Copper and zinc are micronutrients that play a crucial role in many cellular pathways, act as cofactors in enzymatic systems, and hence, modulate enzyme activity. The regulation of these elements in homeostasis is precisely controlled by various mechanisms. Superoxide dismutase (SOD) is an enzyme requiring both copper and zinc for proper functioning. Additionally, there is an interaction between the concentrations of copper and zinc. Dietary ingestion of large amounts of zinc augments intestinal absorption of this trace element, resulting in copper deficiency secondary to zinc excess. The presence of an overabundance of copper and zinc has a detrimental impact on the cardiovascular system; however, the impact on vascular contractility varies. Copper plays a role in the modulation of vascular remodeling in the cardiac tissue, and the phenomenon of cuproptosis has been linked to the pathogenesis of coronary artery disease. The presence of copper has an observable effect on the vasorelaxation mediated by nitric oxide. The maintenance of proper levels of zinc within an organism influences SOD and is essential in the pathogenesis of myocardial ischemia/reperfusion injury. Recently, the effects of metal nanoparticles have been investigated due to their unique characteristics. On the other hand, dietary introduction of metal nanoparticles may result in vascular dysfunction, oxidative stress, and cellular DNA damage. Copper and zinc intake affect cardiovascular function, but more research is needed.

Alcoholic leaf and petal fractions of Taraxacum officinale (dandelion) were previously demonstrated to exert in vitro antioxidant and antithrombotic activities in blood plasma and platelets. Eight-week-old male Wistar rats (n = 6) were supplemented for four weeks with dandelion fractions (694 mg/kg of diet = 11.9 ± 0.6 mg daily). Dandelion leaf and petal fractions, which delivered daily 4.10 ± 0.05 and 1.41 ± 0.07 mg l-chicoric acid, respectively, were shown to exert antioxidative actions, measured as decreased levels of thiobarbituric acid-reactive substances (TBARS) in the spleen (≈0.8-fold, leaves and petals), brain (0.53-fold, leaves) and thoracic arteries (0.59-fold, petals). Moreover, petal fraction increased thiols in the blood plasma (1.58-fold), while leaf fraction decreased protein carbonylation levels (0.59-fold). Additionally, dandelion leaf fractions modified the lipid profile: decreased triglyceride (0.44-fold), total cholesterol (0.73-fold), lipoprotein combine index (0.32-fold) and the atherogenic index of plasma (0.62-fold). Dandelion fractions showed a beneficial decrease effect in the participation of cyclooxygenase products in the noradrenaline-induced vascular contractions of thoracic arteries. Meanwhile, only the dandelion leaf fraction augmented acetylcholine-induced vasodilation and upregulated K_ATP channels. The heart rate and blood pressure were not modified. Dandelion leaf and petal phenolic fractions, enriched with l-chicoric acid, are promising plant materials that may exert in vivo beneficial antioxidant effects.

Seeds of industrial hemp (Cannabis sativa L.) contain a large amount of protein (26.3%), dietary fiber (27.5%), and fatty acids (33.2%), including linoleic, α-linolenic, and some amount of γ-linolenic acid. In our study, obese male Zucker rats (n = 6) at 8 weeks of age were supplemented for a further 4 weeks with either ground hemp seeds (12% diet) or lipid fractions in the form of hemp seed oil (4% diet). Hemp oil decreased blood plasma HDL-cholesterol (x0.76, p ≤ 0.0001), triglycerides (x0.55, p = 0.01), and calculated atherogenic parameters. Meanwhile, hemp seeds decreased HDL-cholesterol (x0.71, p ≤ 0.0001) and total cholesterol (x0.81, p = 0.006) but not the atherogenic index. The plasma antioxidant capacity of water-soluble compounds was decreased by the seeds (x0.30, p = 0.0015), which in turn was associated with a decrease in plasma uric acid (x0.18, p = 0.03). Dietary hemp seeds also decreased plasma urea (x0.80, p = 0.02), while the oil decreased the plasma total protein (x0.90, p = 0.05). Hemp seeds and the oil decreased lipid peroxidation in the blood plasma and in the heart (reflected as malondialdehyde content), improved contraction to noradrenaline, and up-regulated the sensitivity of potassium channels dependent on ATP and Ca²⁺. Meanwhile, acetylcholine-induced vasodilation was improved by hemp seeds exclusively. Dietary supplementation with ground hemp seeds was much more beneficial than the oil, which suggests that the lipid fractions are only partially responsible for this effect.