Allium vegetables, represented here by garlic, onion, and leeks, due to their very richness in a wide range of vitamins and essential minerals, have an immense effect on human health. Notably, these vegetables are a good source of ascorbic acid, which ranges from 9.7 to 15.6 mg/100 g in garlic and vitamin B6, whose concentration as high as 2.04 mg/100 g has been reported for some varieties of garlic (14). Besides, they supply vital minerals such as potassium, calcium, magnesium, and manganese, serving an array of physiologic functions (18, 25–29). Vitamin C is highly essential in collagen synthesis, wound healing, and in preventing oxidative stress. Other than that, the Alliums also contain vitamin B6, which is highly essential in the development of the brain and the development of the immune system, and for amino acid metabolism (21, 30).

Minerals such as phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn), manganese (Mn), sodium (Na), iron (Fe), bromine (Br), iodine (I), selenium (Se), and copper (Cu), in addition to vitamins A, C, B6, and folate, are present in Allium species. Besides that, manganese and selenium minerals are highly abundant in Alliums. Manganese is responsible for bone formation, blood clotting, and reduction of oxidative stress (13, 31). Though manganese and selenium equally contribute to antioxidant activity by the neutralization of free radicals, reducing oxidative stress. Selenium is an essential trace metal with antioxidant properties that actively participates in thyroid function, DNA (deoxyribonucleic acid) synthesis, and protection against oxidative damage and infection (32). These minerals have a shielding effect on the cell and facilitate many enzyme systems of the body.

Alliums form part of the important sources of major and minor nutrients; hence, they are part of a healthy diet. For example, garlic contains approximately 33% carbohydrates and 5–6% protein by dry weight, while being low in fat at around 0.5% (21, 25). Similarly, onions contain about 9% carbohydrates, 1.1% protein, and minimal fat, making them low-calorie but nutrient-dense vegetables (12, 19). The micronutrient profile of Allium is astonishingly attractive. Macronutrients Mineral substances like nitrogen, phosphorus, and potassium were directly associated with growth and quality in crops of this nature; their fertilization has a direct impact on yield (33). Furthermore, garlic chives contain different quantities of mineral substances depending on the plant age; in general, the older plants contain more nitrogen and phosphorus (2, 19).

Allium vegetables, including onions, garlic, leeks, and chives, are generally low in calories, with garlic being the most calorie-rich among them. Among the major benefits of Alliums, it is necessary to outline that they possess very low caloric value and can be used in a great number of diets. Thus, 100 g of raw garlic contain about 149 kcal, while 100 g of raw onions have a value of about 40 kcal (25). This low calorific content allows the inclusion of Alliums in many dishes without piling excess calories within them, which is a concern for people looking to manage body weight (9, 19, 21). Nutritional and phytochemical profiles of Allium vegetables contribute highly due to their rich bioactive profile to their dietary uses and health benefits as depicted in Figure 2. These vegetables contain OSCs, flavonoids, and phenolic compounds along with vitamins, associated with a wide range of health-related properties, which include the prevention of oxidative stress, inflammation, and carcinogenesis (34, 35).

In addition to their culinary appeal, Alliums are also valued for their health benefits. In spite of their highly negligible caloric value, Alliums add a great depth of flavor to dishes, which dispenses with adding any high-fat ingredient or immense seasoning with salt. Most of them serve as seasonings in soups, stews, sauces, and salads, eaten raw, cooked, or fermented. Most culinary traditions cannot do without Alliums in foundational cooking techniques like sautéing or braising, wherein layers of flavor are determined. Their ability to stimulate appetite and be healthy at the same time makes them irreplaceable in cuisines all over the world (36–38).

The preventive healthcare, through the action of functional components in some Allium species on a wide variety of chronic diseases, is highly underlined, especially the OSCs, flavonoids, and saponins. Such bioactive compounds have multiple health properties, including antioxidant, anti-inflammatory, and antimicrobial activities important in such conditions as metabolic syndrome, cardiovascular diseases, and diabetes (8, 39). OSCs, for instance, have been reported to lower blood pressure and cholesterol levels, while flavonoids like quercetin also take part in the anti-cancerous action of garlic. The various phytochemicals in Allium species, apart from improving their nutritional value, support the development of functional foods and nutraceuticals aimed at chronic disease prevention, in line with their relevance in modern dietetic practice. Thus, integrating Allium into common foods will bring immense health benefits in human beings and reduce disease burdens (40, 41).

Allicin’s primary mode of action is its ability to rapidly undergo thiol-disulfide exchange with free sulfhydryl (SH) groups on cysteine residues of vital proteins and enzymes. This process, known as S-thiolation, effectively modifies the function of key cellular targets. Examples include:

Antimicrobial Action: Allicin irreversibly inhibits essential thiol-containing enzymes (e.g., alcohol dehydrogenase) in bacterial and fungal pathogens (3, 44).

Anti-inflammatory Effects: Allicin and its breakdown products react with the cysteine residues of KEAP1, leading to its dissociation from Nrf2 and subsequent activation of the antioxidant response element ARE pathway. Simultaneously, it can suppress the pro-inflammatory NF-B signaling cascade. Due to its high reactivity, allicin is highly unstable, possessing a short half-life (measured in minutes) at physiological pH and temperature. Consequently, its systemic concentration is low. It rapidly breaks down into more stable, lipid-soluble secondary metabolites (45–47).

Apart from allicin, there are many other bioactive sulfur compounds present in garlic and other Alliums. For example, when the amino acid allicin breaks down it forms diallyl sulfides. Diallyl sulfides have been proven to have anticarcinogenic effects as well as cardioprotective effects. It is hypothesized that through inducing apoptosis (programmed cell death) in cancerous cells the diaillyl sulfides inhibit carcinogenesis and modulate systems of enzymes that detoxify carcinogens (48, 49). Thiosulfates are other categories of sulfur derivatives occurring in Allium spp., which have been attributed to both antimicrobial and antioxidant activities as well. Further established various cardiovascular benefits through the improvement in the lipid profile and reduction in blood pressure levels (25, 40). Studies have shown that increasing the number of sulfur atoms (e.g., from mono- to di- to tri-sulfides) enhances redox reactivity by improving electron delocalization and radical stabilization, which enhances their free-radical scavenging potential. For instance, diallyl trisulfide (DATS) exhibits stronger antioxidant activity than DADS (Diallyl disulfide) or diallyl sulfide (DAS) due to the additional sulfur atom improving redox potential and increasing lipophilicity, which facilitates membrane penetration and intracellular activity. Additionally, the presence of alk(en)yl groups contributes to the compound’s electron-donating capacity and hydrophobicity, further enhancing interaction with lipid bilayers and scavenging of lipid peroxyl radicals (50, 51).

Among the most prevailing flavonoids in Allium vegetables, onions have been found to have quercetin, kaempferol, and a few derivatives of quercetin, which contribute to their antioxidant activity (52, 53). For example, different studies report that as high as 36.94% of the flavonoids in onion extracts are quercetin. Antioxidant activities of Allium extracts were quantitatively measured by methods such as the DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assays, which showed high scavenging activities and were positively correlated to flavonoid content in these plants (54–56). In particular, quercetin has evidenced the scavenging of free radicals and influenced cellular signaling pathways that enhance its protective effects against oxidative damage (57). Due to the different flavonoid mechanisms like modulation of many key cellular activities, flavonoids have been mentioned as one of the most potent candidates for therapeutic agents in functional foods. Incorporation of dietary sources of bioactive molecules will vastly improve the health status. Amongst the different flavonoids, quercetin is abundant in Alliums, along with a few others like kaempferol. Quercetin and kaempferol are two phytochemicals that have anti-diabetic action through increasing insulin sensitivity and decreasing blood sugar levels as shown in Figure 4.

The other classes of bioactive compounds in Alliums are the phenolic acids which are also antioxidants. These phenolic compounds include caffeic acid, ferulic acid, and p-coumaric acid reported to prevent initiation of oxidative stress and to prevent lipid peroxidation so important in protection against oxidative-related damage that is associated with aging and chronic diseases (33, 36). Various biological activities of phenolic acids are responsible for the health benefits provided by the vegetables belonging to the genus Allium (30, 48, 58). In addition, the bioactive phytochemicals in Allium vegetables, especially allicin and flavonoids, enhance antioxidant defense and impede tumor development by cell cycle arrest or suppression of angiogenesis (26).

The antioxidant activity of allicin involves several intertwined pathways, among which the most crucial one is the induction of the Nrf2 (nuclear factor erythroid 2–related factor 2) pathway, leading to increased expression of antioxidant enzymes such as HO⁻¹ (heme oxygenase-1) and SO as shown in Figure 5. Thus, it reduces markers of oxidative stress, which includes MDA (malondialdehyde), and enhances cellular antioxidant capacity. Moreover, it exerts an anti-inflammatory effect by inhibiting the NLRP3 inflammasome and NF-kB, further contributing to its protective effects against oxidative damage (61, 62).

Its key bioactive compounds include allicin and a series of thiosulfinates that have shown radical-trapping antioxidant activity, thus neutralized free radicals and shielding cellular components, including DNA and lipids, from oxidative damage. The structure of the compounds, including the number of sulfur atoms and substitution by particular alk(en)yl groups, also confers the antioxidative efficacy by the potential of such compounds to inhibit low-density lipoproteins (LDL) lipid oxidation (61). In addition, it may cause apoptosis in cancerous cells, inhibition of tumor proliferations, modulation of inflammation, leading to its anti-cancer and anti-inflammatory properties (47, 63). Computational studies have pointed out that allicin and related OSCs scavenge ROS (reactive oxygen species) directly, which enhances their antioxidant efficacy (64). Together, these mechanisms support the potential of allicin for application as a therapeutic agent in pathologies characterized by oxidative stress and inflammation, such as cardiovascular diseases and metabolic syndrome (25).

The structure–activity relationship of OSCs supports that the number of sulfur atoms plays a role in modulating antioxidant potency. Compounds with three sulfur atoms (e.g., DATS) tend to have higher redox potentials and greater ability to donate electrons compared to their disulfide or monosulfide analogs (17, 47). This enables more efficient neutralization of ROS. Moreover, longer alk(en)yl chains increase compound lipophilicity, improving their partitioning into lipid membranes where they exert antioxidant action by scavenging lipid radicals and protecting membrane integrity. These effects are synergistic with their influence on cellular signaling pathways, such as upregulation of antioxidant enzymes through Nrf2 activation (62, 65).

Besides, Allium species have been effective in the management of metabolic syndrome by regulating blood sugar levels, reducing cholesterol, and reducing inflammation, hence lowering cardiovascular risks (8, 29). Their various bioactive roles, inclusive of antimicrobial and anti-inflammatory effects, even constitute their roles in the prevention of chronic diseases: cancer, diabetes, and cardiovascular disorders. Dietary inclusion of Allium species may be contributing toward improved health and various disease conditions (66).

Table 3 showed some bioactive compounds in the Allium vegetables and their various health benefits. Garlic contains a higher amount of allicin, diallyl disulfide, and flavonoids responsible for its antioxidant, anti-inflammatory, and cardio-protective actions. Onions are a rich source of quercetin and sulfur compounds, exhibiting cardiovascular health, immunity, and liver detoxification effects, while leeks contain alliin, allicin, and phenolic acids which may favorably affect heart health and cognitive function (29).

Antioxidants from garlic and onion have been pursued in clinical trials for the prevention of chronic diseases. OSCs and flavonoids of garlic and onion have been reported to possess excellent antioxidant, anti-inflammatory, and anti-cancer activities (38). A number of studies have identified compounds with the potential to modulate several signaling pathways implicated in chronic diseases like CVDs (cardiovascular diseases), diabetes, and obesity (16). For instance, bioactive compounds in garlic enhance endothelial function and inhibit lipid peroxidation for vascular protection (27), whereas onion phytomolecules exert a preventive role in non-communicable diseases by acting upon energy metabolism and insulin signaling pathways (38). Clinical evidence has indicated that garlic extracts exhibit antioxidant properties and hence may be of value in the management of chronic diseases like atherosclerosis, diabetes, and hypercholesterolemia. When comparing studies on antioxidant effects, a clear trend emerges: allicin and other OSCs consistently reduce oxidative stress markers such as MDA and increase antioxidant enzyme activity, e.g., SOD (superoxide dismutase), GPx across in vitro and in vivo models. For example, in vitro studies using garlic extract on endothelial and hepatic cells demonstrated strong radical scavenging and Nrf2 activation. In contrast, in vivo models in rats confirmed systemic antioxidant benefits but often required higher doses. Clinical trials, while more limited, show moderate improvement in oxidative stress markers in patients with cardiovascular disease or type 2 diabetes. The variations in observed outcomes may stem from differences in bioavailability, compound stability, dosage, and duration of intervention. Notably, studies using stabilized allicin or encapsulated formulations showed more consistent results than raw garlic preparations (47, 67).

A wide variety of active principles present in most of the Allium spices have been reported to influence various inflammatory pathways. One proposed mechanism involves the interaction of Allium-derived compounds with the TRPV1 receptor, which may contribute to the attenuation of LPS-induced oxidative stress and inflammation, as suggested by animal model studies. However, this pathway represents only one of several possible mechanisms. Other well-characterized pathways implicated in the anti-inflammatory effects of Allium species include suppression of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) and MAPK signaling cascades, which regulate the expression of key pro-inflammatory cytokines such as IL-6, IL-1β, and TNF-α. These converging pathways highlight the complex and multi-targeted nature of Allium’s anti-inflammatory action (9, 69).

Key compounds include OSCs, flavonoids, and phenolic compounds, which exhibit anti-inflammatory properties by modulating cytokine levels and inhibiting pro-inflammatory mediators. As such, the compounds obtained from onions, in particular, propyl propane thiosulfinate (PTS) and its metabolite, propyl propane thiosulfonate (PTSO), were shown to decrease the amount of two pro-inflammatory cytokines: IL-6 and IL-8, possibly pointing to their application in inflammation treatment. Besides that, polysaccharides isolated from Allium tenuissimum could be potential candidates for ameliorating ulcerative colitis by suppressing the TLR4 (toll-like receptor 4)/MyD88/NF-κB pathway, regulating gut microbiota, and inflammatory cytokines levels accordingly (70, 71).

Moreover, onion’s compound, propyl propane thiosulfinate, has been shown to be anti-inflammatory, as evidenced by the reduction in cytokine levels in many tumor cells. Collectively, this shows that Alliums are potentially useful therapeutics for the modulation of inflammation and associated pathologies (68). Further, onion phytomolecules modulate diverse metabolic pathways, including the processes involved in adipogenesis and insulin signaling, with potential preventive properties against obesity and diabetes. Alliums exert potent anti-inflammatory effects mediated via inhibition of essential inflammatory pathways, such as the HIF-1α pathway, which is implicated with sepsis and chronic inflammation (72). Garlic chive-derived vesicle-like nanoparticles (GC-VLNs) exert potent anti-NLRP3 inflammasome activity, suppressing its downstream pathways, such as caspase-1 autocleavage and cytokine release (73–75).

Allium hookeri demonstrates anti-inflammatory action through the inhibition of the proinflammatory cytokines IL-1β, IL-6, IL-13, and TNF-α in a carrageenan-induced air pouch model, which could be attributed to linoleic acid that acts as a potential candidate for anti-inflammatory drug development (74). These dietary organic sulfur compounds of the species Allium, namely, DADS, DMDS, and PDS, significantly repressed NO production and PGE₂ levels and iNOS and COX-2 mRNA expressions (44, 76). Therefore, acting as effective modulators of the inflammatory pathway. Moreover, intake of the species Allium is related to reduced chronic disease risks, therefore being potentially useful dietary interventions in inflammation management and its related diseases. These collectively propose mechanisms whereby Allium vegetables may assume a therapeutic role in the management of chronic diseases through targeting key inflammatory pathways and metabolic dysregulations (77).

The Allium genus is of considerable importance for managing chronic diseases such as CVDs and arthritis by a number of bioactive compounds in general, but with special emphasis on garlic and onion. One major constituent of garlic, allicin, showed cardioprotection by mitigating the most important processes of diseases like atherosclerosis and hypertension: namely, oxidative stress, inflammation, and apoptosis (50). Additionally, anti-inflammatory and antioxidant activities enabling the latter to support metabolic health and possibly reduce the risk of metabolic syndrome have been made possible by OSCs, flavonoids, and phenolics high in species of Allium (8). Besides, some onion phytomolecules have been associated with antiobesity and antidiabetic activities, an implication of a multichannel approach in the prevention of noncommunicable diseases (38). The OSCsin Allium species have also been reported for the prevention of chronic diseases, including but not limited to cancer, cardiovascular diseases, neurological disorders, diabetes, liver diseases, allergy, and arthritis based on their antibacterial and antioxidant activities besides a proposed mechanism of action (29). Garlic has shown potential pharmacotherapeutic use for life chronic ailments, especially cardiovascular diseases and arthritis, based on its antioxidant, anti-inflammatory, and immunomodulatory activities, which may be useful in the management of conditions such as hypertension, rheumatism, and other inflammatory conditions (6, 78). These findings point toward the therapeutic potential of Allium in the management of chronic ailments, thus justifying further clinical exploration (36).

The potent antimicrobial action of Allium compounds stems from their sulfur-containing functional groups and interaction with key microbial processes.

Allicin and Thiol Groups: Allicin’s primary bactericidal mechanism is the S-allylmercapto modification of free thiol-containing proteins (cysteine residues) in bacterial cells. This oxidative reaction forms a mixed disulfide bond, which irreversibly inactivates crucial bacterial enzymes. This leads to catastrophic events within the cell, such as the depletion of the internal glutathione pool, induction of protein aggregation, and the inactivation of key metabolic enzymes necessary for survival and electron flow (81).

Ajoene and Quorum Sensing (QS): Ajoene and related diallyl polysulfides (such as diallyl disulfide (DAS)) are known to interfere with the bacterial quorum sensing (QS) system. QS is a cell-to-cell communication system that regulates group behaviors like the production of virulence factors and biofilm formation. By disrupting this communication, ajoene inhibits the formation of biofilms, a major factor in chronic and resistant infections, and suppresses the production of virulence factors in pathogens like Pseudomonas aeruginosa (82, 83).

Different antimicrobial activities of the Allium species were impressively enlisted within in vitro and in vivo studies, especially referring to garlic. It was identified that garlic extracts exhibited high potency against bacteria, including Staphylococcus aureus-MRSA, and a fungus, Candida albicans, showing a zone of inhibition within a range of 15–35 mm depending on the concentration of the extract (46). The antimicrobial properties are largely attributed to bioactive compounds such as allicin and thiosulfinates, which are present in high concentrations in these extracts. Additionally, studies have shown that chitosan nanoparticles can enhance the antimicrobial efficacy of Allium extracts, particularly against Mycobacterium tuberculosis, suggesting a synergistic effect when combined with traditional treatments (27, 47).

Previously, scientists reviewed 42 selected articles, including 1 in vivo and 41 in vitro studies, they concluded that the antimicrobial properties of the Allium genus essential oils that hadan effect on several microbial species. Evidence proved that these essential oils were multi-potential drugs for their safety and efficacy (45). For instance, some of these OSCs, such as allicin and derivatives like propyl propane thiosulfinate (PTS), exhibit synergistic action against microbes, reaching reductions in bacterial proliferation as high as 99% in ready-to-eat food models (84). Besides this, some aqueous extracts from garlic have been effective against E. coli and C. albicans clinical isolates. These meta-analyses indeed show that Allium extracts inhibit the growth of pathogens such as Listeria monocytogenes and Staphylococcus aureus and hence are a promising candidate for food safety biopreservation strategies. The use of Allium species in therapeutic practices has opened a bright perspective in the fight against microbial resistance and enhanced effectiveness of therapy (45).

Various Allium species, mainly garlic, and onions, have also shown substantial impacts on blood pressure and cholesterol levels, factors of cardiovascular health, via multiple mechanisms as shown in Table 5. Evidence suggests that garlic can lower both systolic and diastolic blood pressures of subjects with hypertension, with apparent effects on the improvement of lipid profiles and reductions in LDL and total cholesterol (85, 86). A systematic review showed that onion supplementation is further helpful in improving metabolic factors, as changes in fat percentages and improvements in the cholesterol level were seen to occur. Flavonoids, particularly flavonols, present in onion, might demonstrate hypolipidemic properties, cardio protection by enhancing endothelial function, hence causing the lowering of blood pressure. These studies have seen the effect of sulfur compounds in garlic enhance the release of NO and impede platelet aggregation, hence lowering blood pressure by some 5–7%, reducing total cholesterol concentration by about 10%, with favorable changes in HDL/LDL ratios (87, 88).

The OSCs in Allium species further produce lipid metabolism that lowers the level of LDL cholesterol, increasing fecal lipid excretion that inhibits conditions of hyperlipidemia (13). Moreover, Allium eriophyllum extracts have shown antihypertensive and lipid-lowering actions through antioxidant mechanisms and sympatholytic activity (46). These different levels of garlic administration in clinical trials have thus shown significant amelioration of the lipid profile and can possibly position it as a natural therapeutic agent against metabolic syndrome as well as in the prevention of cardiovascular diseases (89). Moreover, being a category of phenolic compounds, they are considered to be active antioxidant molecules; their potential for cardiovascular protection was observed with specific types of compounds like catechin. Some OSCs also present in Allium sp. have been associated with the abovementioned beneficial effects, suggesting that they might provide additional benefits in the management of metabolic syndrome and cardiovascular disease risk factors (47, 62, 90). These findings collectively point toward the therapeutic potential of Allium sp. in managing hypertension and dyslipidemia.

In fact, most of the epidemiological studies suggest that the intake of Allium vegetables, particularly garlic, exerts beneficial cardiovascular protective effects. Systematic reviews and meta-analysis present that, statistically, garlic lowers the risk factors for CVD like hypertension, dyslipidemia, and obesity, characterized by a reduction in total cholesterol, LDL-c, and triglycerides, along with increases in HDL-c (87, 91). Further longitudinal studies have supported such findings, showing an inverse relationship between habitual garlic and onion intake and the incidence of CVD and related diseases (92). It is believed that such effects are mediated by the bioactive compounds, such as OSCs in garlic, through mechanisms involving enhanced fibrinolytic activity and decreased platelet aggregation (93). Although the evidence is promising, further clinical studies are needed to identify the underlying mechanisms and optimize dietary recommendations for cardiovascular health (94).

Across the literature, converging evidence supports the cardiovascular benefits of Allium vegetables, especially garlic. In rodent models, allicin and DATS consistently lowered systolic blood pressure and improved lipid profiles, while human clinical studies reported reductions in total cholesterol (~10%) and blood pressure (~5–7%) following garlic supplementation (95). However, discrepancies arise in populations with different baseline diets or health statuses. Some studies using aged garlic extract found more reliable improvements than those using fresh garlic, likely due to enhanced bioavailability and standardization. Furthermore, epidemiological studies generally align in supporting an inverse association between garlic consumption and cardiovascular disease risk, though some variation exists based on geographic and dietary contexts. These patterns underscore the importance of formulation, dosing, and background diet in interpreting study results (96).

Research indicates a significant association between Allium vegetable consumption, particularly garlic, and reduced cancer risk, particularly for digestive system cancers. A study employing Mendelian randomization found that increased garlic intake is linked to a decreased risk of gastric cancer, while onion consumption did not show a statistically significant association with digestive cancers (100). Moreover, a meta-analysis of 25 studies showed that increased intake of Allium vegetables significantly reduces the risk for non-digestive tract cancers, with a summary odds ratio of 0.86 for the highest compared with the lowest consumption (97). The most noticed bioactive components of Allium species include allicin and OSCs, which affect different aspects of cancer, from cell proliferation to apoptosis (94). A meta-analysis of 17 studies demonstrated that high consumption of Allium vegetables-especially garlic and onion-significantly reduces the risk of developing breast cancer, with pooled risk estimates of 0.70, 0.77, and 0.75 for total intake, garlic, and onion, respectively (23). There is also a report that onionscontains more than 400 compounds showing a wide range of pharmacological action that includes anticancer activities. It also points out that most studies are in vitro, while in vivo and clinical explorations concerning reduced cancer risk are scanty (101). Further confirm the potentiality of Allium vegetables for use as dietary interventions in cancer prevention strategies.

The consumption of Allium vegetables, especially garlic and onions, has been associated with several mechanisms that may implicate them in the prevention of cancer (Figure 6). Important bioactive compounds, such as OSCs and flavonoids, have been reported to possess high antioxidant and anticancer activities due to induction of apoptosis, cell cycle arrest, or inhibition of tumor proliferation (102). Certain metabolites, including propyl propane thiosulfinate and propyl propane thiosulfonate, are reported to exert anti-proliferative activity against a wide range of human tumor cell lines, assumed to be at least partially linked to the modulation of oxidative stress and reduction of pro-inflammatory cytokine levels (100). Allium vegetables could exert their anti-cancer properties by induction of apoptosis, mediated by oxidative stress, inhibition of proliferation in tumorigenic cells, reducing the secretion of pro-inflammatory cytokines such as IL-8, IL-6, and IL-17, hence resulting in reduced inflammation and oxidative damage implicated in carcinogenesis (55, 99).

Various cellular pathways inducing cell cycle arrest, promoting apoptosis, and inhibiting angiogenesis are some of the possible methods of cancer prevention induced by principal garlic-derived bioactive compounds, allicin and ajoene, according to animal and in vitro studies (103, 104). The anticancer activity of Allium-derived compounds involves multiple molecular targets and signaling pathways. One key mechanism is the induction of apoptosis via the mitochondrial (intrinsic) pathway. Allicin and DATS, for example, have been shown to modulate the expression of pro-apoptotic (e.g., Bax) and anti-apoptotic proteins (e.g., Bcl-2), leading to mitochondrial membrane permeabilization and activation of the caspase cascade, particularly caspase-3 and -9. Additionally, DATS has been reported to upregulate tumor suppressor protein p53 and downregulate cyclin D1, thereby inducing cell cycle arrest at the G2/M phase in breast and prostate cancer cell lines (105, 106).

Differences in compound efficacy have also been reported across cancer types. For instance, DATS shows pronounced activity against breast (MCF-7), prostate (PC-3), and colon (HT-29) cancer cells, while quercetin from onion is more active in lung and pancreatic models. In vivo studies in xenograft mouse models confirm tumor volume reduction and increased apoptosis markers after treatment with Allium extracts (107). Some early-phase clinical trials have also shown promising results in reducing cancer biomarkers or lesion growth in colorectal and gastric cancers, though further studies are needed.