Synthesis and Analgesic Activity of Annelated Xanthine Derivatives in Experimental Models in Rodents

Leishmania mexicana promotes pain-reducing metabolomic reprogramming in cutaneous lesions

Cutaneous leishmaniasis (CL) is characterized by extensive skin lesions, which are usually painless despite being associated with extensive inflammation. The molecular mechanisms responsible for this analgesia have not been identified. Through untargeted metabolomics, we found enriched anti-nociceptive metabolic pathways in L. mexicana-infected mice. Purines were elevated in infected macrophages and at the lesion site during chronic infection. These purines have anti-inflammatory and analgesic properties by acting through adenosine receptors, inhibiting TRPV1 channels, and promoting IL-10 production. We also found arachidonic acid (AA) metabolism enriched in the ear lesions compared to the non-infected controls. AA is a metabolite of anandamide (AEA) and 2-arachidonoylglycerol (2-AG). These endocannabinoids act on cannabinoid receptors 1 and 2 and TRPV1 channels to exert anti-inflammatory and analgesic effects. Our study provides evidence of metabolic pathways upregulated during L. mexicana infection that may mediate anti-nociceptive effects experienced by CL patients and identifies macrophages as a source of these metabolites.

Recent developments in the synthesis and anti-cancer activity of acridine and xanthine-based molecules

Cancer is the uncontrolled growth and development of abnormal cells which is a major cause of death in both advanced and emerging countries. Although currently chemotherapy is most broadly used among an extensive range of anti-cancer therapies, it includes many demerits, such as highly toxic, side-effects, expensive and partial lack of targeting specificity. So the design and synthesis of new molecules that perform specifically on target proteins in tumor cells is a focus of contemporary research. So many researchers aim for new drugs that will be more efficient, more selective, and less toxic. Because of the interesting structures and significant biological profile, naturally occurring acridines and xanthines as well as their analogues have attracted considerable interest in researchers and technologists. Natural and synthetic acridine derivatives form a significant category of heterocycles having nitrogen that is of considerable interest for organic chemists and biological communities due to their attractive anti-cancer activity. Another important class of therapeutic agents with diverse biological properties including cytotoxic effects is xanthine derivatives which are collectively called xanthines (a group of alkaloids). Among many significant molecules based on the structure of the purine, there is a group of natural xanthines, involving theobromine, caffeine, and theophylline and analogues of xanthine display anti-cancer activity. Hence the present chapter wishes to concentrate the attention on the synthesis and anti-cancer activity of acridine and xanthine-based compounds brilliantly.