Carnosine is known as a natural dipeptide, which inhibits the proliferation of tumor cells throughout its action on mitochondrial respiration and cell glycolysis. However, not much is known about its effects on the metabolism of healthy cells. We explored the effects of Karnozin EXTRA® capsule with different concentrations of L-carnosine, on the cell viability and the expressions of intermediate filament vimentin (VIM) and superoxide dismutase (SOD2) in normal fibroblasts BHK-21/C13. Furthermore, we investigated its action on the energy production of these cells. Cell viability was quantified by the MTT assay. The Clark oxygen electrode (Oxygraph, Hansatech Instruments, England) was used to measure the “intact cell respiration rate”, state 3 of ADP-stimulated oxidation, maximum oxidation capacity and the activities of complexes I, II and IV. Results showed that Karnozin EXTRA® capsule in concentrations of 2 and 5 mM of L-carnosine did not induce toxic effects and morphological changes in treated cells. Our data revealed a dose-dependent immunofluorescent signal amplification of VIM and SOD2 in the BHK-21/C13 cell line. This supplement substantially increased the recorded mitochondrial respiration rates in the examined cell line. Due to the stimulation of mitochondrial energy production in normal fibroblasts, our results suggested that Karnozin EXTRA® is a potentially protective dietary supplement in the prevention of diseases with altered mitochondrial function.

Numerous studies reported about potential effects of L-carnosine in regulation of tumor growth and metabolism. We evaluated the effects of different concentrations of L-carnosine from Karnozin EXTRA (R) supplement on mitochondrial respiratory chain complexes of human embryo lung fibroblasts (MRC-5) and human breast cancer cells (MCF-7), with different energy pathways. Also, we analyzed the proliferation index and expression of various markers of oxidative stress. Treatment with Karnozin EXTRA (R) (concentration of L-carnosine were 2, 5 and 10 mM) for 24 hours gradually decreased the number of cells and changed their morphological features. In both cell lines, a dose-dependent reduction of cell viability was recorded compared to the control group. Also, experimental groups showed a concentration-dependent decrease in fluorescence intensity of SOD2 expressions in MCF-7, while in MRC-5 we noticed higher fluorescence intensity in Carnosine 2 mM group. Treated cells, in both cell lines, showed different intensity of iNOS cytoplasmic immunopositivity in a concentration-dependent manner. In all experimental groups, we noticed an increased expression of marker of oxidative stress-cytochrome P450 2E1 (CYP2E1). The effects of Karnozin EXTRA (R) capsule on mitochondrial respiration, assessed with the Clark-type electrode, were manifested as a reduction of: basal cell respiration, maximum capacity of electron transport chain and mitochondrial ATP-linked respiration. Also, significant decrease in the activity of complex I (NADH-ubiquinone oxidoreductase), complex II (succinate dehydrogenase) and complex IV (cytochrome c oxidase) was observed in both cell lines. Bearing in mind that Karnozin EXTRA (R) is a potential regulator of energy metabolism of MCF-7 and MRC-5, these results provide a good basis for further preclinical and clinical research.

Background/Objectives: Doxorubicin-induced cardiotoxicity (DIC) is driven by oxidative stress and impaired oxidative phosphorylation (OXPHOS). Antioxidant properties of carotenoids in vivo depend on extraction, while their direct role in mitigating DIC remains undetermined. This study evaluated the cardioprotective potential of natural deep eutectic solvents (NADES)-derived pumpkin carotenoid extract in a rat model of DIC. Methods: NADES-derived pumpkin pulp extract was characterized by spectrophotometry and HPLC-DAD. Wistar rats (n = 30) were assigned to six groups: C (control), N (NADES, 1 mL, p.o.), P (extract, 900 µg/kg body weight/day of total carotenoids, p.o.), D (doxorubicin, four i.p. doses, 2 mg/kg), ND (NADES/doxorubicin) and PD (900 µg/kg body weight/day of total carotenoids/doxorubicin). The activity of antioxidant enzymes and mitochondrial respiration in saponin-permeabilized left ventricular fibers using a Clark-type oxygen electrode) was measured. Results: Compared to control, cardiac antioxidant enzyme activities, mitochondrial respiration in complex I–linked respiration, ADP-supported OXPHOS, maximal respiratory capacity, and complex II and IV-linked respiration were significantly impaired by doxorubicin and unaltered by NADES. Co-administration of the extract significantly improved antioxidant enzyme activities (GSH-Px: D group 45 vs. PD group 95 nmol/mg proteins; GR: D group 95 vs. PD group 145 nmol/mg proteins; GST: D group 15 vs. PD group 22 nmol/mg proteins; SOD: D group 9 vs. PD group 17 U/mg proteins) and attenuated mitochondrial respiratory dysfunction compared with doxorubicin-treated group, indicating partial preservation of electron transport system capacity. Conclusions: Despite limitations of the study (single sex, single dose), results suggest NADES-based carotenoid extracts have cardioprotective properties in DIC by enhancing antioxidant defenses and supporting mitochondrial respiration.

Introduction. Elastin and collagen are the key components of bones, cartilage, tendons, skin, lungs and arterial walls. Weak connective tissue disorders and joint hypermobility are pathological conditions where the structure of collagen fibers is changed, resulting in a number of symptoms. The objective of this study was to determine the prevalence of weak connective tissue disorder in second- and third-year students of the Faculty of Medicine of the University of Novi Sad, and to compare muscle strength, pulmonary function and blood pressure between individuals with and without hypermobility. Material and Methods. The study included 100 students (50 females and 50 males) divided into two groups: Group 1 with weak connective tissue and Group 2 with normal connective tissue. The subjects were assessed according to the Beighton score and the Brighton criteria to diagnose hypermobility. Values of blood pressure, pulmonary function and muscle strength were also measured. Results. Analysis of anthropometric parameters and blood pressure values showed significant difference between the groups, including the body height (p=0.014) and body weight (p=0.021) values and systolic (p<0.001) and diastolic (p=0.004) blood pressure values. Dynamometric parameters and lung function values were significantly different between the groups, with vital capacity (p<0.001), forced vital capacity (p=0.05), forced expiratory volume in the 1st second (p=0.025). Lower values were noted in group 1. Conclusion. Weak connective tissue was found with high percentage of students of the Faculty of Medicine of the University of Novi Sad (67%). Blood pressure, lung function vales and dynamometric parameters were significantly lower in group 1.