黑鳗藤新苷A的溶血性及其对卵清白蛋白免疫小鼠的免疫佐剂作用

目的:评价从黑鳗藤根中分离得到的C21甾体苷--黑鳗藤新苷A(stemucronatoside A,SA)的溶血性及免疫佐剂作用。方法:以分光光度法测定黑鳗藤新苷A对血红细胞的溶血百分率;以卵清白蛋白(OVA)100μg,OVA 100μg加氢氧化铝200μg,OVA 100μg加黑鳗藤新苷A 25μg、50μg和100μg于第1 d和15 d分别免疫ICR小鼠,二免后14天,用MTT法检测刀豆蛋白A(Con A),脂多糖(LPS)和OVA诱导脾淋巴细胞增殖反应,ELISA检测血清中的抗OVA抗体效价。结果:黑鳗藤新苷A显示轻微的溶血作用,其引起兔红细胞50%溶血的浓度(HD50)为331.39±26.16μg/ml。黑鳗藤新苷A在剂量为50和100μg时能显著增强Con A,LPS和OVA诱导的OVA受免小鼠脾淋巴细胞增殖反应(P<0.05 orP<0.01 orP<0.001);50μg时能极显著提高OVA受免小鼠血清中OVA特异性抗体IgG,IgG1和IgG2b的水平(P<0.01 orP<0.001)。结论:黑鳗藤新苷A具有较低的溶血性和显著的免疫佐剂活性。

Haemolytic Activities and Adjuvant Effect of Stemucronatoside A on the Immune Responses to Ovalbumin in Mice

AIM: To evaluate haemolytic activities and adjuvant effect of the C-21 steroidal glycoside-stemucronatoside A (SA) from the roots of Stephanotis mucronata. METHOD: The adjuvant potentials on the cellular and humoral immune responses to mice immunized with ovalbumin (OVA) were examined. ICR mice were immunized subcutaneously with OVA 100 μg alone, a mixture of OVA 100 μg and aluminoid 200 μg, or mixture of OVA 100 μg and SA 25, 50 or 100 μg on the first day and fifteenth day. Two weeks later (d 28), concanavalin A (Con A)-, lipopolysaccharide (LPS)- and OVA-stimulated splenocyte proliferation and OVA-specific antibody in serum were investigated. RESULT: SA showed slight haemolytic activities with its concentration inducing 50% of the maximum haemolysis (HD50) being 331.39±26.16 μg/mL. SA significantly enhanced the Con A-, LPS-, and OVA -stimulated splenocyte proliferation in OVA-immunized mice at the doses of 50 and 100 μg (P<0.05 or P<0.01 or P<0.001). The OVA-specific IgG, IgG1 and IgG2b antibody levels in serum were significantly enhanced especially at the concentration of 50 μg compared with OVA control group (P<0.01 or P<0.001). CONCLUSION: SA possesses immunological adjuvant activities and low-haemolytic effect.