白果内酯抗卡氏肺孢子虫体外作用的研究

目的研究不同浓度白果内酯抗体外培养卡氏肺孢子虫的作用。方法接种卡氏肺孢子虫(Pc)于人肝癌细胞(HepG-2)。4h后加入试验药物和对照试剂。白果内酯浓度分别为:150、100、50、25、12.5μM/L;对照药喷他脒:15μM/L;以后每隔1d取1/10培养液观察,分别作对倍稀释PCR和六亚甲基四胺银(GMS)染色计数Pc包囊。结果卡氏肺包子虫在体外培养细胞上的生长高峰出现于第6d,对倍稀释PCR提示,白果内酯50μMol/L以上浓度对Pc均有抑制作用,白果内酯150μMol/L、100μMol/L对Pc的抑制率分别为91.67%和93.75%,与喷他脒95.83%之间比较,P>0.05,提示以上两浓度的白果内酯对Pc的抑制作用与喷他脒15μMol/L相似;白果内酯50μMol/L与各组间差异均有显著性,提示其作用优于空白对照组,而不及白果内酯100μMol/L组,同时随着药物剂量的增加其抗Pc的作用增强;药物对Pc包囊的抑制率白果内酯150μMol/L、100μMol/L分别为58.85%、53.62%,与喷他脒63.01%比较,P>0.05,提示这两个浓度的白果内酯对Pc包囊的抑制作用与喷他脒15μMol/L相似;其余浓度白果内酯与空白对照组间差异无显著性,提示这几种浓度的白果内酯对Pc包囊无明显的抑制作用。结论白果内酯在体外对Pc有明显抑制作用,白果内酯150μMol/L、100μMol/L对Pc的抑制作用与喷他脒相当。

In vitro effect of bilobalide on Pneumocystis carinii

The in vitro effect of bilobalide to inhibit the growth of Pneumocystis carinii was investigated in the present study, in which the drug was added to the 4 hours cultures of human carcinoma cell line HepG-2 cell infected with P. carinii at different concentrations of bilobalide (150, 100, 50, 25, 12.5μMol/L), and pentamidine, 15μMol/L was used as control. The cultural suspensions were withdrawn every other day to detect the presence of P.Carinii by PCR assay after serial dilution, and to find out the cysts of this organism by GMS staining. It was found that the peak of the P. Carinii growth was observed on the 6th day . As demonstrated in the PCR assay, a dose of bilobalide over 50μMol/L could inhibit the growth of P.carinii, and the inhibiting rates of bilobalide at concentration of 150 and 100μMol/L were 91.67% and 93.75% respectively. Both of them were quite similar to that of pentamidine(95.8%). The inhibiting effect of 50μMol/L of bilobalide was not as strong as those of the higher concentration groups, but some inhibiting effect still could be observed in comparison with that of the control group. A positive correlation betweeen the concentration of bilobalide and the growth of P.carinii existed, that is , the higher concentration of bilobalide, the stronger inhibiting effect could be demonstrated. The inhibiting rates of 150 and 100μMol/L of bilobalide to P.carinii cysts were 58.85% and 53.65% respectively, which also quite simular to that of pentamidine (63.01%). No inhibiting effect could be demonstrated with other lower concentrations of bilobalide or blank controls. It is proved that bilobalide can inhibit the growth of P.carinii. It suggests that this drug might be a potential therapeutical and prophylactic agent for P.carinii infection in humans.