Cyanidin-3-glucoside protects the photooxidative damage of retinal pigment epithelium cells by regulating sphingolipid signaling and inhibiting MAPK pathway

Cyanidin-3-glucoside(C3G)is the most common anthocyanin in dark grains and berries and is a food functional factor to improve visual health.However,the mechanisms of C3G on blue light-induced retinal pigment epithelial(RPE)cell photooxidative damage needs further exploration.We investigated the effects of C3G on blue light-irradiated A2E-containing RPE cells and explored whether sphingolipid,mitogen-activated protein kinase(MAPK),and mitochondria-mediated pathways are involved in this mechanism.Blue light irradiation led to mitochondria and lysosome damage in RPE cells,whereas C3G preserved mitochondrial morphology and function and maintained the lysosomal integrity.C3G suppressed the phosphorylation of JNK and p38 MAPK and mitochondria-mediated pathways to inhibit RPE cell apoptosis.Lipidomics data showed that C3G protected RPE cells against blue light-induced lipid peroxidation and apoptosis by maintaining sphingolipids balance.C3G significantly inhibited ceramide(Cer d18:0/15:0,Cer d18:0/16:0 and Cer d18:0/18:0)accumulation and elevated galactosylceramide(GalCer d18:1/15:0 and GalCer d18:1/16:0)levels in the irradiated A2E-containing RPE cells.Furthermore,C3G attenuated cell membrane damage by increasing phosphatidylcholine and phosphatidylserine levels.C3G inhibited apoptosis and preserved the structure of mitochondria and lysosome by regulating sphingolipid signaling and suppression of MAPK activation in RPE cells.Thus,dietary supplementation of C3G prevents retinal photooxidative damage.

Mechanisms of Apigenin-7-glucoside As a Hepatoprotective Agent

Ixeris chinesis (Thunb.) Ankai has been used as a Chinese folk medicine, but only scanty information is available on the physiological and biochemical functions of the compounds extracted from I. chinesis. In the present study the effects of apigenin -7-glucoside (APIG) isolated from I. chinesis against liver injury caused by carbon tetrachloride (CCl4) were investigated. Methods The contents of malondialdehyde (MDA), glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), and reduced glutathione (GSH) were evaluated by spectrophotography. The content of 8-Hydroxydeoxyguanosine (8-OHdG) was measured with high-performance liquid chromatography (HPLC) equipped with electrochemical and UV detection methods. The antioxidant activity of APIG was evaluated using chemiluminescence single photon counting technology. Results CCl4 significantly increased the enzyme activities of GPT and GOT in blood serum, as well as the level of MDA and 8-OHdG in liver tissue, and decreased the levels of GSH. Pretreatment with APIG was able not only to suppress the elevation of GPT, GOT, MDA and 8-OHdG, and inhibit the reduction of GSH in a dose-dependent manner in vivo, but also to reduce the damage of hepatocytes in vitro. On the other hand, we also found that APIG had strong antioxidant activity against reactive oxygen species (ROS) in vitro in a concentration-dependent manner. Conclusion The hepatoprotective activity of APIG is possibly due to its antioxidant properties, acting as scavengers of ROS. These results obtained in vivo and in vitro suggest that APIG has protective effects against hepatic oxidative injury induced by chemicals. Further studies on the pharmaceutical functions and immunological responses of APIG may help its clinical application.

Syringaresinol-4-O-β-D-glucoside alters lipid and glucose metabolism in HepG2 cells and C2C12 myotubes

Syringaresinol-4-O-β-D-glucoside(SSG), a furofuran-type lignan, was found to modulate lipid and glucose metabolism through an activity screen of lipid accumulation and glucose consumption, and was therefore considered as a promising candidate for the prevention and treatment of metabolic disorder,especially in lipid and glucose metabolic homeostasis. In this study, the effects of SSG on lipogenesis and glucose consumption in Hep G2 cells and C2C12 myotubes were further investigated. Treatment with SSG significantly inhibited lipid accumulation by oil red O staining and reduced the intracellular contents of total lipid, cholesterol and triglyceride in Hep G2 cells. No effect was observed on cell viability in the MTT assay at concentrations of 0.1–10 μmol/L. SSG also increased glucose consumption by Hep G2 cells and glucose uptake by C2C12 myotubes. Furthermore, real-time quantitative PCR revealed that the beneficial effects were associated with the down-regulation of sterol regulatory element-binding proteins-1c,-2(SREBP-1c,-2), fatty acid synthase(FAS), acetyl CoA carboxylase(ACC) and hydroxyl methylglutaryl CoA reductase(HMGR), and up-regulation of peroxisome proliferator-activated receptors alpha and gamma(PPARα and PPARγ). SSG also significantly elevated transcription activity of PPARγtested by luciferase assay. These results suggest that SSG is an effective regulator of lipogenesis and glucose consumption and might be a candidate for further research in the prevention and treatment of lipid and glucose metabolic diseases.

尖嘴林檎叶的化学成分

目的对尖嘴林檎干燥叶的抗氧化化学成分进行研究。方法运用硅胶、Sephadex LH-20柱色谱及重结晶等方法进行分离纯化,根据理化性质、波谱数据及参考文献鉴定单体成分结构。结果从尖嘴林檎干燥叶乙酸乙酯部位分离得到9个化合物,分别鉴定为β-谷甾醇(1)、胡萝卜苷(2)、齐墩果酸(3)、熊果酸(4)、阿江酸(5)、白杨素(6)、根皮苷(7)、三叶苷(8)和isoetin 5'-glucoside(9)。结论以上化合物均为首次从该植物中分离得到,化合物5首次从苹果属植物中分离得到,化合物9为首次从蔷薇科植物中分离得到。

In vivo anticancer activity of maesopsin 4—O— β—glucoside isolated from leaves of Artocarpus tonkinensis A.Chev.Ex Gagnep

Objective:To investigate the antitumor effect of maesopsin 4-O-β-glucoside(TAT2) isolated from the leaves of Artocarpus tonkinensis(A.tonkinensis) A.Chev.ex Gagnep.Methods:The antitumor activity of TAT2 was evaluated in Lewis lung carcinoma(LLC) tumor-bearing mice.BALB/c mice had tumors induced by implantation with 2× 10~6 LLC cells into the subcutaneous right posterior Hank.Tumor-bearing mice were treated orally with a range of doses of TAT2 and a standard drug,doxorubicin.Animals were observed for tumor growth and mortality rate.Blood was collected to determine hematological and biochemical parameters.Results TAT2 was isolated from an ethanolic extract of 1.tonkinensis leaves.Its structure was determined by MS and NMR spectroscopy,and identified as TAT2.The compound did not show acute toxicity at the highest dose tested(2 OIK) mg/kg body weight).TAT2 exhibited antitumor activity by decreasing tumor growth,increasing the survival rale,and ameliorating some hematological and biochemical parameters at doses of 100 and 200 mg/kg body weight(P<0.05).Conclusions:These results indicate that TAT2 possesses clear antitumor activity.Due to its bioavailability and low toxicity,and the fact that it could be isolated in a large scale from A.tonkinensis leaves,the compound shows promise as a potential anticancer drug.

云南沉香果壳的化学成分研究

目的研究云南沉香Aquilaria yunnanensis果壳的化学成分。方法采用硅胶、Sephadex LH-20柱色谱和半制备HPLC技术进行分离、纯化,结合理化性质和波谱数据鉴定化合物的结构。结果从云南沉香果壳的95%乙醇提取物的醋酸乙酯萃取部位中分离得到13个化合物,分别鉴定为trans-linalool-3,6-oxide-7-O-β-D-(6′-O-acetyl)-glucoside(1)、苯乙基-8-O-β-D-(6′-O-乙酰基)-葡萄糖苷(2)、芒果苷(3)、鸢尾酚酮-3,5-C-β-D-二葡萄糖苷(4)、山柰酚-3-O-β-D-葡萄糖苷(5)、木犀草素-7-O-β-D-葡萄糖苷(6)、异鼠李素-3-O-β-D-葡萄糖苷(7)、山柰酚-3-O-β-D-(6″-对-香豆酰基)-葡萄糖苷(8)、香叶醇-1-O-β-D-葡萄糖苷(9)、3-[2-甲酰基-5-(羟甲基)-1H-吡咯-1-基]戊二酸(10)、大麻酰胺D(11)、淫羊藿次苷D2(12)、松柏苷(13)。结论化合物1为新的单萜苷类化合物,命名为云南沉香苷C,化合物2为新天然产物,7、9~13为首次从沉香属植物中分离得到,所有化合物均为首次从该植物中分离得到。

The Formation of Anthocyanic Vacuolar Inclusions in Arabidopsis thaliana and Implications for the Sequestration of Anthocyanin Pigments

Anthocyanins are flavonoid pigments that accumulate in the large central vacuole of most plants. Inside the vacuole, anthocyanins can be found uniformly distributed or as part of sub-vacuolar pigment bodies, the Anthocyanic Vacuolar Inclusions （AVIs）. Using Arabidopsis seedlings grown under anthocyanin-inductive conditions as a model to un- derstand how AVIs are formed, we show here that the accumulation of AVIs strongly correlates with the formation of cyanidin 3-glucoside （C3G） and derivatives. Arabidopsis mutants that fail to glycosylate anthocyanidins at the 5-0 position （Sgt mutant） accumulate AVIs in almost every epidermal cell of the cotyledons, as compared to wild-type seedlings, where only a small fraction of the cells show AVIs. A similar phenomenon is observed when seedlings are treated with vanadate. Highlighting a role for autophagy in the formation of the AVIs, we show that various mutants that interfere with the autophagic process （atg mutants） display lower numbers of AVIs, in addition to a reduced accumulation of anthocyanins. Interestingly, vanadate increases the numbers of AVIs in the atg mutants, suggesting that several pathways might participate in AVl formation. Taken together, our results suggest novel mechanisms for the formation of sub-vacuolar compartments capable of accumulating anthocyanin pigments.