Comprehensive review of melatonin as a promising nutritional and nutraceutical supplement

Background

Melatonin is an indoleamine hormone secreted by the pineal gland at night and has an essential role in regulating human circadian rhythms (the internal 24-h clock) and sleep-wake patterns. However, it has recently gained considerable attention for its demonstrated ability in disease management. This review discusses the major biological activities of melatonin, its metabolites as nutritional supplements, and its bioavailability in food sources.

Methods

The information acquisition process involved conducting a comprehensive search across academic databases including PubMed, Scopus, Wiley, Embase, and Springer using relevant keywords. Only the most recent, peer-reviewed articles published in the English language were considered for inclusion.

Results

The molecular mechanisms by which melatonin induces its therapeutic effects have been the subject of various studies.

Conclusion

While melatonin was initially understood to only regulate circadian rhythms, recent studies indicate that it has a far-reaching effect on various organs and physiological systems, such as immunity, cardiovascular function, antioxidant defense, and lipid hemostasis. As a potent antioxidant, anti-cancer, anti-inflammatory, and immunoregulatory agent, multiple therapeutic applications have been proposed for melatonin.

Vitamin B12 status among asymptomatic young adult females and its association with some anthropometric and biochemical parameters: A cross-sectional study from Makkah (cobalamin deficiency in young adult females)

This study was designed to measure the prevalence of vitamin B12 deficiency among young adult females in Makkah City and study its correlation with some anthropometric and biochemical indicators. A cross-sectional study and a detailed questionnaire were used to collect information from 402 young women aged 19 to 22 years, who were university students. Moreover, dietary assessments using a validated food frequency questionnaire and anthropometric measurements were performed. The mean values of serum vitamin B12, serum folate, hemoglobin, and body mass index (BMI) were 343.29 ± 148.16 pg/mL, 12.72 ± 2.62 ng/mL, 12.69 ± 1.41 g/dL, and 22.64 ± 4.24 kg/m2, respectively. About three-quarters of the study sample had normal vitamin B12 levels, while the rest had vitamin B12 deficiency. Meanwhile, a significant negative association (r = -0.201, P = .048) was found between abdominal fat and serum vitamin B12 levels. This study concluded that the young adult females' population from Makkah City is among the risk groups for vitamin B12 deficiency, which is highly correlated with inappropriate values of weight, body fat, and some blood indices. Appropriate dietary interventions and awareness are needed for this population.

Factors associated with the prevalence of malnutrition among adult hemodialytic patients: A two-center study in the Jeddah region, Saudi Arabia

Chronic kidney disease, one of the most common diseases in the world, is characterized by irreversible impairment of the kidney's metabolic, excretory, and endocrine functions. During end-stage renal disease, patients require renal replacement therapy, such as hemodialysis (HD). Protein-energy wasting is a common health problem among HD patients. This study aims to assess the nutritional status of HD patients at two HD centers in Jeddah, Saudi Arabia, and to determine its associated factors. A cross-sectional study was conducted at two different dialysis centers in Jeddah, Saudi Arabia; 211 female and male HD patients. Malnutrition was recognized using the modified-subjective global assessment (M-SGA) comprising two parts: medical history and physical examination. Sociodemographic and health status for all patients were also determined. Patients were classified based on their M-SGA score into two groups: normal and malnourished. Overall, 54.5% of the participants showed malnutrition. Unemployment, low muscle strength and mass, high level of medication use, and high dialysis vintage were positively (P < .05) associated with malnutrition. In conclusion, the M-SGA score indicates a high prevalence of malnutrition among HD patients. These results show the importance of regular assessment and follow-ups for HD patients ensuring better health and nutritional status.

Consumption of Food Components of the Mediterranean Diet Decreases the Risk of Breast Cancer in the Makkah Region, Saudi Arabia: A Case-Control Study

Background

Breast cancer is one of the leading causes of death worldwide, it affects both men and women. In Saudi Arabia, breast cancer has been the most prevalent type of cancer in women, for the past few years. Dietary habits and cultural beliefs vary according to region, and further studies are required to demonstrate the relationship between these dietary habits and cultural beliefs and the risk of developing breast cancer. This study is aimed to discover the relationship between preventive dietary factors of the Mediterranean diet and rates of breast cancer among postmenopausal women in the Makkah region of Saudi Arabia.

Methods

A case-control study was conducted in King Abdulla Medical City Hospital, Makkah, Saudi Arabia and included 432 Saudi female participants: 218 in the control group and 214 breast cancer patients. All participants were postmenopausal, around the same age, and all were ethnically Arab Saudis. Data were obtained using a self-administered validated questionnaire.

Results

Study results showed that a diet that includes 1-2 servings of legumes weekly, 1-5 servings of fish weekly, 1-5 servings of dairy products daily, 3-5 servings of fruits and vegetables daily, and more than one cup of black tea and coffee per day significantly (p < 0.05) reduces the risk of breast cancer.

Conclusion

This study demonstrates that consuming a Mediterranean diet, which includes legumes, fish, fruits and vegetables, black tea, coffee, and low intake of dairy products, works as a preventive factor against breast cancer in postmenopausal females from the Makkah region.

A novel nuclear receptor corepressor complex, N-CoR, contains components of the mammalian SWI/SNF complex and the corepressor KAP-1

Transcriptional silencing by many transcription factors is mediated by the nuclear receptor corepressor (N-CoR). The mechanism by which N-CoR represses basal transcription involves the direct or indirect recruitment of histone deacetylases (HDACs). We have isolated two multiprotein N-CoR complexes, designated N-CoR-1 and N-CoR-2, which possess histone deacetylase activity that is mediated by distinct HDACs. Based on Western blotting using antibodies against known subunits, the only HDAC found in the N-CoR-1 complex was HDAC3. In contrast, N-CoR-2 contained predominantly HDAC1 and HDAC2 as well as several other subunits that are found in the Sin3A.HDAC complex. Using mass spectrometry and Western blotting, we have identified several novel components of the N-CoR-1 complex including the SWI/SNF-related proteins BRG1, BAF 170, BAF 155, BAF 47/INI1, and the corepressor KAP-1 that is involved in silencing heterochromatin. Indirect immunofluorescence has revealed that both KAP-1 and N-CoR colocalize throughout the nucleus. These results suggest that N-CoR is found in distinct multiprotein complexes, which are involved in multiple pathways of transcriptional repression.