RESUMEN
Natural product substances have historically served as the most significant source of new leads for pharmaceutical development. Presently, drug discovery and development have adopted rational approaches to explore herbal resources for treating lifestyle-related diseases such as diabetes. For the treatment of diabetes, Curcumin longa has been extensively studied for evaluation of its antidiabetic potential using various in vivo and in vitro models. Literature resources such as PubMed and Google Scholar have been extensively searched to collect documented studies. Various parts of the plant and extracts have proven antidiabetic effects, namely, anti-hyperglycemic, antioxidant, and anti-inflammatory action, through different mechanisms. It is reported that the plant extract or its phytoconstituents regulate glucose and lipid metabolism. The reported study concluded the diversified antidiabetic role of C. longa and its phytoconstituents and, thus, its potential use as an antidiabetic agent.
RESUMEN
Apicomplexan parasites, through their motor machinery, produce the required propulsive force critical for host cell-entry. The conserved components of this so-called glideosome machinery are myosin A and myosin A Tail Interacting Protein (MTIP). MTIP tethers myosin A to the inner membrane complex of the parasite through 20 amino acid-long C-terminal end of myosin A that makes direct contacts with MTIP, allowing the invasion of Plasmodium falciparum in erythrocytes. Here, we discovered through screening a peptide library, a de-novo peptide ZA1 that binds the myosin A tail domain. We demonstrated that ZA1 bound strongly to myosin A tail and was able to disrupt the native myosin A tail MTIP complex both in vitro and in vivo. We then showed that a shortened peptide derived from ZA1, named ZA1S, was able to bind myosin A and block parasite invasion. Overall, our study identified a novel anti-malarial peptide that could be used in combination with other antimalarials for blocking the invasion of Plasmodium falciparum.
Asunto(s)
Antimaláricos/farmacología , Proteínas de la Membrana/metabolismo , Miosina Tipo IIA no Muscular/metabolismo , Péptidos/farmacología , Plasmodium falciparum/crecimiento & desarrollo , Secuencias de Aminoácidos , Antimaláricos/química , Sitios de Unión , Evaluación Preclínica de Medicamentos , Eritrocitos/parasitología , Ensayos Analíticos de Alto Rendimiento , Humanos , Proteínas de la Membrana/química , Modelos Moleculares , Complejos Multiproteicos/efectos de los fármacos , Miosina Tipo IIA no Muscular/química , Biblioteca de Péptidos , Péptidos/química , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/metabolismo , Unión Proteica , Proteínas Protozoarias/química , Proteínas Protozoarias/metabolismoRESUMEN
OBJECTIVES: Preparations of herbal drugs have drawn considerable interest in scientific community in recent years for the treatment of several stress related health problems including radiation-injury. MATERIALS AND METHODS: An aqueous extract from Valeriana wallichii containing hesperidin as one of its major constituent was evaluated for its ability to protect against radiation-injury in model systems like plasmid deoxyribonucleic acid (DNA) and cultured human fibroblast cells. RESULTS: The extract was found to significantly counter radiation-induced free radicals at 4 h after 5 Gy irradiation, reduced prolonged oxidative stress led increase in mitochondrial mass, enhanced reproductive viability of cultured cells and protected against radiation-induced DNA damage in solution. DISCUSSION: Further studies are required to validate the radioprotective ability of the extract and to develop a safer radioprotective agent.
RESUMEN
Modulation of endogenous gene function, through sequence-specific recognition of double helical DNA via oligonucleotide-directed triplex formation, is a promising approach. Compared to the formation of pyrimidine motif triplexes, which require relatively low pH, purine motif appears to be the most gifted for their stability under physiological conditions. Our previous work has demonstrated formation of magnesium-ion dependent highly stable intermolecular triplexes using a purine third strand of varied lengths, at the purineâ¢pyrimidine (Puâ¢Py) targets of SIV/HIV-2 (vpx) genes (Svinarchuk, F., Monnot, M., Merle, A., Malvy, C., and Fermandjian, S. (1995) Nucleic Acids Res. 23, 3831-3836). Herein, we show that a designed intramolecular version of the 11-bp core sequence of the said targets, which also constitutes an integral, short, and symmetrical segment (G(2)AG(5)AG(2))â¢(C(2)TC(5)TC(2)) of human c-jun protooncogene forms a stable triplex, even in the absence of magnesium. The sequence d-C(2)TC(5)TC(2)T(5)G(2)AG(5)AG(2)T(5)G(2)AG(5)AG(2) (I-Pu) folds back twice onto itself to form an intramolecular triple helix via a double hairpin formation. The design ensures that the orientation of the intact third strand is antiparallel with respect to the oligopurine strand of the duplex. The triple helix formation has been revealed by non-denaturating gel assays, UV-thermal denaturation, and circular dichroism (CD) spectroscopy. The monophasic melting curve, recorded in the presence of sodium, represented the dissociation of intramolecular triplex to single strand in one step; however, the addition of magnesium bestowed thermal stability to the triplex. Formation of intramolecular triple helix at neutral pH in sodium, with or without magnesium cations, was also confirmed by gel electrophoresis. The triplex, mediated by sodium alone, destabilizes in the presence of 5'-C(2)TC(5)TC(2)-3', an oligonucleotide complementary to the 3'-oligopurine segments of I-Pu, whereas in the presence of magnesium the triplex remained impervious. CD spectra showed the signatures of triplex structure with A-like DNA conformation. We suggest that the possible formation of pH and magnesium-independent purine-motif triplexes at genomic Puâ¢Py sequences may be pertinent to gene regulation.