Diabetes mellitus is one of the most common human diseases in the world, the frequency of which is increasing every year. This disease is associated with a violation of the absorption of glucose and develops due to a deficiency of the hormone insulin, resulting in the development of hyperglycemia, a persistent increase in blood glucose [88]. The disease is characterized by a chronic course, as well as a violation of all types of metabolism: carbohydrate, fat, protein, mineral and water–salt. Food products contain various types of carbohydrates. Some of them, such as glucose, consist of one six-membered heterocyclic carbohydrate ring and are absorbed in the intestine unchanged. These substances are broken down by various enzymes in the gastrointestinal tract into glucose molecules and other simple sugars, and are eventually also absorbed into the blood. Thus, glucose is the main carbohydrate of the blood and the whole organism. It plays an exceptional role in the metabolism of the human body: it is the main and universal source of energy for the whole organism. In case of insulin deficiency (type 1 diabetes mellitus) or a violation of the mechanism of interaction of insulin with body cells (type 2 diabetes mellitus), glucose accumulates in the blood in large quantities (hyperglycemia), and body cells (with the exception of insulin-independent organs) lose their main source of energy. To treat this disease, special enzymes are used that inhibit intestinal enzymes that break down complex carbohydrates to glucose, thereby reducing the absorption of glucose at the intestinal level. Currently, there are no conservative treatments that can cure type 2 diabetes mellitus [89]. In some studies, Brassica napus L. seeds have been found to contain angiotensin-converting enzyme (ACE) and dipeptidase-IV (DPP-IV) inhibitory peptides [90]. DPP-IV is a serine protease that helps inactivate glucagon-like peptide-1 when it enters the bloodstream. Preclinical studies show that these peptides exhibit glucose tolerance and high rates of insulin secretion. Thus, Brassica napus L. seeds have potential antidiabetic and antihypertensive properties [84].

Overweight and obesity are the main causes of diabetes and insulin resistance. Violation of the lipid profile is usually observed in patients with diabetes mellitus. Moreover, an increase in adipose tissue, especially visceral fat, is associated with the development of diabetes [91]. Due to the high content of flavonoids, the hypoglycemic properties of rapeseed have been studied. In one study, an experiment was carried out on Wistar rats, which were divided into five groups. Rapeseed extract was administered orally to rats for 4 weeks. As a result, rapeseed extract significantly lowered glucose levels in diabetic rats and helped lower serum triglyceride levels. Thus, rapeseed extract is beneficial for patients with diabetes and has a hypoglycemic effect [92].

The Westernization of eating habits in most countries is characterized by an increase in the consumption of high-calorie foods high in refined sugar, saturated fatty acids (SFAs) and an increased ratio of ω6/ω3 fatty acids. The associated increased prevalence of overweight, obesity and cardiovascular disease is a major public health problem. All these phenomena are the leading cause of disability and death. The consumption of refined oils as a source of lipids that contain high amounts of SFAs but do not contain other biologically active compounds increases the risk of developing these diseases. Dietary intake of cis-monounsaturated and polyunsaturated fatty acids and bioactive antioxidants such as vitamins and phenolic compounds is recognized as a cardioprotective and healthy metabolic effect [93]. Rapeseed is a good source of ω3 polyunsaturated fatty acids (PUFAs) for humans. The oil obtained from this plant contains 8–10% linolenic acid (ALA, 18:3ω3) and has a good ratio of ω6/ω3 acids [94]. Brassica napus L. seeds contain bioactive compounds, including antioxidant vitamins such as tocopherol (mainly alpha-tocopherol), phenolic molecules (canolol, sinapic acid, sinapin), coenzyme Q (CoQ) and phytosterols. These micronutrients have healthy metabolic, anti-inflammatory and physiological effects [95]. Consumption of fatty acids (especially PUFAs) increases the rate of fatty acid oxidation, resulting in peroxisomal and mitochondrial production of hydrogen peroxide. Antioxidant supplementation concomitantly with ω3 PUFAs is an appropriate nutritional strategy to reduce obesity-related metabolic disturbances by altering antioxidant activity and inflammation [96]. Frederic Capel et al. conducted preclinical trials to study the effect of rapeseed oil in the diet of rats in the fight against obesity. The diet consisted of palm oil and rapeseed oil enriched with polyunsaturated fatty acids and a sufficient ratio of ω6/ω3 acids. As a result, the rapeseed oil diet prevented glucose intolerance in rats and also reduced triacylglycerol levels. Thus, enriched rapeseed oil with natural micronutrients has been shown to improve skeletal muscle and adipose tissue metabolism, allowing better management of excess fatty acids and lowering glycemia, which may be beneficial in the long term [97].

Malgorzata Jamka et al. conducted a clinical trial to study the effect of amaranth and rapeseed oil on people suffering from overweight and obesity [98]. Exclusion criteria included a chronic systemic or gastrointestinal disease in anamnesis, liver disease, exocrine pancreatic insufficiency, drugs that affect fat digestion or absorption, pregnancy and lactation. All study participants were randomly assigned to groups I and II. In group I, amaranth oil was administered at a dose of 20 mL per day in the first intervention, and rapeseed oil at a dose of 20 mL per day was administered in the second intervention. Baseline variables included changes in tumor necrosis factor-alpha; adiponectin; oxidized low-density lipoprotein; apolipoproteins (Apo) A1, B and E; and markers of glucose and insulin homeostasis. Rapeseed oil had a greater positive effect on atherosclerosis markers than amaranth oil [99].

Cardiovascular disease is one of the main causes of premature death in many countries and leads to disability in patients. Among cardiovascular diseases, atherosclerosis is the most common pathological process. The progression of atherosclerosis is influenced by factors such as lipid abnormalities, oxidative stress and chronic inflammation [100]. Rapeseed oil is one of the main vegetable oils used in the food industry in many countries. This oil has a low amount of saturated fatty acids and a high amount of monounsaturated fatty acids compared to other edible oils. Additionally, rapeseed oil is a source of linoleic acid, α-linolenic acid and other essential fatty acids [101]. Various studies show that rapeseed oil can lower serum total cholesterol and low-density lipoprotein cholesterol. The phytosterols contained in rapeseed oil have a hypocholesterolemic effect by inhibiting the absorption of cholesterol [102]. Trace elements present in the composition of rapeseed oil can prevent the occurrence of atherosclerosis. One study conducted on laboratory rats examined the effect of rapeseed oil on risk factors for atherosclerosis. As a result of the study, after the consumption of oil in rats, the levels of triglycerides and plasma cholesterol decreased markedly. Thus, rapeseed oil prevents atherogenesis by improving plasma oxidative stress, the lipid profile and inflammation [103].

Antioxidants are substances that have the ability to scavenge free radicals due to their redox properties. Natural antioxidants are safer and have fewer side effects compared to synthetic antioxidants [104]. Antioxidant activity, α-amylase inhibitory activity as well as antibacterial activity of rapeseed extract have been previously studied. When obtaining the extract, methanol was used as a solvent. The antioxidant activity of the extract was studied by DPPH analysis, in which at 125 (µg/m) extract, the DPPH value was 42.36 ± 3.26. The data obtained confirm the presence of antioxidant properties of the methanol extract of rapeseed. The high content of phenols and flavonoids in the rapeseed extract contributes to the manifestation of antioxidant properties [105]. Aleksandra Szydłowska-Czerniak et al. used three different analytical methods to determine the antioxidant capacity of rapeseed: ferric-reducing antioxidant power (FRAP), 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC). Mean ORAC values for methanolic rapeseed extracts (4092–12,989 mmol Trolox/100 g) were significantly higher than FRAP and DPPH values (6218–7641 and 6238–7645 mmol Trolox/100 g, respectively) [106]. In another study, four modified methods were used to determine the antioxidant activity of rapeseed oil: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric-reducing antioxidant capacity (CUPRAC) and ferric-reducing antioxidant power (FRAP). The obtained values of DPPH, ABTS, CUPRAC and FRAP of rapeseed oil were 126–586, 400–1998, 455–1913 and 72–291 µmol TE 100 g⁻¹, respectively [107].

Azzurra Stefanucci et al. studied the antioxidant activity and enzymatic inhibitory ability of rapeseed extract. This extract contains flavonoids, glucosinolates, sinapic acid and disaccharides. According to the analysis of DPPH, the extract showed antioxidant activity as a result of studying the ability to scavenge radicals. The enzymatic inhibitory effect of the extract against acetylcholinesterase was studied using standard in vitro bioassays. In total, glucosinolates are healthy phytochemicals with antioxidant effects to the body [108].

Jovicic Dusica et al. studied the antioxidant activity of rapeseed leaves and roots at different stages of growth and grown under different field conditions. The study was conducted on the following parameters: the activity of the superoxide dismutase enzyme, the activity of glutathione peroxidase, the intensity of lipid peroxidation, the content of glutathione and the total antioxidant activity. As a result, the antioxidant activity of all studied parameters in all genotypes, both in leaves and roots, was higher in plants grown on Solonetz compared to plants grown on Chernozem [109].

A subcritical water extract of rapeseed has been studied as an antiviral agent against the A/H1N1 virus. At maximum non-toxic concentrations, the subcritical aqueous extract showed antiviral activity against influenza A/H1N1 virus compared to other extracts of n-hexane, ethanol or hot water. The addition of 0.5 mg/mL subcritical aqueous extract to the culture medium resulted in 50.35% viability of kidney cells of dogs infected with influenza A/H1N1 virus. Thus, the extract had antiviral activity against influenza virus infection. The data obtained indicate the prospect of using rapeseed extract as an antiviral agent [110].

Hepatitis C virus is one of the main causes of chronic liver disease. With about 170 million cases in the world, it remains a serious public health problem [111]. Treatment of hepatitis C is ineffective in most cases, and is also long-term and expensive. At the same time, there is still no vaccine against this infection in practical healthcare. One study investigated the antiviral activity of an extract of a transgenic hepatitis C virus core protein derived from rapeseed and rHCVcp derived from Escherichia coli. Mice immunized with the transgenic core protein oil developed a strong humoral (IgG) and Th1-dependent cellular response, manifested by high levels of IFN-γ and a lower IgG1/IgG2a ratio and secretion of IL-4. The results of intracellular cytokine staining showed that immunization with transgenic core protein oil in mice triggered both CD4+ and CD8+ T cells to release IFN-γ, while CD4+ cells were mainly activated by Freund’s adjuvant. The data obtained are important for the development of a hepatitis C vaccine and indicate the potential of the antigen obtained from rapeseed [85,112].

Another study shows that the alcohol extract of rapeseed has an antibacterial effect on some types of pathogenic bacteria. The study was carried out using good diffusion agar and disk diffusion agar for Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. A minimum inhibitory concentration and minimum bactericidal concentration test was performed using serial dilutions in vitro. As a result, the alcohol extract of rapeseed prevented the growth of the above pathogenic bacteria, in which the minimum inhibitory concentration varied from 12.5 mg/mL to 100 mg/mL. Rapeseed oil has been used in the treatment of various types of diseases and skin infections in Pakistan. The oil is obtained from rapeseed by extraction with n-hexane. The antibacterial activity of rapeseed oil was studied on four microorganisms, namely Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Klebsiella pneumonia, causing some infections.

Film with rapeseed extract obtained by supercritical carbon dioxide extraction also showed antibacterial activity against pathogenic microorganisms. An in vitro study was conducted in which the decimal reductive concentration and the minimum bactericidal concentration for pathogens were determined. Terpenoids, diterpenes and sesquiterpenes were found in the composition of this extract using gas chromatography. The study of antibacterial and fungicidal activity of rapeseed extract was carried out on four strains of pathogenic microorganisms, namely S. aureus, E. coli, P. aeruginosa and C. albicans. As a result, the rapeseed extract exhibited biological activity against C. albicans at a dilution of 1:32 and against E. coli at a dilution of 1:8. However, no inhibitory ability was found for P. aeruginosa and S. aureus. Thus, the data obtained indicate the potential of using rapeseed extract as an antibacterial agent in the pharmaceutical industry [114].

Cancer is considered one of the dysregulations of basic cellular functions such as growth signaling, anti-apoptotic signaling, gene stability and immune response [115]. Every year, the number of patients with cancer and the mortality rate from this disease increase [116]. Currently, Brassica plant metabolites are becoming new sources of anticancer therapy. Bioactive compounds in these plants exhibit anticancer activity against the main types of tumors [86]. Numerous clinical studies have been conducted to explore effective treatments for cancer. However, later, their toxic and side effects had a negative impact on patients. Radiation therapy and chemotherapy have serious side effects on healthy cells. Targeted therapies and immunotherapy are considered among the most effective cancer treatments, but they are applied to limited patients and are expensive therapies. In this regard, combination therapy replacing monotherapy has recently been used to prevent their side effects [117]. Moreover, searches are underway for new and effective drugs with reduced side and toxic effects. Plant metabolites are the source of a wide range of biological activities, such as anti-inflammatory, antimicrobial, anticancer and antianalgesic activity [118]. Among anticancer drugs, more than 60% of drugs are obtained from plant materials. Plants belonging to the Brassicaceae family are a rich source of glucosinolates, which are widely used as biologically active compounds [119]. Active metabolites of glucosinolates are used in various forms of cancer. For example, sulforaphane is used in the treatment of prostate cancer by helping to inhibit the growth of prostate cancer tumors. It also helps in the treatment of breast cancer, ovarian cancer and melanoma [120]. Erucin is effective in the treatment of pancreatic tumors, hepatocellular carcinoma and breast cancer. Indole-3-carbinol prevents colon cancer, hepatocellular carcinoma, breast cancer and prostate cancer [121].

It is now known that rapeseed may have chemoprotective and antitumor properties. Some researchers believe that the antitumor effect may be associated with the effective purification of reactive oxygen species by various rapeseed extracts [122]. In particular, brassinosteroids present in rapeseed extracts have an anticancer effect. The steroid fraction of the chloroform extract of rapeseed exhibits cytotoxic activity against certain types of human cancer cells. Cell death occurs due to the induction of caspase activity and inhibition of the Bcl-2 protein, mainly in prostate cancer cells [123]. Some results from other studies suggest that a diet based on omega-3 fatty acids helps to slow prostate tumorigenesis by lowering estradiol and testosterone levels by suppressing cell proliferation in C3(1) Tag mice [124]. Rape root extract has an anticancer effect by inhibiting the proliferation of human Hep G2 cancer cells. Other data indicate that γ-tocopherol in rapeseed extract may potentially reduce the risk of prostate cancer [125].

Breast cancer is one of the main oncological diseases frequently found in women in developed countries [126]. Some studies show that plant-derived protein hydrolysates can prevent cancer. Peptides are bioavailable chemical compounds compared to proteins and free amino acids. Thus, they can replace chemotherapy due to their effective tissue penetration and low toxicity [127]. Rapeseed meal is a by-product of the agro-industrial sector, which contains a large amount of proteins and peptides with anticancer properties. In one study, an enzymatic digest of rapeseed protein inhibited the proliferation of a breast cancer cell line. The protein isolate was extracted from the alkaline extract of rapeseed. As a result, all obtained protein hydrolysates exhibited an antiproliferative effect on MCF-7 cells [128].

Hypertension is high blood pressure, which is a serious pathological condition that significantly increases the risk of developing diseases of the cardiovascular system, brain, kidneys and other diseases. In the modern world, the prevalence of arterial hypertension is 30–45% among the adult population [129]. Blood pressure is the force exerted by circulating blood on the arteries, the most important blood vessels in the body. Hypertension is characterized by an excessive increase in blood pressure. It is predicted that the number of patients with this disease by 2025 will be 1.6 billion [130]. Rapeseed-derived peptides can be used to treat arterial hypertension. One in vivo study in mice examined the safety and antihypertensive properties of rapeseed peptides in synergy with captopril. According to toxicity studies, the maximum tolerated dose exceeded 25 g kg⁻¹ body weight per day in mice, i.e., rapeseed peptides are non-toxic. Moreover, rapeseed peptides synergistically increased the amplitude of captopril lowering blood pressure by 9% and increased the time of antihypertensive activity in hypertensive rats by 20% [87]. Thus, rapeseed peptides can be used in the development of an antihypertensive agent that helps lower blood pressure.