Fixing lymphatics improves glucose metabolism

Paneth cell: The missing link between obesity, MASH and portal hypertension

Obesity is a global health crisis, with its prevalence steadily rising over the past few decades. One concerning consequence of obesity is its association with metabolic associated steatohepatitis [MASH], portal hypertension and liver cirrhosis. Cirrhosis is irreversible, but stages of liver disease before the development of cirrhosis are reversible with appropriate interventions. Studies have brought into light new entities that influences the pathophysiology of portal hypertension. This review provides evidence supporting that, Paneth cells[PCs] in the intestinal epithelium, which remained enigmatic for a century, are the maneuverer of pathophysiology of portal hypertension and obesity. PC dysfunction can cause perturbation of the intestinal microbiota and changes in intestinal permeability, which are the potential triggers of systemic inflammation. Thus, it can offer unique opportunities to understand the pathophysiology of portal hypertension for intervention strategies.

Smart design approaches for orally administered lipophilic prodrugs to promote lymphatic transport

Challenges to effective delivery of drugs following oral administration has attracted growing interest over recent decades. Small molecule drugs (<1000 Da) are generally absorbed across the gastrointestinal tract into the portal blood and further transported to the systemic circulation via the liver. This can result in a significant reduction to the oral bioavailability of drugs that are metabolically labile and ultimately lead to ineffective exposure and treatment. Targeting drug delivery to the intestinal lymphatics is attracting increased attention as an alternative route of drug transportation providing multiple benefits. These include bypassing hepatic first-pass metabolism and selectively targeting disease reservoirs residing within the lymphatic system. The particular physicochemical requirements for drugs to be able to access the lymphatics after oral delivery include high lipophilicity (logP>5) and high long-chain triglyceride solubility (> 50 mg/g), properties required to enable drug association with the lipoprotein transport pathway. The majority of small molecule drugs, however, are not this lipophilic and therefore not substantially transported via the intestinal lymph. This has contributed to a growing body of investigation into prodrug approaches to deliver drugs to the lymphatic system by chemical manipulation. Optimised lipophilic prodrugs have the potential to increase lymphatic transport thereby improving oral pharmacokinetics via a reduction in first pass metabolism and may also target of disease-specific reservoirs within the lymphatics. This may provide advantages for current pharmacotherapy approaches for a wide array of pathological conditions, e.g. immune disease, cancer and metabolic disease, and also presents a promising approach for advanced vaccination strategies. In this review, specific emphasis is placed on medicinal chemistry strategies that have been successfully employed to design lipophilic prodrugs to deliberately enable lymphatic transport. Recent progress and opportunities in medicinal chemistry and drug delivery that enable new platforms for efficacious and safe delivery of drugs are critically evaluated.