5-Hydroxytryptamine 2C(5-HT2C) receptor is one of the major targets of anti-obesity agents, due to its role in regulation of appetite. In the present study, the 70% EtO H extract of the roots of Bupleurum chinense was...5-Hydroxytryptamine 2C(5-HT2C) receptor is one of the major targets of anti-obesity agents, due to its role in regulation of appetite. In the present study, the 70% EtO H extract of the roots of Bupleurum chinense was revealed to have agonistic activity on 5-HT2 C receptor, and the subsequent bioassay-guided isolation led to identification of several saikosaponins as the active constituents with 5-HT2 C receptor agonistic activity in vitro and anti-obesity activity in vivo. The new compound, 22-oxosaikosaponin d(1), was determined by extensive spectroscopic analyses(HR-ESI-MS, IR, and 1D and 2D NMR). The primary structure-activity relationship study suggested that the intramolecular ether bond between C-13 and C-28 and the number of sugars at C-3 position were closely related to the 5-HT2 C receptor agonistic activity. Saikosaponin a(3), the main saponin in B. chinense, showed obviously agonistic activity on 5-HT2 C receptor with an EC50 value of 21.08 ± 0.33 μmol×L^(–1) in vitro and could reduce food intake by 39.1% and 69.2%, and weight gain by 13.6% and 16.4%, respectively, at 3.0 and 6.0 mg×kg^(–1) in vivo. This investigation provided valuable information for the potential use of B. chinense as anti-obesity agent.展开更多
Traditionally, determination of inhibitory potency of complement inhibitors is performed by the hemolytic assay. However, this assay is not applicable to the lectin pathway, thus impeding the understanding of compleme...Traditionally, determination of inhibitory potency of complement inhibitors is performed by the hemolytic assay. However, this assay is not applicable to the lectin pathway, thus impeding the understanding of complement inhibitors against the overall function of the complement system. The main objective of our study was to develop a specific enzyme-linked immunosorbent assay(ELISA) as an alternative method to assess the anti-complement activity, particularly against the lectin pathway. By using respective coating substrates against different activation pathways, followed by capturing the stable C3c fragments, our ELISA method can be used to screen complement inhibitors against the classical pathway and the lectin pathway. The inhibitory effect of suramin on the classical pathway, as measured by our hemolytic assay is consistent with previous reports. Further assessment of suramin and Bupleurum polysaccharides against the lectin pathway showed a good reproducibility of the method. Comparison of the lectin pathway IC50 between Bupleurum smithii var. parvifolium polysaccharides(1.055 mg/mL) and Bupleurum chinense polysaccharides(0.98 mg/mL) showed that, similar to the classical and alterative pathway, these two Bupleurum polysaccharides had comparable anti-complementary properties against the lectin pathway. The results demonstrate that the described ELISA assay can compensate for the shortcomings of the hemolytic assay in lectin pathway.展开更多
基金supported by the National Science Foundation of China(No.81573322)the Hundred-Talent Program of CAS+1 种基金the CAS"Light of West China"Programthe Youth Innovation Promotion Association of CAS
文摘5-Hydroxytryptamine 2C(5-HT2C) receptor is one of the major targets of anti-obesity agents, due to its role in regulation of appetite. In the present study, the 70% EtO H extract of the roots of Bupleurum chinense was revealed to have agonistic activity on 5-HT2 C receptor, and the subsequent bioassay-guided isolation led to identification of several saikosaponins as the active constituents with 5-HT2 C receptor agonistic activity in vitro and anti-obesity activity in vivo. The new compound, 22-oxosaikosaponin d(1), was determined by extensive spectroscopic analyses(HR-ESI-MS, IR, and 1D and 2D NMR). The primary structure-activity relationship study suggested that the intramolecular ether bond between C-13 and C-28 and the number of sugars at C-3 position were closely related to the 5-HT2 C receptor agonistic activity. Saikosaponin a(3), the main saponin in B. chinense, showed obviously agonistic activity on 5-HT2 C receptor with an EC50 value of 21.08 ± 0.33 μmol×L^(–1) in vitro and could reduce food intake by 39.1% and 69.2%, and weight gain by 13.6% and 16.4%, respectively, at 3.0 and 6.0 mg×kg^(–1) in vivo. This investigation provided valuable information for the potential use of B. chinense as anti-obesity agent.
基金supported by grants from the National Natural Science Foundation of China (Nos. 81274165, 81330089 and 30925042)the State Key Program for Innovative Drugs from the Ministry of Science and Technology of the people’s Republic of China (No. 2012ZX09301001-003)+1 种基金the Science and Technology Commission of Shanghai Municipality (Nos. 12JC1400800 and 10XD1405900)Fudan's Undergraduate Research Opportunities Program (Xiyuan, No. 102305)
文摘Traditionally, determination of inhibitory potency of complement inhibitors is performed by the hemolytic assay. However, this assay is not applicable to the lectin pathway, thus impeding the understanding of complement inhibitors against the overall function of the complement system. The main objective of our study was to develop a specific enzyme-linked immunosorbent assay(ELISA) as an alternative method to assess the anti-complement activity, particularly against the lectin pathway. By using respective coating substrates against different activation pathways, followed by capturing the stable C3c fragments, our ELISA method can be used to screen complement inhibitors against the classical pathway and the lectin pathway. The inhibitory effect of suramin on the classical pathway, as measured by our hemolytic assay is consistent with previous reports. Further assessment of suramin and Bupleurum polysaccharides against the lectin pathway showed a good reproducibility of the method. Comparison of the lectin pathway IC50 between Bupleurum smithii var. parvifolium polysaccharides(1.055 mg/mL) and Bupleurum chinense polysaccharides(0.98 mg/mL) showed that, similar to the classical and alterative pathway, these two Bupleurum polysaccharides had comparable anti-complementary properties against the lectin pathway. The results demonstrate that the described ELISA assay can compensate for the shortcomings of the hemolytic assay in lectin pathway.
