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A key perception of energy homeostasis is the recognition of a mutual regulation between biological clock and cell metabolism. For instance, the regular occurrences of appetite and satiety is not incessant over 24 h, but is instead organized temporally over the 24 h and the light/dark cycle. In mammals, the temporal regulation of metabolism, physiology and behaviour about 24 h is regulated by a complex system of manifold cellular clocks, synchronized via neuronal and hormonal cues by a master clock situated in the suprachiasmatic nuclei of the hypothalamus. Chronic disturbance of circadian rhythms, as seen in human shift-workers (up to 20% of the dynamic populace), has been linked with the advancement of numerous unfavourable mental and metabolic disturbances, suggesting that metabolic processes and biological clock are tightly linked with each other. Comprehension of the functional associations among circadian desynchronization and general health in animal model systems and humans, nevertheless, is still meagre. To sum up, this research topic covers a broad assortment of functional connections amid circadian rhythms and metabolism at molecular, cellular, tissue, organ and organism level. [ABSTRACT FROM AUTHOR]

Rhythmicity is observed in transcriptional expression of a wide range of clock-controlled genes which regulate a variety of normal cell functions like cell division and proliferation. The human circadian timing system functions to co-ordinate humoral, physiological, and behavioral mechanism to promote sleep and waking behavior. The rhythms are generated by neural structures in the hypothalamus that function as a biological clock. Modern lifestyle is also turning to be a relevant factor promoting desynchrony, especially in individuals staying for long hours awake during the night and with disturbed sleep patterns. Chronotherapeutics is relatively new concept in medicine. The main goal of chronotherapeutics is the enhancement of the desired effects of medications and control of their adverse effects. This review addresses the role of circadian rhythms in tumorigenesis. [ABSTRACT FROM AUTHOR]

Cancer is still one of the major causes of mortality in both developing and developed countries. At present, in spite of intensive interventions, a large number of patients suffer from poor prognosis. Also, regarding some phytochemicals, only beneficial effects on cancer-related symptoms or on quality of life have been reported and no positive results exist for their antitumor actions. This review was focused on the phytochemicals whole beneficial effects on various types of cancer have been supported by clinical trials. This review discusses how a disruption of the "biological clock" or circadian rhythms could be involved in the development of these diseases as circadian rhythms control multiple physiological processes such as wake/sleep cycles, hormonal levels, body temperature, metabolism, and immune system. [ABSTRACT FROM AUTHOR]

Disorganized redox homeostasis is a main factor causing a number of diseases and it is imperative to comprehend the orchestration of circadian clock under oxidative stress in the organism, Drosophila melanogaster. This investigation analyses the influence of hesperidin on the circadian rhythms of lipid peroxidation products and antioxidants during rotenone-stimulated oxidative stress in fruit fly. The characteristics of rhythms of thiobarbituric acid reactive substances (TBARS), antioxidants (superoxide dismutase (SOD) and catalase (CAT)) were noticeably decreased in rotenone administered flies. Supplementation of hesperidin to rotenone-treated flies increased the mesor and modulated the amplitudes of antioxidants and conspicuously decreased the mesor values of TBARS. In addition, delays in acrophase in rotenone-induced flies were reversed by hesperidin treatment. Thus, treatment of hesperidin caused normalization of the altered rhythms. Disorganization of 24 h rhythms in markers of redox homeostasis was observed during rotenone treatment and the impairment is severe in circadian clock mutant (Cryb) flies. Reversibility of rhythms was prominent subsequent to hesperidin treatment in wild-type flies than (Cryb) flies. These observations denote a role of circadian clock in redox homeostasis and the use of Drosophila model in screening putative antioxidative phytomedicines prior to their usage in mammalian systems. [ABSTRACT FROM PUBLISHER]

Aim: Alteration of circadian systems can cause cancer and affects its development and response to therapeutics. The present study investigates whether cancer can disrupt circadian locomotor rhythms and evaluated the influence of melatonin (MLT) and oxaliplatin on the levels of antioxidants and circadian locomotor activity rhythms in N-nitrosodiethylamine (NDEA)-induced liver tumor in Indian field mouse (Mus booduga). Materials and Methods: Effects of NDEA, NDEA, and MLT, as well as NDEA and oxaliplatin, on levels of mice liver marker enzymes and antioxidants and their circadian locomotor activity rhythm were assessed. Results: Treatment of mice with NDEA caused significant alteration of their liver marker enzymes [aspartate transaminase and alanine transaminase; P< 0.05 Duncan's multiple range test (DMRT) test] antioxidant levels (superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase; P< 0.05, DMRT test] and circadian locomotor activity rhythm, which were abrogated when the animals were also given MLT or the anticancer drug, oxaliplatin. Conclusion: Our study demonstrated that the circadian clock was disturbed by hepatocarcinogenesis and the effects could be reversed by the chronobiotic, MLT. [ABSTRACT FROM AUTHOR]

Highlights: [•] The 24h rhythms under oxidative stress in Drosophila are studied. [•] Abolishment of per mRNA rhythm in H2O2 treated flies was seen. [•] Reversibility of ROS homeostasis rhythms under Bacopa treatment was noticed. [•] Circadian clock is sensitive to oxidative stress, particularly in cryb mutant. [Copyright &y& Elsevier]

Introduction: Suprachiasmatic nuclei (SCN) contained a variety of neurotransmitters and neuropeptides, and many of them could influence the activities of the circadian pacemaker. Glutamate was the major excitatory neurotransmitter in the mammalian central nervous system (CNS) and in SCN. Materials and Methods: Monosodium glutamate (MSG) (50 mg / kg body weight) was administered subcutaneously for 60 days to Wistar rats; open-field behavioral activity and 24-hour rhythms of glucose, cholesterol, total protein, phospholipids, aspartate transaminase (AST), and alkaline phosphatase (ALT) were studied under conditions of constant light (LL). Results: An open-field behavioral test showed that peripheral movement, central movement, rearing and grooming, were significantly decreased in LL, MSG and LL (MSG-treated) rats when compared with the control rats. The study revealed that the acrophase, amplitude, and mesor values of the glucose, protein, lipid profile, and liver marker enzymes of these rhythms were found to be altered in the experimental group rats when compared with the control rats. Conclusion: Monosodium glutamate, under constant light, modulated the circadian rhythms of lipid profiles and liver marker enzymes, which could be due to glutamate conveying the photic information to the SCN. [ABSTRACT FROM AUTHOR]

To compare the effects of α-ketoglutarate (α-KG) and melatonin on 24-h rhythmicity of oxidative stress in N-nitrosodiethylamine (NDEA)-injected Wistar male rats, melatonin (5 mg/kg i.p.) or α-KG (2 g/kg through an intragastric tube) was given daily for 20 weeks. In blood collected at 6 time points during a 24-h period, serum activity of aspartate transaminase (AST) and alanine transaminase (ALT) and the levels of α-fetoprotein (α-FP) were measured as markers of liver function. To assess lipid peroxidation and the antioxidant status, plasma levels of thiobarbituric acid reactive substances (TBARS) and of reduced glutathione (GSH) were measured, together with the activity of erythrocyte superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST). NDEA augmented mesor and amplitude of rhythms in AST and ALT activity and plasma α-FP levels and mesor values of plasma TBARS, while decreasing mesor values of plasma GSH and erythrocyte SOD, CAT, GPx and GST. Acrophases were delayed by NDEA in all cases except for α-FP rhythm, which became phase-advanced. Co-administration of melatonin or α-KG partially counteracted the effects of NDEA. Melatonin decreased mesor of plasma TBARS and augmented mesor of SOD activity. The results indicate that melatonin and α-KG are effective in protecting from NDEA-induced perturbation of 24-h rhythms in oxidative stress. Melatonin augmented antioxidant defense in rats. [ABSTRACT FROM AUTHOR]