The circadian rhythm regulates the 24-hour physiological and behavioral cycles through endogenous molecular clocks governed by core clock genes via the transcription-translation feedback loop (TTFL). In mammals, the suprachiasmatic nucleus (SCN) serves as the central pacemaker, coordinating the timing of physiological processes throughout the body by regulating clock genes such as CLOCK, BMAL1, PER, and CRY. The molecular clocks of peripheral tissues and cells are synchronized by the SCN through TTFLs to regulate metabolism, immunity, and energy homeostasis. Numerous studies indicate that circadian rhythm disruption is closely related to obesity, type 2 diabetes, metabolic syndrome and other diseases, and the mechanism involves the dysregulation of glucose and lipid metabolism, abnormal insulin signaling and low-grade inflammation. In recent years, small-molecule compounds targeting the core clock components such as CRY, REV-ERB, and ROR have been identified and shown potential to modulate metabolic diseases by stabilizing or inhibiting the activity of key clock proteins. This review summarizes the mechanisms and advances in these compounds, and explores the challenges and future directions for their clinical translation, providing insights for chronotherapy-based metabolic disease interventions.
Humans ; Metabolic Diseases/physiopathology* ; Animals ; Circadian Rhythm/physiology* ; Biological Clocks/drug effects* ; CLOCK Proteins/physiology* ; Circadian Clocks/physiology* ; Suprachiasmatic Nucleus/physiology*

Hepatic fibrosis is a key pathological process in the development of chronic liver disease to cirrhosis, and its core mechanism involves the activation of hepatic stellate cells(HSC) and abnormal deposition of extracellular matrix(ECM). Although existing treatments, such as antiviral drugs, can delay disease progression, they have the problem of single therapeutic targets and cannot reverse fibrosis. Accordingly, multidimensional intervention strategies are urgently needed. Recent studies have shown that circadian rhythm disorders aggravate hepatic fibrosis by regulating metabolism, immunity, and inflammation. Traditional Chinese medicine(TCM) plays a unique role in restoring the circadian clock via multi-target and holistic regulation. This paper establishes a three-dimensional network by systematically integrating biological clock, metabolism, and immunity for the first time to elucidate the scientific connotation of the theory of time-concerned treatment of TCM, and proposes a new strategy for the development of time-targeted compound prescriptions, providing innovative ideas for the treatment of hepatic fibrosis.
Humans ; Liver Cirrhosis/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Circadian Rhythm/drug effects* ; Animals ; Medicine, Chinese Traditional ; Hepatic Stellate Cells/drug effects*

OBJECTIVES: To assess the regulatory effect of cannabidiol (CBD) on circadian rhythm sleep disorders following general anesthesia and explore its potential mechanism in a rat model of propofol-induced rhythm sleep disorder. METHODS: An electrode was embedded in the skull for cortical EEG recording in 24 male SD rats, which were randomized into control, propofol, CBD treatment, and diazepam treatment groups (n=6). Eight days later, a single dose of propofol (10 mg/kg) was injected via the tail vein with anesthesia maintenance for 3 h in the latter 3 groups, and daily treatment with saline, CBD or diazepam was administered via gavage; the control rats received only saline injection. A wireless system was used for collecting EEG, EMG, and body temperature data within 72 h after propofol injection. After data collection, blood samples and hypothalamic tissue samples were collected for determining serum levels of oxidative stress markers and hypothalamic expressions of the key clock proteins. RESULTS: Compared with the control rats, the rats with CBD treatment showed significantly increased sleep time at night (20:00-6:00), especially during the time period of 4:00-6:00 am. Compared with the rats in propofol group, which had prolonged SWS time and increased sleep episodes during 18:00-24:00 and sleep-wake transitions, the CBD-treated rats exhibited a significant reduction of SWS time and fewer SWS-to-active-awake transitions with increased SWS aspects and sleep-wake transitions at night (24:00-08:00). Diazepam treatment produced similar effect to CBD but with a weaker effect on sleep-wake transitions. Propofol caused significant changes in protein expressions and redox state, which were effectively reversed by CBD treatment. CONCLUSIONS CBD can improve sleep structure and circadian rhythm in rats with propofol-induced sleep disorder possibly by regulating hypothalamic expressions of the key circadian clock proteins, suggesting a new treatment option for perioperative sleep disorders.
Animals ; Rats, Sprague-Dawley ; Male ; Cannabidiol/therapeutic use* ; Rats ; Circadian Rhythm/drug effects* ; Propofol/adverse effects* ; Anesthesia, General/adverse effects* ; Sleep Wake Disorders/chemically induced* ; Hypothalamus/metabolism* ; Electroencephalography

Diabetes is a widespread, rapidly increasing metabolic disease that is driven by hyperglycemia. Early glycemic control is of primary importance to avoid vascular complications including development of retinal disorders leading to blindness, end-stage renal disease, and accelerated atherosclerosis with a higher risk of myocardial infarction, stroke and limb amputations. Even after hyperglycemia has been brought under control, "metabolic memory," a cluster of irreversible metabolic changes that allow diabetes to progress, may persist depending on the duration of hyperglycemia. Manipulation of bile acid (BA) receptors and the BA pool have been shown to be useful in establishing glycemic control in diabetes due to their ability to regulate energy metabolism by binding and activating nuclear transcription factors such as farnesoid X receptor (FXR) in liver and intestine as well as the G-protein coupled receptor, TGR5, in enteroendocrine cells and pancreatic β-cells. The downstream targets of BA activated FXR, FGF15/21, are also important for glucose/insulin homeostasis. In this review we will discuss the effect of BAs on glucose and lipid metabolism and explore recent research on establishing glycemic control in diabetes through the manipulation of BAs and their receptors in the liver, intestine and pancreas, alteration of the enterohepatic circulation, bariatric surgery and alignment of circadian rhythms.
Animals ; Bile Acids and Salts ; blood ; metabolism ; Blood Glucose ; drug effects ; metabolism ; Circadian Rhythm ; Diabetes Mellitus ; blood ; drug therapy ; metabolism ; Energy Metabolism ; Homeostasis ; Humans ; Hyperglycemia ; metabolism ; physiopathology ; Hypoglycemic Agents ; therapeutic use ; Intestinal Mucosa ; metabolism ; Intestines ; drug effects ; Lipid Metabolism ; Liver ; drug effects ; metabolism ; Receptors, Cytoplasmic and Nuclear ; metabolism ; Receptors, G-Protein-Coupled ; metabolism ; Signal Transduction

BACKGROUNDParkinson's disease (PD) patients with long-term levodopa (L-DOPA) treatment are suffering from severe circadian dysfunction. However, it is hard to distinguish that the circadian disturbance in patients is due to the disease progression itself, or is affected by L-DOPA replacement therapy. This study was to investigate the role of L-DOPA on the circadian dysfunction in a rat model of PD.

METHODSThe rat model of PD was constructed by a bilateral striatal injection with 6-hydroxydopamine (6-OHDA), followed by administration of saline or 25 mg/kg L-DOPA for 21 consecutive days. Rotarod test, footprint test, and open-field test were carried out to evaluate the motor function. Striatum, suprachiasmatic nucleus (SCN), liver, and plasma were collected at 6:00, 12:00, 18:00, and 24:00. Quantitative real-time polymerase chain reaction was used to examine the expression of clock genes. Enzyme-linked immunosorbent assay was used to determine the secretion level of cortisol and melatonin. High-performance liquid chromatography was used to measure the neurotransmitters. Analysis of variance was used for data analysis.

RESULTSL-DOPA alleviated the motor deficits induced by 6-OHDA lesions in the footprint and open-field test ( P < 0.01, P < 0.001, respectively). After L-DOPA treatment, Bmal1 decreased in the SCN compared with 6-OHDA group at 12:00 ( P < 0.01) and 24:00 ( P < 0.001). In the striatum, the expression of Bmal1, Rorα was lower than that in the 6-OHDA group at 18:00 (P < 0.05) and L-DOPA seemed to delay the peak of Per2 to 24:00. In liver, L-DOPA did not affect the rhythmicity and expression of these clock genes (P > 0.05). In addition, the cortisol secretion was increased (P > 0.05), but melatonin was further inhibited after L-DOPA treatment at 6:00 (P < 0.01).

CONCLUSIONSIn the circadian system of advanced PD rat models, circadian dysfunction is not only contributed by the degeneration of the disease itself but also long-term L-DOPA therapy may further aggravate it.

Animals ; Blotting, Western ; Body Weight ; drug effects ; Circadian Rhythm ; drug effects ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique ; Levodopa ; therapeutic use ; Male ; Oxidopamine ; toxicity ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction

PURPOSE: To evaluate the effects of a bimatoprost/timolol fixed combination (BTFC) and a latanoprost/timolol fixed combination (LTFC) on diurnal intraocular pressure (IOP) and anterior ocular parameters in healthy subjects. METHODS: We enrolled 58 healthy subjects in this prospective clinical study. Thirty subjects were treated with BTFC and 28 subjects were treated with LTFC. IOP was measured every 2 hours except from 01:00 and 05:00. Axial length, corneal curvature, and anterior chamber depth were obtained using the IOL master at baseline and 24 hours later. Adverse events were assessed by patient interview and by slit lamp examination. RESULTS: The largest difference in IOP between treated and untreated eyes 8 hours after instillation was 1.67 mmHg in the BTFC group (p < 0.001). The largest difference in IOP between treated and untreated eyes 10 hours after instillation was 1.93 mmHg in the LTFC group (p < 0.001). For anterior ocular parameters such as axial length, corneal curvature, anterior chamber depth at baseline and 24 hours after instillation, there were no significant differences between the baseline and 24-hour values in either the BTFC or LTFC group. The most frequently occurring adverse event was conjunctival hyperemia, which was found in 33.3% (n = 10) of the BTFC group and 25.0% (n = 7) of the LTFC group (p = 0.486). CONCLUSIONS: BTFC and LTFC provided a significant reduction in IOP from baseline without changing any anterior ocular parameters. Our results provide a reference for monocular trials to assess the effect of eye drops in a clinical condition.
Adult ; Aged ; Aged, 80 and over ; Amides/*administration & dosage ; Antihypertensive Agents/administration & dosage ; Circadian Rhythm/*physiology ; Cloprostenol/administration & dosage/*analogs & derivatives ; Dose-Response Relationship, Drug ; Drug Therapy, Combination ; Female ; Follow-Up Studies ; Glaucoma, Open-Angle/drug therapy/*physiopathology ; Healthy Volunteers ; Humans ; Intraocular Pressure/drug effects/*physiology ; Male ; Middle Aged ; Ophthalmic Solutions ; Prospective Studies ; Prostaglandins F, Synthetic/*administration & dosage ; Timolol/*administration & dosage ; Tonometry, Ocular ; Treatment Outcome

PURPOSE: To evaluate the effects of a bimatoprost/timolol fixed combination (BTFC) and a latanoprost/timolol fixed combination (LTFC) on diurnal intraocular pressure (IOP) and anterior ocular parameters in healthy subjects. METHODS: We enrolled 58 healthy subjects in this prospective clinical study. Thirty subjects were treated with BTFC and 28 subjects were treated with LTFC. IOP was measured every 2 hours except from 01:00 and 05:00. Axial length, corneal curvature, and anterior chamber depth were obtained using the IOL master at baseline and 24 hours later. Adverse events were assessed by patient interview and by slit lamp examination. RESULTS: The largest difference in IOP between treated and untreated eyes 8 hours after instillation was 1.67 mmHg in the BTFC group (p < 0.001). The largest difference in IOP between treated and untreated eyes 10 hours after instillation was 1.93 mmHg in the LTFC group (p < 0.001). For anterior ocular parameters such as axial length, corneal curvature, anterior chamber depth at baseline and 24 hours after instillation, there were no significant differences between the baseline and 24-hour values in either the BTFC or LTFC group. The most frequently occurring adverse event was conjunctival hyperemia, which was found in 33.3% (n = 10) of the BTFC group and 25.0% (n = 7) of the LTFC group (p = 0.486). CONCLUSIONS: BTFC and LTFC provided a significant reduction in IOP from baseline without changing any anterior ocular parameters. Our results provide a reference for monocular trials to assess the effect of eye drops in a clinical condition.
Adult ; Aged ; Aged, 80 and over ; Amides/*administration & dosage ; Antihypertensive Agents/administration & dosage ; Circadian Rhythm/*physiology ; Cloprostenol/administration & dosage/*analogs & derivatives ; Dose-Response Relationship, Drug ; Drug Therapy, Combination ; Female ; Follow-Up Studies ; Glaucoma, Open-Angle/drug therapy/*physiopathology ; Healthy Volunteers ; Humans ; Intraocular Pressure/drug effects/*physiology ; Male ; Middle Aged ; Ophthalmic Solutions ; Prospective Studies ; Prostaglandins F, Synthetic/*administration & dosage ; Timolol/*administration & dosage ; Tonometry, Ocular ; Treatment Outcome

This study investigated the effects of benazepril administered in the morning or evening on the diurnal variation of renin-angiotensin-aldosterone system (RAAS) and clock genes in the kidney. The male Wistar rat models of 5/6 subtotal nephrectomy (STNx) were established. Animals were randomly divided into 4 groups: sham STNx group (control), STNx group, morning benazepril group (MB) and evening benazepril group (EB). Benazepril was intragastrically administered at a dose of 10 mg/kg/day at 07:00 and 19:00 in the MB group and EB group respectively for 12 weeks. All the animals were synchronized to the light:dark cycle of 12:12 for 12 weeks. Systolic blood pressure (SBP), 24-h urinary protein excretion and renal function were measured at 11 weeks. Blood samples and kidneys were collected every 4 h throughout a day to detect the expression pattern of renin activity (RA), angiotensin II (AngII) and aldosterone (Ald) by radioimmunoassay (RIA) and the mRNA expression profile of clock genes (bmal1, dbp and per2) by real-time PCR at 12 weeks. Our results showed that no significant differences were noted in the SBP, 24-h urine protein excretion and renal function between the MB and EB groups. There were no significant differences in average Ald and RA content of a day between the MB group and EB group. The expression peak of bmal1 mRNA was phase-delayed by 4 to 8 h, and the diurnal variation of per2 and dbp mRNA diminished in the MB and EB groups compared with the control and STNx groups. It was concluded when the similar SBP reduction, RAAS inhibition and clock gene profile were achieved with optimal dose of benazepril, morning versus evening dosing of benazepril has the same renoprotection effects.
Animals ; Antihypertensive Agents ; administration & dosage ; Benzazepines ; administration & dosage ; CLOCK Proteins ; metabolism ; Circadian Rhythm ; Drug Chronotherapy ; Gene Expression Profiling ; Hypertension, Renal ; drug therapy ; physiopathology ; Kidney ; drug effects ; physiopathology ; surgery ; Male ; Nephrectomy ; Rats ; Rats, Wistar ; Renin-Angiotensin System ; drug effects ; Treatment Outcome

OBJECTIVETo observe the effect of Chinese herbal medicine for calming Gan (肝) and suppressing hyperactive yang (平肝潜阳, CGSHY) on arterial elasticity function and the circadian rhythm of blood pressure in patients with essential hypertension (EH).

METHODSAdopting a parallel, randomized design, sixty-four patients with EH of stages I and II were randomly divided into two groups according to a random number table, with 32 in each group. The patients in the treatment group were treated with CGSHY and those in the control group were treated with Enalapril. All patients were given 24-h ambulatory blood pressure monitoring (ABPM) before and after a 12-week treatment. Trough/peak (T/P) ratios of systolic and diastolic blood pressure (SBP & DBP) of each group were calculated. The circadian rhythm of their blood pressure was observed at the same time. The changes in elasticity of the carotid artery in the patients, including stiffness parameter (β), pressure-strain elastic modulus (Ep), arterial compliance (AC), augmentation index (AI), and pulse wave velocity (PVWβ) were determined by the echo-tracking technique before and after a 12-week treatment. In the meantime, their levels of nitric oxide (NO) and endothelin-1 (ET-1) were measured respectively.

RESULTSAfter treatment, all parameters in the 24-h ABPM and the elasticity of the carotid artery (β, Ep, AC and PVWβ) were markedly improved, the level of NO was increased, and ET-1 was decreased in both groups as compared with values before treatment (P<0.05 or P<0.01). Further, the improvements in the ratio of T/P of SBP & DBP and in the level of NO and ET-1 in the treatment group were more significant than those in the control group (P<0.05). There were no significant differences in all parameters in the ABPM monitoring and the elasticity of the carotid artery, the recovery of blood pressure circadian rhythm, and the therapeutic effect of antihypertension in EH patients between the two groups (P>0.05).

CONCLUSIONSChinese herbal medicine for CGSHY may lower the blood pressure smoothly and recover the circadian rhythm of blood pressure in EH patients. They may also improve the carotid elasticity of EH patients similar to that of Enalapril. The mechanism of action of Chinese herbs on EH might be related to the regulation of vascular endothelium function.

Antihypertensive Agents ; Arteries ; drug effects ; physiopathology ; Blood Pressure ; drug effects ; physiology ; Blood Pressure Monitoring, Ambulatory ; Circadian Rhythm ; drug effects ; physiology ; Drugs, Chinese Herbal ; therapeutic use ; Elasticity ; drug effects ; physiology ; Enalapril ; pharmacology ; therapeutic use ; Endothelin-1 ; metabolism ; Female ; Humans ; Hypertension ; drug therapy ; physiopathology ; Male ; Middle Aged ; Nitric Oxide ; metabolism ; Time Factors ; Treatment Outcome ; Yin-Yang

This study was focused on the circadian rhythms of DNA synthesis and the expression of c-myc gene in untreated and treated Eca-109 cells in human oesophageal cancer with isorhmnetin. The circadian rhythms of 3H-TdR incorporation and expression of c-myc gene in untreated and treated Eca-109 cells were measured by 3H-thymidine uptake assay and flow cytometry. The data collected were analyzed by ANOVA and Cosinor method. DNA synthesis and expression of c-myc gene in untreated group varied according to circadian time with statistical significance, the distribution curves of both DNA synthesis and the expression level of c-myc were fit for cosinor changes. The circadian rhythms of DNA synthesis and circadian parameters of c-myc expression in treated Eca-109 cells changed. The circadian parameters of DNA synthesis and expression level of c-myc varied after treatment by isorhmnetin. The effects of isorhmnetin on cell proliferation and c-myc expression reached the highest level from 20: 00 to 0: 00. The results provide a guidance for instituting the chemotherapy and chronotherapy of human tumors, when isorhmnetin is for use as anti-cancer agent.
Circadian Rhythm ; drug effects ; DNA ; biosynthesis ; Esophageal Neoplasms ; genetics ; metabolism ; pathology ; Flavonols ; pharmacology ; Humans ; Proto-Oncogene Proteins c-myc ; biosynthesis ; genetics ; Quercetin ; analogs & derivatives ; Tumor Cells, Cultured