The prevalence of obesity has reached alarming levels, which is considered a major risk factor for several metabolic diseases, including type 2 diabetes (T2D), non-alcoholic fatty liver, atherosclerosis, and ischemic cardiovascular disease. Obesity-induced chronic, low-grade inflammation may lead to insulin resistance, and it is well-recognized that macrophages play a major role in such inflammation. In the current review, the molecular mechanisms underlying macrophages, low-grade tissue inflammation, insulin resistance, and T2D are described. Also, the role of macrophages in obesity-induced insulin resistance is presented, and therapeutic drugs and recent advances targeting macrophages for the treatment of T2D are introduced.

Background: Transdermal drug delivery system (TDDS) curing rheumatoid arthritis (RA) for long-term treatment can improve patients’ compliance and reduce the accumulation of drug side effects. However, TDDS is constrained by the tight junction of the stratum corneum and low permeation efficiency. It is necessary to adopt proper permeation methods to ensure the therapeutic effect. The transethosome (TE), which is derived from transfersome and ethosome (E), containing a high content of ethanol along with an edge activator or permeation enhancer, has superior deformability and higher permeation efficiency. Methods and Results: In this study, sinomenine hydrochloride-loaded TE was decorated with ascorbic acid to form antioxidant surface transethosome (AS-TE). It was revealed that TE and AS-TE containing sodium deoxycholate can effectively increase the entrapment efficiency of hydrophilic drug, and has superior deformability and higher permeation efficiency than E group. The plasma pharmacokinetics of rabbits showed that TE group and AS-TE group had similar blood concentration and bioavailability; however, micro-dialysis on synovial fluid demonstrated that AS-TE group had higher drug concentration. In RA rat models, the alleviation of the joint swell of AS-TE group was more obvious in the course of 3 weeks of treatment. The inflammatory cytokines and erythrocyte sedimentation rate were significantly lower than those in the negative control group and TE1 group. Conclusion: AS-TE, which can enhance transdermal permeability and drug deposition for the oxidant stress of RA, had further research potential to serve as a TDDS of RA.

Cardiovascular and metabolic disease (CMD) remains a main cause of premature death worldwide. Berberine (BBR), a lipid-lowering botanic compound with diversified potency against metabolic disorders, is a promising candidate for ameliorating CMD. The liver is the target of BBR so that liver-site accumulation could be important for fulfilling its therapeutic effect. In this study a rational designed micelle (CTA-Mic) consisting of α-tocopheryl hydrophobic core and on-site detachable polyethylene glycol-thiol shell is developed for effective liver deposition of BBR. The bio-distribution analysis proves that the accumulation of BBR in liver is increased by 248.8% assisted by micelles. Up-regulation of a range of energy-related genes is detectable in the HepG2 cells and in vivo. In the high fat diet-fed mice, BBR-CTA-Mic intervention remarkably improves metabolic profiles and reduces the formation of aortic arch plaque. Our results provide proof-of-concept for a liver-targeting strategy to ameliorate CMD using natural medicines facilitated by Nano-technology.