Saxifraga Stolonifera And Its Main Bioactives And Their Anti-Tumor Effects On Lewis Lung Carcinoma-bearing Mice

Saxifraga stolonifera(L.).Meeb(S.stolonifera)is an evergreen and herbaceous herb,which can be used as a landscape plant for ornamental and drug for treatment.The aim of this study is to identify the main bioactive components in S.stolonifera and evaluate the anti-tumor effects of this herb on Lewis lung carcinoma-bearing mice.Furthermore,in order to investigate whether the three main components identified in S.stolonifera has anti-tumor effects,we injected the Lewis lung carcinoma-bearing mice with multiple standard substances of gallic acid,protocatechUic acid and bergenin.Above all,the results of this study will provide an important theoretical basis for evaluating the anti-tumor effect of S.stolonifera,and also will promote the comprehensive utilization of S.stolonifera.The main results are listed as follows:(1)In this study,the contents of crude polysaccharide and amino acids in S.stolonifera were quantified and,we also identified and quantified the main bioactive components in the ethanol extract of S.stolonifera.The results showed that the content of crude polysaccharide in S.stolonifera was 6.80%.Among the amino acids in S.stolonifera,the content of valine was highest(26.24 mg/g)and the content of cysteine was lowest(0.19 mg/g).Moreover,there were four main bioactive components measured by HPLC and mass spectrometry in the herb,which were gallic acid,norbergenin,protocatechuic acid and bergenin,respectively.For the reason that there was no standard substance for norbergenin on the market,only gallic acid,protocatechuic acid and bergenin were quantified in this study and the contents of these three components in the dried powder of S.stolonifera were 0.361,0.060,2.872 mg/g.In addition,we also found that there were big differences in the distribution of these three components between the above-ground and underground parts of lyophilized S.stolonifera,and the results showed that the content of gallic acid in above-ground part of lyophilized S.stolonifera was about five times that of underground part,meanwhile the contents of protocatechuic acid and bergenin in underground parts of lyophilized S.stolonifera were five times and eight times that of above-ground part.In addition,we also found that lyophilized S.stolonifera from different places in China has big differences in the contents of these three bioactive components.(2)In this study,the toxicology of S.stolonifera for C57 mice was evaluated and the result showed that the herb had no toxicology to C57 mice.For further investigation of the anti-tumor effects of the herb,Lewis lung carcinoma-bearing mice were fed with S.stolonifera for 15 days,and the results showed that S.stolonifera could inhibit the growth of lung tumors,and its rate of lung tumor inhibition can reach up to 49.2%.In addition,we found that the herb could also cause tumor cell necrosis and decrease microvessel density by observing the tumor tissue of Lewis lung carcinoma-bearing mice after treated with S.stolonifera.Moreover,S.stolonifera could promote apoptosis of lung tumors in Lewis mice,together with a decrease in gene Bcl2 expression and an increase in gene p53,Sox30 and Bax expression.(3)In this study,the anti-tumor effects of gallic acid,protocatechuic acid and bergenin were evaluated by injecting the Lewis lung carcinoma-bearing mice with multiple standard substances of gallic acid,protocatechuic acid and bergenin(GPB).The results showed that the injection of GPB could increase microvascular vascular density(MVD)by raising the level of protein CD34,and inhibit lung tumour growth significantly by inducing apoptosis of lung tumour cells,and the inhibition rate could reach up to 41.00%.In addition,the combined injection of GPB has low side effects and even has regenerative effects on the immune system and the hematologic system of Lewis lung carcinoma-bearing mice.These results suggest that GPB has obvious anti-angiogenesis and anti-tumour effects on Lewis lung carcinoma-bearing mice.Further studies are needed to explore the detailed mechanisms and to explore GPB as a new lead compound for lung cancer therapy.