Marine and terrestrial environments are rich sources of various bioactive substances, which have been used by humans since prehistoric times. Nowadays, due to advances in chemical sciences, new substances are still discovered, and their chemical structures and biological properties are constantly explored. Drugs obtained from natural sources are used commonly in medicine, particularly in cancer and infectious diseases treatment. Naphthyridines, isolated mainly from marine organisms and terrestrial plants, represent prominent examples of naturally derived agents. They are a class of heterocyclic compounds containing a fused system of two pyridine rings, possessing six isomers depending on the nitrogen atom’s location. In this review, biological activity of naphthyridines obtained from various natural sources was summarized. According to previous studies, the naphthyridine alkaloids displayed multiple activities, i.a., antiinfectious, anticancer, neurological, psychotropic, affecting cardiovascular system, and immune response. Their wide range of activity makes them a fascinating object of research with prospects for use in therapeutic purposes.

Introduction: Obesity is a civilization disease of the 21 st century. The prevalence of obesity and overweight among children and adolescents is constantly increasing. BMI (body mass index) and WHR (waist to hip ratio) are methods of obesity assessment recommended by the WHO. Also, the WtHR (waist to height ratio), which takes into account height, is one of the most popular methods of diagnosing childhood obesity. A more recent diagnostic indicator is the FMI (fat mass index), which considers the percentage of the patient's body fat. The aim of the study was to compare the methods of assessing obesity in children and adolescents using the following indicators: BMI, WHR, WtHR, and FMI and to determine the consistency of the results obtained with them. Material and methods:The study included 195 children aged 11-18 years, from whom the following data were collected: height, weight, waist circumference, and percentage of body fat. The calculated indices (BMI, WHR, WtHR, FMI), expressed in SDS, were compared using the Bland-Altman test, Passing-Bablok regression, and the slope chart. Results: The fewest diagnoses of obesity were shown by FMI SDS (15.9%) and the highest by WHR SDS (28.7%). WHR SDS showed the least consistent results with BMI SDS. Significant statistical differences were found between BMI SDS and both FMI SDS and WtHR SDS. Conclusions: BMI, as the most acceptable obesity indicator, can be used as a screening method for assessing obesity. However, patients with boundary BMI values should be examined more precisely, using more than one index. FMI is recommended.

Background: Despite the dynamic development of medicine, globally cancer diseases remain the second leading cause of death. Therefore, there is a strong necessity to improve chemotherapy regimens and search for new anticancer agents. Pyridocarbazoles are compounds with confirmed antitumor properties based on multimodal mechanisms, i.a. DNA intercalation and topoisomerase II-DNA complex inhibition. One of them, S16020, displayed a wide spectrum of activity. Objective: The aim of the study was to investigate the antitumor potency of six S16020 derivatives, synthesized according to the SAR (structure-activity relationship) method. Methods: The biological evaluation included influence on cancer cell viability, proliferation, and migration, as well as P-glycoprotein activity. NHDF, A549, MCF-7, LoVo, and LoVo/DX cell lines were used in the study. Results: All derivatives displayed low toxicity to normal (NHDF) cells at 1 and 2 µM (≤ 20% of cell growth inhibition). The highest reduction in cell viability was noted in A549 cells which was accompanied by significant disruption of cells proliferation and motility. Compound 1 exhibited the strongest cytotoxic, antiproliferative, and antimigratory effects, higher than the reference olivacine. A significant reduction in P-glycoprotein activity was found for derivatives 6 and 1. Conclusion: S16020 derivatives could be considered as potential candidates for new anticancer drugs.