[Effects of theanine on monoamine neurotransmitters and related genes in cerebral ischemia-reperfusion injury rats].

OBJECTIVE: To study the effects of theanine on dopamine (DA), 5-hydroxy tryptamine (5-TH) and glutamate receptor 2 (GluR2) mRNA, phospholipase-γ1 (PLC-γ1) mRNA in cerebral ischemia-reperfusion injury rats and explore the mechanism of protective effects of theanine on the induced brain injury by ischemia-reperfusion in rats. METHODS: According to random number table, a total of 56 sprague-dawley rats in SPF grade about six-week old and 100 - 120 grams weighting were divided into five groups according to the body weight levels: model group (n = 12), sham-operation group (n = 8), low theanine group (10 mg/kg), middle theanine group (30 mg/kg) and high theanine group (90 mg/kg). There were 12 rats in each of the theanine group. The rats in model group and sham-operation groups were given distilled water, and the rats in theanine groups were given corresponding theanine solution intragastrically for fifteen days. Then the cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion (MCAO). The score of neurological behavior was evaluated at the 3rd and 24th hours after reperfusion. Rats were sacrificed at 24 hours after reperfusion, the concentrations of DA, 5-HT and theanine in rats brain following ischemia-reperfusion were determined. At the same time, we determined the levels of reactive oxygen species (ROS) and activities of catalase (CAT) in mitochondria of brain. The expressions of GluR2 mRNA and PLC-γ1 mRNA in rat brain were examined by reverse transcription polymerase chain reaction (RT-PCR) technique. RESULTS: The score of neurological behavior of rats in model group, theanine-low, middle, high dose groups at the 3rd hour was 6.000 ± 0.926, 4.100 ± 0.738, 3.444 ± 0.726 and 2.250 ± 0.886 respectively (F = 29.70, P < 0.01), and the score at the 24th hour in these groups was 6.625 ± 0.916, 5.000 ± 0.817, 3.667 ± 0.707 and 2.625 ± 0.916 respectively(F = 34.68, P < 0.01). The concentration of DA in model group, theanine-low, middle, high dose groups and sham-operation group was (10.26 ± 1.12), (12.48 ± 1.09), (14.55 ± 0.94), (15.97 ± 0.92) and (11.98 ± 0.63) µg/g respectively (F = 43.76, P < 0.01). The concentration of 5-HT in these groups was (1.091 ± 0.160), (0.818 ± 0.101), (0.571 ± 0.050), (0.453 ± 0.111) and (0.863 ± 0.063) µg/g respectively (F = 48.68, P < 0.01). The level of ROS was (3.072 ± 0.503), (1.331 ± 0.268), (1.295 ± 0.061), (0.804 ± 0.200) and (2.158 ± 0.218) U×min⁻¹×mg⁻¹ (F = 80.82, P < 0.01) respectively and the activities of CAT in these groups were (4.880 ± 1.121), (8.405 ± 1.356), (9.535 ± 2.511), (15.090 ± 4.054) and (21.260 ± 6.054) U/g respectively (F = 28.58, P < 0.01). The expressions of GluR2 mRNA were 0.842 ± 0.020, 1.063 ± 0.100, 1.170 ± 0.152, 1.254 ± 0.131 and 1.012 ± 0.056 respectively (F = 9.23, P < 0.01). The expressions of PLC-γ1 mRNA in these groups were 0.737 ± 0.090, 0.887 ± 0.045, 0.963 ± 0.025, 0.991 ± 0.049 and 0.867 ± 0.079 respectively(F = 10.24, P < 0.01). CONCLUSION: Theanine has a protective effect on the induced brain injury by ischemia-reperfusion in rats, which might be associated with its interaction with monoamine neurotransmitters and up-regulating the expressions of GluR2 mRNA and PLC-γ1 mRNA.

[The effects of lycopene on reactive oxygen species and anoxic damage in ischemia reperfusion injury in rats].

OBJECTIVE: To study the protective effects of lycopene (LP) on cerebral ischemia-reperfusion injury induced by focal cerebral ischemia and oxidative stress in rats. METHODS: 48 male Sprague-Dawley (SD) rats were randomly assigned into five groups: A (20 mg/kg LP), B (5 mg/kg LP), C (salad oil), D (salad oil) and E (basic feed control). A, B and C groups were given LP or salad oil orally for 15 d, then cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion (MCAO) and D group was used as fake surgery control. The contents of reactive oxygen species (ROS), nitric oxide (NO), lactic acid (LD) and the activities of nitric oxide synthetase (NOS) in cortex were measured at 24 h after reperfusion. The levels of HIF-1alpha mRNA and Bcl-2 mRNA in hippocampi were determined by using reverse transcription polymerase chain reaction (RT- PCR) technique. RESULTS: ROS levels of A, B, C, D and E groups were (114.23 +/- 18.91), (135.89 +/- 14.17), (171.37 +/- 25.76), (94.24 +/- 2.23) and (92.06 +/- 5.59) fluorescence intensity value/g protein, respectively (F = 9.038, P < 0.01); levels of NO were (6.60 +/- 0.77), (7.13 +/- 0.47), (8.38 +/- 0.80), (5.52 +/- 0.16) and (5.23 +/- 0.51) micromol/g protein respectively (F = 10.197, P < 0.01); levels of NOS were (0.817 +/- 0.016), (0.875 +/- 0.095), (1.030 +/- 0.101), (0.557 +/- 0.094) and (0.595 +/- 0.066) U/mg protein respectively (F = 14.555, P < 0.01); levels of LD were (0.381 +/- 0.069), (0.446 +/- 0.012), (0.576 +/- 0.059), (0.359 +/- 0.021) and (0.310 +/- 0.036) mmol/g protein respectively (F = 10.043, P < 0.01); HIF-1alpha mRNA expression levels in hippocampi were 0.865 +/- 0.274, 0.635 +/- 0.069, 0.491 +/- 0.067, 0.375 +/- 0.052 and 0.361 +/- 0.087, respectively (F = 40.520, P < 0.01); and Bcl-2 mRNA expression levels in hippocampi were 0.263 +/- 0.033, 0.330 +/- 0.028, 0.198 +/- 0.034, 0.304 +/- 0.039 and 0.236 +/- 0.025, respectively (F = 11.003, P < 0.01). CONCLUSION: The protective effects of LP may be related with its abilities of decreasing ROS and LD cumulation, alleviating inflammation and up-regulating the expression of protective genes.

[Effects of grape seed proanthocyanidins extracts on experimental diabetic nephropathy in rats].

OBJECTIVE: To study the effects of grape seed proanthocyanidins extracts(GSPE) and its mechanism on early renal lesions of diabetic rats. METHODS: Diabetic rats induced by alloxan were given GSPE intragastrically for 6 weeks, then the antioxidative indexes and NO content, NOS activity in kidney and serum were measured, and the renal function indexes were tested as well. RESULTS: Compared with the diabetic group, the urinary protein/24h, levels of blood urea nitrogen(BUN)and serum creatinine(SCr), creatinine clearance rate(CCr) and the ratio of kidney weight/body weight were decreased, the SOD activity in kidney was raised while MDA content was fall in the GSPE group(high dose), and the differences were all significant. The NO content in the kidney and NOS activity in kidney and serum decreased in the GSPE (low dose)group, and there was significant difference when compared with diabetic group( P <0.05) . CONCLUSION: GSPE has the effect in protecting kidney of diabetic rats, the mechanism might be related with its action in increasing the renal antioxidative ability,decreasing the content of NO and the activity of NOS in kidney and serum.