Effect of Flavonoids in Hawthorn and Vitamin C Prevents Hypertension in Rats Induced by Heat Exposure.

BACKGROUND: Excessive oxidative stress is associated with hypertension in professional high-temperature working conditions. Polyphenols exhibit a cardioprotective effect. Hawthorn contains high amounts of flavonoids, though its effect on hypertension protection has yet to be studied. This study aims to investigate this effect of extract of hawthorn (EH) or its combination with vitamin C (Vit. C) in rats induced by working under a hot environment. METHODS: Forty-two male rats were randomly divided into a control group under normal temperature and six treatment groups exposed at 33 ± 1 °C along with 1 h of daily treadmill running. They were orally provided with water, Vit. C (14mg/kg), EH (125, 250, and 500 mg/kg), and EH500 + Vit. C, once a day for four weeks. RESULTS: Both EH and Vit. C alone reduced the systolic and diastolic blood pressure of rats exposed to the heat environment; however, their joint supplementation completely maintained their blood pressure to the normal level throughout the experimental period. No morphological changes were found on the intima of aorta. Moreover, the co-supplementation of EH and Vit. C prevented the changes of heat exposure in inducing oxidative stress markers, such as glutathione peroxidase, catalase, total antioxidant capacity, and nitric oxide; the synergistic action was more effective than either individual treatment of EH and Vit. C. Furthermore, the administration of EH had more potent effects on increasing superoxide dismutase, IL-2, the 70 kilodalton heat shock proteins and high sensitivity C reactive protein, and decreasing serum malondialdehyde and lipofuscin in vascular tissue than those in Vit. C group. CONCLUSIONS: A strong synergistic effect of EH and Vit. C on the prevention of hypertension under heat exposure was established, as they inhibited the oxidative stress state. This study also sets up a novel intervention strategy in animal models for investigation on the early phases of hypertension induced by heat exposure.

[Maintenance effect of polyglycosides of Tripterygium wilfordii on remission in postoperative Crohn disease].

OBJECTIVE: To observe the maintenance effect of polyglycosides of Tripterygium wilfordii (GTW) on remission in postoperative Crohn disease (CD). METHODS: From 2005 to 2007, 45 adult cases of postoperative Crohn disease were randomly divided into two groups, GTW group and mesalazine group, which received GTW and mesalazine treatment respectively. CD activity index (CDAI) and clinical markers were collected at 0, 3, 6, 12 months or at the onset of symptoms. Ileocolonoscopy was performed at the end of the trial (1 year after operation) or at the onset of symptoms, and recurrence score were recorded. RESULTS: No clinical recurrence was ascertained in both groups at 3 months. Four patients (18.2%) in GTW group relapsed and 5 (21.7%) in mesalazine group relapsed at 6 months (P=0.530). Seven patients (31.8%) in GTW group and 9 (39.1%) in mesalazine group relapsed at one year (P=0.421). Ten patients (45.5%) in GTW group had endoscopic recurrence compared with 14 (60.9%) in mesalazine group at one year(P=0.231). There were no significant differences between two groups. CONCLUSION: GTW is similar to mesalazine in maintenance of remission of postoperative Crohn disease.

[Effect of enteral supplement of arginine on intestinal adaptation and its mechanism in experimental rats with short bowel syndrome].

OBJECTIVE: To evaluate the effect of enteral supplement of arginine on intestinal adaptation in rats with short bowel syndrome (SBS) and to study its mechanism. METHODS: SD rats were randomly assigned to three groups: sham rats (Con), SBS rats (SB) and SBS rats supplemented with enteral arginine (SB-Arg). All the animals received isonitrogenic and isocaloric enteral nutrition, except that SB-Arg rats received enteral nutrition supplemented with arginine (300 mg kg(-1) d(-1)). Fat absorbability, plasma free fatty acids, parameters of intestinal adaptation, enterocytes proliferation and apoptosis were determined. RESULTS: After massive small bowel resection, rats had significant bowel adaptation. Compared with SB rats, SB-Arg rats demonstrated a significant increase in fat absorbability [(84.9+/-3.2)% vs [(81.3+/-3.9)%], plasma level of free fatty acids [(650.0+/-86.5) vs (289.5+/-76.9) mg/L], ileal mucosal weight [(18.0+/-3.5) vs (13.5+/-3.0) mg cm(-1) 100 g(-1)], ileal DNA content [(29.6+/-3.3) vs (26.0+/-2.6) microg cm(-1) 100 g(-1)], jejunal mucosal protein content [(65.5+/-7.3) vs (59.8+/-6.2) microg cm(-1) 100 g(-1)], ileal mucosal protein content[(39.2+/-2.3) vs(35.4+/-2.3) microg cm(-1) 100 g(-1)], jejunal mucosal proliferation index [31+/-4 vs 22+/-3] and ileal mucosal proliferation index [32+/-2 vs 25+/-3] (all P<0.05). Moreover, jejunal and ileal villus length, crypt depth and mucosal thickness in SBS-Arg rats were higher than those in SB rats (P<0.05). CONCLUSIONS: In rat SBS model, enteral supplement of arginine appears to stimulate intestinal structural and functional adaptation. The mechanism may be that arginine can stimulate enterocyte proliferation and inhibit enterocyte apoptosis.