黄芩甙元和槲皮黄酮对牙本质胶原耐酶解能力的影响

Effect of baicalein and quercetin on enzymatic resistance of dentin collagen

目的 评估黄芩甙元和槲皮黄酮对牙本质胶原耐酶解能力的影响,为寻找理想的牙本质粘接预处理剂提供实验基础.方法 黄芩甙元、槲皮黄酮及原花色素以20％二甲基亚砜乙醇溶液作为溶剂,配制成质量浓度为50 g/L的预处理剂,制备脱矿牙本质试件（黄芩甙元组、槲皮黄酮组及原花色素组,每组19个试件）.37℃下预处理剂孵育24 h后,于酶解液中（含Ⅰ型胶原酶）进行消化.空白对照组和阴性对照组（每组19个试件）以20％二甲基亚砜乙醇溶液作为预处理剂,空白对照组所用酶解液不含Ⅰ型胶原酶.分别测试酶解24 h后各组试件的极限拉伸强度（每组10个试件）及酶解液羟脯氨酸含量（每组6个试件）,场发射扫描电镜观察酶解12h后牙本质胶原形貌（每组3个试件）.结果 酶解24 h后,黄芩甙元组极限拉伸强度最高[（16.00±1.31） MPa],其次为原花色素组[（12.64±0.91） MPa]、空白对照组[（7.84±1.18） MPa]、槲皮黄酮组[（3.20±1.07） MPa]、阴性对照组（0 MPa）,各组间差异均有统计学意义（P＜0.01）.空白对照组酶解液羟脯氨酸含量最低[（0.40±0.16） mg/L],其次为黄芩甙元组[（2.95±0.18） mg/L]、原花色素组[（4.78±0.38 mg/L]、槲皮黄酮组[（28.22± 1.53） mg/L]、阴性对照组[（34.39±0.39） mg/L],各组间差异均有统计学意义（P＜0.01）.酶解12h后场发射扫描电镜显示空白对照组牙本质胶原网络完整;阴性对照组胶原网络完全断裂塌陷;槲皮黄酮组大部分胶原被降解;原花色素组仅少量胶原断裂塌陷;黄芩甙元组胶原网络基本维持完整.结论 50 g/L黄芩甙元和槲皮黄酮均可提高牙本质胶原的耐酶解能力,其中黄芩甙元作用优于原花色素,槲皮黄酮作用弱于原花色素.

Objective To investigate the effect of baicalein and quercetin on the enzymatic resistance of dentin matrix collagen.Methods Baicalein,quercetin and proanthocyanidin were dissolved in 20％ dimethyl sulfoxide （DMSO） ethanol and prepared into pretreatment agents with a concentration of 50 g/L.Demineralized dentin specimens were prepared and immersed in pretreatment agents at 37 ℃ for 24 h,then they were digested in solution containing type Ⅰ collagenase.The pretreatment agents of blank control group and negative control group were 20％ DMSO ethanol,blank control group were digested in solution without collagenase.The ultimate tensile strength （UTS） and the hydroxyproline content of enzymolysis liquid in each group were measured respectively after collagenase digestion for 24 h,the dentin collagen morphology were observed under a field emission scanning electron microscopic （FE-SEM） after collagenase digestion for 12 h.Results After collagenase digestion for 24 h,the baicalein group had the highest UTS [（16.00 ± 1.31） MPa],followed by proanthocyanidin group [（12.64 ± 0.91） MPa],blank control group [（7.84± 1.18） MPa],quercetin group [（3.20± 1.07） MPa],and negative control group （0 MPa）.Significant differences were detected among the UTS in each two group （P＜0.01）.The hydroxyproline content in blank control group was the lowest [（0.40 ± 0.16） mg/L],followed by baicalein group[（2.95 ± 0.18） mg/L],proanthocyanidin group [（4.78±0.38） mg/L],quercetin group[（28.22± 1.53） mg/L],and negative control group [（34.39±0.39） mg/L].There were significant differences among the hydroxyproline contents in each group （P＜ 0.01）.After collagenase digestion for 12 h,intact collagen network could be seen in blank control group under a FE-SEM.Collagen network in negative control group suffered nearly complete destruction and collapsed.In quercetin group,most of collagen collapsed.In proanthocyanidin group,a small portion of collagen destruction and collapse could be seen.In baicalein group,collagen network remained intact.Conclusions The use of baicalein and quercetin could improve enzymatic resistance of dentin matrix collagen at a concentration of 50 g/L.The effect of baicalein was better than that of proanthocyanidin while the effect of quercetin was weaker than that of proanthocyanidin.