Crosstalk Between Aging, Circadian Rhythm, and Melatonin.

Circadian rhythms (CRs) are 24-hour periodic oscillations governed by an endogenous circadian pacemaker located in the suprachiasmatic nucleus (SCN), which organizes the physiology and behavior of organisms. Circadian rhythm disruption (CRD) is also indicative of the aging process. In mammals, melatonin is primarily synthesized in the pineal gland and participates in a variety of multifaceted intracellular signaling networks and has been shown to synchronize CRs. Endogenous melatonin synthesis and its release tend to decrease progressively with advancing age. Older individuals experience frequent CR disruption, which hastens the process of aging. A profound understanding of the relationship between CRs and aging has the potential to improve existing treatments and facilitate development of novel chronotherapies that target age-related disorders. This review article aims to examine the circadian regulatory mechanisms in which melatonin plays a key role in signaling. We describe the basic architecture of the molecular circadian clock and its functional decline with age in detail. Furthermore, we discuss the role of melatonin in regulation of the circadian pacemaker and redox homeostasis during aging. Moreover, we also discuss the protective effect of exogenous melatonin supplementation in age-dependent CR disruption, which sheds light on this pleiotropic molecule and how it can be used as an effective chronotherapeutic medicine.

Moringa oleifera leaf extract induces osteogenic-like differentiation of human osteosarcoma SaOS2 cells.

Introduction: Moringa oleifera is known as a 'natural nutrition of the tropics' because it provides vital nutritional supplements and a variety of pharmacological benefits. The focus of this study was to elucidate the dose dependent effects of Moringa oleifera leaf (MOL) extract on the growth of the human osteoblast-like osteosarcoma SaOS-2 cell line and primary osteoblast cells. Methods: Trypan blue & tetrazolium assay, intracellular ROS generation, chromatin condensation, cell cycle analysis, alkaline phosphatase (ALP), mineralization, and osteogenic gene expression were tested on both treated and untreated osteosarcoma SaOS-2 cells. Results: As revealed by cell viability assay, growth activity was observed at concentrations 25 and 50 µg/mL of MOL extract, whereas 100 and 200 µg/mL doses decreased the proliferation activity, resulting in ROS production and chromatin condensation. Cell cycle study revealed that MOL extract at 50 and 100 µg/mL concentrations arrested the cells in the G2/M phase. Low doses increased the ALP levels, mineralization, and expression of the bone morphogenetic protein 2 (BMP2) and runt-related transcription factor 2 (Runx2) genes in osteoblast-like SaOS-2 cells, however, high doses inhibited the proliferation properties of MOL extract. Through AutoDock Vina and iGEMDOCK 2.1, the interaction of active components of MOL, such as ß-sitosterol, quercetin and kaempferol, with BMP2 and Runx2 proteins revealed a reasonable binding affinity. Moreover, these components did not show any Lipinski's rule of five violation and showed predictable pharmacokinetic properties. Conclusion: The results of the biphasic dose-response of MOL extract on the growth activity of osteoblast-like SaOS-2 cells and in silico binding interface, may provide a therapeutic and/or preventive implication in prospective drug development.

Effect of high-dose zinc supplementation with oral hypoglycemic agents on glycemic control and inflammation in type-2 diabetic nephropathy patients.

OBJECTIVE: The study aims to evaluate the effect of zinc sulfate on markers of glycemic control, lipid profile and inflammation in type-2 diabetes with microalbuminuria patients. MATERIALS AND METHODS: Type-2 diabetes with microalbuminuria patients on oral hypoglycemic agents (OHA) and angiotensin converting enzyme (ACE) inhibitors were selected and divided into 2 groups: One group (n = 27) continued with OHA alone, second group (n = 27) was on OHA and in addition 50 mg elemental zinc as zinc sulphate supplementation for 12 weeks. Fasting, post-prandial blood glucose, glycosylated hemoglobin, lipid profiles, inflammatory marker hs-CRP and urine microalbumin were measured. RESULTS: There were no significant differences in biochemical status among groups at baseline. After receiving zinc, the mean fasting blood glucose (FBS), post-prandial blood glucose (PPBS) and glycosylated hemoglobin (HbA1c) were decreased significantly (P = 0.0001). Significant decrease was observed in TG (P = 0.002) and VLDL-cholesterol (P = 0.002), whereas there was no significant decrease in TC and LDL-cholesterol. The high-density lipoprotein (HDL) cholesterol was significantly (P = 0.0001) increased from baseline. Zinc supplementation had significant effects in decreasing serum hs-CRP from 10.51 ± 1.68 mg/L to 7.75 ± 1.56 mg/L (P = 0.0001) and microalbumin level from 146.87 ± 30.83 mg/day to 80.70 ± 33.99 mg/day (P = 0.0001). There were no significant changes in the levels of all these parameters in OHA group. CONCLUSION: Our results conclude that supplementation of zinc improved the effectiveness of OHA and may be beneficial in decreasing blood glucose, TG, urinary albumin excretion and inflammation in diabetic nephropathy patients and thus reducing the risk of complications.