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Natural products (NPs) play an irreplaceable role in the intervention of various diseases and have been considered a critical source of drug development. Many new pharmacodynamic compounds with potential clinical applications have recently been derived from NPs. These compounds range from small molecules to polysaccharides, polypeptides, proteins, self-assembled nanoparticles, and extracellular vesicles. This review summarizes various active substances found in NPs. The investigation of active substances in NPs can potentiate new drug development and promote the in-depth comprehension of the mechanism of action of NPs that can be beneficial in the prevention and treatment of human diseases.
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Mitochondria regulate a range of important physiological and biochemical cellular processes including apoptotic cell death, energy production, calcium homeostasis, oxidative stress, and lipid metabolism. Given their role as the 'engines' of cells, their dysfunction is associated with a variety of disease states. Exploring the relationship between mitochondrial function and disease can reveal the mechanism(s) of drug activity and disease pathology. In this review, we summarized the methods of evaluating the structure and function of mitochondria, including the morphology, membrane fluidity, membrane potential, opening of the membrane permeability transition pore, inner membrane permeabilization, mitochondrial dynamics, mitophagy, oxidative stress, energy metabolism-related enzymes, apoptotic pathway related proteins, calcium concentration, DNA copy number, oxygen consumption, ß-oxidation-related genes and proteins, cardiolipin content, and adenosine triphosphate content. We believe that the information presented in this review will help explore the pathological processes of mitochondria in the occurrence and development of diseases, as well as the activity and mechanism of drugs, and the discovery of new drugs.
Assuntos
Cálcio , Mitocôndrias , Cálcio/metabolismo , Cardiolipinas/metabolismo , Humanos , Potencial da Membrana Mitocondrial , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Mitofagia , Estresse OxidativoRESUMO
OBJECTIVE: To explore the significance of colonic epithelial cell apoptosis and tumor necrosis factor α (TNF-α) changing in pathogenesis of melanosis coli (MC) in guinea pig and the molecular mechanism of rhubarb (Rhu) in inducing the disease, by means of using different dosages of Rhu to induce the disease. METHODS: One hundred and forty-four male guinea pigs, clean grade, were randomized according to their body weight into 5 groups, the untreated normal group and the 4 Rhu groups treated, respectively, with different doses of Rhu, 3 g/kg·d for low dose (Rhu-l) group, 6 g/kg·d for moderate dose (Rhu-m) group, 12 g/kg·d for high dose (Rhu-h) group and 24 g/kg·d for super-high dose (Rhu-s) group via gastric infusion. All animals were sacrificed 60 days later, their viscera were taken for observing the pathologic and morphologic changes with HE, melanin and melatonin staining, and the apoptosis of colonic epithelial cells was detected with TUNEL stain and transmission electric microscopy. In addition, the levels of TNF-α in serum and colonic tissue were measured using ELISA and RT-PCR. RESULTS: The pathological changes of MC could be found by naked eye in all Rhu groups, especially apparent at caecum and proximal end of colon, but did not found in gallbladder, jejunum and ileum. In normal guinea pigs, the colonic membrane was pink in color with no apparent pigment deposition. Membranous color deepened in the Rhu groups depending on the dosage of Rhu used. MC scoring showed the highest scores revealed in the Rhu-s group (6.00±0.00), which was significantly different to those in the Rhu-l (3.86±0.69), Rhu-m (4.43±0.79) and Rhu-h groups (4.88±0.35, all P<0.05). Levels of cell apoptosis in colon and TNF-α in serum in all Rhu groups were higher than those in the normal group (P<0.01), but showed no significant difference among the Rhu groups (P>0.05). Moreover, a positive correlation was found in the degree of induced MC with apoptosis rate and TNF-α level. CONCLUSIONS: Rhu (anthraquinone purgatives) had apparent effect on inducing MC; its molecular mechanism is maybe to destroy intestinal mucosal barrier and advance proinflammatory factor TNF-α releasing, which leads to colonic epithelial cells apoptosis, and finally induce the change of MC due to the deposition of brown pigments, i.e. the macrophage phagocytized apoptotic body, on the colonic membrane.