1.
Effect of proanthocyanidins on blood pressure: A systematic review and meta-analysis of randomized controlled trials.
Ren, J, An, J, Chen, M, Yang, H, Ma, Y
Pharmacological research. 2021;:105329
Abstract
BACKGROUND Hypertension is a common chronic disease that can lead to serious health problems. Previous studies have not drawn a consistent conclusion about the effect of proanthocyanidins (PCs) on blood pressure (BP). This systematic review and meta-analysis aims to evaluate the effect of PCs supplementation on blood pressure (BP). METHODS A comprehensive literature search was performed in 6 databases (Pubmed, Scopus, ISI Web of Science, the Cochrane Library, Embase and Google Scholar) to identify the randomized controlled trials (RCTs) that evaluated the BP-lowering effect of PCs. Subgroup and sensitivity analyses were conducted to evaluate the potential heterogeneity. Meta-regression analysis was used to evaluate dose effects of PCs on BP. RESULTS A total of 6 studies comprising 376 subjects were included in our meta-analysis to estimate the pooled effect size. This meta-analysis suggested that PCs supplementation could significantly reduce systolic blood pressure (SBP) (WMD: -4.598 mmHg; 95 % CI: -8.037, -1.159; I2 = 33.7 %; p = 0.009), diastolic blood pressure (DBP) (WMD: -2.750 mmHg; 95 % CI: -5.087, -0.412; I2 = 0.0 %; p = 0.021) and mean arterial pressure (MAP) (WMD: -3.366 mmHg; 95 % CI: -6.719, -0.041 mmHg; I2 = 0.0 %; p = 0.049), but had no significant effect on pulse pressure (PP) (WMD: -2.131 mmHg; 95 % CI: -6.292, 2.030; I2 = 0.0 %; p = 0.315). When the studies were stratified according to the duration of the study, there was a significant reduction on SBP in the subset of the trials with <12 weeks of duration. On the contrary, there was a significant reduction on DBP in the subset of the trials with ≥12 weeks of duration. The Subgroup analysis by BMI indicated that a significant reduction on SBP for people with a higher BMI (BMI ≥ 25) and a significant reduction on DBP for people with a lower BMI (BMI < 25). Additional subgroup analysis revealed low-dose-PCs (<245 mg/day) could significantly reduce SBP, DBP and MAP. The meta-regression analyses did not indicate the dose effects of PCs on SBP, DBP, PP and MAP. CONCLUSION Based on the current findings, PCs supplementation may be a useful treatment of hypertensive patients as well as a preventive measure in the prehypertensive and healthy subjects. However, further investigation is needed to confirm these results.
2.
Combination Therapy of Nifedipine and Sulphonylureas Exhibits a Mutual Antagonistic Effect on the Endothelial Cell Dysfunction Induced by Hyperglycemia Linked to Vascular Disease.
Wang, LP, Jiang, Y, Yang, H, Peng, C, Zhang, C, Tao, X, Xie, HH
Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology. 2016;(6):2337-47
Abstract
BACKGROUND/AIMS: By inducing severe endothelial impairment, hypertension and diabetes are two leading causes of morbidity and mortality. Hypertensive patients with concomitant diabetes must take both antihypertensive and hypoglycaemic medications, for which there is a lack of experimental and clinical guidelines. This study aimed to examine the interaction between these two types of medication on the endothelial cell function. METHODS The effect of antihypertensive (nifedipine and irbesartan) and anti-diabetic (metformin and glibenclamide/glimepiride) drugs on human umbilical vein cells (HUVECs) function was examined using a modified Boyden chamber assay. The intracellular NO and O2- levels of HUVECs were detected through flow cytometry. RESULTS Our findings showed that nifedipine/sulphonylurea monotherapy significantly attenuated high glucose-induced (33 mM) HUVECs migration incapacity, while combination therapy of nifedipine and glibenclamide/glimepiride showed no protective effect. Both nifedipine/metformin monotherapy and combined therapy significantly mitigated the migration incapacity induced by high glucose in HUVECs. Combined with either metformin or sulphonylureas, irbesartan therapy was able to attenuate the high glucose-induced migration incapacity of HUVECs. Nifedipine monotherapy decreased the O2- levels and increased the NO levels in in vitro-cultured HUVECs treated with high glucose. However, the combination therapy of nifedipine and glibenclamide increased the O2- levels and decreased the NO levels compared to the nifedipine monotherapeutic group. CONCLUSION The nifedipine and glibenclamide/glimepiride combination exerted a mutual antagonistic effect on the protection from high glucose-induced impairment in endothelial cells, which might be partially attributed to the increased O2- level and decreased NO level. These results imply that calcium channel blockers + sulphonylurea combination therapy warrants further attention in patients suffering from both hypertension and diabetes.