Study On Structural Characterization And Anti-tumor Activity In Vivo Of Polysaccharide From Coriadrum Sativum L.

Coriadrum Sativum L.is usually used as a spice in culinary and is also as a common medicinal plant resource with effective pharmacological functions such as hypoglycemic,anti-inflammatory,antioxidant anti-cancer.Previous investigations on C.sativum L.are mostly focused on volatile oil from seeds and the alcohol extracts from leaves,while there are still large gaps on the studies of water extracts especially polysaccharide,which may have stronger biological activities without cytotoxicity due to its good water solubility and leachability compared with essential oil.Accordingly,in order to fully develop this medicinal plant resource and expand its potential use,the objective of present work was to extract a new polysaccharide from C.sativum L.and conducted the bio-relevant research on the structural characteristics and anti-tumor activity that evaluates the putative mechanisms of action.The extraction process was optimized by single factor experiment and response surface methodology(RSM)yielding 4.56±0.17%(n=3),where material-to-liquid ratio1:21 g/m L,extraction time 188 min,extraction temperature 81°C and extraction times 3.After protein removal,dialysis and Sephadex G-200 purification,a homogenous fraction were obtained and named CSP.The average molecular weight of CSP was 1.30×10~3 k Da and the content of total sugar,total acid and protein of CSP were 90.16±0.83%,8.37±0.51%,0.62±0.13%,respectively.The monosaccharide composition of CSP was rhamnose,arabinose,galactose,glucose,and galacturonic acid(Molar ratio:1.52:8.14:20.85:1:2.42),which suggested CSP was an acidic polysaccharide.Combined FT-IR and NMR,found CSP was a pyranose,containingα-andβ-glycosidic bond withα-L-Araf-(1→,→6)-β-D-Galp-(1→,→4)-α-Galp A-(1→,→2 4)-α-L-Rhap-(1→andα-D-Glc.SEM images showed that CSP was stacked in fragmental accumulation and arranged tightly and regularly.Congo red experiment and circular dichroism proved that CSP did not contain three helix structure.By establishing the H22 tumor-bearing mouse model,the body weight,tumor weight,thymus index and spleen index of mice were recorded,finding that CSP could inhibit tumor growth and have no immunosuppressive side effects on immune organs.HE staining showed that CSP-treated group presented pathological changes and apoptotic characteristics in varying degrees,appearing cellular nuclear fragmentation and nuclear debris inducing by CSP,indicating that polysaccharide from C.sativum L.has the certain effect of anti-tumor.Combining Annexin V-FITC/PI double-staining,PI staining and JC-1,it was found that the primary mechanism of inhibiting tumor growth comprised induction of apoptosis and S-phase arrest.And the apoptosis might be realized through the mitochondrial pathway.In summary,the data obtained would provide an important basis for the application of C.sativum L.as a promising and potential anti-liver cancer supplement in functional food or medical industries.