Neuroprotective effects of total saponins from Rubus parvifolius L. on cerebral ischemia/reperfusion injury in rats

This study examines the neuroprotective effects and mechanisms of action of total saponins from Rubus parvifolius L. （TSRP） on focal cerebral ischemia and reperfusion injury in rats. Focal cerebral ischemia and reperfusion injury was performed in rats using the suture method. The results indicate that intragastric injection of TSRP, at 5, 10 and 20 mg/kg, could decrease neurological impairment, reduce cerebral infarct volume, diminish pathological changes, and significantly inhibit the apoptosis of neurons surrounding the ischemic area. In addition, TSRP upregulated the expression of the anti-apoptotic factor Bcl-2, at the protein and mRNA levels, and it downregulated the expression of the pro-apoptotic factor Bax, at the protein and mRNA levels. These findings indicate that TSRP protects against cerebral ischemia/reperfusion injury, and that it may do so by regulating the expression of Bcl-2 and Bax.

Isolation and Chemotaxonomic Significance of Chemical Constituents from Rubus parvifolius

Objective To study the chemical constituents from the roots of Rubus parvifolius. Methods The chemical constituents were extracted and purified by silica gel column chromatography. NMR spectra were used for structural identification. Results Phytochemical study on the roots of R. parvifolius led to the isolation of one ceramide （1）, two anthraquinones （2 and 3）, four triterpenoids （4-7）, two flavonoids （8 and 9）, one fatty acid ester （10）, and two sterols （1 1 and 12）. Conclusion Compound 1 is isolated from the plants of family Rosaceae for the first time, and compounds 2-5 are isolated from genus Rubus for the first time. Though R. parvifolius shares the same major chemical types （triterpenoid, flavonoid, and anthraquinone） with those of R. alceaefolius, a substituent of R. parvifolius, their individual constituents are different. In addition, R. parvifolius contains ceramide （1） with high concentration, while caffeoylquinic acid reported in R. alceaefolius has not been found in R. parvifolius. Furthermore, the results from our phytochemical study are consistent with the DNA phylogenic relationship between R. parvifolius and R. alceaefolius （two separated subgenera）, suggesting that the substitution of the former species with the latter one in folk medicine might not be suitable.

Total Saponins of Rubus Parvifolius L.Exhibited Anti-Leukemia Effect in vivo through STAT3 and eIF4E Signaling Pathways

Objective： To investigate the anti-leukemia effect of total saponins of Rubus parvifo/ius L. （TSRP） on K562 cell xenografts in nude mice and the mechanisms of action. Methods： The K562 cell xenografts in nude mice were established, and then randomly divided into 5 groups, the control group, the cytosine arabinoside group（Am-c） and 3 TSRP groups （20, 40 and 100 mg/kg）. The tumor volume and mass of each group of nude mice were measured and the anti-tumor rates of TSRP were calculated subsequently. The apoptosis status of tumor cells was detected by hematoxylin-eosin （HE） and terminal dexynucleotidyl transferase （TdT）-mediated dUTP nick end labeling （TUNEL） staining analysis. Finally, the activities of apoptosis related signaling of signal transducer and activator of transcription 3 （STAT3）, eukaryotic initiation factor 4E （eIF4E） and B-cell lymphoma-2 （bcl-2） were determined with immunohistochemistry tests. Results： Subcutaneous injection of K562 cells induced tumor formation in nude mice, and the TSRP treated group showed a significant inhibitory effect on tumor formation. The nude mice treated with TSRP showed a significant decrease in tumor growth rate and tumor weight in comparison to the control group （all P〈0.05）. The HE staining and TUNEL assay showed that TSRP induced cell death by apoptosis. The immunohistochemical assay showed down-regulation of the bcl-2 gene in the TSRP treated cells. The phosphorylation levels of elF4E and STAT3 were decreased obviously after the treatment of TSRP. Conclusion： TSRP had an excellent tumor-suppressing effect on K562 cells in the nude mice xenograft model, suggesting that TSPR can be developed as a promising anti-chronic myeloide leukemia drug.

Rubus Parvifolius L.Inhibited the Growth of Leukemia K562 Cells in Vitro and in Vivo

Objective：To determine the antiproliferative activity of Rubus parvifolius L.（RP）extract,its medicinal serum and RP total saponins（RPTS）against K562 cells in vitro and in vivo.Methods：Nude mice models bearing leukemia tumors were treated with different concentrations of RP extract.The size,weight and histopathological change of leukemic tumors were determined.Semi-solid agar culture and methylthiazolyl tetrazolium（MTT）assay were used to determine in vitro the inhibition of colony formation and proliferation of K562 cells respectively by different concentrations of RP medicinal serum and RPTS.Results：RP extract had a tumor inhibition rate of 84.8%when administered to mice at a dose of 1.0 g/day of crude RP root equivalent.Semi-solid agar culture of K562cells in the presence of 20%（v/v）of RP medicinal serum and 150 mg/L RPTS demonstrated a 50.8%and 100%inhibition of the colony forming unit（CFU）-K562,respectively.The same doses of RP medicinal serum and RPTS showed a proliferation inhibition of 31.4%and 86.3%,respectively against K562 cells in MTT assay.Conclusion：RP extract and RPTS show effective antiproliferative activity against myeloid leukemia cells in vitro and in vivo.

Triterpenoids from the roots of Rubus parvifolius

Two new oleanane-type triterpenoids, parvifolactone A(1) and rubuside P(2), together with 11 known triterpenoids, fupenzic acid(3), 18,19-seco,2α,3α-dihydroxyl-19-oxo-urs-11,13(18)-dien-28-oic acid(4), euscaphic acid(5), maslinic acid(6), 1β-hydroxyeuscaphic acid(7), 2α,3α,19α,23-tetrahydroxyolean-12-en-28-oic acid(8), 2α,3β,19α,23-tetrahydroxyurs-12-en-28-oic acid(9), glucosyl pinfaensate(10), rubuside J(11), 2α,3α,19α,23-tetrahydroxyurs-12-en-24,28-dioic acid(12), and 2α,3β,19α- trihydroxyurs-12-en-23,28-dioic acid(13), were isolated from the roots of Rubus parvifolius.