Current possibilities of ACE inhibitor and ARB combination in arterial hypertension and its complications

Inhibition of Angiotensin Converting Enzyme, Angiotensin II Receptor Blocking, and Blood Pressure Lowering Bioactivity across Plant Families

Hypertension is a major risk factor for coronary heart disease, kidney disease, and stroke. Interest in medicinal or nutraceutical plant bioactives to reduce hypertension has increased dramatically. The main biological regulation of mammalian blood pressure is via the renin-angiotensin-aldosterone system. The key enzyme is angiotensin converting enzyme (ACE) that converts angiotensin I into the powerful vasoconstrictor, angiotensin II. Angiotensin II binds to its receptors (AT1) on smooth muscle cells of the arteriole vasculature causing vasoconstriction and elevation of blood pressure. This review focuses on the in vitro and in vivo reports of plant-derived extracts that inhibit ACE activity, block angiotensin II receptor binding and demonstrate hypotensive activity in animal or human studies. We describe 74 families of plants that exhibited significant ACE inhibitory activity and 16 plant families with potential AT1 receptor blocking activity, according to in vitro studies. From 43 plant families including some of those with in vitro bioactivity, the extracts from 73 plant species lowered blood pressure in various normotensive or hypertensive in vivo models by the oral route. Of these, 19 species from 15 families lowered human BP when administered orally. Some of the active plant extracts, isolated bioactives and BP-lowering mechanisms are discussed.

Liuwei Dihuang Pills Enhance the Effect of Western Medicine in Treating Diabetic Nephropathy: A Meta-Analysis of Randomized Controlled Trials

Objectives. To assess the effectiveness and adverse effects of adding Liuwei Dihuang Pills (LDP) to Western medicine for treating diabetic nephropathy. Methods. Studies were retrieved from seven electronic databases, including PubMed, Embase, The Cochrane Library, CBM, CNKI, Chinese Scientific Journal Database (VIP), and Wanfang Data until November 2015. Study selection, data extraction, quality assessment, and data analyses were conducted according to Cochrane standards. Meta-analysis was performed on the overall therapeutic efficacy of hyperglycemia and renal functions, and the study also analyzed adverse events. Results. A total of 1,275 patients from 18 studies were included. The methodological quality of these included trials was generally low. We found that adding LDP can lower patients' FBG (MD: −0.36 [−0.46, −0.25], P < 0.00001), PBG (MD: −1.10 [−1.35, −0.85], P < 0.00001), and HbA1c (MD: −0.14 [−0.49, 0.21], P = 0.43). There were also improvements in lowering patients' BUN (MD: −0.67 [−0.89, −0.45], P < 0.00001), SCr (MD: −0.96 [−1.53, −0.39], P < 0.00001), 24 h UTP (SMD: −1.26 [−2.38, −0.15], P < 0.00001), UAER (MD: −26.18 [−27.51, −24.85], P < 0.00001), and UmAlb (SMD: −1.72 [−2.67, −0.77], P < 0.00001). Conclusion. There is encouraging evidence that adding LDP to Western medicine might improve treatment outcomes of diabetic nephropathy, including hyperglycemia and renal functions. However, the evidence remains weak. More rigorous high-quality trials are warranted to substantiate or refute the results.

Deficiency of angiotensinogen in hepatocytes markedly decreases blood pressure in lean and obese male mice

We recently demonstrated that adipocyte deficiency of angiotensinogen (AGT) ablated high-fat diet-induced elevations in plasma angiotensin II (Ang II) concentrations and obesity-hypertension in male mice. Hepatocytes are the predominant source of systemic AGT. Therefore, in this study, we defined the contribution of hepatocyte-derived AGT to obesity-induced elevations in plasma AGT concentrations and hypertension. Male Agt(fl/fl) mice expressing albumin-driven Cre recombinase were bred to female Agt(fl/fl) mice to generate Agt(fl/fl) or hepatocyte AGT-deficient male mice (Agt(Alb)). Mice were fed a low-fat or high-fat diet for 16 weeks. Hepatocyte AGT deficiency had no significant effect on body weight. Plasma AGT concentrations were increased in obese Agt(fl/fl) mice. Hepatocyte AGT deficiency markedly reduced plasma AGT and Ang II concentrations in lean and obese mice. Moreover, hepatocyte AGT deficiency reduced the content and release of AGT from adipose explants. Systolic blood pressure was markedly decreased in lean (by 18 mm Hg) and obese Agt(Alb) mice (by 54 mm Hg) compared with Agt(fl/fl) controls. To define mechanisms, we quantified effects of Ang II on mRNA abundance of megalin, an AGT uptake transporter, in 3T3-L1 adipocytes. Ang II stimulated adipocyte megalin mRNA abundance and decreased media AGT concentrations. These results demonstrate that hepatocytes are the predominant source of systemic AGT in both lean and obese mice. Moreover, reductions in plasma angiotensin concentrations in obese hepatocyte AGT-deficient mice may have limited megalin-dependent uptake of AGT into adipocytes for the production of Ang II in the development of obesity-hypertension.

The selected traditional chinese medicinal formulas for treating diabetic nephropathy: perspective of modern science

With the increasing patients and limited therapeutic options, diabetic nephropathy (DN) is a long-term complication of diabetic mellitus. The precise mechanism of DN is not yet fully understood and the effective blockade of the progression of nephropathy remains a therapeutic challenge. Application of traditional Chinese medicine (TCM) for diabetes and its related complications has received increasing attention due to its wide availability, low side effects, and proven therapeutic mechanisms and benefits. In the current review, we mainly focus on the recent laboratory studies of the TCM formulas including Wu-Ling-San (Poria Five Powder; Wǔ Líng Sǎn), Danggui-Buxue-Tang (Tangkuei and Astragalus Decoction; Dāng Guī Bǔ Xuè Tang), and Danggui-Shaoyao-San (Tangkuei and Paeonia Formula; Dāng Guī Sháo Yào Sǎn), conducted by the Committee on Chinese Medicine and Pharmacy at the Department of Health of Taiwan Government, in the amelioration of DN. These selected TCM formulas have anti-diabetic properties, with antihyperglycemic activity accompanied by amelioration of advanced glycation end product–mediated renal damage in streptozotocin-induced diabetic rats. However, the renoprotective effects of the selected TCM formulas did not correlate with suppressing renal renin–angiotensin system hyperactivity in diabetic rats. These TCM formulas also have the capacity to ameliorate the defective antioxidative defense system, leading to modulation of the oxidative stress, thereby resulting in downregulation of nuclear factor-kB as well as transforming growth factor-β1 and, consequently, attenuation of extracellular matrix components such as fibronectin or type IV collagen expression in diabetic renal cortex tissue. More detailed mechanistic researches and long-term clinical evaluations, as well as evaluation of safety of the selected TCM formulas are needed for their future applications in DN therapy.

Beneficial effect of traditional chinese medicinal formula danggui-shaoyao-san on advanced glycation end-product-mediated renal injury in streptozotocin-diabetic rats

The present study was undertaken to characterize the effects of Danggui-Shaoyao-San (DSS), a famous traditional Chinese medicine formula consisting of six herbal medicines, on diabetic nephropathy. Streptozotocin-induced diabetic rats were orally administrated DSS (2.8 g kg⁻¹ per day) for 12 consecutive weeks. DSS partially decreased the high plasma glucose level in diabetic rats. Diabetic-dependent alterations in urinary albumin, 24-hour urinary albumin excretion rate, and creatinine clearance as well as the kidney hypertrophy (kidney weight/body weight ratio) and glomerular mesangial matrix expansion were ameliorated after 12 weeks of DSS treatment. The increased expression of nuclear factor-κB as well as transforming growth factor-β₁ and the progressive accumulation of type IV collagen in kidney of diabetic rats were also attenuated by DSS. Not only the elevated levels of advanced glycation end products (AGEs) and N^ε-(carboxymethyl)lysine but also the higher levels of lipid peroxidation products in kidney of diabetic rats were ameliorated by DSS. Decreased activity of superoxide diamutase and glutathione peroxidase in kidney of diabetic rats was enhanced by DSS. These data demonstrated that the renoprotective effects of DSS in STZ-diabetic rats not only were attributable to regulate plasma glucose to attenuate AGEs expression in diabetic glomeruli but also likely reflected its antioxidant activity.