Detection and characterization of natural and inducible lectins in human serum

AbstractThis study was performed to detect and characterise the possible occurrence of natural and inducible lectins in human serum by hemagglutination method, wherein, the serum was treated using exogenous elicitors, namely, proteases and detergents.Natural and inducible lectins were detected and characterised in human serum. Untreated serum agglutinated buffalo and rabbit RBC, while serum treated with pronase, trypsin, α-chymotrypsin or SDS for the very first time, agglutinated hen/hen and sheep RBC within 15min in a dosimetric manner. Cross adsorption test revealed that both trypsin and α-chymotrypsin-treated serum showed similar RBC adsorption pattern. The lectin activity in untreated, pronase-treated serum was cation independent and moderately sensitive/insensitive to calcium chelator EDTA, whereas, trypsin-treated serum was cation dependent as well as EDTA sensitive (sheep RBC), cation independent and EDTA insensitive (hen RBC). Hemagglutination of untreated serum was inhibited by certain glycosides and di-, oligo-saccharides, whereas, activity in pronase-treated serum was inhibited by hexosamines. By contrast, hemagglutination of trypsin-treated serum showed specificity for acetylated mannosamine as well as sialic acid for sheep RBC and certain glycoproteins for hen RBC.Thus, we have detected inducible lectins with distinct ligand binding specificity, upon treatment of human serum with proteases, namely, pronase and trypsin. Nevertheless, lectin activity was found in untreated human serum too with different ligand specificity

Zeaxanthin and ocular health, from bench to bedside

Cataracts, glaucoma, and age-related macular degeneration are known as major ocular problems which cause blindness among the elderly population worldwide. Oxidative stress plays an important role in both the initiation and progression of ocular problems and with respect to this; dietary antioxidants can serve as a therapeutic strategy for the improvement of ocular health. Zeaxanthin is known as one of the most important and common xanthophyll carotenoids, possessing multiple therapeutic effects such as strong antioxidant and pro-oxidant behaviour as well as anti-inflammatory effects. A growing body of literature shows that zeaxanthin mitigates ocular problems and suppresses oxidative stress in the retinal tissues. This paper aims to critically review the available literature regarding the beneficial effects of zeaxanthin on ocular problems with emphasis on its chemistry, bioavailability, and sources