Effect and mechanism of picroside n on p38 mitogen activated protein kinase signal transduction pathway after cerebral ischemia/reperfusion in rats / 解剖学报

Objective To explore the neuroprotective effect and mechanism of picroside II on p38 mitogen activated protein kinase (p38 MAPK) signal transduction pathway after cerebral ischemia/reperfusion injury in rats. Methods A total of 150 healthy male Wistar rats were subject to establish middle cerebral artery occlusion/reperfusion (MCAO/R) models by inserting a monofilament thread. All rats were randomly divided into sham group, model group, picroside (Pier) group, anisomycin (Anis, agonist of p38 MAPK) group, Anis+Picr group, SB203580 (SB, inhibitor of p38 MAPK) group and SB+Picr group. The neurobehavioral function was evaluated by modified neurological severity score points (mNSS) test. The structure of neuron was observed using HE staining. The apoptotic cells were counted using TUNEL assay. The expression of phosphorylated p38 MAPK (p-p38 MAPK) in cortex was determined using the immunohistochemistry. And the expressions of p-p38 MAPK, phosphorylated MAPK activated protein kinase-2 (p-MK2), phosphorylated cytoplasm phospholipase A2 (p-cPLA2), interleukin-6 (IL-6) and tumor necrotic factor a (TNF-α) were determined by Western blotting. Results No neurological behavioral malfunction was found in sham group. In model group, the damage of neuron was worsened, while the neurobehavioral function score, apoptotic cell index and the expressions of p-p38 MAPK, p-MK2, p-cPLA2,IL-6 and TNF-α increased significantly than those in control group. No significant difference was found in TNF-α. In Pier group, SB group and SB+Picr group, the damage of neuron was lighter, the neurological behavioral function was improved, the number of apoptotic cells and the expressions of p-p38 MAPK, p- MK2, p-cPLA2 and IL-6 decreased significantly than those in model group. In Anis group and Anis + Pier group, the damage was worsen, the cerebral infarction was larger, and the expressions of p-p38 MAPK, p-MK2, p-cPLA2 and IL-6 increased significantly than those in control group. Conclusion Picroside II can protect the neuron from the apoptosis and inflammation reaction after MCAO/R by inhibiting p38 MAPK signal transduction pathway in rats.

Picroside II attenuates fatty acid accumulation in HepG2 cells via modulation of fatty acid uptake and synthesis

BACKGROUND/AIMS: Hepatic steatosis is caused by an imbalance between free fatty acids (FFAs) uptake, utilization, storage, and disposal. Understanding the molecular mechanisms involved in FFAs accumulation and its modulation could drive the development of potential therapies for Nonalcoholic fatty liver disease. The aim of the current study was to explore the effects of picroside II, a phytoactive found in Picrorhiza kurroa, on fatty acid accumulation vis-à-vis silibinin, a known hepatoprotective phytoactive from Silybum marianum. METHODS: HepG2 cells were loaded with FFAs (oleic acid:palmitic acid/2:1) for 20 hours to mimic hepatic steatosis. The FFAs concentration achieving maximum fat accumulation and minimal cytotoxicity (500 μM) was standardized. HepG2 cells were exposed to the standardized FFAs concentration with and without picroside II pretreatment. RESULTS: Picroside II pretreatment inhibited FFAs-induced lipid accumulation by attenuating the expression of fatty acid transport protein 5, sterol regulatory element binding protein 1 and stearoyl CoA desaturase. Preatreatment with picroside II was also found to decrease the expression of forkhead box protein O1 and phosphoenolpyruvate carboxykinase. CONCLUSIONS: These findings suggest that picroside II effectively attenuated fatty acid accumulation by decreasing FFAs uptake and lipogenesis. Picroside II also decreased the expression of gluconeogenic genes.

The effect of picroside II on the ERK1/2 signal transduction pathway and its neuroprotective effect on the cerebral ischemic injury in rats / 中华行为医学与脑科学杂志

Objective To explore the neuroprotective effect and mechanism of picroside II on ERK1/2 signal transduction pathway after cerebral ischemia injury in rats.Methods The focal cerebral is-chemic models were established by inserting a monofilament threads into middle cerebral artery occlusion (MCAO) in 100 Wistar rats and treated by injecting picroside II (20 mg/kg) intraperitoneally.The neu-robehavioral function was evaluated by modified neurological severity score points ( mNSS) test.The cerebral infarct volume was measured by tetrazolium chloride ( TTC) staining.The apoptotic cells were counted by terminal deoxynucleotidyl transferase dUTP nick end labeling ( TUNEL) assay.The expression of pERK1/2 in cortex was determined by the immunohistochemistry ( IHC) and Western Blot ( WB) .Results mNSS test showed that severe neurological dysfunction was found in model and LPS groups,and the scores of mNSS were significantly increased;meanwhile the scores of mNSS in treatment group and U0126 group were signifi-cantly lower than that in model and LPS groups (P<0.05).TUNEL assay showed that the apoptotic cell inde-xes (ACI) in different groups were (0.06±0.02),(0.27±0.03),(0.07±0.02),(0.26±0.03)and(0.09± 0.05) ,and the ACI in treatment and U0126 groups was obviously lower than that in model and LPS groups (P<0.05) .With IHC and WB,pERK1/2 level in model group was the highest,which was slightly higher than that of LPS group,and pERK1/2 expression in treatment and U0126 groups was significantly decreased com-pared with that in model and LPS groups (P<0.05) .Conclusion The activation of ERK1/2 by cerebral is-chemia could induce the cell apoptosis.Picroside II might reduce cell apoptosis by inhibiting the activation of ERK1/2 in ischemic brain injury.

Online HPLC-DPPH method for antioxidant activity of Picrorhiza kurroa Royle ex Benth. and characterization of kutkoside by Ultra-Performance LC-electrospray ionization quadrupole time-of-flight mass spectrometry.

Picrorhiza kurroa Royle ex Benth., is widely used in the Indian systems of medicine for the treatment of various liver ailments. Since, the role of oxi­dative stress in the pathogenesis of liver injury has become generally recognized, in present study the free radical scavenging effect of P. kurroa was assessed by on-line HPLC-DPPH and colorimetric DPPH methods. The comparative study on antioxidant activity of P. kurroa extracts by both methods revealed that colorimetric method showed very less free radical scavenging effect while HPLC-DPPH method showed high activity. Further, the kutkoside, an important ingredient of a potent hepatoprotective formulation “kutkin/ picroliv” was investigated for its chemical composition by ultra-performance liquid chromatography coupled with diode array detection/electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-DAD/ESI-QTOF-MS). Kutkoside was considered to be a single compound and reported as picroside-II or kutkoside, however, present investigation illustrated that kutkoside is a mixture of iridoid glycosides namely, picroside II, picroside IV and 6-ferulloylcatalpol.

Synergistic protective effect of picroside Ⅱ and NGF on PC12 cells against oxidative stress induced by H2O2 / 中国临床药理学与治疗学

AIM: To study the synergistic protective effect of picrosideII and NGF for the oxidative stress on PC12 cells induced by hydrogen peroxide (H2O2). METHODS: The fluorescent probe 6-carboxy-2',7'-dichlorodihydrofluorescein (CDCFH) was used to assess the intracellular reactiveoxygen species (ROS) level, and MTT assay, morphological observation as well aslactate dehydrogenase (LDH) leakage were conducted to measure cellular injury. RESULTS: The H2O2-induced cytotoxicity was significantly attenuated in the presence of picroside II (25 μg/mL) and NGF (2 ng/mL). Cultures with this combined treatment possessed decreased level of ROS while increased cell survival, as compared to that of picroside II or NGF alone-treated cells. Accordingly, it was concluded that their synergistic protective activities against oxidative stress in vitro were demonstrated in various aspects including reversing morphological changes, enhancingthe ability of cell proliferation and ROS scavenging. CONCLUSION: Such action supports the therapeutic potential of picroside II and NGF in treating nervous disorders based on their synergistic effect.