Hamid Reza Sadeghnia

Increased oxidative stress has been implicated in the mechanisms of delayed neuronal cell death following cerebral ischemic insult. In this study, we investigated whether safranal, an active constituent of Crocus sativus L. stigmas, may ameliorate ischemia-reperfusion injury (IRI)-induced oxidative damage in rat hippocampus. Male NMRI rats were divided into six groups, namely, sham, control, ischemia and ischemia treated with safranal (four groups). The transient global cerebral ischemia was induced using four-vessel-occlusion method for 20 min. Safranal was injected intraperitoneally (727.5 mg/kg, 363.75 mg/kg, 145.5 mg/kg, and 72.75 mg/kg body weight) 5 min. prior to reperfusion and the administration was continued every 24 hours for 72 hours after induction of ischemia. The markers of oxidative stress including thiobarbituric acid reactive substances (TBARS), total sulfhydryl (SH) groups and antioxidant capacity of hippocampus (using FRAP assay) were measured. The transient global cerebral ischemia induced a significant increase in TBARS levels (p<0.001), decrement in both antioxidant power (FRAP value) (p<0.05) and total sulfhydryl (SH) concentrations (p<0.001) in comparison with sham-operated animals. Following safranal administration the total SH contents (3.2 vs. 0.7micromol/g, p<0.001, safranal 727.5 mg/kg) and antioxidant capacity (4.12 vs. 1.16 micromol/g, p<0.001; 727.5 mg/kg) were elevated in hippocampus in comparison with ischemic group. The MDA level was declined significantly in hippocampus (52.31 vs. 159.70 nmol/g, p<0.001; 727.5 mg/kg). It is concluded that safranal have some protective effects on different markers of oxidative damage in hippocampal tissue from ischemic rats.

PI3K/AKT/mTOR signaling pathway is one of the key dysregulated pathways in different tumor types, including colorectal cancer (CRC). Activation of this pathway is shown to be related with cellular transformation, tumor progression, cell survival, and drug resistance. There is growing body of data evaluating the value of PI3K/AKT/mTOR inhibitors in CRC (e.g., BEZ235, NVP-BEZ235, OSI-027, everolimus, MK-2206, KRX-0401, BYL719, and BKM120). This report summarizes the current knowledge about PI3K/AKT pathway and its cross talk with ERK/MAPK and mTOR pathways with particular emphasis on the value of targeting this pathway as a potential therapeutic target in treatment of colorectal cancer. J. Cell. Biochem. 119: 2460-2469, 2018. © 2017 Wiley Periodicals, Inc.

PURPOSE: The generation of reactive oxygen species and lipid peroxidation are associated with tissue injury following ischemic insult; therefore, the use of antioxidants appears rational in the improvement of kidney diseases therapy. The aim of the present study was to assess the effect of aqueous saffron extract (Crocus sativus L.) and its active constituent, crocin, on oxidative stress following renal ischemia-reperfusion injury (IRI) in rats. METHODS: The cellular redox status (thiobarbituric acid reactive species (TBARS) and total thiol levels) and antioxidant power (using ferric reducing/antioxidant power test) were assessed in control and ischemic groups. The left kidney was exposed to warm ischemia for 60 min followed by reperfusion for 90 min. The macerated aqueous extract of saffron (with doses of 5, 20 and 80 mg/kg, i.p.) and crocin (with doses of 50, 200 and 400 mg/kg, i.p.) were administrated prior to induction of ischemia. Normal saline (10 ml/kg, i.p.) was injected to control group and a sham group that did not have ischemia-reperfusion. RESULTS: Ischemia-reperfusion (IR) caused a significant increase in TBARS levels (p<0.001) and decrement in both antioxidant power (FRAP value) (p<0.05) and total thiol concentration (p<0.001) in kidney homogenate samples. In crocin pretreated groups, a reduction in TBARS levels (from 85.8 +/- 5.4 to 20.9 +/- 1.5 nmol/g tissue, p<0.001; 400 mg/kg) and elevation in antioxidant power (FRAP value) (from 3.05 +/- 0.16 to 4.15 +/- 0.16 micromol/g tissue, p<0.001; 400 mg/kg) and total thiol concentrations (from 0.38 +/- 0.03 to 0.62 +/- 0.03 mM, p<0.001; 200 mg/kg), as compared with control group, were observed. The aqueous extract also reduced lipid peroxidation products (from 85.8 +/- 5.4 to 15.9 +/- 2.6 nmol/g tissue, p<0.001; 80 mg/kg) and increased antioxidant power (from 2.98 +/- 0.11 to 5.97 +/- 0.56 micromol/g tissue, p<0.001; 80 mg/kg) in ischemia-reperfusion injured rat kidneys. CONCLUSION: This study therefore suggests that the aqueous saffron extract (Crocus sativus L.) and its active constituent, crocin, may be useful agents for the prevention of renal ischemia-reperfusion (IR)-induced oxidative injury in rats.

Cerebral ischemia produces brain damage and related behavioral deficits such as memory. In this study, a rat model of chronic cerebral hypoperfusion was used to determine whether saffron extract and crocin, which are potent antioxidants and free radical scavengers, can reduce vascular cognitive impairment. Male adult Wistar rats were administered different doses of an aqueous solution of crocin or hydroalcohol extract of saffron intraperitoneally (i.p.) 5 days after permanent occlusion of the common carotid arteries. Spatial learning and memory were assessed in training trials, 7-11 days after common carotid artery ligation using the Morris water maze. The results showed that the escape latency time was significantly reduced from 24.64 s in the control group to 8.77 and 10.47 s by crocin (25 mg/kg) and saffron extract (250 mg/kg). The traveled distance to find the platform was also changed from 772 cm in the control group to 251 and 294 cm in the crocin (25 mg/kg) and saffron extract (250 mg/kg) groups. The percentages of time spent in the target quadrant, in comparison with the control group (24.16%), increased to 34.25% in the crocin (25 mg/kg) and 34.85% in the saffron extract (250 mg/kg) group. This study suggests that saffron extract and crocin improve spatial cognitive abilities following chronic cerebral hypoperfusion and that these effects may be related to the antioxidant effects of these compounds.