Pseudoginsenoside-F11 attenuates cognitive dysfunction and tau phosphorylation in sporadic Alzheimer's disease rat model.

We previously reported that pseudoginsenoside-F11 (PF11), an ocotillol-type saponin, significantly ameliorated Alzheimer's disease (AD)-associated cognitive defects in APP/PS1 and SAMP8 mice by inhibiting Aß aggregation and tau hyperphosphorylation, suggesting a potential therapeutic effect of PF11 in the treatment of AD. In the present study we further evaluated the therapeutic effects of PF11 on relieving cognitive impairment in a rat model of sporadic AD (SAD). SAD was induced in rats by bilateral icv infusion of streptozotocin (STZ, 3 mg/kg). The rats were treated with PF11 (2, 4, 8 mg·kg-1·d-1, ig) or a positive control drug donepezil (5 mg·kg-1·d-1, ig) for 4 weeks. Their cognitive function was assessed in the nest building, Y-maze, and Morris water maze tests. We showed that STZ icv infusion significantly affected the cognitive function, tau phosphorylation, and insulin signaling pathway in the hippocampus. Furthermore, STZ icv infusion resulted in significant upregulation of the calpain I/cyclin-dependent protein kinase 5 (CDK5) signaling pathway in the hippocampus. Oral administration of PF11 dose-dependently ameliorated STZ-induced learning and memory defects. In addition, PF11 treatment markedly reduced the neuronal loss, protected the synapse structure, and modulated STZ-induced expression of tau phosphorylation by regulating the insulin signaling pathway and calpain I/CDK5 signaling pathway in the hippocampus. Donepezil treatment exerted similar beneficial effects in STZ-infused rats as the high dose of PF11 did. This study highlights the excellent therapeutic potential of PF11 in managing AD.

[Study on effects of different habitat processing methods of Salviae Miltiorrhizae Radix et Rhizoma in rats with acute myocardial ischemia].

To investigate the effects of different habitat processing methods of Salviae Miltiorrhizae Radix et Rhizoma on acute myocardial ischemia induced by pituitrin in rats. In this experiment, the tail vein injection of pituitrin was used to induce acute myocardial ischemia in rats. Electrocardiograph(ECG) heart rate and ΔST changes were recorded, and the levels of creatine kinase isoenzyme(CK-MB), lactate dehydrogenase(LDH), superoxide dismutase(SOD) and malondialdehyde(MDA) in serum of rats were detected to comprehensively evaluate the effects of six processing methods of Salviae Miltiorrhizae Radix et Rhizoma on serum biochemical indexes of rats with acute myocardial injury. The ECG results showed that the Salviae Miltiorrhizae Radix et Rhizoma dried in a drying oven had a good effect on the improvement of heart rate and ΔST of electrocardiogram after ischemia, and all the other groups had some protective effects to different degrees. The results of biochemical indexes in serum of each group after ischemia showed that the activity of CK-MB decreased most significantly in Salviae Miltiorrhizae Radix et Rhizoma high-dose group with drying in a drying oven after sweating and losing weight in a drying oven, high-dose group with drying in the shade and low-dose group with drying in the shade. The activity of LDH decreased most significantly in Salviae Miltiorrhizae Radix et Rhizoma high-dose group with drying in the shade and low-dose group of drying in the shade. The activity of SOD increased most significantly in Salviae Miltiorrhizae Radix et Rhizoma low-dose group with drying in sun, low-dose group with drying in sun after sweating and losing weight in sun, and low-dose group with drying in a drying oven. The activity of MDA decreased most significantly in Salviae Miltiorrhizae Radix et Rhizoma low-dose group with drying in sun. The comprehensive scoring results showed that the highest score was obtained in Salviae Miltiorrhizae Radix et Rhizoma high-dose group with drying in the shade while the scores of other treatment groups were higher than that of the model group. It could be seen that the Salviae Miltiorrhizae Radix et Rhizoma dried in a drying oven had a good improvement effect on electrocardiograph indexes after acute myocardial injury, the Salviae Miltiorrhizae Radix et Rhizoma dried in the shade had a good improvement effect on serum myocardial enzymes after acute myocardial injury, and the other processing methods had a certain protective effect on myocardial injury. The six processing methods evaluated by pharmacodynamics showed that the Salviae Miltiorrhizae Radix et Rhizoma dried in the shade and dried in a drying oven had good efficacy.

Inhibition of PDE5 attenuates streptozotocin-induced neuroinflammation and tau hyperphosphorylation in a streptozotocin-treated rat model.

Intracerebroventricular (icv) streptozotocin (STZ) injection decreases cerebral insulin signal pathway function and produces multiple effects that resemble the molecular, pathological, and behavioural features of Sporadic Alzheimer's disease (SAD). We previously reported that yonkenafil (yonk), the analogue of sildenafil and a novel PDE5 inhibitor exerts an anti-amyloidogenesis effect by regulating the Aß level and inhibiting the expression of ß-amyloid precursor protein in the APP/PS1 transgenic mice model. In this study, the effects of yonk on cognitive behaviors as well as the pathological features in streptozotocin-induced SAD rat model were investigated. The results demonstrated that administration of yonk at doses of 3 and 10 mg/kg for three weeks significantly improved cognitive deficits, attenuated STZ-induced neuronal death, inhibited the over-activation of microglia and astrocytes and the levels of pro-inflammatory markers, as well as decreased PDE5 protein expression in the hippocampus. Furthermore, yonk (3 mg/kg) notably prevented changes in tau hyperphosphorylation, decreased IRS-1and JNK phosphorylation and increased the GSK3ß (ser9) phosphorylation induced by STZ. In summary, these data suggested that yonk significantly reversed STZ-induced memory deficits by inhibiting the over-activation of microglia and astrocytes, as well as ameliorated the levels of pro-inflammatory makers and tau hyperphosphorylation through regulating GSK3ß signalling pathway.

[Determination and comparison of metal elements in Huai radix rehmanniae at different grades by ICP-MS].

The Huai radix rehmanniae at different grades was pretreated by wet digestion, and then the metal elements in the radix rehmanniae and the prepared sample by steaming method were determined using ICP-MS. The results indicate that there is no obvious difference in the metal elements between the different grades and between the dried radix rehmanniae and its corresponding prepared product. There are elements Zn, Cu, Cr, Fe, Mn, Sn, Ni, Mo, Go, etc. in radix rehmanniae, among which the contents of Ca, Fe, Al, Zn and Cu are higher; the metal elements beneficial to human body in dried radix rehmanniae are relative lower than that in the prepared one. The elements such as Co, Ni, Cr, Mn, etc. in radix rehmanniae have poison effects on human body when their contents are more than a certain threshold value, although they are human essential elements. Element Pb is harmful to human body, which should be controlled and reduced/eliminated in the processing procedure. The determination and comparison of the metal elements in radix rehmanniae at different grades can provide useful information about the comprehensive evaluation of dried radix rehmanniae and their prepared products.