Effects of Extract of Prunella Vulgaris Combined with Chemotherapeutic Agents on Lymphoma Cells
|Keywords||Prunella vulgaris anti-tumor effect sensitization Raji cell|
Background and ObjectiveThe malignant lymphoma is a maligant proliferative disease that generates from the human immune system cells and their precursor cells. The incidence rate of malignant lymphoma ranks the 11th in malignant tumors in our country, which often occurs in young and seriously endangers the health and lives of human beings. Currently, combined chemotherapy is the common modality of the treatment of malignant lymphoma. It plays an important role in improving the curative rate and remarkably prolonging the disease-free interval of sufferers, though it has inevitably adverse reactions, such as bone marrow surpression and the decreasing of immune system, which make it difficult for the patients to compete the full course of treatment. Moreover, Primary or secondry drug resistance during treatment has become one of the tough problems of clinical therapy of the malignant tumor. Therefore, it is time to seek new anti-tumor drugs with high therapeutic effect and mild adverse reaction. In recent years, scientist have done a lot of researches and found that the traditional Chinese medicine and the extract of which could exert their anti-tumor effects by inducing tumor cell apoptosis.Prunella vulgaris L is a traditional Chinese herbal medicine that has detoxification and detumescence effects. People had been using it to treat malignant tumor such as thyroid cancer, lymphoma, parotidean carcinoma, tonsillar cancer, nasopharyngeal carcinoma for a long time. The modern pharmacology has proved that Prunella vulgaris L has broad pharmacological activities. The experiments in vivo and vitro showed that it has certain anti-tumor effect. However, it has not been reported that Prunella vulgaris combined with chemotherapeutic agents has effects on proliferation and cell cycle of lymphoma cells.This experiment observed the effects of extract of Prunella vulgaris （PVE） combined with chemotherapeutic agents on proliferation and cell cycle of lymphoma cells by the anti-tumor experimental methods vitro, and explored the mechanisms of anti-tomor action of PVE combined with chemotherapeutic agents, which offers experimental foundations for clinical application.MethodsApplying the technology of cell culture in vitro, the growth inhibition rate of Raji cells treated with PVE combined with Paclitaxel （TAX）, Adriamycin（ADM）, Cisplatin （DDP）, Methotrexate（MTX）, Vincristine（VCR） and Cytrarabine（Ara-c）, respectively, were examined by MTT assay. The distribution of cell cycle of Raji cells were tested by flow cytometry. The expression of apoptosis related protein survivin and caspase-3 were detected by immunocytochemistry. The SPSS13.0 statistical software package was used to carry on statistical processing, the t-test was used to compare the two sample means and the single factor analysis of variance was used to compare any two above, a=0.05 was taken as the significance level and P <0.05 had statistical significance.Results1. The effect of growth inhibition of PVE on Raji cellsPVE could notably inhibit the growth of Raji cells, and there was the statistical difference between experimental group and control group, and the inhibition enhanced along with the increasing dosage, by a dose-dependent manner. The IC50 was 30.26μg/ml.2. The effects of growth inhibition of six chemotherapeutic agents on Raji cellsThe growth of Raji cells could be inhibited partially after being treated by TAX, ADM, MTX, DDP, Arc-a, VCR for 48h and the inhibitory effect enhanced along with the increasing dosage.3. The effect of growth inhibition of PVE combined with six chemotherapeutic agents on Raji cellsPVE could enhance the growth inhibition of TAX and DDP on Raji cells. The effect that PVE elevated the sensitivity of Raji cells to ADM was obvious in low concentration, while the effect of Ara-c was obvious in high concentration. The inhibitory rates of PVE combined with MTX and VCR were not significantly different from those with MTX and VCR alone.4. The effect of PVE combined with TAX on cell cycle of Raji cellsThe typical hypodiploid apoptotic peaks were observed after Raji cells treated by TAX alone and combined with PVE. As compared with TAX group, PVE+TAX resulted in a reduction of the S phase cell population, but an increase of G2～M phase cell population.5. The influence of PVE on the expression of protein survivin and protein caspase-3 of Raji cellsThe results of immunocytochemistry showed that the expression of survivin was down-regulated and the expression of caspase-3 was up-regulated after Raji cells were treated by PVE （30μg/ml） for 48h. The difference between experimental group and control group had statistical significance （P<0.05）.Conclusions1. PVE could notably inhibit the proliferation of Raji cells and the effect of anti-proliferation showed a dose-dependent manner. The IC50 was 30.26μg/ml.2. PVE could elevate the sensitivity of Raji cells to TAX、DDP、ADM、Ara-c.3. PVE combined with TAX could result in a reduction of the S phase cell population and an increase of G2～M phase cell population.4. The expression of survivin was down-regulated and the expression of caspase-3 was up-regulated after Raji cells being treated by PVE.