RESUMO
Aging is associated with changes in circulating levels of various molecules, some of which remain undefined. We find that concentrations of circulating taurine decline with aging in mice, monkeys, and humans. A reversal of this decline through taurine supplementation increased the health span (the period of healthy living) and life span in mice and health span in monkeys. Mechanistically, taurine reduced cellular senescence, protected against telomerase deficiency, suppressed mitochondrial dysfunction, decreased DNA damage, and attenuated inflammaging. In humans, lower taurine concentrations correlated with several age-related diseases and taurine concentrations increased after acute endurance exercise. Thus, taurine deficiency may be a driver of aging because its reversal increases health span in worms, rodents, and primates and life span in worms and rodents. Clinical trials in humans seem warranted to test whether taurine deficiency might drive aging in humans.
Assuntos
Envelhecimento , Taurina , Animais , Humanos , Camundongos , Envelhecimento/sangue , Envelhecimento/efeitos dos fármacos , Envelhecimento/metabolismo , Senescência Celular , Haplorrinos , Longevidade/efeitos dos fármacos , Longevidade/fisiologia , Taurina/sangue , Taurina/deficiência , Taurina/farmacologia , Suplementos Nutricionais , Dano ao DNA/efeitos dos fármacos , Telomerase/metabolismoRESUMO
Niclosamide (NIC), an anthelminthic drug, is found to be promising in overcoming the problem of various types of drug-resistant cancer. In spite of strong anti-proliferative effect, NIC shows low aqueous solubility, leading to poor bioavailability. To overcome this limitation, and enhance its physicochemical properties and pharmacokinetic profile, we used co-crystallization technique as a promising strategy. In this work, we brought together the crystal and particle engineering at a time using spray drying to enhance physicochemical and aerodynamic properties of co-crystal particle for inhalation purpose. We investigated the formation and evaluation of pharmaceutical co-crystals of niclosamide-nicotinamide (NIC-NCT) prepared by rapid, continuous and scalable spray drying method and compared with conventional solvent evaporation technique. The newly formed co-crystal was evaluated by XRPD, FTIR, Raman spectroscopy and DSC, which showed an indication of formation of H bonds between drug (NIC) and co-former (NCT) as a major binding force in co-crystal development. The particle geometry of co-crystals including spherical shape, size 1-5 µm and aerodynamic properties (ED, 97.1 ± 8.9%; MMAD, 3.61 ± 0.87 µm; FPF, 71.74 ± 6.9% and GSD 1.46) attributes suitable for inhalation. For spray-dried co-crystal systems, an improvement in solubility characteristics (≥ 14.8-fold) was observed, relative to pure drug. To investigate the anti-proliferative activity, NIC-NCT co-crystals were investigated on A549 human lung adenomas cells, which showed a superior cytotoxic activity compared with pure drug. Mechanistically, NIC-NCT co-crystals enhanced autophagic flux in cancer cell which demonstrates autophagy-mediated cell death as shown by confocal microscopy. This technique could help in improving bioavailability of drug, hence reducing the need for high dosages and signifying a novel paradigm for future clinical applications.
Assuntos
Autofagia/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Niacinamida/farmacologia , Niclosamida/farmacologia , Administração por Inalação , Varredura Diferencial de Calorimetria , Cristalização , Dessecação , Composição de Medicamentos , Niacinamida/administração & dosagem , Niclosamida/administração & dosagem , Tamanho da Partícula , Solubilidade , Análise Espectral RamanRESUMO
Growing rates of tuberculosis (TB) superbugs are alarming, which has hampered the progress made to-date to control this infectious disease, and new drug candidates are few. Epigallocatechin gallate (EGCG), a major polyphenolic compound from green tea extract, shows powerful efficacy against TB bacteria in in vitro studies. However, the therapeutic efficacy of the molecule is limited due to poor pharmacokinetics and low bioavailability following oral administration. Aiming to improve the treatment outcomes of EGCG therapy, we investigated whether encapsulation and pulmonary delivery of the molecule would allow the direct targeting of the site of infection without compromising the activity. Microencapsulation of EGCG was realized by scalable spray-freeze-drying (SFD) technology, forming free-flowing micrometer-sized microspheres (epigallocatechin-3-gallate-loaded trehalose microspheres, EGCG-t-MS) of trehalose sugar. These porous microspheres exhibited appropriate aerodynamic parameters and high encapsulation efficiencies. In vitro studies demonstrated that EGCG-t-MS exhibited dose- and time-dependent killing of TB bacteria inside mouse macrophages by cellular mechanisms of lysosome acidification and autophagy induction. In a preclinical study on TB-infected Balb/c mice model (4 weeks of infection), we demonstrate that the microencapsulated EGCG, administered 5 days/week for 6 weeks by pulmonary delivery, showed exceptional efficacy compared to oral treatment of free drug. This treatment approach exhibited therapeutic outcomes by resolution of inflammation in the infected lungs and significant reduction (P < 0.05) in bacterial burden (up to â¼2.54 Log10 CFU) compared to untreated control and orally treated mice groups. No pathological granulomas, lesions, and inflammation were observed in the histopathological investigation, compared to untreated controls. The encouraging results of the study may pave the avenues for future use of EGCG in TB therapeutics by targeted pulmonary delivery and lead to its translational success.
Assuntos
Mycobacterium tuberculosis , Chá , Animais , Autofagia , Catequina/análogos & derivados , Pulmão , Camundongos , PolifenóisRESUMO
BACKGROUND: A multidisciplinary approach involving healthcare students for health promotion has been recommended. With this view, the primary phase of the integrated health promotion program (IHPP) was designed and pilot tested. METHODS: A pre-post-intervention study was conducted among 55 housewives of two self-help groups in India. The intervention consisted of a motivational interview, interactive session with a nutritionist, group discussion, personal hygiene training, and an illustrative reinforcement leaflet. Interventions were provided by trained dental students. The evaluation was based on outcomes from six tools specifically tailored for the program. These were the health self-regulation self-efficacy scale (HSSS), visual analogue scale (VAS) for self-health perception, oral health knowledge and attitude questionnaire, motivational interview, group discussion, and personal hygiene demonstration test. RESULTS: Statistically significant change in mean pre- and postprogram scores in HSSS (P < 0.001), its two components, metacognitive component, action component, as well as VAS (P = 0.001) indicated a change in health-related perceptions in the participants. Mean oral health knowledge score (6.1), as well as attitude score (3.8), was fair. Most of the participants were able to demonstrate personal hygiene and tooth brushing correctly; take collective decisions about their health, plan changes in their diet, and resolve upon bringing about healthy changes in their lifestyle. CONCLUSION: The program evaluation indicated successful intervention and may be replicated in a larger population. Healthcare student population may be used in developing countries to bring about an attitude change in the underprivileged population through an IHPP.
RESUMO
Antiangiogenic therapy is important for the treatment of gynecological cancer. However, the therapeutic benefit derived from these treatments is transient, predominantly due to the selective activation of compensatory proangiogenic pathways that lead to rapid development of resistance. We aimed to identify and target potential alternative signaling to anti-vascular endothelial growth factor (VEGF) therapy, with a view toward developing a combination of antiangiogenic agents to provide extended therapeutic benefits. We developed a preclinical in vivo phenotypic resistance model of ovarian cancer resistant to antiangiogenic therapy. We measured dynamic changes in secreted chemokines and angiogenic signaling in tumors and plasma in response to anti-VEGF treatment, as tumors advanced from the initial responsive phase to progressive disease. In tumors that progressed following sorafenib treatment, gene and protein expression levels of proangiogenic CXC chemokines and their receptors were significantly elevated, compared with responsive tumors. The chemokine (C-X-C motif) ligand 8 (CXCL8), also known as interleukin-8 (IL-8) increase was time-dependent and coincided with the dynamics of tumor progression. We used SB225002, a pharmacological inhibitor of chemokine (C-X-C motif) receptor 2 (CXCR2), to disrupt the CXC chemokine-mediated functions of ovarian cancer cells in in vitro assays of cell growth inhibition, spheroid formation, and cell migration. The combination of CXCR2 inhibitor with sorafenib led to a synergistic inhibition of cell growth in vitro, and further stabilized tumor progression following sorafenib in vivo. Our results suggest that CXCR2-mediated chemokines may represent an important compensatory pathway that promotes resistance to antiangiogenic therapy in ovarian cancer. Thus, simultaneous blockage of this proangiogenic cytokine pathway using CXCR2 inhibitors and the VEGF receptor (VEGFR) pathway could improve the outcomes of antiangiogenic therapy.