Enzymes play key roles in different cellular processes, for example, in signal transduction, cell differentiation and proliferation, metabolic processes, DNA damage repair, apoptosis, and response to stress. A deregulation of enzymes has been considered one of the first causes of several diseases, including cancers. In the last several years, enzyme inhibitors, being good candidates as drugs in the pathogenic processes, have received an increasing amount of attention for their potential application in pharmacology. The marine environment is considered a challenging source of enzyme inhibitors for pharmacological applications. In this review, we report on secondary metabolites with enzyme inhibitory activity, focusing our attention on marine sponges and bacteria as promising sources. In the case of sponges, we only reported the kinase inhibitors, because this class was the most representative isolated so far from these marine organisms.

In the Mediterranean Sea, the Strait of Messina (MS) is a very peculiar area, connecting highly different regions and representing a privileged observatory for an early comprehension and assessment of ecosystems shifts. It is hypothesized that the outbreaks observed near the coast of many sites in the Mediterranean Sea may be the result of transport of permanent populations of P. noctiluca in pelagic waters to the coast, caused by specific hydrodynamic conditions. By both visual observations and numerical experiments our objective is twofold: (A) to help clarify whether the basin of the Aeolian Islands Archipelago (AIA), in the Southern Tyrrhenian Sea (STS), may be the site from which large populations of P. noctiluca are transported to the MS, and (B) to evaluate whether the upwelling turbulent system of the MS can be an energetic opportunity for this species. It should offer a rich habitat without jeopardizing the overall survival of the population, that is subject to stranding due to strong currents. Although very different, the two involved ecosystems (AIA and MS ) are complementary for the success of Pelagia noctiluca life cycle. Outputs obtained by coupling the 3D hydrodynamic model (SHYFEM) with a Lagrangian particle tracking model support the hypothesis of a connectivity between these two ecosystems, particularly in the first half of the year, indicating the coastal areas around the AIA as potential optimal source location for Pelagia larval stages. We support the very attractive hypothesis that two connected systems exist, the former one favours Pelagia's reproduction and acts as a nursery and the latter favours its growth due to higher productivity. We speculate that the reproductive population of the AIA is not permanent, but is renewed every year by individuals who have fed and quickly grown in the MS and who are passively transported by downwelling along canyon "corridors".

Centropages typicus is a temperate calanoid copepod occurring in Atlantic and Mediterranean coastal waters, where its reproductive biology and population dynamics are well-known. C. typicus has also been suggested as a key species for monitoring the impact of environmental changes on copepod secondary production. The aim of this study is to investigate the seasonal and interannual reproductive (egg production and egg hatching success) and feeding (fecal pellet production) traits, population abundance and structure (sex ratio) of C. typicus over a 20-year period at the Long-Term Ecological Research site MareChiara (LTER-MC) in the Gulf of Naples (Central Tyrrhenian Sea, Western Mediterranean Sea), identifying specific trends and patterns. At a seasonal scale, egg production and hatching success were tightly linked with maxima in February-March, driving the juvenile and adult springtime population peaks but showing a poor correlation with phytoplankton abundance, pointing to an omnivorous diet. At a multiannual scale, an observed decrease in the population is backed up by a reduction in egg production, despite an increase in hatching success. The results of this study provide new elements to comprehend the links between C. typicus functional traits, population dynamics, and environmental factors and highlight the importance of running LTER series to monitor the trends in natural environments.