#1131 Significant reno-cardio-metabolic protection by the food additive Flexovital in a murine model combining unilateral nephrectomy and Western diet
Authors: Carvalho Lucas , Tyden Maria , Fellström Bengt , de Oliveira Monteiro Matheus Morais , Andersson Daniel , Schiffer Tomas , Carlström Mattias 
Published: May 2024

Abstract

Background and Aims
Cardiovascular complications are major threats in advanced renal failure and metabolic dysfunction with several unmet medical needs. This study aimed to investigate the therapeutic effects of a special food additive (FLEXOVITAL) in a newly developed mouse model of reno-cardio-metabolic disease, induced by moderate renal failure in combination with a special Western diet.

Method
Male C57BL/6J mice (4 weeks old, n = 18) were subject to unilateral nephrectomy (UNX), fed a Western diet rich in fat carbohydrates and salt (WD), and were followed for 12 weeks compared with SHAM-operated mice on standard chow (n = 19). One group of UNX+WD mice (n = 8) was fed a food additive (FLEXOVITAL; FLX) containing extracts of Rhodiola rosea, beetroot, and the amino acids arginine and citrulline. Body weight (BW), blood pressure (tail-cuff), endothelial-dependent vasorelaxation (myograph), glucose metabolism (IPGTT), body fat and lean mass composition (DEXA), adipocyte area, renal function (Glomerular Filtration Rate (GFR) by plasma clearance of FITC-inulin), and mitochondrial function (Oroboros, High-resolution respirometry) were measured together with biochemical analysis of heart injury (Troponin-I), inflammation (IL6) and histological analyses of the kidney and heart.

Results
BW gain was seen in the UNX+WD and SHAM group, and was 25% less in the FLX group (p &lt; 0.05). The fat/lean-mass ratio increased by 17% (p &lt; 0.01) and the adipocyte area by 31% (p &lt; 0.001) in the UNX+WD group but was virtually normalized in the FLX group (p &lt; 0.01). Fasting and non-fasting glucose levels became elevated in the UNX+WD group and were reduced in the FLX group (p &lt; 0.05). Impaired glucose clearance in the UNX+WD group, was partially prevented by FLX. BP significantly increased in the UNX+WD group (MAP = 78 → 90 mmHg, p &lt; 0.001), and was largely prevented by FLX (MAP = 82 mmHg, p &lt; 0.01). Endothelial function was significantly impaired in the UNX+WD group (p &lt; 0.01) and partially preserved in the FLX group (p &lt; 0.05). GFR was reduced by almost 60% in the UNX+WD group but improved with a 75% protective effect in the FLX group (p &lt; 0.05). Significant glomerular injuries with mesangial proliferation were observed in the UNX+WD group (p &lt; 0.001) but were less pronounced in the FLX group (p &lt; 0.01). Tubular injury score (1-10) increased from 1 in SHAM to 6.5 in the UNX+WD group and was partly protected (4.5) in the FLX group (p &lt; 0.05). Troponin-I levels were 15 pg/ml in the SHAM group, markedly increased in the UNX+WD group (p &lt; 0.001), whereas completely reversed in the FLX group (p &lt; 0.01). No significant histological cardiac injuries or deviations could be demonstrated. Inflammatory activity (IL6) increased by 88% in the UNX+WD there was a trend of reduction in mice with FLX. Mitochondrial oxygen efficiency (P/O ratio) was improved in the kidneys of the FLX group compared to the UNX+WD group (p &lt; 0.05).

Conclusion
In the present multiorgan disease model, significant renal, cardiovascular, and metabolic dysfunction/injuries emerge in mice with a moderate reduction of renal function when fed a Western diet rich in fat, carbohydrates, and salt. Protective effects were noted by dietary FLX treatment in most functional assessments made in the model. This indicates FLX is a potential new treatment in patients with reno-cardio-metabolic disease. The next phase involves confirming these findings in the clinical setting.