Natural products for managing metabolic syndrome: a scoping review

Introduction Metabolic syndrome comprises a collection of metabolic disorders stemming from factors like genetic predisposition, inadequate nutrition, stress, decreased physical activity, aging, and ethnicity. Although traditional pharmaceutical treatments exist for metabolic syndrome, their limited popularity is attributed to high costs and adverse effects. Consequently, natural products with fewer side effects have been explored for managing this condition. This literature review aims to explore the role of natural products including herbs, botanicals, vitamins, minerals, probiotics, and dietary supplements in managing metabolic syndrome. Methods This scoping review was conducted in five steps, involving the formulation of a research question, the retrieval and extraction of relevant studies, the selection of pertinent studies, the organization of information into tables, and the reporting of results. Data was collected from various databases including Embase, Science Direct, PubMed, Google Scholar, Scopus, and Web of Science, with a focus on studies published from 2010 to the present, available in English and with full-text accessibility. Results We identified 1,259 articles, screened their titles, abstracts, and full texts, ultimately incorporating 169 pertinent articles into this review (comprising 90 review articles, 32 trial articles, 6 in vitro articles, 38 in vivo articles, 1 experimental article and 2 observational articles). The study’s outcomes revealed that natural products, encompassing plants and their derivatives, vitamins and supplements, as well as probiotics, can exert a beneficial influence on metabolic syndrome by regulating blood sugar, blood pressure, lipid profiles, obesity, and abnormal cholesterol and triglyceride levels. Conclusion The current study underscores the significance of natural products in addressing metabolic syndrome. Consequently, it is advisable to conduct further extensive research to assess the efficacy of these products, potentially integrating them into treatment regimens for individuals with metabolic syndrome.


Introduction
Metabolic syndrome (MetS) is a cluster of metabolic disorders, including impairments in protein, glucose, lipid, and carbohydrate (Di et al., 2019).It is characterized by a combination of risk factors for atherosclerotic cardiovascular diseases (ASCVD) and type 2 diabetes (Hou et al., 2019;Nna et al., 2023).These risk factors lead to the development of high blood pressure, high blood sugar or diabetes, obesity, excess abdominal fat, and abnormal cholesterol or triglyceride levels (Hou et al., 2019).The diagnosis of metabolic syndrome typically requires the presence of three or more of the following conditions: (Di et al., 2019): waist circumference ≥102 cm in men and ≥88 cm in women, (Nna et al., 2023), triglycerides ≥150 mg/dL or undergoing drug therapy for high triglycerides, (Hou et al., 2019), HDL-C < 40 mg/ dL in men and <50 mg/dL in women or undergoing drug therapy for lowering cholesterol, (Jang et al., 2016a), systolic blood pressure ≥130 mmHg, diastolic blood pressure ≥85 mmHg or undergoing antihypertensive treatment for individuals with a history of hypertension, and (van der Pal et al., 2018) fasting glucose ≥100 mg/ dL or undergoing treatment to control glucose levels (Jang et al., 2016a;van der Pal et al., 2018).However, the specific measurement for waist size may vary slightly based on country and ethnicity (Jang et al., 2016a).Factors contributing to the development of metabolic syndrome include genetic predisposition, poor dietary habits, stress, sedentary lifestyle, age, and ethnicity (Raja Kumar et al., 2019;Nna et al., 2023).Some of these factors, such as diet and physical activity, can be managed over time (Raja Kumar et al., 2019).
The treatment of metabolic syndrome has traditionally involved dietary modifications and the use of chemical drugs targeting specific biochemical pathways involved in food metabolism (Hameed and Al-Ameri, 2022).Beta-blockers, statins, fibrates and glibenclamide are usually known as the most commonly used drugs for patients with metabolic syndrome (Gharipour et al., 2011).However, these drugs are often costly, poorly tolerated by patients, associated with various side effects and do not have sustainable effectiveness (Nigussie, 2021).Additionally, typically represent monotherapy and address only a limited range of health outcomes associated with metabolic disorders (Tola et al., 2023).Consequently, there is a need to explore and develop alternative and complementary approaches with fewer complications for managing metabolic diseases (Nigussie, 2021).
Complementary and alternative medicine (CAM) has been used globally for centuries and consists of a wide range of therapies (Suganya et al., 2017;Adeniyi et al., 2021;Nasiri et al., 2023).One of these treatments is the use of natural products (Nasiri et al., 2023).Many medicinal plants and natural products are considered by the public as a safe and natural alternative to synthetic drugs (Waltenberger et al., 2016b).It has been shown that natural products or their derivatives are a valuable source of therapeutic agents (Atanasov et al., 2015;Fadhel and Hassan, 2023).Growing evidence indicates that natural products and their bioactive compounds can provide various benefits to the human health (Nainu et al., 2023).Natural products such as herbal drugs in addition to their secondary metabolites act as endless sources of promising drug leads that revealed significant anti-inflammatory as well as anti-obesity potential (Youssef et al., 2022).They revealed higher safety margins, eco-friendly, and less expensive with respect to synthetic chemical entities (Li et al., 2021).Consistent with this approach, researchers have focused on natural products in the field of prevention or treatment of MetS (Dong et al., 2012;Taghipour et al., 2019).In this regard, a study by Jang et al. (2016) demonstrated the effect of herbal medicines on reducing waist circumference, blood glucose, blood lipids, and blood pressure, suggesting their potential for treating metabolic syndrome (Jang et al., 2016a).Sabarathinam et al. (2022) highlighted that certain plant extracts contain natural active components that target multiple biological pathways, offering the opportunity to address various defects associated with metabolic syndrome simultaneously (Sabarathinam et al., 2022).Additionally, a study by Taghipour et al. (2019) revealed that Plant-based natural products improve obesityassociated MetS such as hyperglycemia, hyperlipidemia, and insulin resistance, reduce systolic and diastolic blood pressure, and reduce body weight gain (Taghipour et al., 2019).
Metabolic syndrome is now recognized as a disease with developmental origins, and it has become a significant focus of recent research (Hou et al., 2019).Given the increasing popularity of complementary and alternative medicine (CAM) for managing various health conditions, including metabolic syndrome, a review of the existing literature is crucial to comprehend the scope of CAM usage, its reported effectiveness, and potential safety considerations in relation to metabolic syndrome.While there is evidence suggesting that certain natural products can positively affect components of metabolic syndrome (Jang et al., 2016a;Taghipour et al., 2019;Sabarathinam et al., 2022), a comprehensive review is necessary to evaluate the quality of this evidence.Moreover, there are still gaps in understanding which natural products show the most promising outcomes, their mechanisms of action, and their potential interactions with conventional therapies.A scoping review can help identify these gaps and guide the design of future studies.
Healthcare practitioners and patients require evidence-based information to make informed decisions about the use of natural products for managing metabolic syndrome.Therefore, conducting a scoping review can offer a comprehensive overview of the current state of knowledge and help elucidate the potential role of natural products in this field.This scoping review aimed to investigate natural products in the management of metabolic syndrome.botanicals, vitamins, minerals, probiotics, and dietary supplements) are delineated, and the researchers also employed this keywords to devise an optimal search strategy.For this purpose, researchers conducted searches across several databases, including Embase, Science Direct, PubMed, Google Scholar, Scopus, and Web of Science.They used a range of keywords such as "herbs", "botanicals", "vitamins", "minerals", "probiotics", "dietary supplements", "natural product", "essential oils" and "metabolic syndrome" to retrieve information from these databases.

Inclusion and exclusion criteria
The inclusion criteria included reviewing all experimental, quasi-experimental, systematic and Meta-analysis, clinical trial, review, interventional, observational, in vivo and in vitro articles, A full texts articles which were published in reputable journals were included.Additionally, articles related to animal phases were considered.The exclusion criteria covered articles that did not specifically investigate the impact of complementary and alternative medicine on metabolic syndrome, studies published before 2010, and studies published in languages other than English.

Selection of relevant studies
Initially, one of the researchers imported all search results from the databases into the EndNote Desktop program, with duplicates removed.Subsequently, two researchers independently reviewed articles titles and abstracts based on predetermined eligibility criteria.Any discrepancies in study selection between the two researchers were resolved through a full-text evaluation.Efforts were made to obtain inaccessible articles and unpublished data by contacting the corresponding authors of eligible studies.Initially, 1,256 articles were identified through the database search.Following the elimination of 83 duplicates, 1,176 titles and abstracts were screened, leading to the review of 311 full texts.All of them underwent assessment for eligibility criteria culminating in the inclusion of 169 articles in the study (see Figure 1).Furthermore, the reference lists of the extracted articles were examined, but no additional articles meeting the inclusion criteria were identified for this study.
Data extraction and synthesis were carried out using a standardized form, which included categories such as study identifiers (study's author, year of publication), country and language, study type, study objective, sample size, materials and methods, results, and conclusion(s).To comprehensively understand the research landscape on natural products for the treatment of metabolic syndrome (MetS), researchers have adopted a systematic approach to categorize studies based on their methodology and focus.This classification includes clinical trials, in vitro and in vivo studies, observational studies, and review studies.Clinical trials provide empirical evidence on the efficacy and safety of interventions in human subjects, while in vitro and in vivo studies offer mechanistic insights into the effects of natural products on metabolic pathways and physiological functions.Observational studies identify associations between product consumption, natural outcomes related to metabolic syndrome, and contributing populations.These studies are referred to as original studies (see Table 1).Additionally, review studies provide a synthesis of the existing literature and highlight the importance of herbs and natural products in addressing MetS; therefore, they are considered complementary studies.Studies are categorized based on the type of natural product investigated, including herbs, vitamins, minerals, probiotics, and dietary supplements.

Quality assessment of articles
The Mixed Methods Appraisal Tool (MMAT) was used to evaluate the quality of the studies (Pace et al., 2012).Each section of the tool is categorized based on the research design employed.This tool is valuable for assessing the appropriateness of a study's objective, methods, study design, data collection, study selection, data analysis, presentation of findings, discussion, and conclusion(s).The quality of the articles and their inclusion after data extraction are determined by reviewing these aspects.Articles in each domain are assessed for quality using a percentage scale ranging from 25% (indicating that only one criterion is met) to 100% (indicating that all criteria are met).In this study, articles scoring below 25% are considered low quality, while those scoring above 80% are considered high quality (Pace et al., 2012;Madlabana et al., 2020).Based on the findings of the current study, the evaluation of article quality yielded an average score of 67.5%.

Results
The analysis of Table 1 data presents a comprehensive view of the impact of natural products on metabolic syndrome, reflecting a broad spectrum of research methodologies including clinical trials, in vitro and in vivo studies, and observational analyses.This diversity underscores the multifaceted approach in investigating the potential of natural interventions.Categorization by type of natural product reveals a predominant focus on plant-based interventions, signalling a notable scientific interest in exploring their efficacy in addressing metabolic syndrome.However, amidst the majority of studies demonstrating high to moderate quality, one in vivo article stands out for its notably low quality.Nonetheless, the collective outcomes suggest promising benefits associated with natural products, spanning various metabolic parameters such as blood pressure, glucose levels, lipid profile, and markers of obesity.These findings underscore the potential utility of natural interventions in managing the complexities of metabolic syndrome.
The predominance of clinical trials and in vivo studies in Table 1 underscores a comprehensive approach to investigating the therapeutic potential of natural products for managing metabolic syndrome.Clinical trials, being directly relevant to human health outcomes, provide crucial evidence regarding the efficacy and safety of interventions in real-world settings, reflecting a commitment to evidence-based medicine.Additionally, the inclusion of in vivo studies offers valuable insights into the underlying biological mechanisms of natural interventions, informing the design and interpretation of clinical trials.This diversity of research approaches not only contributes to a nuanced understanding of the efficacy and safety profiles of natural products but also highlights their translational potential from preclinical research to clinical practice.
Several plants exhibit promising effects through mechanisms such as antibacterial activity (Ghitea et al., 2021), antioxidant properties (Basu et al., 2013;Lopes et al., 2014), and the presence of bioactive compounds (Jakubczyk et al., 2021).These mechanisms contribute to the prevention of inflammation and insulin resistance (Kulabas et al., 2018), reduction of fat mass, and even serve as sources of essential amino acids and prebiotics (du Preez et al., 2021).Additionally, certain plants show potential in improving kidney function (Owis et al., 2017), regulating glucose and fatty acid metabolism (Reshidan et al., 2019), and balancing lipoprotein secretion and energy homeostasis (Singh et al., 2017).Furthermore, some plants demonstrate the ability to restore abnormal blood glucose regulation and rebalance intestinal microbiota (Wang et al., 2020), thus presenting multifaceted approaches to addressing metabolic syndrome.
However, evaluations also reveal complexities and contradictions within the findings.For instance, while the majority of plants studied exhibit beneficial effects, the use of green Elettaria cardamomum in one particular in vivo study led to unexpected outcomes.Contrary to expectations, green cardamom was found to exacerbate obesity, impair liver function, and adversely affect cardiovascular structure and function (Bhaswant et al., 2015).On the other hand, one clinical trial concluded that Ganoderma lucidum had no significant impact on hyperglycemia and cardiovascular risk factors (Klupp et al., 2016).Similarly, another clinical trial found that Cuminum cyminum L only decreased diastolic blood pressure without affecting other parameters of metabolic syndrome (Morovati et al., 2019).Additionally, the results of a clinical trial study indicated that Nigella Sativa failed to yield no significant differences between the two study groups regarding BMI, blood serum glucose, blood pressure, weight, WC and cholesterol levels (Mohtashami, 2019).

Vitamins and minerals
The results gleaned from studies investigating the impact of vitamins and minerals on metabolic syndrome and its components shed light on the potential benefits and limitations of various vitamin interventions.Specifically, vitamins C, D, E, A, B2, and U and zinc have demonstrated efficacy in influencing key parameters associated with metabolic syndrome, including blood pressure, blood glucose levels, lipid profiles, obesity, cholesterol, and triglycerides (Kelishadi et al., 2010;Farag et al., 2018;Farag et al., 2019;Ferreira et al., 2020).Additionally, these vitamins have shown promise in reducing DNA damage and oxidative stress (Wenclewska et al., 2019), as well as inflammatory markers (Erbaş et al., 2014;Mazur-Bialy and Pocheć, 2016;Salekzamani et al., 2017), while also decreasing plasma non-esterified fatty acids (NEFA), thereby contributing to the improvement of metabolic syndrome.However, critical evaluation of the findings reveals inconsistencies and challenges in translating these results into clinical practice.For instance, two clinical trial studies reported no significant effect of vitamin E on endothelial function, insulin levels, or glucose levels, highlighting a discrepancy between theoretical benefits and observed outcomes (Manning et al., 2013;Ahmadi et al., 2014).Similarly, two other clinical trials found that vitamin D supplementation failed to yield beneficial effects on cardiometabolic risk factors, high-sensitivity C-reactive protein levels, and carotid intima-media thickness (Salekzamani et al., 2016;Salekzamani et al., 2017).

Dietary supplements
Dietary supplements represent another category of natural products that have shown promise in addressing various aspects of metabolic syndrome, as indicated by the findings of studies included in this review.These supplements have demonstrated the ability to mitigate early growth restriction and inhibit fat accumulation by effectively modulating key metabolic parameters such as blood pressure, blood glucose levels, dyslipidemia, obesity, cholesterol, and triglycerides (Pedersen et al., 2010;Barrios-Ramos et al., 2012;Usui et al., 2013;McPherson et al., 2016;Ak et al., 2018;Sanchez-Rodriguez et al., 2018;Ramírez-Higuera et al., 2020;Shen et al., 2020;Ruyvaran et al., 2022).Additionally, they have been associated with improvements in insulin resistance (Mert et al., 2022), exerting antioxidant and anti-inflammatory effects (Nimrouzi et al., 2020), reducing oxidative stress (Pilar et al., 2017), decreasing coronary artery resistance (Pérez-Torres et al., 2016), and ameliorating inflammatory fatty liver conditions such as steatohepatitis (Al-Okbi et al., 2014).Noteworthy among these supplements are nutrients, garlic, as well as vegetable and animal oils.Despite various findings on the effectiveness of nutritional supplements for metabolic syndrome, an observational study yielded inconclusive results.It showed that black seed exhibited no significant difference between the two studied groups in terms of BMI, serum glucose, blood pressure, weight, waist circumference, and cholesterol levels (Hi and Endang, 2020).

Discussion
This scoping review was conducted to investigate the influence of natural products on metabolic syndrome.Based on the findings from the reviewed studies, we obtained a wide range of natural products, including herbs, vitamins, minerals and dietary supplements that affected the treatment and prevention of metabolic syndrome.These products have effects on blood pressure, blood sugar, obesity, waist circumference fat, and abnormal cholesterol or triglyceride levels.
The findings of this research show that plants play a role in improving metabolic syndrome by influencing blood glucose levels, lipid profile, obesity, cholesterol, and triglyceride levels.Various studies have identified a wide range of plants for this purpose.For instance, a review study by Pérez-Muñoz et al. (2022) (Pérez-Muñoz et al., 2022) demonstrated that the Eryngium plant reduces LDL and HDL levels, improves glucose metabolism, and controls dyslipidemia and blood glucose.In another study, Akber Aisa et al. (2019) (Aisa et al., 2019) found that Cicer arietinum L modulates glycemic response and regulates dyslipidemia.A systematic review and meta-analysis by García-Muñoz et al. (2023) (García-Muñoz et al., 2023) reported the effectiveness of Hibiscus sabdariffa in weight loss, reduction of fat tissue, lowering blood pressure, and improving lipid profiles.Apart from studies directly emphasizing the effects of plants on the main components of metabolic syndrome, some studies have also shown that plants can improve metabolic syndrome through antibacterial activities, antioxidant properties, anti-inflammatory activities, and reduction of insulin resistance.One such plant is spirulina, which possesses anti-inflammatory properties.By reducing inflammation, this herb can help improve vascular function and blood pressure, thereby positively impacting metabolic health (Yousefi et al., 2018).
Green tea and turmeric also possess antioxidant and antiinflammatory properties.In metabolic syndrome, chronic lowgrade inflammation and oxidative stress can contribute to insulin resistance and impaired glucose metabolism.Therefore, these herbs can help mitigate these effects, leading to improved insulin sensitivity and lower blood sugar levels (Basu et al., 2013;Amin et al., 2015).Additionally, green tea contains polyphenols such as epigallocatechin gallate (EGCG), which have demonstrated the potential to increase fat oxidation and thermogenesis, aiding in weight management (Basu et al., 2013;Wong et al., 2020).Another herb that can assist in regulating blood sugar levels is cinnamon, which can impact fat storage and metabolism by regulating blood sugar levels (Mollazadeh and Hosseinzadeh, 2016).
Contrary to the aforementioned findings, some studies present conflicting results and suggest that herbs may not have a significant impact on metabolic syndrome and its components.For instance, one study revealed that G. lucidum does not exhibit a significant effect on blood sugar and cardiovascular risk factors (Klupp et al., 2016).Similarly, another study found that Nigella Sativa did not yield statistically significant differences between the two study groups regarding BMI, blood serum glucose, blood pressure, weight, waist circumference, and cholesterol levels (Mohtashami, 2019).Additionally, according to the results of another study, E. cardamomum was associated with obesity, liver dysfunction, and adverse effects on cardiovascular structure and function (Bhaswant et al., 2015).Several factors could contribute to these discrepancies in results.Variations in study design, such as sample size and duration, as well as the diversity of bioactive compounds in plants, may be among the reasons.Demographic differences, dosage variations, and confounding variables such as diet and lifestyle could also play a role.Furthermore, publication bias, study quality, and the inherent complexity of metabolic syndrome itself contribute to variability in outcomes.Ultimately, these findings underscore the necessity for further research, particularly clinical trials, to elucidate the precise mechanisms and potential adverse effects associated with specific herbal interventions for metabolic syndrome.
It is important to note that the mechanisms of action for natural products can vary widely, and not all natural products have been extensively studied in the context of metabolic syndrome.Additionally, individual responses to natural products can vary, and their effects may depend on factors such as dosage, duration of use, and specific characteristics of a person with metabolic syndrome.Therefore, it is necessary to conduct research, particularly clinical studies, on the effect of natural products on the components of metabolic syndrome.
Another finding of the present study suggests that vitamins and minerals can play an effective role in managing metabolic syndrome and its components.For instance, the study by Melguizo-Rodríguez et al. (2021) (Melguizo-Rodríguez et al., 2021) demonstrated that vitamin D supplementation improves lipid profile, insulin resistance, hyperglycemia, obesity, and high blood pressure.Similarly, Moukayed & Grant et al. (2019) (Moukayed and Grant, 2019)discovered that vitamin D possesses antiinflammatory properties, inhibits primary adipogenesis, enhances glucose absorption, mitigates hyperleptinemia, ameliorates insulin resistance, and reduces high blood pressure.Wong et al. ( 2020) (Wong et al., 2020) confirmed the antioxidant and antiinflammatory properties of vitamin C.
However, there are also several studies that contradict the positive effects of vitamins and nutrients on metabolic syndrome.Ahmadi et al. (2014) (Ahmadi et al., 2014) and Manning et al. ( 2015) (Manning et al., 2013) reported no significant effects of vitamin E on endothelial function, insulin levels, or glucose levels.Similarly, studies by Salekzamani et al. (2017) (Salekzamani et al., 2017) and Salekzamani et al. (2016) (Salekzamani et al., 2016) (Panchal et al., 2017) suggested conflicting results regarding the effect of these micronutrients on metabolic syndrome.
The inconsistency in findings regarding the effect of vitamins on metabolic syndrome can be attributed to several factors.Variations in study design, such as sample size, duration of intervention, and methods used to measure outcomes, can lead to conflicting results.Studies with small sample sizes or short durations may fail to capture the full effects of vitamins and nutrients on components of the metabolic syndrome.Additionally, differences in study population characteristics, including age, gender, ethnicity, and baseline health status, can influence the response to vitamin and nutrient supplementation.What proves effective in one population may not yield the same results in another.
Furthermore, vitamins may interact with other nutrients or medications, potentially influencing their effects on metabolic syndrome, and these interactions can differ between studies.Conversely, the dose and duration of vitamin and nutrient supplementation can significantly impact their effectiveness.Therefore, it is essential to design studies with optimal doses and longer durations to observe the significant effects of vitamins and nutrients on the components of metabolic syndrome.
The results of the present study also confirmed the effect of food supplements, including nutrients and vegetable and animal oils, on the components of metabolic syndrome.Vegetable and animal oils exert their effect on metabolic syndrome through a combination of factors.The composition of their fatty acids plays an essential role.Oils rich in unsaturated fats, such as olive oil and certain vegetable oils, as well as those containing omega-3 fatty acids, such as flaxseed and fish oil, help improve lipid profiles and reduce inflammation, and are beneficial for people with metabolic syndrome.The results of the studies by Nimrouzi et al. (2020) (Nimrouzi et al., 2020), Mert et al. (2022) (Mert et al., 2022), and Al-Okbi et al. (2014) (Al-Okbi et al., 2014) confirmed these findings.Additionally, Olid et al. (2023) (Olid et al., 2023) stated that olive oil has antimicrobial activity to keep blood pressure low.
The results of a study showed that omega-3 fatty acids, which are found in some natural products such as flax seeds, have demonstrated the ability to reduce the levels of triglycerides and cholesterol by decreasing the production of triglycerides in the liver and increasing the clearance of triglycerides from the bloodstream (Yang et al., 2020).Additionally, flaxseed oil exhibited the ability to reduce oxidative stress in a study (Mohammadifard et al., 2021).
Garlic is another food supplement that contains allicin, and by increasing the production of nitric oxide in the blood vessels, it induces vasodilation.This widening of blood vessels can lead to a decrease in resistance to blood flow and subsequently result in a decrease in blood pressure (Al Disi et al., 2016).However, the results of Hi et al.'s study (2020) (Hi and Endang, 2020) showed that black seed oil did not cause significant differences in BMI, blood glucose, blood pressure, and cholesterol levels between the two groups.Furthermore, the results of Tamtaji et al. (2020) (Tamtaji et al., 2020) indicated that flaxseed oil had no effect on certain inflammatory factors and other biomarkers of oxidative stress.Similarly, Pastor et al. (2021) (Pastor et al., 2021) demonstrated that olive oil has no effect on metabolic syndrome.
Biological variability among participants, genetic factors, publication bias, different study designs, varied doses, and the overlap of some foods with dietary supplements may have influenced the study results, highlighting the importance of welldesigned randomized controlled trials.Systematic reviews are essential to elucidate the true effects of dietary supplements on metabolic syndrome and to provide evidence-based recommendations.
The strength of the present study lies in comprehensive exploration of natural products in relation to their potential impact on metabolic syndrome and its components.This broad perspective adds to the existing body of knowledge and provides valuable insights into the potential benefits of these products for people with metabolic syndrome.However, this study also had limitations.For instance, despite the researchers' efforts to obtain the full text of the articles, this was not achieved in the case of some articles, and as a result, some related articles were excluded from the research.Additionally, while eligible articles were identified and reviewed, it is possible that some unpublished studies may have been missed.Utilizing specific entry criteria, such as excluding articles published before 2010 in this study, may result in the omission of relevant articles.However, the researchers in this particular case adopted this criterion to enhancing the organization of the articles.Also, Utilizing a particular search strategy in articles may result in the omission of related articles.

Conclusion
This study underscores the considerable potential of natural products, including herbs, vitamins, minerals, and dietary supplements, in effectively managing metabolic syndrome.These interventions offer promising avenues for addressing various aspects of metabolic syndrome through diverse mechanisms of action.Among natural products, the study found that plants have been the subject of more research compared to other categories.While both positive and negative effects have been observed across all categories of natural products, there appears to be more uncertainty surrounding the effects of vitamins.This suggests that the effects of vitamins are often unclear and may differ depending on the specific circumstances.However, the study acknowledges the need for further research to validate these findings and determine the optimal dosage and duration of supplementation.Long-term randomized controlled trials with larger sample sizes are particularly necessary to provide more conclusive evidence regarding the efficacy and safety of natural products in managing metabolic syndrome.

FIGURE 1 Flowchart
FIGURE 1Flowchart of review and selection of articles.
indicated that vitamin D supplementation failed to yield beneficial effects on cardiometabolic risk factors, high-sensitivity C-reactive protein levels, and carotid intima-media thickness.AlAnouti et al.'s study (2020) (AlAnouti et al., 2020)also demonstrated the limited impact of vitamin D on improving dyslipidemia.Furthermore, Panchalet al. (2017)

TABLE 1
Studies conducted on the effect of different natural products on metabolic syndrome.

TABLE 1 (
Continued) Studies conducted on the effect of different natural products on metabolic syndrome.

TABLE 1 (
Continued) Studies conducted on the effect of different natural products on metabolic syndrome.

TABLE 1 (
Continued) Studies conducted on the effect of different natural products on metabolic syndrome.

TABLE 1 (
Continued) Studies conducted on the effect of different natural products on metabolic syndrome.

TABLE 1 (
Continued) Studies conducted on the effect of different natural products on metabolic syndrome.

TABLE 1 (
Continued) Studies conducted on the effect of different natural products on metabolic syndrome.

TABLE 1 (
Continued) Studies conducted on the effect of different natural products on metabolic syndrome.Dried herbal powder consisting of Amomi Cortex, Paeoniae Radix, Moutan Cortex, Persicae Semen and Hoelen mixed with honey.).