Cilnidipine, the N- and L-type calcium channel antagonist, reduced on 24-h urinary catecholamines and C-peptide in hypertensive non-insulin-dependent diabetes mellitus

Cilnidipine and magnesium sulfate supplement ameliorates hyperglycemia, dyslipidemia and inhibits oxidative-stress in fructose-induced diabetic rats

The study was designed to evaluate the safety and efficacy of cilnidipine (CLN) and Mg-supplementation in fructose-induced diabetic rats. Diabetes was induced into male Wister rats by feeding fructose (10% solution) in drinking water for 8 weeks. Diabetic rats were subjected for the oral administration of CLN1 (1 mg/kg/day) and CLN10 (10 mg/kg/day), and/or methyl cellulose (0.5%) as vehicle for 28 days. After 14 days of CLN treatment, MgSO₄ (1%) was added to CLN1 and CLN10 groups for another 14 days. Age-matched healthy rats were used as normal control. After 28 days body weights were measured and organ weight to body ratio was calculated. Serum samples were analysed for fasting blood sugar (FBS), glycosylated hemoglobin (HbA1c), uric acid, lipid profiles, tri-iodothyronine (T₃) and thyroid stimulating hormone (TSH), serum glutamic pyruvic transaminase (SGPT), serum glutamic oxaloacetic transaminase (SGOT), creatine phosphokinase myocardial-band (CK-MB), creatinine, albumin, electrolytes. Oral glucose tolerance tests (OGTT), liver histopathology and in-vivo antioxidant activities were also performed. The survival rate in diabetic rats was 100% after the oral administration of CLN, Mg-supplement and/or vehicle. A significant reduction in FBS levels and improvement in OGTT were observed in CLN10, CLN1+Mg and CLN10 + Mg groups after 28 days. Further, the treatment ameliorated serum lipid profile, uric acid, and albumin levels. The groups CLN10 and CLN10 + Mg improved HbA1c, liver glycogen, creatinine, T₃, TSH levels and electrolytes in diabetic rats. Moreover, liver from CLN10 and CLN10 + Mg groups showed preservation of cellular architecture as evidenced by attenuation of inflammatory markers SGPT, SGOT and CK-MB; and the levels of superoxide dismutase (SOD), catalase (CAT), glutathione, malondialdehyde (MDA), markers of oxidative stress were significantly improved. CLN exerted prominent effects in the amelioration of hyperglycemia, dyslipidemia and reduced hepatic inflammation; and Mg-supplementation might have some beneficial effects on diabetic complications and oxidative stress in fructose-induced diabetic rats.

Efficacy of Cilnidipine (L/N-type Calcium Channel Blocker) in Treatment of Hypertension: A Meta-Analysis of Randomized and Non-randomized Controlled Trials

INTRODUCTION

 Hypertension is one of the most common cardiovascular diseases, and the prevalence of hypertension continues to rise across the globe. National and international guidelines recommend angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), diuretics, and beta-blockers for the management of hypertension. CCBs are among the most used antihypertensive medications and Cilnidipine is a newer dihydropyridine CCB shown to have a prolonged antihypertensive property.

OBJECTIVE

 This meta-analysis of comparative randomized and non-randomized clinical trials evaluated the effect of Cilnidipine monotherapy or combination therapy on systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse rate (PR) over 48 weeks of therapy.

STUDY DESIGN

 PubMed (MEDLINE) and Google scholar databases were searched to identify studies designed to evaluate the effects of Cilnidipine in the treatment of hypertensive patients. The study criteria for inclusion into the meta-analysis were all prospective, randomized, and non-randomized clinical studies published till March 2021, studies published in a peer-reviewed journal, the inclusion of patients with hypertension, assessment of blood pressure and heart rate, and a follow-up of four weeks or longer. The initial search identified 82 potential articles; of these, 24 met the inclusion criteria. Studies with <4 weeks treatment period and those not having a CCB were excluded.

OUTCOMES

 Change in SBP, DBP, and PR from baseline at the end of therapy compared between the Cilnidipine and other CCB's.

RESULTS

Cilnidipine caused a significant reduction (p<0.05) in SBP, DBP, and PR at end of therapy, whereas the reduction in SBP, DBP, and PR with Cilnidipine was similar to other CCB's (p>0.05). The results of this meta-analysis revealed that there were no significant differences in the efficacy in the treatment of hypertensive patients with Cilnidipine and the other therapies.

CONCLUSION

 Cilnidipine has similar anti-hypertensive effects compared with other first-line antihypertensive drugs commonly used in practice. We recommend Cilnidipine as a novel first-line CCB for the management of hypertension either as a monotherapy or as a combination therapy.

An N-/L-type calcium channel blocker, cilnidipine, suppresses autonomic, electrical, and structural remodelling associated with atrial fibrillation

AIMS

Autonomic dysfunction can promote atrial fibrillation (AF) and results from AF-related remodelling. N-type Ca2+-channels (NTCCs) at sympathetic nerve terminals mediate Ca2+-entry that triggers neurotransmitter release. AF-associated remodelling plays an important role in AF pathophysiology but the effects of NTCC inhibition on such remodelling is unknown. Here, we investigated the ability of a clinically available Ca2+-channel blocker (CCB) with NTCC-blocking activity to suppress the arrhythmogenic effects of AF-promoting remodelling in dogs.

METHODS AND RESULTS

Mongrel dogs were kept in AF by right atrial tachypacing at 600 bpm. Four groups were studied under short-term AF (7 days): (i) Shams, instrumented but without tachypacing (n = 5); (ii) a placebo group, tachypaced while receiving placebo (n = 6); (iii) a control tachypacing group receiving nifedipine (10 mg orally twice-daily; n = 5), an L-type CCB; and (iv) a cilnidipine group, subjected to tachypacing and treatment with cilnidipine (10 mg orally twice-daily; n = 7), an N-/L-type CCB. With cilnidipine therapy, dogs with 1-week AF showed significantly reduced autonomic changes reflected by heart rate variability (decreases in RMSSD and pNN50) and plasma norepinephrine concentrations. In addition, cilnidipine-treated dogs had decreased extracellular matrix gene expression vs. nifedipine-dogs. As in previous work, atrial fibrosis had not yet developed after 1-week AF, so three additional groups were studied under longer-term AF (21 days): (i) Shams, instrumented without tachypacing or drug therapy (n = 8); (ii) a placebo group, tachypaced while receiving placebo (n = 8); (iii) a cilnidipine group, subjected to tachypacing during treatment with cilnidipine (10 mg twice-daily; n = 8). Cilnidipine attenuated 3-week AF effects on AF duration and atrial conduction, and suppressed AF-induced increases in fibrous-tissue content, decreases in connexin-43 expression and reductions in sodium-channel expression.

CONCLUSIONS

Cilnidipine, a commercially available NTCC-blocking drug, prevents AF-induced autonomic, electrical and structural remodelling, along with associated AF promotion.

Effects of cilnidipine on sympathetic nerve activity and cardiorenal function in hypertensive patients with type 2 diabetes mellitus: association with BNP and aldosterone levels

AIMS

Hypertension stimulates the sympathetic nervous system and this phenomenon is exacerbated by diabetes mellitus. We investigated the effects of cilnidipine, an N/L-type calcium channel blocker, on aspects of this system in patients with type 2 diabetes mellitus.

METHODS

In 33 hypertensive patients with type 2 diabetes mellitus treated with a calcium channel blocker other than cilnidipine, we evaluated the influence of switching to cilnidipine on blood pressure, heart rate, catecholamine, plasma renin and aldosterone concentration, brain natriuretic peptide, urine liver-type fatty acid binding protein, and urinary albumin excretion ratio in the same patients by a cross-over design. Other biochemical parameters were also evaluated.

RESULTS

Switching to cilnidipine did not change blood pressure but caused reduction in catecholamine concentrations in blood and urine and plasma aldosterone concentration, accompanied by significant reduction in brain natriuretic peptide, urine liver-type fatty acid binding protein, and albumin excretion ratio. These parameters other than brain natriuretic peptide were significantly increased after cilnidipine was changed to the original calcium channel blocker.

CONCLUSIONS

In 33 hypertensive patients with type 2 diabetes mellitus, compared to other calcium channel blockers, cilnidipine suppressed sympathetic nerve activity and aldosterone, and significantly improved markers of cardiorenal disorders. Therefore, cilnidipine may be an important calcium channel blocker for use in combination with renin-angiotensin-aldosterone system inhibitors when dealing with hypertension complicated with diabetes mellitus.

Switching to an L/N-type calcium channel blocker shows renoprotective effects in patients with chronic kidney disease: the Kyoto Cilnidipine Study

OBJECTIVE

This open-label, randomized controlled trial investigated the effects of cilnidipine, an L/N-type calcium channel blocker (CCB), in patients with chronic kidney disease (CKD).

METHODS

Sixty patients with CKD and well-controlled hypertension being treated with a renin- angiotensin system (RAS) inhibitor and an L-type CCB (L-CCB) were randomly assigned either to switch from the L-CCB to cilnidipine after a 4-week observation period or to continue with L-CCB treatment. Blood pressure, heart rate and renal function were monitored for 12 months. Data were available for analysis from 50 patients: 24 from the cilnidipine group and 26 from the L-CCB group.

RESULTS

Blood pressure was well controlled in both groups. After 12 months, proteinuria and heart rate were significantly decreased in the cilnidipine group, but proteinuria increased and heart rate remained unchanged in the L-CCB group. There was a significant positive correlation between the percentage changes in proteinuria and heart rate.

CONCLUSIONS

Cilnidipine has antihypertensive effects equivalent to those of L-CCBs. In patients with CKD, proteinuria can be decreased by switching from an L-CCB to cilnidipine, thereby improving renal function.

Dopamine and renal function and blood pressure regulation

Dopamine is an important regulator of systemic blood pressure via multiple mechanisms. It affects fluid and electrolyte balance by its actions on renal hemodynamics and epithelial ion and water transport and by regulation of hormones and humoral agents. The kidney synthesizes dopamine from circulating or filtered L-DOPA independently from innervation. The major determinants of the renal tubular synthesis/release of dopamine are probably sodium intake and intracellular sodium. Dopamine exerts its actions via two families of cell surface receptors, D1-like receptors comprising D1R and D5R, and D2-like receptors comprising D2R, D3R, and D4R, and by interactions with other G protein-coupled receptors. D1-like receptors are linked to vasodilation, while the effect of D2-like receptors on the vasculature is variable and probably dependent upon the state of nerve activity. Dopamine secreted into the tubular lumen acts mainly via D1-like receptors in an autocrine/paracrine manner to regulate ion transport in the proximal and distal nephron. These effects are mediated mainly by tubular mechanisms and augmented by hemodynamic mechanisms. The natriuretic effect of D1-like receptors is caused by inhibition of ion transport in the apical and basolateral membranes. D2-like receptors participate in the inhibition of ion transport during conditions of euvolemia and moderate volume expansion. Dopamine also controls ion transport and blood pressure by regulating the production of reactive oxygen species and the inflammatory response. Essential hypertension is associated with abnormalities in dopamine production, receptor number, and/or posttranslational modification.

Renoprotective effect of N-type Ca channel blockade in diabetic nephropathy

OBJECTIVE

This study aimed to investigate the renoprotective effect on diabetic nephropathy of a novel class of Ca(2+) channel blocker, cilnidipine, that inhibits both L-type and N-type Ca(2+) channels; a conventional L-type Ca(2+) channel blocker was substituted with cilnidipine in type 2 diabetic patients with albuminuria.

METHODS

Urinary albumin index (UAI), serum creatinine, and blood pressure were measured in 38 outpatients with type 2 diabetes receiving amlodipine, an L-type Ca(2+) channel blocker, in addition to an angiotensin I converting enzyme inhibitor and/or an angiotensin type 1 receptor blocker. Amlodipine was then substituted with cilnidipine, and the same parameters were measured after 3 months.

RESULTS

Although blood pressure was not significantly changed after substitution with cilnidipine, log-transformed UAI was significantly decreased (P=.004) with a mean reduction of 28% [95% confidence interval (CI)=11-42]. Serum creatinine was significantly (P=.04) increased (from 0.82+/-0.22 to 0.86+/-0.23 mg/dl). When the subjects were divided into two groups according to the change in serum creatinine, UAI change was significant only in those with an increase in serum creatinine, who exhibited a mean reduction of UAI of 39% (95% CI=16-56, P=.005), but not in those without an increase in serum creatinine, whose mean reduction of UAI was 18% (95% CI=-12 to 40, P=.2).

CONCLUSIONS

In patients with diabetic nephropathy, blocking N-type Ca(2+) channels with a new class of Ca(2+) channel blocker resulted in a significant reduction in albuminuria, suggesting a renoprotective effect of N-type Ca(2+) channel blockade, even when combined with renin-angiotensin inhibition.

Protective effect of cerebrocrast on rat brain ischaemia induced by occlusion of both common carotid arteries

Diabetes mellitus is accompanied by several cardiovascular complications including atherosclerosis, cerebral ischaemia and stroke. We examined the neuroprotective effect of a 1,4-dihydropyridine derivative cerebrocrast (C, a new antidiabetic agent, synthesized in the Latvian Institute of Organic Synthesis) on the level of ATP in the brain, and on changes of the EEG and ECG, as well as blood pressure parameters in anaesthetized Wistar male rats before and during 10-min occlusion of both common carotid arteries. Cerebrocrast was administered i.v. at doses of 1.0 and 10 microg/kg in the v. femoralis 20 min prior to ischaemia. After 10-min ischaemia animals were decapitated and the brain was immediately frozen in liquid nitrogen and subsequently used for analysis of changes of ATP contention. Cerebrocrast, administered at doses of 1.0 and 10 microg/kg 20 min prior to occlusion of both common carotid arteries, completely prevented a fall in the ATP content of brain compared with the control rats. In control rats the content of ATP in brain during ischaemia decreased from 2.77 +/- 0.22 (basal level) to 1.74 +/- 0.20 micromol/g as a result of ischaemia. By administration of cerebrocrast 20 min before occlusion of the arteries, the content of ATP in the brain remained at the level of preischaemia (1.0 microg/kg C + ischaemia 2.82 +/- 0.36; 10 microg/kg C + ischaemia 2.42 +/- 0.22 micromol/g). Analysis of EEG parameters both before and during 10 min of occlusion showed that at a C dose of 1.0 microg/kg before occlusion produced a regular alpha rhythm during ischaemia and prevented cerebral bioelectric activity from significant changes. The depression of basal rhythm was observed at a C dose of 10 microg/kg during ischaemia in two rats out of six as well as an increase in the ECG ST segment above the isoelectric line. Blood pressure was decreased by about 10-20 mm Hg. We propose that pretreatment of rats with cerebrocrast at doses of 1.0 or 10 microg/kg 20 min prior to ischaemia can prevent ischaemic damage of rat brain, maintain necessary energy consumption, promote ATP production in brain cells, and prevent significant changes in EEG and ECG parameters. These properties are important in diabetes mellitus and its evoked cardiovascular complications as stroke, ischaemia, etc.

Structure–activity relationship study of 1,4-dihydropyridine derivatives blocking N-type calcium channels

Cilnidipine is a 1,4-dihydropyridine derived L/N-type calcium channel dual blocker possessing neuroprotective and analgesic effects which are related to its N-type calcium channel inhibitory activity. In order to find specific N-type calcium channel blockers with the least effects on cardiovascular system, we performed structure-activity relationship study on APJ2708, which is a derivative of cilnidipine, and found a promising N-type calcium channel blocker 21b possessing analgesic effect in vivo with a 1600-fold lower activity against L-type calcium channels than that of cilnidipine.

Comparison between cilnidipine and amlodipine besilate with respect to proteinuria in hypertensive patients with renal diseases

Unlike other dihydropyridine calcium channel blockers (CCBs), cilnidipine has been reported to exert an N-type calcium-channel-blocking activity and to reduce sympathetic hyperactivity. This study compared cilnidipine and amlodipine with respect to their effects on renal function and proteinuria. Twenty-eight proteinuric hypertensive outpatients (13 men and 15 women, aged 62+/-2 years) who had been maintained on CCBs for more than 3 months were randomly assigned to a group receiving amlodipine besilate (14 patients) or a group receiving cilnidipine (14 patients). CCBs were increased in dosage or other drugs were added until blood pressure decreased below 140/90 mmHg, but no inhibitors of the renin-angiotensin (RA) system were added or changed in dosage. Before and at 6 and 12 months after randomization, the concentrations of urine protein, urine albumin, serum and urine creatinine (Cr), and serum beta2-microglobulin were determined. The amlodipine group showed a significant increase in proteinuria, while the increase was suppressed in the cilnidipine group. The rate of increase in proteinuria at 12 months was 87% (95% confidence interval (CI) -10 to 184) of the baseline value with amlodipine and 4% (95% CI -69 to 77) of baseline with cilnidipine, a significant intergroup difference (p<0.05). The mean blood pressure remained in the 96-99 mmHg range until 12 months after randomization, showing no significant difference between the two groups. The cilnidipine group showed an increase in serum Cr levels (baseline vs. 12 months, 1.36+/-0.20 vs. 1.50+/-0.23 mg/dl, p<0.01). Overall, an inverse correlation existed between the changes in Cr and proteinuria (r= -0.477, p<0.01). These results suggest that cilnidipine results in a greater suppression of the increase in proteinuria and greater reduction in glomerular filtration rate than amlodipine, and that these effects are similar between cilnidipine and RA inhibitors. However, additional large-cohort and longer-term studies will be needed to clarify whether cilnidipine is superior to other CCBs in maintaining renal function.

Neuroprotective Effects of a Dual L/N-type Ca2+ Channel Blocker Cilnidipine in the Rat Focal Brain Ischemia Model

Although a blockade or lack of N-type Ca(2+) channels has been reported to suppress neuronal pathological processes in several animal models of pain and ischemic brain injury, information is still limited regarding the neuroprotective effects of a dual L/N-type Ca(2+) channel blocker, cilnidipine. In this study, we assessed the effects of cilnidipine in the rat focal brain ischemia model to analyze its potential utility for hypertensive patients with cerebral infarction. In an anesthetized rat model, cerebral vasodilator actions of cilnidipine were detected at hypotensive doses, which was less potent than those of an L-type Ca(2+) channel blocker, nilvadipine. In the rat focal brain ischemia model, an anti-hypertensive and anti-sympathetic dose of cilnidipine could reduce the size of cerebral infarction, whereas an equipotent hypotensive dose of nilvadipine failed to affect it. These results suggest that N-type Ca(2+) channel-blocking profile of cilnidipine may contribute its neuroprotective action in the animal focal brain ischemia model. Thus, treatment of hypertension with cilnidipine may prevent severe consequences after brain attack.

Effect of cilnidipine on insulin sensitivity in patients with essential hypertension

To clarify the effect of cilnidipine, a long-acting dihydropyridine Ca-antagonist that blocks both L- and N-type Ca(2+)-channels, on insulin sensitivity, cilnidipine at 5 to 10 mg/day was administered to ten patients with essential hypertension for 12 weeks. Mean age and body mass index (BMI) were 57.7 +/- 5.0 (SEM) years old and 27.1 +/- 1.5, respectively. Blood pressure, serum levels of catecholamines, glucose and lipid were determined before and after the treatment. Insulin sensitivity was also measured by a euglycemic hyperinsulinemic clamp method using an artificial pancreas (STG-22; Nikiso, Tokyo, Japan) before and after the treatment. Cilnidipine administration significantly lowered blood pressure from 154/96 to 137/84 mmHg (p<0.05). The glucose infusion rate was significantly increased by 20.8%, from 3.27 +/- 0.36 to 3.95 +/- 0.55 mg/kg/min (p<0.05). HbA1C and serum lipid levels such as total cholesterol and triglyceride were not altered. In addition, cilnidipine treatment did not significantly increase serum norepinephrine levels (278 +/- 25.2 vs. 332 +/- 33.6 pg/ml). Our results suggest that cilnidipine improves insulin sensitivity, possibly due to its exerting a vasodilatory action without stimulating sympathetic nervous activity.

Neuronal Ca2+ Channel Blocking Action of an Antihypertensive Drug, Cilnidipine, in IMR-32 Human Neuroblastoma Cells

Although the anti-sympathetic mechanisms of the antihypertensive drug cilnidipine have been analyzed in neuronal cells derived from rodents, there is little information regarding the effects of cilnidipine in human neuronal cells. We investigated the effects of cilnidipine on N-type Ca2+ channels in IMR-32 human neuroblastoma cells using fura-2-based microfluorimetry. The ratio of the intensities of the emitted fluorescence at an excitation wavelength of 340 nm to that at 380 nm was calibrated to estimate the intracellular concentration of Ca2+. Stimulation of IMR-32 cells by 40 mmol/l KCl immediately increased the intensities ratio. In the presence of 10 micromol/l of nifedipine to block L-type Ca2+ channels, omega-conotoxin GVIA, a selective N-type Ca2+ channel blocker, in a concentration of 1 micromol/l suppressed the elevation of the intensities ratio induced by 40 mmol/l KCl. Similarly, cilnidipine in a concentration of 10 micromo/l suppressed the elevation of the ratio induced by 40 mmol/l KCl, and this suppression was effectively inhibited after the treatment with omega-conotoxin GVIA. These results suggest that cilnidipine potentially inhibits N-type Ca2+ channels in human neuronal cells and might be applied as a prospective therapeutic tool to provide neuronal protection as well as its antihypertensive effects and anti-sympathetic actions.