Studies On Anti-tumor Effect Of Crude Polysaccharides Extract From Hedyotis Diffusa Willd

Hedyotis diffusa Willd [Oldenlandia diffusa （Willd.） Roxb.], is an annual herbaceousplant of the genus Hedyotis Linn of Rubiaeeae. It also known as the White cross grass,Tang Huang, and crane tongue grass, first recorded in “Shen Nong’s Herbal Classic” as oneof the well-known Chinese traditional medicines. Hedyotis diffusa Willd is widely used forthe treatment of sore throat, snake bites, inflammations, etc.At present, the studies of Polysaccharides have become a most active field in thenatural pharmaceutical chemistry. In order to develop and make use of Hedyotis diffusaWilld better and provide scientific data for the Chinese traditional medicine modernization,we have studied the anti-tumor effect of crude polysaccharides extract from Hedyotisdiffusa Willd in this paper.1. Referring to the related literatures, we reviewed the latest research progress ofHedyotis diffusa Willd in several aspects, such as plant morphology, chemical constituents,and the pharmacological activity of Hedyotis diffusa Willd and polysaccharides.2. Using the solvent extraction method to extract polysaccharides,and determinedthe polysaccharide content is24.6768%by the phenol-sulfuric acid method; then, purifiedcrude polysaccharides extract from Hedyotis diffusa Willd to produce concentratescontaining polysaccharide extract18.7mg/mL, and identified the extract withanthrone-H2SO4colorimetry and Molish, to prove that it is a polysaccharide.3. According to acute toxicity testing of crude polysaccharides extract from Hedyotisdiffusa Willd, failed to get LD50. The maximum dosage experiment: measured themaximum administered dose is598.4g/kg·d in mice, and learned polysaccharide extractbasically non-toxic. The anti-free radical experiment: the free radical scavenge ability ofcrude polysaccharides extract from Hedyotis diffusa Willd is tested with hydroxyl radicaland superoxide anion radical．The results indicated that polysaccharide extract fromHedyotis diffusa Willd can scavenge free radical efficiently，IC－50=1.55710mg/mL，（O2·）IC50=5.68009mg/mL. Anti-tumor experiment in vitro: used MTT method to detect thepolysaccharide extract of Hedyotis diffusa Willd on SMMC-7721cell and SGC-7901. Theresults show that the extract from Hedyotis diffusa Willd inhibited the growth of human tumor cells obvious． Based on the statistical analysis, for SMMC-7721cell:24h，IC50=29.09mg·mL^-1；48h， IC50=13.06mg·mL^-1; for SGC-7901cell:24h，IC50=13.32mg·mL^-1；48h，IC50=23.47mg·mL^-1. The apoptosis of the cells were observedthrough the inverted microscope. With cell morphological comparison, found apoptosissigns in the dose group.This study shows that the crude polysaccharides extract from Hedyotis diffusa Willdhave anti-tumor efficacy. Although detected the anti-tumor mechanisms in the experiment,but didn’t separate them into the monomer. So, the future experiments will further separatethe mixture, and detect anti-tumor effect. Through the further research, hope to find out lowtoxicity and highly effective anti-tumor compounds, and provide a basis theory for thedevelopment of anti-tumor medicine.