Analysis of Triterpenoids Component in Loquat Leaf Herbs and Its Preparations by HPLC / 医药导报

Objective To determine the triterpenoid content in Loquat leaf by using HPLC method and to explore the feasibility of ursolic acid and oleanolic acid as the quantitative markers for determination of Loquat leaf and its preparations.Methods Two desugaring methods of Loquat leaf extracts were compared.The contents of ursolic acid and oleanolic acid in Loquat leaf as well as preparations were measured based on a system of HPLC,with a Dumas Diamonsil C18 column (250 mm×4.6 mm,5 μm) was used as analytical column.The mobile phase was consisted of acetonitrile-0.1% phosphoric acid (95∶5) with the flow rate of 0.5 mL·min-1.The column temperature was 30 ℃,the injection volume was 10 μL, the detective wavelength was 210 nm.Results Ursolic acid and oleanolic acid were measured in both Loquat leaf and its preparations,and their contents were fairy stable and comparable.Conclusion Ursolic acid and oleanolic acid can be served as quantitative markers for the determination of Loquat leaf and its preparations.

Increased radiosensitivity of gliomas C6 cell and osteosarcoma MG63 cells by triterpene acids of Ioquat leaf / 中华放射医学与防护杂志

Objective To study the increased radiosensitivity of tumor cells by triterpene acids of loquat leaf (TAL) and mechanism.Methods C6 and MG63 cells were pretreated by TAL,and then were exposed to X-rays at 1,2,3,5,7 Gy.Clonogenic assay was used to evaluate those tumor cells survival fraction (SF) to calculate the sensitization enhancement ratios (SER) of TAL.The cellular micronuclei ratios of tumor cells were analyzed by micronuclei assay.Additionally,the changes of Rad51 and XRCC4 levels were observed by RT-PCR and Western blot.Results D0 values were decreased to 1.31 and 2.85 Gy in C6 and MG63 cells by TAL pretreatment respectively.The SER value of the effect of TAL on C6 and MG63 cells was 1.73 and 2.04,respectively.There was a statistical difference in the cellular micronuclei ratios between tumor cells with TAL above 2 Gy and those without TAL (C6:t =-8.372--2.476,P ＜0.05 ; MG63:t =-4.03--2.557,P ＜ 0.05).TAL attenuated the expression of XRCC4 at transcriptional and translational level,but not for Rad51,a key gene in homologous recombination repair (HRR).Conclusions TAL pretreatment could increase the lethal effect of X-rays on tumor cells in vitro.The mechanism might be involved in the inhibition of non-homologous end joining (NHEJ).

Comparison on Contents among Extracts from Loquat Leaf and Gruffs Using Alcohol as Solvent / 中国药房

OBJECTIVE:To further exploit the active components from Loquat leaf and its gruffs.METHODS:The chief components in loquat leaf and its gruffs were extracted by ultrasound extraction and Soxhlet extraction,respectively,the sepa?ration of ursolic acid and other constituents was performed by HPLC,and the relative amounts of which were determined and compared.RESULTS:Soxhlet extraction is superior to ultrasound extraction in the extraction of loquat leaf and8components in gruffs.Under the same extraction method,the content of ursolic acid in loquat leaves is equivalent to that of gruffs.Besides,the contents of6components in gruffs were above those in loquat leaves.CONCLUSION:The essential component-triterpenic acid in loquat leaves suffered no loss after extraction with water,the active components in gruffs can be further exploited.

Effect of MAPK signal transduction pathway on the expression of TNF-? in alveolar macrophage of chronic bronchitis rats and the target of TAL / 中国药理学通报

Aim To investigate the effect of MAPK signal transduction pathway on the expression of TNF-? in AM(alveolar macrophage) of CB(chronic bronchitis) rats,meanwhile,to initially discuss the possible regulated target of TAL(triterpene acids of loquat.leaf),to explain the mechanism about anti-inflammatory action of TAL on CB rats.Methods The depurated AM was incubated with the special inhibitors of MAPK signal transduction pathway respectively(ERK,p38 or JNK) and the expression of TNF-? was observed by RT-PCR and Western blot.Using factorial design,TNF-? level in AM culture supernatant was detected by ELISA.Results The special inhibitors of ERK(PD98059) and p38(SB203580) could change the expression of TNF-? in AM of CB rats apparently.Factorial analysis shows there is statistical significance between TAL,PD98059/SB203580 and mixture of them.Conclusions TAL reducing the expression of TNF-? may be related with the inhibition of ERK and p38 signal transduction pathway.It may be one of the mechanisms by which TAL has the preventive and therapeutic effects on chronic bronchitis.