[Effect of Cordyceps sinensis powder on renal oxidative stress and mitochondria functions in 5/6 nephrectomized rats].

OBJECTIVE: To observe the effect of Cordyceps sinensis (CS) powder on renal oxidative stress and mitochondria functions in 5/6 nephrectomized rats, and to primarily explore its possible mechanisms. METHODS: Totally 30 male Sprague-Dawley rats were divided into the sham-operation group, the model group, and the treatment group by random digit table, 10 in each group. A chronic kidney disease (CKD) rat model was prepared by one step 5/6 nephrectomy. Rats in the treatment group were intragastrically administered with CS powder solution at the daily dose of 2 g/kg, once per day. Equal volume of double distilled water was intragastrically administered to rats in the sham-operation group and the model group. All medication lasted for 12 weeks. The general condition of rats, their body weight, blood pressure, 24 h proteinuria, urinary N-acetyl-ß-D-glucosaminidase (NAG), serum creatinine (SCr) , and blood urea nitrogen (BUN) were assessed before surgery, at week 2, 4, 6, 8, 10, and 10 after surgery. Pathological changes of renal tissues were observed under light microscope. Morphological changes of mitochondria in renal tubular epithelial cells were observed under transmission electron microscope. Activities of antioxidant enzymes including reduced glutathione (GSH), manganese superoxide dismutase (MnSOD), and malondialdehyde (MDA) in fresh renal tissue homogenate were detected. Mitochondria of renal tissues were extracted to detect levels of mitochondrial membrane potential and changes of reactive oxygen species (ROS). And expressions of cytochrome-C (Cyto-C) and prohibitin in both mitochondria and cytoplasm of the renal cortex were also measured by Western blot. RESULTS: (1) Compared with the sham-operation group, body weight was significantly decreased at week 2 (P <0. 01), but blood pressure increased at week 4 (P <0. 05) in the model group. Compared with the model group, body weight was significantly increased at week 12 (P <0. 01), but blood pressure decreased at week 8 (P < 0. 01) in the treatment group. (2) Compared with the sham-operation group, 24 h proteinuria, urinary NAG, blood SCr and BUN significantly increased in the model group (all P <0. 01). Compared with the model group, blood and urinary biochemical indices all significantly decreased in the treatment group (all P <0. 01). (3) Results of pathological renal scoring: Glomerular sclerosis index, scoring for tubulointerstitial fibrosis, degree of tubulointerstitial inflammatory infiltration were all obviously higher in the model group than in the sham-operation group (all P <0. 01). All the aforesaid indices were more obviously improved in the treatment group than in the model group (all P <0. 01). (4) Compared with the sham-operation group, activities of MnSOD and GSH-Px were significantly reduced, but MDA contents obviously increased in the renal cortex of the model group (all P <0. 01). Compared with the model group, activities of MnSOD and GSH-Px obviously increased (P <0. 05, P <0. 01), but MDA contents obviously decreased in the renal cortex of the treatment group (P <0. 01). (5) Compared with the sham-operation group, the mitochondrial membrane potential significantly decreased, but ROS levels significantly increased in the model group (all P <0.01). Compared with the model group, mitochondrial transmembrane potential increased in the treatment group, thereby inhibiting the tendency of increased production of ROS (both P < 0. 01). (6) Results of Western blot showed that, compared with the sham-operation group, expression levels of mitochondrial Cyto-C and Prohibitin were significantly reduced in the renal cortex (P <0. 01), but significantly elevated in the cytoplasm of the model group (P <0. 01). Compared with the model group, each index was obviously improved in the treatment group with statistical difference (P <0. 05, P <0. 01). CONCLUSION: CS powder had renal protection, and its mechanism might partially depend on in- hibition of oxidative stress and protection for mitochondria.

Ultrasound-assisted extraction of phenolic antioxidants from Acacia confusa flowers and buds.

Acacia confusa Merr. (Leguminosae), a species native to Taiwan, is widely distributed on the hills and lowlands of Taiwan, and has been used in traditional medicines. In this study, the application of ultrasound-assisted extraction was used to extract the phenolic compounds from A. confusa flowers and buds for the first time. Among the extraction methods, it can significantly enhance the contents of phenolic compounds and antioxidant activities in A. confusa flower and bud extracts using ultrasound-assisted extraction (10 min×12 times). Considering both the solvent consumption and the time needed for extraction, ultrasound-assisted extraction was found to be the most practical approach for the rapid and efficient extraction of bioactive phenolic constituents. In addition, gallic acid, myricitrin-3-rhamnoside, quercitrin-3-rhamnoside, europetin-3-rhamnoside, kaempferol-3-rhamnoside, rhamnetin-3-glucoside, and rhamnetin-3-rhamnoside were also quantified in different extracts by RP-HPLC. It is clear that ultrasound-assisted extraction is an efficient method for extracting phenolic compounds from A. confusa flowers and buds.

[High glucose and tea polyphenols on expression of matrix metalloproteinase-2 and extracellular matrix metalloproteinase inducer in human umbilical vein endothelial cells].

OBJECTIVE: To investigate the effects of high glucose on expression of matrix metalloproteinase-2 (MMP-2) and extracellular matrix metalloproteinase inducer (EMMPRIN) in human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were cultured in DMEM media containing high glucose with or without polyphenols for 24 hours respectively. The activity of MMP-2 in the supernatant was detected by zymography. The expression of MMP-2 mRNA and protein in HUVECs were detected by RT-PCR and Western blot respectively. The expression of EMMPRIN mRNA and protein in the cells were determined by RT-PCR as well as immunocytochemistry and Western blot respectively. RESULTS: The expression of MMP-2 and EMMPRIN mRNA were suppressed by a high concentration of glucose. Both the MMP-2 activity and protein level of EMMPRIN expression were also significantly decreased. Polyphenols abolished all the above changes of HUVECs induced by a high glucose level (P < 0.05). CONCLUSIONS: An acute high glucose stimulation down-regulates the activity of MMP-2, the expressions of MMP-2 and EMMPRIN at RNA and protein levels in the endothelial cells, which may play an important roles in diabetic vascular complications in the early phase. Polyphenols treatment can diminish the detrimental effects of high glucose on HUVECs.

[Neuroprotective effects of Astragulus membranaceus on hypoxia-ischemia brain damage in neonatal rat hippocampus].

OBJECTIVE: To study neuroprotective effects of astragulus membraneaceus on a neonatal rat hippocampus of hypoxia-ischemia brain damage (HIBD). METHOD: The neonatal hypoxia-ischemia model was established with 7-day-old rat pups. Brain injury was examined by neuron death rate in the hippocampal CA1 area. Caspase-3 (cysteinyl aspartate-specific proteinase) mRNA expression in ipsilateral hippocampal was measured by half-quantitative reverse transcription and polymerization chain reaction (RT-PCR). 90-day-old rats were used in tri-equal-arm maze to observe discrimination learning ability. Sham, model and astragulus-membraneaceus treated groups were set up. RESULT: In model group, caspase-3 mRNA showed an increase at 6h, with maximum arrivimg at 24 h - 48 h after HI. In astragulus-membraneaceus treated group, neurons death rate and caspase-3 mRNA were significantly reduced by astragulus membraneaceus, and discrimination learning ability of developed rats were improved obviously. CONCLUSION: Astragulus membraneaceus has a strong protective effect on neuronal damage in the immature rat hippocampus, which is ralated reducing caspase-3 expression.