Effect of senolytic drugs in young female mice chemically induced to estropause.

AIMS: This study aimed to assess metabolic responses and senescent cell burden in young female mice induced to estropause and treated with senolytic drugs. MAIN METHODS: Estropause was induced by 4-vinylcyclohexene diepoxide (VCD) injection in two-month-old mice. The senolytics dasatinib and quercetin (D + Q) or fisetin were given by oral gavage once a month from five to 11 months of age. KEY FINDINGS: VCD-induced estropause led to increased body mass and reduced albumin concentrations compared to untreated cyclic mice, without affecting insulin sensitivity, lipid profile, liver enzymes, or total proteins. Estropause decreased catalase activity in adipose tissue but had no significant effect on other redox parameters in adipose and hepatic tissues. Fisetin treatment reduced ROS levels in the hepatic tissue of estropause mice. Estropause did not influence senescence-associated beta-galactosidase activity in adipose and hepatic tissues but increased senescent cell markers and fibrosis in ovaries. Senolytic treatment did not decrease ovarian cellular senescence induced by estropause. SIGNIFICANCE: Overall, the findings suggest that estropause leads to minor metabolic changes in young females, and the senolytics D + Q and fisetin had no protective effects despite increased ovarian senescence.

Dynamics of serum exosome microRNA profile altered by chemically induced estropause and rescued by estrogen therapy in female mice.

The decline in the ovarian reserve leads to menopause and reduced serum estrogens. MicroRNAs are small non-coding RNAs, which can regulate gene expression and be secreted by cells and trafficked in serum via exosomes. Serum miRNAs regulate tissue function and disease development. Therefore, the aim of this study was to identify miRNA profiles in serum exosomes of mice induced to estropause and treated with 17ß-estradiol (E2). Female mice were divided into three groups including control (CTL), injected with 4-Vinylcyclohexene diepoxide (VCD), and injected with VCD plus E2 (VCD + E2). Estropause was confirmed by acyclicity and a significant reduction in the number of ovarian follicles (p < 0.05). Body mass gain during estropause was higher in VCD and VCD + E2 compared to CTL females (p = 0.02). Sequencing of miRNAs was performed from exosomes extracted from serum, and 402 miRNAs were detected. Eight miRNAs were differentially regulated between CTL and VCD groups, seven miRNAs regulated between CTL and VCD + E2 groups, and ten miRNAs regulated between VCD and VCD + E2 groups. Only miR-200a-3p and miR-200b-3p were up-regulated in both serum exosomes and ovarian tissue in both VCD groups, suggesting that these exosomal miRNAs could be associated with ovarian activity. In the hepatic tissue, only miR-370-3p (p = 0.02) was up-regulated in the VCD + E2 group, as observed in serum. Our results suggest that VCD-induced estropause and E2 replacement have an impact on the profile of serum exosomal miRNAs. The miR-200 family was increased in serum exosomes and ovarian tissue and may be a candidate biomarker of ovarian function.

Absolute Configuration and Antileishmanial Activity of (-)-Cyclocolorenone Isolated from Duguetia lanceolata (Annonaceae).

BACKGROUND: The fractionation of the n-hexane phase of the EtOH extract from the leaves of Duguetia lanceolata (Annonaceae) led to the identification of the sesquiterpene (-)-cyclocolorenone. OBJECTIVES: Chemical characterization, including determination of the absolute stereochemistry, and in vitro evaluation of antileishmanial activity of the sesquiterpene (-)-cyclocolorenone, isolated from D. lanceolata, were carried out. METHODS: (-)-Cyclocolorenone was isolated from D. lanceolata leaves using different chromatographic steps and its structure was defined by analysis of NMR and ESI-HRMS data. Additionally, the absolute configuration of (-)-cyclocolorenone was ambiguously assigned by means of vibrational circular dichroism (VCD). Antileishmanial activity of (-)-cyclocolorenone was evaluated on promastigote and amastigote forms of Leishmania (Leishmania) amazonensis. The integrity of the cell membrane of L. (L.) amazonensis was analyzed using the SYTOX green probe. RESULTS: (-)-(1R,6S,7R,10R)-Cyclocolorenone displayed activity against promastigotes and amastigotes forms of L. (L.) amazonensis with IC50 of 4.54 and 28.44 µM, respectively. Furthermore, this compound was non-toxic in J774 macrophage cells (CC50 > 458.71 µM) with a selectivity index > 100 (promastigotes) and > 32.2 (amastigotes). Additionally, (-)-cyclocolorenone was observed to target the parasite cell membrane. CONCLUSION: Obtained data suggested that (-)-cyclocolorenone, in which absolute configuration was determined, can be considered as a scaffold for the development of new drugs for the treatment of leishmaniasis.

Vibrational circular dichroism enantiomeric similarity index improvement for absolute configuration discrimination using individual infrared scaling factors.

The use of IR individual scaling factors (ISF) for the correction of DFT-calculated frequencies, and its effect on IR and VCD similarity functions, has been evaluated using (+)-(R)-3-methylcyclopentanone as a probe molecule. Contrary to using a single scaling factor to improve spectra matching, this approach sequentially searches for the optimal scaling factor for each calculated transition using a computational search algorithm to maximize the overlap of the calculated and observed IR spectra expressed as the IR similarity (SIR ) function. The obtained ISFs are then applied to the calculated frequencies, which are used to produce a scaled VCD spectrum for comparison with the observed trace, thereby yielding enantiomeric similarity index (ESI) values as a similarity measure. This procedure provides a significant improvement of the SIR and ESI values when compared with the use of a single scale factor, showing 15.1% and 34.1% in average increments, respectively, and values as high as 0.98 and 0.94, respectively. When a set of manually found ISFs is used, most differences in SIR and ESI performance disappear, and nearly perfect spectra matches are found throughout the levels of theory tested. This suggests that the observed differences in computed IR/VCD spectra with commonly used levels of theory are related to differences in frequency rather than to intensity accuracy. Finally, the use of ISFs is expected to enhance the ability to aide stereochemical assignments, particularly in cases where sufficiently accurate frequencies are difficult to obtain due to the system size or complexity.

Sesquiterpene Lactones from Calea pinnatifida: Absolute Configuration and Structural Requirements for Antitumor Activity.

This work describes the chromatographic fractionation of the aerial parts of Calea pinnatifida and the structural characterization and determination of the absolute configuration of the isolated compounds as well as their antitumor potential. The HPLC fractionation of the CH2Cl2 phase of the MeOH extract from the leaves of C. pinnatifida led to the isolation of two related sesquiterpene lactones (STLs): calein C (1) and calealactone B (2). Additionally, during the purification process, a derivative of calein C (3) was formed as a product of the Michael addition of MeOH. The structures of Compounds 1-3 were established based on spectroscopic and spectrometric data, while the absolute stereochemistry was established by vibrational circular dichroism. In order to evaluate the effect of the conjugated double bonds on the cytotoxic activity of STLs, Compounds 1-3 were tested against anaplastic (KTC-2) and papillary (TPC-1) thyroid carcinoma cells. Calein C was the most active of the STLs, and displayed activity against both KTC-2 and TPC-1. On the other hand, the calein C derivative (3) was the least cytotoxic of all the compounds tested. These results are promising and suggest the importance of studying sesquiterpene lactones isolated from C. pinnatifida in terms of antitumor activity, especially considering the effects of α,ß-unsaturated carbonyl systems.

Diterpenoids with inhibitory activity of nitrite production from Croton floribundus.

ETHNOPHARMACOLOGICAL RELEVANCE: Croton floribundus Spreng. (Euphorbiaceae), popularly known as Capixinguí, stands out due to its widespread use in traditional medicine to treat wounds, syphilis, hemorrhoids, eye diseases and as a purgative. AIM OF THE STUDY: To characterize clerodanes diterpenes from C. floribundus and to evaluate the effects of the fraction and diterpenes (1-5) on inhibition of nitrite production. MATERIALS AND METHODS: The hydroethanolic root extract of C. floribundus was fractionated on a solid phase extraction column to obtain the fraction named Fr80%. From this, five compounds were obtained and characterized. The absolute configuration of compound 1 was determined by a combination of electronic and vibrational circular dichroism spectroscopies. Additionally, compounds 1-5 were evaluated for their inhibitory effects on nitrite production induced by lipopolysaccharide (LPS) in RAW 264 macrophage cell. RESULTS: Five clerodane diterpenoids were characterized, and the absolute stereochemistry of 1 was established as 3R,4R,5R,8R,9R,10S,12S. The IC50 values obtained through inhibition of nitrite production were 28.52 ±â€¯2.21 µM (1), 40.26 ±â€¯2.79 µM (2), 25.47 ±â€¯2.16 µM (3), 35.78 ±â€¯2.93 µM (4) and 40.58 ±â€¯4.78 µM (5). In the tested concentrations, the samples presented low toxicity in macrophages. CONCLUSIONS: Four new diterpenes were characterized from C. floribundus, these being croflorins A-D (1-4) and a known halimane (5). These compounds exhibited inhibitory effect on nitrite production.

Enantiomeric Mixtures in Natural Product Chemistry: Separation and Absolute Configuration Assignment.

Chiral natural product molecules are generally assumed to be biosynthesized in an enantiomerically pure or enriched fashion. Nevertheless, a significant amount of racemates or enantiomerically enriched mixtures has been reported from natural sources. This number is estimated to be even larger since the enantiomeric purity of secondary metabolites is rarely checked in the natural product isolation pipeline. This latter fact may have drastic effects on the evaluation of the biological activity of chiral natural products. A second bottleneck is the determination of their absolute configurations. Despite the widespread use of optical rotation and electronic circular dichroism, most of the stereochemical assignments are based on empirical correlations with similar compounds reported in the literature. As an alternative, the combination of vibrational circular dichroism and quantum chemical calculations has emerged as a powerful and reliable tool for both conformational and configurational analysis of natural products, even for those lacking UV-Vis chromophores. In this review, we aim to provide the reader with a critical overview of the occurrence of enantiomeric mixtures of secondary metabolites in nature as well the best practices for their detection, enantioselective separation using liquid chromatography, and determination of absolute configuration by means of vibrational circular dichroism and density functional theory calculations.

Structure, Absolute Configuration, and Antiproliferative Activity of Abietane and Icetexane Diterpenoids from Salvia ballotiflora.

From the aerial parts of Salvia ballotiflora, eleven diterpenoids were isolated; among them, four icetexanes and one abietane (1-5) are reported for the first time. Their structures were established by spectroscopic means, mainly ¹H- and 13C-NMR, including 1D and 2D homo- and hetero-nuclear experiments. Most of the isolated diterpenoids were tested for their antiproliferative, anti-inflammatory, and radical scavenging activities using the sulforhodamine B assay on six cancer cell lines, the TPA-induced ear edema test in mice, and the reduction of the DPPH assay, respectively. Some diterpenoids showed anti-proliferative activity, these being icetexanes 6 and 3, which were the most active with IC50 (µM) = 0.27 ± 0.08 and 1.40 ± 0.03, respectively, for U251 (human glioblastoma) and IC50 (µM) = 0.0.46 ± 0.05 and 0.82 ± 0.06 for SKLU-1 (human lung adenocarcinoma), when compared with adriamycin (IC50 (µM) = 0.08 ± 0.003 and 0.05 ± 0.003, as the positive control), respectively. Compounds 3 and 10 showed significant reduction of the induced ear edema of 37.4 ± 2.8 and 25.4 ± 3.0% (at 1.0 µmol/ear), respectively. Compound 4 was the sole active diterpenoid in the antioxidant assay (IC50 = 98. 4 ± 3.3), using α-tocopherol as the positive control (IC50 (µM) = 31.7 ± 1.04). The diterpenoid profile found is of chemotaxonomic relevance and reinforces the evolutionary link of S. ballotiflora with other members of the section Tomentellae.

Comparison of cyclophosphamide-thalidomide-dexamethasone to bortezomib-cyclophosphamide-dexamethasone as induction therapy for multiple myeloma patients in Brazil.

OBJECTIVE/BACKGROUND: Chemotherapy followed by autologous hematopoietic stem cell transplantation (HSCT) remains the standard treatment for multiple myeloma (MM). Thalidomide or bortezomib may be combined with cyclophosphamide and dexamethasone, in what are known as the CTD and VCD protocols, respectively. The objective of this study was to evaluate the clinical characteristics and response rates obtained with CTD and VCD, observing whether the inclusion of bortezomib to treat MM patients in Brazil increases therapeutic efficiency. METHODS: Forty-three MM patients treated with induction protocols CTD and VCD between January 2010 and March 2015 were included. The parameters analyzed were staging, frequency of comorbidities prior to treatment, response rates obtained at each induction cycle, progression-free survival, and overall survival of patients. RESULTS: Very good partial response and complete response obtained with the VCD protocol were superior, compared with the CTD treatment. The presence of comorbidities was similar in the two groups, except kidney failure, which prevailed in the VCD group. Also, 78.3% and 48.3% of patients treated with the VCD and CTD protocols underwent autologous HSCT, respectively. In patients given the VCD protocol, 45.5% had complete response before autologous HSCT. Among those given CTD, this number was only 7.1% (p=0.023). Disease progression after autologous HSCT did not differ between the two groups. CONCLUSION: VCD afforded better responses than the CTD protocol, and improved patient condition before autologous HSCT. However, more studies are necessary including more patients and addressing various clinical conditions, besides the analysis of cost-effectiveness of these treatments.

Preparative chiral separation and absolute configuration of the synthetic pterocarpanquinone LQB-118.

The racemic pterocarpanquinone LQB-118 is active, in mice and hamsters, against tegumentary and visceral leishmaniasis. This compound also presents antiinflammatory and antineoplastic activity in mice. The low level of toxicity observed in these studies makes LQB-118 a promising drug candidate. In order to conduct further biological testing to investigate enantioselectivity in the above-mentioned activities, a multimilligram amount of each enantiomer of LQB-118 was produced. Furthermore, vibrational circular dichroism (VCD) and Density Functional Theory (DFT) calculations were used to determine unambiguously their absolute configurations. The comparison of experimental and calculated VCD data led to the assignment of (-)-LQB-118 as 7aR,12aR and, consequently, (+)-LQB-118 as 7aS12aS.

A novel scoring system to distinguish vocal cord dysfunction from asthma.

BACKGROUND: Vocal cord dysfunction is often misdiagnosed and mistreated as asthma, which can lead to increased and unnecessary medication use and increased health care utilization. OBJECTIVE: To develop a valid scoring index that could help distinguish vocal cord dysfunction from asthma. METHODS: We compared the demographics, comorbidities, clinical symptoms, and symptom triggers of subjects with vocal cord dysfunction (n = 89) and those with asthma (n = 59). By using multivariable logistic regression, we identified distinguishing features associated with vocal cord dysfunction, which were weighted and used to generate a novel score. The scoring index also was tested in an independent sample with documented vocal cord dysfunction (n = 72). RESULTS: We identified symptoms of throat tightness and dysphonia, the absence of wheezing, and the presence of odors as a symptom trigger as key features of vocal cord dysfunction that distinguish it from asthma. We developed a weighted index based on these characteristics, the Pittsburgh Vocal Cord Dysfunction Index. By using a cutoff of ≥4, this index had good sensitivity (0.83) and specificity (0.95) for the diagnosis of vocal cord dysfunction. The scoring index also performed reasonably well in the independent convenience sample with laryngoscopy-proven vocal cord dysfunction and accurately made the diagnosis in 77.8% of subjects. CONCLUSION: The Pittsburgh Vocal Cord Dysfunction Index is proposed as a simple, valid, and easy-to-use tool for diagnosing vocal cord dysfunction. If confirmed by a prospective evaluation in broader use, it may have significant clinical utility by facilitating a timely and accurate diagnosis of vocal cord dysfunction, thereby preventing misdiagnosis and mistreatment as asthma. Future prospective validation studies will need to be performed.