Nicousamide, a potent inhibitor of phosphorylation by TGF-β receptor II

Nicousamide attenuates renal dysfunction and glomerular injury in remnant kidneys by inhibiting TGF-β1 internalisation and renin activity

Nicousamide has been shown to exert renal protective effects against diabetic nephropathy and has moved to a phase II clinical trial in China for diabetic nephropathy indication. To expand its clinical indications, 5/6-nephrectomised rats were used to mimic glomerular and vascular sclerosis and tubulointerstitial scarring, with subsequent progression towards end-stage renal disease. Adult Wistar rats underwent 5/6 nephrectomy to induce the development of chronic kidney disease, with a sham operation performed as a control. The nephrectomised animals were treated orally with either saline, nicousamide (7.5,15, or 45 mg/kg), benazepril (4 mg/kg), or losartan (10 mg/kg) daily for 20 weeks. At 8, 16, and 20 weeks of treatment, blood pressure was measured in each animal, and blood and urine samples were collected for biochemical analysis, while kidney remnants were collected for histological examination. Levels of fibronectin and transforming growth factor beta 1 (TGF-β1) were measured in kidneys by immunohistochemistry. Renin activity in the plasma was measured by an enzyme-linked immunosorbent assay. The results showed that nicousamide treatment significantly reduced systemic hypertension, proteinuria, and blood urea nitrogen (P < 0.05), effectively alleviated glomerular sclerosis scores and tubulointerstitial injuries in a dose-dependent manner (P < 0.01), and markedly decreased fibronectin and TGF-β1 levels in kidney tissues of the 5/6-nephrectomised animals. In vitro studies suggested that nicousamide could moderately inhibit the renin activity and strongly block the TGF-β1 internalisation into fibroblast cells. In summary, nicousamide may protect from renal failure through dual targeting, which involves a TGF-β1-dependent mechanism and inhibition of renin activity.

Nicousamide normalizes renovascular hypertension in two-kidney one-clip hypertensive rats

Nicousamide, a coumarin-aspirin compound, was proven to have a renal protective effect on diabetic and hypertensive nephropathy. The present study aimed to investigate the anti-hypertensive effect of nicousamide and its action mechanisms. The two-kidney one-clip (2K1C) hypertensive animal model was introduced in this study. Subsequent to treatment with nicousamide for three weeks, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured, and the plasma concentration of angiotensin II (Ang II), nitric oxide (NO), endothelin-1 (ET-1), nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP) was examined. Results showed that nicousamide markedly decreased SBP as well as DBP on renovascular hypertensive rats (P<0.05). Nicousamide also reduced the Ang II and ET-1 concentration (P<0.05) in the plasma of hypertensive rats while increasing the plasma NO level (P<0.05). Nicousamide treatment did not show a marked effect on the NOS and CGRP concentrations in animal plasma (P>0.05).

Renal-protective effect of nicousamide on hypertensive nephropathy in spontaneously hypertensive rats

Previous studies have demonstrated that a novel coumarin-aspirin derivative, nicousamide, has a significant renal-protective effect on diabetic nephropathy. The present study aimed to investigate the beneficial effect of nicousamide on hypertensive nephropathy, as well as the underlying mechanisms in spontaneously hypertensive rats (SHRs). SHRs were treated orally with saline, nicousamide at 15, 30 and 45 mg/kg, and losartan (10 mg/kg) daily for 17 weeks, during which blood pressure (BP) was measured every four weeks. At the end of the 17-week treatment, blood and urine samples were collected for biochemical analysis and kidney tissues were obtained for histopathological and reverse transcription-polymerase chain reaction (RT-PCR) analyses. The concentration of angiotensin (Ang) II in plasma was also examined. Results showed that nicousamide effectively attenuated the progression of hypertensive nephropathy by decreasing urinary albumin excretion (UAE) and blood urea nitrogen (BUN). This could significantly decrease BP (less effectively compared to losartan) and the incidence of glomerulosclerosis and glomerular arteriosclerosis, adequately alleviating tubular impairment. Nicousamide markedly reduced the plasma Ang II level in SHRs and reduced mRNA expression of angiotensin-converting enzyme (ACE) and chymase in the kidneys of SHRs. Thus, nicousamide may retard the progression of hypertensive nephropathy. Although the underlying mechanisms have yet to be fully elucidated, this may involve blocking of the renin-Ang system.