Broccoli is often considered a nutritional powerhouse because of its numerous health benefits and nutrient density. Broccoli is an excellent source of vitamins C, K, and A. It also contains several important minerals, such as potassium, calcium, and iron. Broccoli contains several antioxidants, including vitamins C and E, β-carotene, and various flavonoids ^[1][2][12,13]. Antioxidants help protect cells from damage caused by harmful free radicals and reduce the risk of chronic diseases ^[3][14]. Broccoli is a good source of dietary fiber, which aids digestion, promotes a feeling of fullness, and contributes to a healthy digestive system ^[2][13]. Broccoli’s fiber, antioxidants, and anti-inflammatory properties contribute to heart health. It can help lower cholesterol, maintain healthy blood pressure, and improve cardiovascular function. The high levels of vitamin A and other antioxidants in broccoli support eye health and may help prevent age-related macular degeneration and cataracts ^[3][4][14,15]. Its high vitamin C content boosts the immune system and promotes collagen production, wound healing, and iron absorption ^[4][5][6][7][15,16,17,18]. Broccoli is a good calcium source, essential for maintaining strong bones and preventing osteoporosis ^[8][9][19,20]. It also contains vitamin K, which is essential for bone health. Broccoli is low in calories but high in fiber, making it a filling food that can help control weight and promote a healthy metabolism ^[10][21]. The fiber content in broccoli supports a healthy digestive system, regulating bowel movements and promoting a healthy gut microbiome ^[11][22]. Overall, broccoli offers various health benefits due to its rich nutrient content. From promoting heart health to supporting digestion and bone health, this cruciferous vegetable provides a versatile and tasty way to improve your overall well-being.

Inflammation is a natural response of the immune system to protect the body from injury, infection, or other harmful stimuli. However, chronic inflammation can be detrimental to health and contribute to various diseases such as heart disease, arthritis, and certain types of cancer. Herbs and vegetables can positively reduce inflammation due to their high content of phytochemicals, antioxidants, and other bioactive compounds. Research suggests that sulforaphane, found in broccoli ^[10][12][21,23], may help reduce inflammation by inhibiting the activity of certain enzymes that promote inflammation in the body. It has also been found to stimulate the production of antioxidant enzymes that protect cells from inflammation-related damage ^[13][14][24,25]. When inflammation persists over a long period, it can create an environment that promotes the growth and survival of cancer cells. Chronic inflammation can lead to the release of additional cytokines and growth factors that can stimulate cell proliferation and support the formation of new blood vessels to supply nutrients to the growing tumor. Inflammatory cells can also produce enzymes that degrade the extracellular matrix, allowing cancer cells to invade surrounding tissues and metastasize to distant organs. Several types of cancer are closely related to chronic inflammation ^[14][15][25,26]. For example, prolonged inflammation of the gastrointestinal tract, as occurring in inflammatory bowel disease (e.g., Crohn’s disease, ulcerative colitis), increases the risk of developing colorectal cancer. In addition, chronic hepatitis B or C virus infections can lead to liver inflammation and increase the likelihood of liver cancer (hepatocellular carcinoma). Similarly, chronic human papillomavirus (HPV) infections can cause cervix inflammation and contribute to the development of cervical cancer.

Glucosinolates are a group of sulfur-containing compounds found in cruciferous vegetables such as broccoli, cauliflower, kale, Brussels sprouts, and cabbage. These compounds are responsible for the characteristic pungent aroma and bitter taste of these vegetables. Glucosinolates are secondary metabolites that serve as natural defenses in plants. When plant tissue is damaged by chopping or chewing, an enzyme called myrosinase encounters glucosinolates, leading to their degradation and the formation of various bioactive compounds. One of the major degradation products of glucosinolates is an isothiocyanate called sulforaphane, which has attracted considerable attention because of its potential health benefits. The isothiocyanate sulforaphane was first recognized as an enzyme inducer in the II phase and was associated with anti-cancer effects. Studies have shown that sulforaphane has a direct effect on cancer cell proliferation ^{[16][17][18][19]}[34,35,36,37]. In addition, sulforaphane also shows various biological activities such as antihypertensive, cardioprotective, and complementary treatment in type 2 diabetes. Conversely, nitrile has no significant cancer-preventive effect ^{[19][20][21][22][23][24]}[37,38,39,40,41,42]. Broccoli is rich in sulforaphane, a sulfur-containing compound that has been extensively studied for its anti-cancer properties. Sulforaphane has been found to have the ability to inhibit the growth of cancer cells and induce apoptosis in various types of cancer, including breast, prostate, lung, and colorectal cancers ^[25][43]. An earlier study revealed that sulforaphane enhances the drug-mediated cytotoxicity in SCC12 and SCC38 squamous cell carcinomas of the head and neck ^[26][27][44,45]. It works by modulating multiple cellular pathways involved in cancer development and progression in several types of cancer, including breast, prostate, lung, colon, and liver cancer. Recently, Zhang et al. (2022) reported that sulforaphane interferes with the RAF/MEK/ERK signaling pathway to inhibit actin stress fiber formation and thereby prevent breast cancer cell metastasis ^[28][46]. The preceding review suggests that sulforaphane exerts its therapeutic effects through a variety of mechanisms, such as detoxification of carcinogens and oxidants by blocking phase I metabolic enzymes and arresting the cell cycle in phases G2/M and G1 to inhibit cell proliferation. However, the most striking observation was the ability of sulforaphane to enhance the effects of several classes of anticancer agents, including paclitaxel, docetaxel, and gemcitabine, through additive and synergistic effects ^[28][46]. Indole-3-carbinol (I3C) is a compound found naturally in cruciferous vegetables such as broccoli, cauliflower, cabbage, and Brussels sprouts. It has been of interest to researchers due to its potential health benefits, particularly in relation to cancer prevention. Studies suggest that I3C may have anticancer properties. On the other hand, indole-3-carbinol is a well-known chemo preventive drug with a variety of biological effects, which include promoting tumor cell death and inhibiting angiogenesis and inflammation ^[29][47]. It is believed to exert its effects through various mechanisms, including altering estrogen metabolism, inducing cell cycle arrest, promoting apoptosis, and inhibiting angiogenesis. I3C has been described as a potent inducer of cytochrome-P450-dependent metabolism of estrogen. Estrogen is critical for the development of recurrent respiratory papillomatosis by promoting epithelial proliferation and enhancing human papillomavirus gene expression ^[30][48]. Quercetin is a flavonoid found in broccoli that has anti-inflammatory properties. It can inhibit the production of inflammatory substances and help reduce inflammation in the body. The MAPK pathway plays a role in cell signaling and the regulation of various cellular processes, including inflammation, and there is limited evidence specifically linking quercetin’s effect on this pathway. Quercetin has been shown to modulate several signaling pathways, including NF-κB and PI3K/Akt, which are involved in inflammation. However, the direct inhibition of the MAPK pathway by quercetin is not well established ^[16][34]. Broccoli is an excellent source of vitamin C, which is a potent antioxidant. Vitamin C scavenges free radicals and helps regenerate other antioxidants in the body, such as vitamin E ^{[31][32][33][34][35]}[49,50,51,52,53]. It plays a crucial role in protecting cells and tissues from oxidative damage. Broccoli contains various flavonoids and phenolic compounds known for their antioxidant properties ^[34][35][52,53]. These compounds, such as kaempferol and quercetin, can neutralize free radicals and reduce oxidative stress in the body. Glucosinolates are sulfur containing plant secondary metabolites found in broccoli that are involved in cancer prevention and have antioxidant properties. Glucosinolates are converted into sulforaphane, has been shown to enhance the body’s natural antioxidant defenses and reduce oxidative stress ^[36][37][38][54,55,56]. Broccoli contains carotenoids such as β-carotene and lutein, which act as antioxidants. These compounds can help protect cells from damage caused by free radicals, particularly in tissues like the eyes and skin ^{[38][39][40][41]}[56,57,58,59]. Broccoli is a good source of selenium, a mineral that is an essential component of antioxidant enzymes, including glutathione peroxidase ^[41][42][59,60]. These enzymes help neutralize harmful free radicals and reduce oxidative stress. Consuming broccoli and other antioxidant-rich foods as part of a balanced diet may help reduce oxidative stress, support cellular health, and lower the risk of chronic diseases associated with oxidative damage, such as cardiovascular diseases, certain cancers, and neurodegenerative disorders ^[43][44][61,62].

3. Antibacterial Properties

Antioxidants may enhance the efficacy of antimicrobial therapies. Some studies suggest that combining antioxidants with antimicrobial agents such as antibiotics or antiviral drugs may enhance their efficacy by reducing oxidative-stress-induced host tissue damage and supporting the immune system’s response to infection. While antioxidants are primarily known for their ability to counteract oxidative stress, some specific antioxidants have also been found to have natural antimicrobial properties. For example, certain plant antioxidants, such as flavonoids and polyphenols, have been shown to have antimicrobial activity against a range of microorganisms, including bacteria, viruses, and fungi ^{[45][46][47][48]}[63,64,65,66]. ROS plays a critical role in the immune response against bacterial infections. When the body recognizes bacteria, immune cells such as neutrophils and macrophages are activated to eliminate the invading pathogens ^[49][67]. In addition, immune cells generate ROS, such as superoxide anions (O²⁻), hydrogen peroxide (H₂O₂), and hydroxyl radicals (OH⁻), through a process called respiratory burst. The production of ROS is a rapid and effective defense mechanism aimed at killing bacteria or inhibiting their growth and can directly damage bacterial cells. ROS can react with various cellular components of bacteria, including lipids, proteins, and nucleic acids, resulting in oxidative damage and disruption of essential cellular processes ^[50][68]. This oxidative stress can lead to membrane damage, protein dysfunction, and DNA/RNA damage, ultimately resulting in bacterial death ^[51][69]. ROS also functions as a signaling molecule in immune cells. It can regulate immune cell activation, migration, and cytokine production, which is essential for an effective immune response against bacterial infections ^[52][70]. While ROS effectively kills bacteria, some bacterial pathogens have evolved mechanisms to counteract or neutralize ^[50][53][68,71]. Certain bacteria produce enzymes such as catalase and superoxide dismutase that help break down ROS and protect the bacteria from oxidative damage. In this way, the bacteria can bypass the immune response and survive in the host. ROS serves as an effective antimicrobial agent that directly damages bacterial cells and helps eliminate pathogens. However, some bacteria have developed strategies to counteract and can evade the immune response. Therefore, the balance between the production of ROS and antioxidant defense is critical for an effective immune response against bacterial infections ^[50][68]. Even though antioxidants are primarily recognized for their function in combating oxidative stress and their potential health benefits, it has been discovered that certain antioxidants also possess antibacterial properties. Broccoli is often highlighted for its potential antibacterial effects, which can contribute to overall health and the prevention of bacterial infections. Broccoli contains certain compounds such as glucosinolates and isothiocyanates that have been shown to have antibacterial activity. Sulforaphane may have antibacterial activity against Helicobacter pylori, a bacterium associated with gastric ulcers and gastrointestinal infections ^{[50][51][52][53][54]}[68,69,70,71,72]. In addition to sulforaphane, other compounds in broccoli, such as indole-3-carbinol and phenolic compounds, have also shown some antimicrobial activity in laboratory studies. These compounds have shown inhibitory activity against certain strains of bacteria, including Escherichia coli and Staphylococcus aureus ^[54][55][72,73]. On the other hand, biofilms can contribute to bacterial persistence and resistance, making them more difficult to treat with antibiotics. By inhibiting biofilm formation, bacterial load is reduced. In this context, 3,3’-diindolylmethane (DIM), a bioactive component of broccoli, may act as an inhibitor of biofilm formation and cause a reduction in bacterial load ^[56][74]. Bacterial contamination in food is a common cause of foodborne illnesses. Broccoli’s antibacterial properties, particularly its ability to inhibit the growth of certain bacteria, can help reduce the risk of foodborne infections. It can potentially hinder the growth of pathogens such as Escherichia coli, Salmonella sp., and Listeria monocytogenes, which are commonly associated with foodborne outbreaks. Antibiotic resistance is a growing concern in healthcare. Certain bacteria have become resistant to commonly used antibiotics, making infections more difficult to treat. Broccoli’s antibacterial properties, particularly its ability to inhibit the growth of antibiotic-resistant strains, have garnered interest as a potential natural alternative or adjunct to traditional antibiotics. Further research is needed to fully understand the effectiveness and mechanisms of action in this context.