Function And Mechanism Of Traditional Chinese Medicine Rhubarb On Cancer Cell Line And Innate Immune Regulation

Objective: Screening of natural products for anti-tumoractivity is a new subject in the field of tumor therapy. Weexamined the cell biology and molecular biology of carcinomacells and lymphocyte cells treated with the extracts of Chineseherbal medicines. Many cancer patients have taken thesemedicines for abstrictions, but their effects at the cellular levelon cancer cell are largely unknown. The aim of the present studywas to observe the anticancer effect of Rhubarb extract andinvestigate the mechanism; to enlarge the application oftraditional Chinese medicine and provide experiment data; toproduce the scientific evidence for developing andmanufacturing new antitumor drugs.Methods1 Rhubarb extract was prepared.2 The acute toxicity of Rhubarb extract in mice was measu-red by LD50 test with different drug dosages of Rhubarb extract.3 Using the colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5biphenyl tetrazolium (MTT) cell proliferation assay, weinvestigated the suppressive effect of Rhubarb extract on theproliferation of tumor cells such as esophagus carcinoma cellline TE13, gastric carcinoma cell line BGC823, liver cancer cellline BEL7402 and colon cancer cell line Colon26 up to 48h invitro. The proliferation of TE13 line was observed at 24 hours,48 hours and 72 hours.4 The proliferation quantity of esophagus carcinoma cellsand peripheral blood lymphocytes of the esophagus carcinomapatients were analyzed using MTT assay with and without thetreatment of Rhubarb extract in concentrations of10-10000μg/ml up to 48h.5 A serum pharmacological study on proliferation effectsof Rhubarb extract was also done. Rhubarb extract's bloodserum was prepared at first. The proliferation quantity ofesophagus carcinoma cells and peripheral blood lymphocytes ofthe patients and esophagus carcinoma cell line TE13 treated bythe above serum were analyzed using MTT assay with thetreatment of Rhubarb extract.6 The level of serum total complement activity in the miceafter being treated with and without Rhubarb extract weredetected. The complement activity result was measured by thetrace fast plate complement activity assay.7 The levels of erythrocyte CR1 adherence function in themice after being treated with and without Rhubarb extract weredetected also. The erythrocyte CR1 adherence function activityresult was measured by the complement activating yeast rosetteassay.8 Augmentation of natural killer (NK) cell killing activitywas studied in vitro. NK cells from spleen cells of normal micetreated with and without Rhubarb extract were observed in vitrofor their cytotoxicity against YAC-1 cells. In the meantime, theproliferation quantity of mice spleen cells was measured afterthem being treated with PHA.9 The models bearing tumor mice had been constructed byinjecting H-22 tumor cells. Then their antitumor activity wasobserved with being treated Rhubarb extract in vivo.Results1 The LD50 of Rhubarb extract was about 8043mg/kg, with95% confidence limits 6400-9667mg/kg.2 Rhubarb extract can markedly inhibit the proliferation oftumor cells such as esophagus carcinoma cell line TE13, gastriccarcinoma cell line BGC823 and live carcinoma cell lineBEL7402 and Colon26 in vitro. Rhubarb can inhibit tumor cellsin a concentration and time-dependent manner at 10-100μg/ml,The extract (100μg/ml) significantly inhibited TE13,BGC823,BEL7402,Colon26 tumor cells. Inhibitory rates were 51.9%,37.8%,42.8%,62.5% respectively, that of DDP were 46.7%,56.9%, 53.5% and 33.4%. The inhibitory effect on TE13 wasenhanced with overtime.3 When the esophagus carcinoma cell and peripheral bloodlymphocyte of the esophagus carcinoma patients werespecifically stimulated with Rhubarb extract (10-100μg/ml).Inhibitory rates at Rhubarb extract 100μg/ml remarkablyinhibited than that of the controls. It was significantlytime-dependent. Inhibitory rates were 37.9% and 30.1%respectively. The inhibitory effect was equal to that of DDP(P>0.05).4 A serum pharmacological study on proliferation effects ofRhubarb extract was utilized. The proliferation quantity ofesophagus carcinoma cell and peripheral blood lymphocyte ofthe patient and esophagus carcinoma cell line TE13 wereinhibited by Rhubarb extract's blood serum. They can facilitatethe apoptosis tumor cells in a concentration dependent manner.The extract (100mg/ml) exhibited significant inhibitory effect;they were 36.7%. Peripheral blood lymphocyte was alsosignificantly inhabited after being treated extract (100mg/ml).The inhibitory rate was 33.0%. They were not comparable withthe DDP (31.2%). (P>0.05).5 Rhubarb extract can significantly increase erythrocyteCR1 adherence function in the mice measured by complementactivating yeast rosette assay. The results showed that the levelsof erythrocyte CR1 adherence function were higher in thedrug-treated group than in the control group in a dose-dependentmanner. The mice erythrocyte CR1 adherence functions weresignificantly higher at the high and middle dose than that ofcontrol group (P< 0.05). The adherence function of the low dosegroup(17.2) was little higher than that of control group(15.5) (P>0.05).6 The levels of complement activity in the mice aftertreated with Rhubarb extract were detected by the trace fastplate complement activity assay. It appeared lower in aconcentration dependent manner compared with the controlgroup (P< 0.05). The complement activity of the low dose groupwas a little lower than that of the control group (P>0.05).7 Pretreatment of spleen NK cells primarily with Rhubarbover 48h significantly enhanced their cytotoxicity againstYAC-1 cells in vitro. NK cells of three dose groups were highlycytotoxic against YAC-1, increasing the destruction of YAC-1by 39.0%,28.7% and 17.7%. It was higher than control (15.4%).PHA stronger stimulates spleen cells of the high dose group thancontrol group (P< 0.05).8 The general condition of being tested mice were muchbetter than that of control mice after being treated with Rhubarbextract, with tumor growing slowly and life time beingprolonged(P < 0.05).Conclusion: The results suggest that the Chinese herbalmedicine Rhubarb extract is a low toxicity drug. Rhubarbextract was cytotoxic to variety of cancer cells. It shows doseand time dependent manner effect. But it has a weaker inhibiteffect on peripheral blood lymphocyte. It significantly comparedto their effect on normal cells, and Rhubarb reduces carcinomalesions and prolongs the survival. The reaction of the tumorcells to these extracts was similar to conventionalchemotherapeutic drugs (DDP). We used the MTT colorimetricassay to measure Rhubarb extract activity of mice spleen. Theresults showed that the Rhubarb extract activity of immunized...