Cellular and molecular mechanisms of tissue protection by lipophilic calcium channel blockers

New Insights into the Nephroprotective Potential of Lercanidipine

Kidneys are responsible for many crucial biological processes in the human body, including maintaining the water-electrolyte balance, pH, and blood pressure (BP), along with the elimination of toxins. Despite this, chronic kidney disease (CKD), which affects more and more people, is a disease that develops insidiously without causing any symptoms at first. The main purpose of this article is to summarize the existing literature on lercanidipine, with a particular focus on its nephroprotective properties. Lercanidipine is a third-generation dihydropyridine (DHP) blocker of calcium channels, and as such it possesses unique qualities such as high lipophilicity and high vascular selectivity. Furthermore, it acts by reversibly inhibiting L-type and T-type calcium channels responsible for exerting positive renal effects. It has been shown to reduce tissue inflammation and tubulointerstitial fibrosis, contributing to a decrease in proteinuria. Moreover, it exhibited antioxidative effects and increased expression of molecules responsible for repairing damaged tissues. It also decreased cell proliferation, preventing thickening of the vascular lumen. This article summarizes studies simultaneously comparing the effect of lercanidipine with other antihypertensive drugs. There is still a lack of studies on the medications used in patients with CKD, and an even greater lack of studies on those used in patients with concomitant hypertension. Therefore, further studies on lercanidipine and its potential in hypertensive patients with coexisting CKD are required.

Astrocytic nutritional dysfunction associated with hypoxia-induced neuronal vulnerability in stroke-prone spontaneously hypertensive rats

Stroke-prone spontaneously hypertensive rats (SHRSP) is a valuable animal model to investigate human strokes. SHRSP Izumo strain (Izm) neurons are highly sensitive to blood supply changes. Furthermore, SHRSP/Izm astrocytes show various abnormalities upon hypoxic stimulation compared to control Wistar Kyoto (WKY/Izm) rats. This study aimed to describe stroke-related characteristics of SHRSP/Izm-derived neurons and astrocytes. In addition, we discuss the role of astrocytes in the development of stroke in SHRSP/Izm model. In SHRSP/Izm, neuronal death is induced upon reoxygenation after hypoxia. Furthermore, it was shown that SHRSP/Izm astrocytes show significantly reduced lactate production and supply ability to nerve cells when subjected to hypoxic stimulation. In particular, decreased lactate production and monocarboxylic acid transporter (MCT) expression in SHRSP/Izm astrocytes are factors that induce neuronal cell death. Remarkable differences in glial cell line-derived neurotrophic factor (GDNF) expression and L-serine production were also observed in SHRSP/Izm-derived astrocytes compared to WKY/Izm. Reduced production of both GDNF and L-serine contributes to diminished neuronal survival. The differences between SHRSP/Izm and WKY/Izm astrocyte cellular properties may contribute to compromised neuronal nutrition and induction of neuronal death. These properties are likely to be the factors that enhance stroke in SHRSP/Izm.

Lercanidipine in the Management of Hypertension: An Update

Calcium channel blockers (CCBs), particularly dihydropyridine-CCBs, (DHP-CCBs), have an established role in antihypertensive therapy, either as monotherapy or in combination with other antihypertensive drugs. Two hundred and fifty-one papers published in PubMed in English between January 1, 1990, and October 31, 2016, were identified using the keyword "lercanidipine." Lercanidipine is a lipophilic third-generation DHP-CCB, characterized by high vascular selectivity and persistence in the smooth muscle cell membranes. Lercanidipine is devoid of sympathetic activation, and unlike the first and second generation of DHP-CCBs, it dilates both the afferent and the efferent glomerular arteries, while preserving the intraglomerular pressure. In addition, lercanidipine prevents renal damage induced by angiotensin II and demonstrates anti-inflammatory, antioxidant, and anti-atherogenic properties through an increasing bioavailability of endothelial nitric oxide. It is associated with a regression of microvascular structural modifications in hypertensive patients. The efficacy of lercanidipine has been demonstrated in patients with different degrees of hypertension, in the young and elderly and in patients with isolated systolic hypertension. In patients with diabetes and renal impairment, lercanidipine displays a renal protection with a significant decrease of microalbuminuria and improvement of creatinine clearance. Lercanidipine is well tolerated and is associated with a very low rate of adverse events, particularly ankle edema, compared with amlodipine and nifedipine. In conclusion, lercanidipine produces a sustained blood pressure-lowering activity with a high rate of responder/normalized patients, associated with a favorable tolerability profile.

Neuroprotective effect of lercanidipine in middle cerebral artery occlusion model of stroke in rats

Oxidative stress, inflammation and apoptotic neuronal cell death are cardinal mechanisms involved in the cascade of acute ischemic stroke. Lercanidipine apart from calcium channel blocking activity possesses anti-oxidant, anti-inflammatory and anti-apoptotic properties. In the present study, we investigated neuroprotective efficacy and therapeutic time window of lercanidipine in a 2h middle cerebral artery occlusion (MCAo) model in male Wistar rats. The study design included: acute (pre-treatment and post-treatment) and sub-acute studies. In acute studies (pre-treatment) lercanidipine (0.25, 0.5 and 1mg/kg, i.p.) was administered 60min prior MCAo. The rats were assessed 24h post-MCAo for neurological deficit score (NDS), motor deficit paradigms (grip test and rota rod) and cerebral infarction via 2,3,5-triphenyltetrazolium chloride (TTC) staining. The most effective dose was found to be at 0.5mg/kg, i.p., which was considered for further studies. Regional cerebral blood flow (rCBF) was monitored till 120min post-reperfusion to assess vasodilatory property of lercanidipine (0.5mg/kg, i.p.) administered at two different time points: 60min post-MCAo and 15min post-reperfusion. In acute studies (post-treatment) lercanidipine (0.5mg/kg, i.p.) was administered 15min, 120min and 240min post-reperfusion. Based on NDS and cerebral infarction via TTC staining assessed 24h post-MCAo, effectiveness was evident upto 120min. For sub-acute studies same dose/vehicle was repeated for next 3days and magnetic resonance imaging (MRI) was performed 96h after the last dose. Biochemical markers estimated in rat brain cortex 24h post-MCAo were oxidative stress (malondialdehyde, reduced glutathione, nitric oxide, superoxide dismutase), blood brain barrier damage (matrix metalloproteinases-2 and -9) and apoptotic (caspase-3 and -9). Lercanidipine significantly reduced NDS, motor deficits and cerebral infarction volume as compared to the control group. Lercanidipine (60min post-MCAo) significantly increased rCBF (86%) as compared to vehicle treated MCAo group (64%) 120min post-reperfusion, but failed to show vasodilatation with 15min post-reperfusion group. Lercanidipine (13.78±2.78%) significantly attenuated percentage infarct volume as evident from diffusion-weighted (DWI) and T2-weighted images as compared to vehicle treated MCAo group (25.90±2.44%) investigated 96h post-MCAo. The apparent diffusion coefficient (ADC) was also significantly improved in lercanidipine group as compared to control group. Biochemical alterations were significantly ameliorated by lercanidipine till 120min post-reperfusion group and MMP-9 inhibition observed even with 240min group. Thus, lercanidipine revealed significant neuroprotective effect mediated through attenuation of oxidative stress, inflammation and apoptosis.

Effect of Lercanidipine on Kidney Microanatomy in Cohen-Rosenthal Diabetic Hypertensive Rats

The study was undertaken to determine the effect of treatment with the dihydropyridine-type calcium antagonist lercanidipine on the renal vasculature in Cohen-Rosenthal diabetic hypertensive rats, a genetic model of hypertension associated with type 2 diabetes mellitus. Eight animals were given a daily oral dose of 3 mg/kg lercanidipine in drinking water for 8 weeks, and 6 control animals received no treatment. The effects on blood pressure, glucose level, and kidney microanatomy were evaluated. Lercanidipine reduced systolic blood pressure and glucose level. In the control group small arteries and glomerular arterioles exhibited wall thickening and luminal narrowing. Lercanidipine administration prevented the changes in small-sized arteries and glomerular arterioles. The glomerular changes observed in the untreated Cohen-Rosenthal diabetic hypertensive rats were not seen in the lercanidipine-treated animals. Lercanidipine also had beneficial effects on the renal vasculature, suggesting that the compound may be considered for treating hypertension associated with diabetes.

Can lercanidipine improve renal function in patients with atherosclerotic renal artery stenosis undergoing renal artery intervention?

OBJECTIVE

To investigate the renal-protective effect of lercanidipine in patients undergoing renal artery intervention.

METHODS

A prospective, single-center, cohort study was conducted and patients, 30-75 years of age, with atherosclerotic renal artery stenosis were consecutively enrolled between September 2011 and October 2012. Lercanidipine (10-20 mg/day) was regularly taken after the intervention. Follow up visits were performed at 3 and 6 months after the intervention. Serum creatinine, clinical blood pressure, 24 hour ambulatory blood pressure, pulse wave velocity, and 24 hour urine protein were assessed. Adverse events were recorded.

RESULTS

In total, 55 patients (mean age 63.5 ± 8.9 years) were enrolled and 52 completed the study. Renal function, estimated glomerular filtration rate (eGFR) and 24 hour urine protein at 3 months after the intervention were not statistically different compared with the baseline. At 6 months after the intervention eGFR significantly increased versus baseline (78 ± 23 ml/min/1.73 m(2) vs 71 ± 21 ml/min/1.73 m(2), p = 0.021); 24 hour urine protein decreased significantly (0.02 g [IQR, 0.01-0.1] vs 0.03 g [IQR, 0.01-0.28], p = 0.042). Blood pressure control improved at 3 months and 6 months after the intervention. The need for antihypertensive drugs decreased; clinical systolic blood pressure, diastolic blood pressure and 24 hour average systolic blood pressure and diastolic blood pressure decreased. The pulse wave velocity decreased after 3 and 6 months. At the end of follow-up, none of the following adverse events occurred: death, dialysis, myocardial infarction or stroke. Mild lower extremity edema occurred in only one patient. No other side effects occurred.

CONCLUSIONS

This study showed that lercanidipine can improve renal function in patients undergoing renal artery intervention.

Ginsenoside Rb1 selectively inhibits the activity of L-type voltage-gated calcium channels in cultured rat hippocampal neurons

AIM

To investigate the effect of ginsenoside Rb1 on voltage-gated calcium currents in cultured rat hippocampal neurons and the modulatory mechanism.

METHODS

Cultured hippocampal neurons were prepared from Sprague Dawley rat embryos. Whole-cell configuration of the patch-clamp technique was used to record the voltage-gated calcium currents (VGCCs) from the hippocampal neurons,and the effect of Rb1 was examined.

RESULTS

Rb1 (2-100 μmol/L) inhibited VGCCs in a concentration-dependent manner, and the current was mostly recovered upon wash-out. The specific L-type Ca(2+) channel inhibitor nifedipine (10 μmol/L) occluded Rb1-induced inhibition on VGCCs. Neither the selective N-type Ca(2+) channel blocker ω-conotoxin-GVIA (1 μmol/L), nor the selective P/Q-type Ca(2+) channel blocker ω-agatoxin IVA (30 nmol/L) diminished Rb1-sensitive VGCCs. Rb1 induced a leftward shift of the steady-state inactivation curve of I(Ca) to a negative potential without affecting its activation kinetics or reversal potential in the I-V curve. The inhibitory effect of Rb1 was neither abolished by the adenylyl cyclase activator forskolin (10 μmol/L), nor by the PKA inhibitor H-89 (10 μmol/L).

CONCLUSION

Ginsenoside Rb1 selectively inhibits the activity of L-type voltage-gated calcium channels, without affecting the N-type or P/Q-type Ca(2+) channels in hippocampal neurons. cAMP-PKA signaling pathway is not involved in this effect.

The role of fixed-dose combinations in the management of hypertension: focus on lercanidipine-enalapril

Achieving optimal blood pressure (BP) control is the most important single issue in the management of hypertension, and in most patients, it is difficult or impossible to achieve target levels with one drug. Blocking two or more regulatory systems provides a more effective and more physiologic reduction in BP, and current guidelines have recommended the use of combination therapy as first-line treatment, or early in the management of hypertension. Fixed-dose combination therapy is an efficacious, relatively safe and cost-effective treatment option in most patients with essential hypertension. Of note, the once-daily administration of a fixed-dose enalapril/lercanidipine, by bringing together two distinct and complementary mechanisms of action, reduces BP effectively and has the potential for improved target organ protection relative to either class agent alone.

Ginsenosides: are any of them candidates for drugs acting on the central nervous system?

The last two decades have shown a marked expansion in the number of publications regarding the effects of Panax ginseng. Ginsenosides, which are unique saponins isolated from Panax ginseng, are the pharmacologically active ingredients in ginseng, responsible for its effects on the central nervous system (CNS) and the peripheral nervous system. Recent studies have shown that ginsenosides regulate various types of ion channels, such as voltage-dependent and ligand-gated ion channels, in neuronal and heterologously expressed cells. Ginsenosides inhibit voltage-dependent Ca(2+), K(+), and Na(+) channel activities in a stereospecific manner. Ginsenosides also inhibit ligand-gated ion channels such as N-methyl-d-aspartate, some subtypes of nicotinic acetylcholine, and 5-hydroxytryptamine type 3 receptors. Competition and site-directed mutagenesis experiments revealed that ginsenosides interact with ligand-binding sites or channel pore sites and inhibit open states of ion channels. This review will introduce recent findings and advances on ginsenoside-induced regulation of ion channel activities in the CNS, and will further expand the possibilities that ginsenosides may be useful and potentially therapeutic choices in the treatment of neurodegenerative disorders.

Benidipine, an anti-hypertensive drug, inhibits reactive oxygen species production in polymorphonuclear leukocytes and oxidative stress in salt-loaded stroke-prone spontaneously hypertensive rats

Oxidative stress is associated with exacerbation of renal injuries in hypertension. In clinical studies benidipine hydrochloride (benidipine), a dihydropyridine calcium channel blocker with antioxidant activity, reduced oxidative stress. However, the mechanism of suppression of oxidative stress remains to be fully characterized. Reactive oxygen species production by polymorphonuclear leukocyte plays important pathological roles in hypertension. Therefore, we examined the effects of benidipine both on reactive oxygen species production of human polymorphonuclear leukocytes and oxidative stress of an animal model. Human peripheral polymorphonuclear leukocytes or polymorphonuclear leukocyte-like differentiated HL-60 cells were used to examine effects of benidipine (0.1-30 microM) on formyl-Met-Leu-Phe-induced reactive oxygen species production, calcium mobilization, NADPH oxidase activation and phosphorylation of protein kinase C substrates. High-salt (8% NaCl) loaded stroke-prone spontaneously hypertensive rats were treated with or without benidipine (1, 3, 10 mg/kg/day) for 2 weeks, and thiobarbituric acid reactive substances, a plasma oxidative stress marker, and renal expression of oxidative stress-induced genes were measured. Benidipine concentration-dependently suppressed formyl-Met-Leu-Phe-induced reactive oxygen species production in polymorphonuclear leukocytes more potently than other calcium channel blockers such as amlodipine, azelnidipine, nitrendipine and nifedipine. Benidipine partially inhibited all of intracellular Ca(2+) elevation, protein kinase C activation and NADPH oxidase activation. Salt loading in stroke-prone spontaneously hypertensive rats augmented plasma thiobarbituric acid reactive substances levels; renal dysfunction; and renal expression of transforming growth factor-beta, collagen I and collagen III mRNAs; which were attenuated by benidipine treatment. These results indicate that benidipine prevents the polymorphonuclear leukocyte-derived reactive oxygen species production, which is due at least in part to its antioxidant action and inhibition of Ca(2+)/protein kinase C/NADPH oxidase signaling. The attenuation of reactive oxygen species production might contribute to the drug's reduction of oxidative stress and renal injuries in hypertension.

Are differences in calcium antagonists relevant across all stages of nephropathy or only proteinuric nephropathy?

PURPOSE OF REVIEW

The main effects of classic calcium antagonists are mediated by the inhibition of L-type calcium channels broadly distributed within the renal vascular bed. Calcium antagonists act predominantly on the afferent arterioles, and dihydropyridines can favour the increase in glomerular hypertension and progression of kidney diseases, in particular when systemic blood pressure remains uncontrolled.

RECENT FINDINGS

Calcium antagonists have been widely used in clinical practice because of their antihypertensive capacity. The prevention of renal damage is a very important aim of antihypertensive therapy. This is particularly so taking into account the high prevalence of chronic kidney disease in the general population. Non-dihydropyridines such as verapamil have been shown to possess an antiproteinuric effect that could be particularly relevant.

SUMMARY

Recent data from clinical trials have confirmed that, in hypertensive patients with preserved renal function or with chronic kidney disease, calcium antagonists are effective antihypertensive drugs to be considered alone or in combination with an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. In those patients presenting with proteinuric kidney disease, non-dihydropyridines could reduce proteinuria to a greater degree than dihydropyridines.

Hypertension, possible vascular protection and lercanidipine

Systemic hypertension is a major global problem contributing to enormous disease burden, premature morbidity and mortality. A substantial majority of hypertensive patients require long-term drug therapy for appropriate blood pressure control. Although there are many classes of antihypertensive drugs for clinical use, calcium channel blockers (CCBs) have a special role in the management of hypertension owing to their well established safety and efficacy among the CCBs; the dihydropyridines (DHPs) are recognized for their predictable efficacy and dependability to achieve the recommended target goals of treatment. The older DHPs, such as nifedipine, felodipine and amlodipine, can cause bothersome side effects, such as ankle edema. The new-generation lipophilic DHP CCBs, such as lercanidipine, offer an advantage of less frequent occurrence of ankle edema. Furthermore, lercanidipine (in contrast to older DHPs) exerts favorable cardiorenal effects. Lercanidipine administered alone or in combination with other antihypertensive drugs represents a useful treatment option for efficient blood pressure control without causing significant adverse effects.