described synergies. Our results highlight how mitotic signaling pathways which are frequently overridden in malignant transformation might be exploited to disrupt the robustness of cancer cells, ultimately sensitizing them to stress-targeted therapies. This approach provides a new therapeutic rationale for human cancers, with important implications for tumors still lacking effective treatment, and for those that frequently relapse after treatment with available therapies.

Grade I meningiomas with atypical characteristics: a worse prognosis.

OBJECTIVE: The study reviewed the histology of cases of grade I meningiomas with spontaneous necrosis, grade I without necrosis and grade II meningiomas, to evaluate the histological and immunohistochemical factors of the patients' prognosis, while correlating the clinicopathological features with the clinical follow-up of the patients. METHODS: A review of 47 cases from the Department of Pathology of UNIFESP was performed and the samples were submitted to immunohistochemical examination with the p53 protein, Ki-67 cell proliferation factor and progesterone receptor markers. RESULTS: A greater expression was found in the progression of several degrees of aggressiveness for p53 and Ki-67, and a higher frequency of progesterone receptors in the lower degrees. CONCLUSIONS: The group of grade I meningiomas with spontaneous necrosis showed histological and immunohistochemical indexes that approximate those of the grade II meningioma. This suggests a worse prognosis for grade I meningiomas with necrosis.

Grade I meningiomas with atypical characteristics: a worse prognosis / Meningiomas grau I com características atípicas: um pior prognóstico

ABSTRACT The study reviewed the histology of cases of grade I meningiomas with spontaneous necrosis, grade I without necrosis and grade II meningiomas, to evaluate the histological and immunohistochemical factors of the patients' prognosis, while correlating the clinicopathological features with the clinical follow-up of the patients. A review of 47 cases from the Department of Pathology of UNIFESP was performed and the samples were submitted to immunohistochemical examination with the p53 protein, Ki-67 cell proliferation factor and progesterone receptor markers. A greater expression was found in the progression of several degrees of aggressiveness for p53 and Ki-67, and a higher frequency of progesterone receptors in the lower degrees. The group of grade I meningiomas with spontaneous necrosis showed histological and immunohistochemical indexes that approximate those of the grade II meningioma. This suggests a worse prognosis for grade I meningiomas with necrosis.

RESUMO O objetivo do estudo foi realizar a revisão histológica de casos de meningiomas grau I com necrose espontânea, grau I sem necrose e grau II para avaliar os fatores histológicos e imunohistoquímicos de prognóstico dos pacientes, correlacionando informações no âmbito clínico-patológico com o seguimento clínico dos pacientes. Foi realizada revisão de 47 casos do Departamento de Patologia da UNIFESP e as amostras foram submetidas a exame imunohistoquímico com os marcadores proteína p53, fator de proliferação celular Ki-67 e receptor de progesterona. Verificou-se maior expressão na progressão dos diversos graus de agressividade para p53 e Ki-67 e maior frequência de receptores de progesterona nos menores graus. O grupo dos meningiomas grau I com necrose espontânea apresentou índices histológicos e imuno-histoquímicos que se aproximam dos meningiomas grau II. Isto sugere um pior prognóstico dos meningiomas grau I com necrose.

Analogs of the Scorpion Venom Peptide Stigmurin: Structural Assessment, Toxicity, and Increased Antimicrobial Activity.

Scorpion venom is a rich source of biologically active components and various peptides with high-potential therapeutic use that have been characterized for their antimicrobial and antiproliferative activities. Stigmurin is a peptide identified from the Tityus stigmurus venom gland with high antibacterial and antiproliferative activities and low toxicity. Amino acid substitutions in peptides without a disulfide bridge sequence have been made with the aim of reducing their toxicity and increasing their biological activities. The purpose of this study was to evaluate the structural conformation and structural stability, as well as antimicrobial, antiproliferative, and hemolytic activities of two peptide analogs to Stigmurin, denominated StigA6 and StigA16. In silico analysis revealed the α-helix structure for both analog peptides, which was confirmed by circular dichroism. Data showed that the net charge and hydrophobic moment of the analog peptides were higher than those for Stigmurin, which can explain the increase in antimicrobial activity presented by them. Both analog peptides exhibited activity on cancerous cells similar to the native peptide; however, they were less toxic when tested on the normal cell line. These results reveal a potential biotechnological application of the analog peptides StigA6 and StigA16 as prototypes to new therapeutic agents.

Zornioside, a dihydrochalcone C-glycoside, and other compounds from Zornia brasiliensis

ABSTRACT The secondary metabolites of the aerial parts of Zornia brasiliensis Vogel, Fabaceae, and the biological activity of one of these secondary metabolites were characterized in this study. A phytochemical investigation was performed using chromatographic techniques including analytical and preparative reverse-phase HPLC column sequences, which resulted in the isolation of fourteen compounds: one previously undescribed C-glycosylated dihydrochalcone (zornioside), one cyclitol (D-pinitol), one glycosylated megastigmane (roseoside) and eleven phenolic compounds: 7-methoxyflavanone, 7,4'-dimethoxyisoflavone, medicarpin, 2'-4'-dihydroxychalcone, onionin, isoorientin-3'-O-methyl ether, isovitexin, glycosylated (Z)-O-coumaric acid, glycosylated (E)-O-coumaric acid, dihydromelilotoside, and isoorientin. The structures of the isolated compounds were determined based on 1D and 2D-NMR, HRESIMS, IR and CD spectroscopic analyses. The cytotoxic activity of zornoside was assessed against tumor cell lines (MCF-7, HCC1954, T-47D, 4T1, HL60), and a non-tumor cell line (RAW264.7) using MTT assay. The compound zornioside was selectively cytotoxic for HL60 leukemia cells (IC50: 37.26 µM).

Computer-aided Drug Design Applied to Parkinson Targets.

BACKGROUND: Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by debilitating motor deficits, as well as autonomic problems, cognitive declines, changes in affect and sleep disturbances. Although the scientific community has performed great efforts in the study of PD, and from the most diverse points of view, the disease remains incurable. The exact mechanism underlying its progression is unclear, but oxidative stress, mitochondrial dysfunction and inflammation are thought to play major roles in the etiology. OBJECTIVE: Current pharmacological therapies for the treatment of Parkinson's disease are mostly inadequate, and new therapeutic agents are much needed. METHODS: In this review, recent advances in computer-aided drug design for the rational design of new compounds against Parkinson disease; using methods such as Quantitative Structure-Activity Relationships (QSAR), molecular docking, molecular dynamics and pharmacophore modeling are discussed. RESULTS: In this review, four targets were selected: the enzyme monoamine oxidase, dopamine agonists, acetylcholine receptors, and adenosine receptors. CONCLUSION: Computer aided-drug design enables the creation of theoretical models that can be used in a large database to virtually screen for and identify novel candidate molecules.

Docking Studies for Multi-Target Drugs.

The most basic principle of drug action is found in the lock and key model, where the highest possible affinity for a target that also avoids side effects is desired. For many years this was understood as being "one drug, for one target, for one disease", however researchers began to observe that certain diseases are best treated with multi-target drugs. In recent years, studies have sought out polypharmacological compounds acting on multiple targets against complex (multifactorial) diseases, such as cancer, neurodegenerative disease, and certain infections. One of the computational tools used in research for multifunctional drugs is Molecular Docking. Through this methodology of Computer-Aided Drug Design, we observe complexes formed between ligands and interesting targets (often many), for a particular disease. This review reports on docking studies as used in investigations of new multi-target compounds; it also shows the various ways that such studies are used in the search for multifunctional compounds.

Toxicity and antitumor efficacy of Croton polyandrus oil against Ehrlich ascites carcinoma cells

ABSTRACT The essential oil from Croton polyandrus Spreng., Euphorbiaceae, leaves was tested for the toxicity and antitumor activity. The concentration producing 50% hemolysis was 141 µg/ml on mice erythrocytes. In the acute toxicological study, the estimated LD50 was 447.18 mg/kg. The essential oil did not induce increase in number of micronucleated erythrocytes, suggesting low genotoxicity. Essential oil (100 or 150 mg/kg) showed significant antitumor activity in Ehrlich ascitic carcinoma model. We observed that essential oil induces cell-cycle arrest at the G0/G1 phase, and increases the sub-G1 peak, which represents a marker of cell death by apoptosis. Survival also increased for the treated animals. The toxicological analyses revealed reduction in body weight, increased aspartate aminotransferase and alanine aminotransferase activity, hematological changes, and a thymus index reduction. These data suggest gastrointestinal and liver toxicity, anemia, leukopenia/lymphocytopenia, and immunosuppressive effects. Histopathological analysis revealed the weak hepatotoxicity of essential oil. In summary, essential oil of C. polyandrus displays in vivo antitumor activity and moderate toxicity.

Chemical composition, antitumor activity, and toxicity of essential oil from the leaves of Lippia microphylla.

The chemical composition, antitumor activity and toxicity of the essential oil from Lippia microphylla leaves (OEL) were investigated. The major constituents were thymol (46.5%), carvacrol (31.7%), p-cymene (9%), and γ-terpinene (2.9%). To evaluate the toxicity of OEL in non-tumor cells, the hemolytic assay with Swiss mice erythrocytes was performed. The concentration producing 50% hemolysis (HC50) was 300 µg/mL. Sarcoma 180 tumor growth was inhibited in vivo 38% at 50 mg/kg, and 60% at 100 mg/kg, whereas 5-FU at 50 mg/kg caused 86% inhibition. OEL displays moderate gastrointestinal and hematological toxicity along with causing some alteration in liver function and morphology. However, the changes were considered reversible and negligible in comparison to the effects of several anticancer drugs. In summary, OEL displays in vivo antitumor activity and a moderate toxicity, which suggests further pharmacological study.

Ribifolin, an orbitide from Jatropha ribifolia, and its potential antimalarial activity.

A new orbitide named ribifolin was isolated and characterized from Jatropha ribifolia using mass spectrometry, NMR spectroscopy, quantitative amino acid analysis, molecular dynamics/simulated annealing, and Raman optical activity measurements and calculations. Ribifolin (1) and its linear form (1a) were synthesized by solid-phase peptide synthesis, followed by evaluation of its antiplasmodial and cytotoxicity activities. Compound 1 was moderately effective (IC50 = 42 µM) against the Plasmodium falciparum strain 3D7.

Essential oil from the leaves of Xylopia langsdorfiana (Annonaceae) as a possible spasmolytic agent.

Xylopia langsdorfiana A. St.-Hil. &Tul. (Annonaceae) is popularly known in the northeast of Brazil as 'pimenteira da terra', and an essential oil (XL-OE) was extracted from its leaves. Since Xylopia species are cited in folk medicine and diterpenes from X. langsdorfiana have spasmolytic activity, this study aimed to investigate a possible spasmolytic action of XL-OE on smooth muscle models. XL-OE (243 and 729 µg/mL) showed low pharmacologic efficacy on guinea pig trachea and rat aorta and uterus. However, in guinea pig ileum, XL-OE (27-729 µg/mL) inhibited carbachol or histamine-induced phasic contractions (1 µM) in a significant and concentration-dependent manner. In addition, XL-OE (81 µg/mL) reduced fluorescence intensity in ileal myocytes stimulated by histamine, indicating a decrease in cytosolic calcium concentration, which could explain the spasmolytic activity. Thus, XL-OE proved to be a promising natural product to be used in gastrointestinal diseases acting by modulating the cytosolic calcium concentration.