The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor, classically associated with the regulation of xenobiotic metabolism in response to environmental toxins. In recent years, transgenic rodent models have implicated AhR in aging and longevity. Moreover, several AhR ligands, such as resveratrol and quercetin, are compounds proven to extend the lifespan of model organisms. In this paper, we first review AhR biology with a focus on aging and highlight several AhR ligands with potential anti-aging properties. We outline how AhR-driven expression of xenobiotic metabolism genes into old age may be a key mechanism through which moderate induction of AhR elicits positive benefits on longevity and healthspan. Furthermore, via integration of publicly available datasets, we show that liver-specific AhR target genes are enriched among genes subject to epigenetic aging. Changes to epigenetic states can profoundly affect transcription factor binding and are a hallmark of the aging process. We suggest that the interplay between AhR and epigenetic aging should be the subject of future research and outline several key gaps in the current literature. Finally, we recommend that a broad range of non-toxic AhR ligands should be investigated for their potential to promote healthspan and longevity.

We explore the relationship between epigenetic aging and drug metabolism. We review current evidence for changes in drug metabolism in normal aging, followed by a description of how epigenetic modi... Tweetable abstract Evidence is emerging that epigenetic aging affects the regulation of genes involved in drug metabolism and transport. This may stimulate development of new biomarkers for drug sa...

Background: The level of fasting blood glucose (FBG) is influenced by several factors, including health status, genetics, and diet. Some studies have reported a beneficial effect of Ramadan Intermittent Fasting (RIF) on diabetic patients. However, clinical observations have shown that diabetes is exacerbated in some patients. Aim: This study aims to investigate the influence of RIF on the FBG level, a biomarker of hyperglycemia and diabetes, and to identify factors associated with variations in FBG levels during RIF among diabetic patients. Methods: This study is a cross-sectional study. We monitored the FBG levels of 181 type II diabetic patients over a two-month period, from 20 February to 20 April 2023, which represents the Islamic lunar months of Shaban (8th month) and Ramadan (9th month). Ramadan provides a prominent month of intermittent fasting practice for studying its physiological effects on diabetes. We collected clinical data from each participant, including demographic information, co-morbidities, and medications used during this period. Results: Based on our findings, diabetic patients were classified into three groups depending on the influence of RIF on FBG levels: the positively affected group (44%), whose average FBG levels were reduced; the neutrally affected group (24%), whose average FBG levels did not change; and the negatively affected group (32%), whose average FBG levels increased during the fasting month of Ramadan compared to the previous month. Furthermore, we found that the positive effect of RIF was more frequent among obese, non-geriatric, and male diabetic patients, while the negative effect of RIF was more frequent among patients who were not adhering to the medication. Conclusions: This study concludes that RIF affects FBG levels differently among diabetic patients. These findings should be taken into consideration when treating diabetic patients during the fasting month of Ramadan, and further studies are needed to identify (1) factors associated with inter-individual variation in the response to RIF and (2) those who are great candidates for RIF.