An in vitro based investigation of the cytotoxic effect of water extracts of the Chinese herbal remedy LD on cancer cells

HL60 and HT29 cancer cell lines were exposed to water extracts of LD (1:10, 1:50, 1:100 and/or 1:1000 prepared from a 3 mg/30 ml stock) and for both cell lines growth, apoptotic induction, alterations in cell cycle characteristics and genotoxicity were investigated. The specificity of the action of LD on these cancer cell lines was also investigated by determining its effect on human peripheral blood lymphocytes. Preliminary chemical analysis was carried out to identify cytotoxic constituents of LD using HPLC and LCMS.LD was significantly cytotoxic to, and induced apoptosis in, both cell lines. Apoptotic induction appeared to be cell cycle independent at all concentrations of LD used (1:10, 1:50 and 1:100) for the HL60 cell lines and at 1:10 for the HT29 cell line. At 1:50 and 1:100 apoptotic induction by LD appeared to be cell cycle dependent. LD caused significant genotoxic damage to both cell lines compared to their respective controls. The specificity study showed that LD exerted a moderate cytotoxic action against non-proliferating and proliferating blood lymphocytes but not apoptosis. Chemical analysis showed that a number of fractions were found to exert a significant growth inhibitory effect. However, the molecular weights of compounds within these fractions did not correspond to those from the herbal constituents of LD.It is possible that LD may have some chemotherapeutic potential. However, further studies are required to determine its cytotoxic constituents.Long Dan Xie Gan Wan (LD) is traditionally used for the treatment of a range of conditions, including gall stones, gall bladder diseases, hepatitis, herpes, shingles, cystitis, hyperthyroidism, migraines and jaundice. The traditional ingredients typically used to make LD are Radix Scutellariae (Huang Qui), Fructus Gardeniae (Zhi zi), Radix glycyrrhizae (Gan cao), Radix rehmanniae (Di huang), Radix Gentianae (Long dan), Radix angelicae sinensis (Dang gui), Semen Plantaginis (Che qian zi), Radix Bupleuri