Phytochemical Compounds and Their Antibacterial Activity of Species of the Fabaceae Family Located in Tamaulipas, Mexico: Review

1. Introduction

Since ancient times, plants have been used for a wide variety of purposes, including the treatment of diseases due to the presence of bioactive compounds with therapeutic properties, such as the control of infectious diseases in animals and humans [1,2]. Both the World Health Organization (WHO) [3], and the World Organisation for Animal Health (WOAH) [4] have declared antimicrobial resistance to be one of the greatest threats to public health and animal health worldwide [3,4]. For this reason, the current need lies in the search for new alternatives to treat bacterial infections that are resistant to existing antimicrobial agents. One of these alternatives is the exploration of natural compounds, particularly those derived from plants, as they produce secondary metabolites that provide adaptive advantages, such as defense against herbivores and pathogens, and therefore represent potential candidates as medicinal compounds [5,6,7,8].

Species belonging to the Fabaceae family are recognized for their chemical diversity and their multiple applications in both traditional and modern medicine [9]. The Fabaceae family comprises 770 genera and nearly 19,500 species worldwide [10]. Their high adaptive capacity defines them as a cosmopolitan family [10,11], with notable diversity in temperate and warm regions, as well as in rainforests, dry forests, and semidesert areas [10,12].

In Mexico, Fabaceae is the second richest family in terms of species, including trees, shrubs, and perennial or annual herbs [10]. Species within this family have significant economic importance, as they are used for food, timber, forestry resources, and forage. Additionally, through symbiosis with bacteria, they contribute to nitrogen fixation in soil [10,12], and some species have also been used in traditional medicine [11,12]. Among their medicinal uses, anti-inflammatory, antiseptic, and antimicrobial properties stand out, attributed to secondary metabolites such as flavonoids, tannins, alkaloids, and saponins, which exert effects on various bacterial microorganisms [9,11].

Although Tamaulipas possesses rich plant biodiversity and a significant ethnobotanical context, the medicinal use of Fabaceae species is limited, and available information mainly derives from community-based knowledge [13]. However, in other regions of Mexico and around the world, studies have been conducted on the antibacterial activity of phytochemical compounds from Fabaceae species against pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella Typhi [14].

The aim of this study is to provide a comprehensive review of the Fabaceae species present in Tamaulipas and to evaluate whether these species have been the subject of research in Mexico or other regions of the world related to the extraction of chemical compounds with antibacterial, antifungal, or other therapeutic activities.

2. Results and Discussion

2.1. Applications in Traditional Medicine

This study provides a detailed analysis of 347 Fabaceae species from the state of Tamaulipas, distributed across 81 genera. The family is globally recognized for its economic importance, particularly in the areas of food production and human and animal health. Additionally, the characteristics of these species allow their use as timber resources, dyes, resins, and other products [11,15]. This review includes information generated in 16 countries, including Mexico, which accounted for 28% of the studies analyzed; however, none of the reviewed studies correspond to the state of Tamaulipas. Of the total species recorded for the state, the global search revealed that only 64 species have been studied for the extraction of phytochemical compounds, and of these, only 46 have been documented in traditional medicine for the treatment of various ailments (Table 1). In contrast, research conducted in communities within Tamaulipas indicates that the traditional use of Fabaceae comprises only 4–5% of the total plant species present in the region [13].

The traditional uses attributed to these plants (46 species) primarily address digestive ailments, representing 32% of the reported uses. These species are commonly used to manage symptoms such as diarrhea, vomiting, and stomach pain [15,16]. In Mexico, species such as Prosopis sp. and Vachelia sp., which have a wide distribution, have long been used to treat diarrhea and stomach discomfort [17,18,19]. The second most common category includes dermatological problems (18%), covering a broad range of skin conditions from mild irritations to severe infections [20,21,22]. Additionally, 15% of traditional applications focus on the treatment of parasitic infections [23,24].

Fabaceae species are also used to treat renal and urinary problems, respiratory conditions, inflammation, and other therapeutic purposes, due to the presence of active compounds such as tannins, flavonoids, alkaloids, and terpenes, which possess significant biological effects. The fact that these species are used across diverse cultures demonstrates the widespread nature of traditional medicinal knowledge and suggests their usefulness both in ancestral remedies and in contemporary treatments [11].

2.2. Extraction Methods

Table 2 presents the analysis of the most frequently used extraction techniques and solvents. For this section, the biological form of the species and the plant organ employed were considered. Five main extraction techniques were documented: maceration, hydro distillation, percolation, reflux, and Soxhlet. The most widely used method was maceration, applied in 47.7% of the studies due to its operational simplicity and compatibility with thermosensitive compounds, as it is performed at room temperature [77]. This technique, based on the prolonged immersion of plant material in solvents, is accessible for laboratories with limited resources [78,79]. However, it requires large volumes of solvent, the extraction process tends to be lengthy, and aqueous extracts may require preservatives to reduce the risk of microbial contamination [77].

The Soxhlet method, used in 10.8% of the studies, was the second most common technique. It is characterized by its efficiency in the continuous extraction of thermostable compounds and its suitability for volatile solvents. One of its major advantages is the ability to obtain larger extract yields using smaller amounts of solvent. Nevertheless, the continuous extraction at high temperatures makes it unsuitable for plant materials containing thermolabile compounds, which limits its application for certain heat-sensitive metabolites [80,81].

The reflux method was employed in 7.70% of the studies, and hydro distillation in 4.60%. Percolation, applied in only 1.50% of the reviewed studies, was the least used technique. These methods are preferred for obtaining volatile compounds, although their implementation requires more specialized equipment [82,83] (Figure 1).

2.2.1. Solvents

The choice of solvent for the extraction of phytochemicals is essential and depends on both the chemical characteristics of the target compounds and the specific plant material used. The type of metabolite sought helps determine the most appropriate solvent, as each compound dissolves more efficiently in solvents of different polarity. Polar compounds are best extracted with solvents such as methanol or ethanol, whereas non-polar metabolites are commonly extracted with solvents such as hexane. The plant organ selected for extraction is also an important factor [81].

Polar compounds typically require solvents such as water, methanol, or ethanol, due to their polar nature. Conversely, non-polar compounds are extracted using non-polar solvents such as hexane or dichloromethane [80]. The most frequently used solvents in the reviewed studies were methanol, distilled water, ethanol, ethyl acetate, acetone, and hexane (Figure 2). Methanol, used in 21.50% of the extraction assays, was the most common solvent; its intermediate polarity facilitates the extraction of a wide range of secondary metabolites [84]. However, its toxicity limits its applicability, as exposure through ingestion, inhalation, or skin contact can pose significant risks.

As safer alternatives, ethanol and distilled water have gained importance due to their favorable safety profiles and, in the case of ethanol, its lower environmental impact [80,85]. Ethanol, in particular, stands out for achieving extraction recoveries of up to 80% for metabolites such as flavanones and triterpenoids [86]. Hexane, a petroleum-derived solvent, presents economic and environmental challenges because its recovery requires substantial energy input, and it is volatile, toxic, and flammable. A less invasive alternative to hexane is ethyl acetate, which offers lower risk, reduced environmental impact, and greater sustainability [87].

2.2.2. Biological Categories

Las The biological form categories of the plant species included shrubs, trees, herbs, and climbers. Herbaceous and tree species were the most frequently studied, accounting for 36% and 31% of the records, respectively. These categories are most commonly collected and analyzed in ethnobotanical studies due to their abundance, availability, and ease of collection in the field, making them more accessible for research. Shrub species followed in lower proportion, and climbers were the least represented (Figure 3) [88,89].

The review shows that, of the 66 published studies, 39% used leaves, as they contain high concentrations of active compounds such as polyphenols and alkaloids, which exhibit antioxidant, anticancer, and anti-inflammatory properties [88,90]. A study on Dendrobium officinale demonstrated that its leaves contain higher levels of polyphenols and lipids, supporting their potential as a source of bioactive compounds [91].

Seeds, used in 13.8% of the studies, are valued mainly for their content of essential oils and antioxidant compounds. These metabolites have significant therapeutic applications [92]. The least used organs were stems, bark, inflorescences, fruits, and roots (Figure 4).

2.3. Isolated Compounds

Table 3 provides a detailed analysis of the bioactive compounds isolated from the studied plant species and their associated therapeutic properties. Phenols and flavonoids were the most common compounds, exhibiting antioxidant, antibacterial, and antifungal activities [93,94]. In addition, the extracts contained alkaloids, tannins, saponins, terpenoids, essential oils, lectins, and isoflavones, each contributing diverse therapeutic effects depending on the isolated compound.

2.3.1. Properties of the Main Isolated Compounds

Phenols and flavonoids: These are the most common antioxidants in plants and exhibit antibacterial and antifungal activities [25,26]. The antibacterial mechanisms of flavonoids include inhibition of nucleic acid synthesis, disruption and damage of the bacterial cytoplasmic membrane, and inhibition of biofilm formation [95].

Alkaloids: Their mechanism of action primarily involves the disruption and destruction of the bacterial cell membrane. Alkaloids demonstrate broad-spectrum activity against both Gram-positive and Gram-negative bacteria [96].

Tannins: They exhibit antimicrobial, antidiabetic, and anti-inflammatory properties [36,47]. These compounds are soluble in water, alcohol, and acetone, and by interacting with proteins in the bacterial plasma membrane, they interfere with enzymatic function and inhibit microbial activity [97].

Saponins: They display cytotoxic activity through induction of cell death in both tumor and normal cell lines, which limits their use in consumer products [98].

Terpenoids: Although less frequent, they possess antimicrobial and antifungal activities. Their high lipid affinity and low molecular weight allow them to interact with and disrupt the cell membrane, leading to cell death or inhibiting key fungal processes such as germination and sporulation [99].

Essential oils: Their hydrophobic nature disrupts the lipid structure of cell membranes, increasing permeability and causing leakage of intracellular contents, resulting in cell death. They exhibit strong antimicrobial activity, particularly against Gram-positive bacteria [99,100].

Lectins: They exhibit antibacterial properties by inhibiting bacterial growth through recognition of specific carbohydrates present on bacterial surfaces, triggering immune responses without necessarily causing bacterial death [101].

2.4. Evaluated Microorganisms

The effects of the isolated compounds have been evaluated primarily against the following microorganisms:

A)

Staphylococcus aureus (Gram-positive bacterium), a clinically important pathogen. Studies indicate that it is particularly sensitive to phenols, flavonoids, alkaloids, and essential oils [14,102,103].

B)

Escherichia coli (Gram-negative bacterium), inhibited by tannins, terpenoids, and hydrolyzed proteins. Tannins modulate the bacterial cell membrane, while specific terpenoids produce significant inhibition zones (5.5–6 mm). Antimicrobial flavonoids act by inhibiting DNA gyrase, thereby affecting cell replication [14].

C)

Candida albicans (yeast-like fungus), which exhibits sensitivity to lectins, flavonoids, and essential oils [14,103].

Other evaluated microorganisms include Gram-positive bacteria (Bacillus subtilis, Listeria monocytogenes), Gram-negative bacteria (Pseudomonas aeruginosa, Pseudomonas syringae, Neisseria gonorrhoeae, Salmonella spp., Proteus vulgaris), filamentous fungi (Aspergillus niger, Fusarium oxysporum, Penicillium italicum, Rhizoctonia solani), yeasts (Cryptococcus neoformans, Candida tropicalis), phytopathogenic fungi (Colletotrichum gloeosporioides, Helminthosporium maydis, Sclerotinia sclerotiorum), and pathogenic parasites (Leishmania donovani, Plasmodium falciparum, Naegleria fowleri) (Table 3).

It is important to note that tannins exhibit stronger activity against Gram-positive bacteria compared to Gram-negative ones, with their action being slower due to the double membrane characteristic of the latter [104]. Conversely, terpenoids such as carvacrol, limonene, and linalool act against both groups, showing greater effectiveness against S. aureus, E. coli, and Salmonella spp., while Pseudomonas spp. and Streptococcus spp. tend to be more resistant [14].

2.5. Antimicrobial Evaluation Techniques

A variety of methods were employed to assess the antimicrobial effects of the plant extracts, with a total of 10 different techniques identified. Approximately 70% of the methodologies were primarily focused on bacterial testing. Among the most frequently used assays, disk and well diffusion emerged as the predominant technique, applied in 47.17% of the analyzed studies, followed by microdilution variants, which accounted for 19.81% of the cases. This distribution aligns with the widespread acceptance and applicability of these techniques in microbiology due to their simplicity, low cost, and ease of implementation. Notably, 15.11% of the reviewed studies did not report the specific technique used [105].

The disk diffusion method is an in vitro assay that determines the susceptibility of microorganisms to antimicrobial agents by observing inhibition zones around disks impregnated with the compound of interest. Its popularity stems from several advantages: it is a relatively rapid and straightforward technique, suitable when evaluating multiple compounds against various microorganisms, and it does not require sophisticated equipment or large quantities of reagents, making it accessible for laboratories with limited resources [106].

However, disk diffusion presents inherent limitations. The results are primarily qualitative or semiquantitative, indicating microbial susceptibility or resistance but not providing an exact measurement of the minimum inhibitory concentration (MIC). Additionally, the method can be influenced by factors such as the solubility of the tested compound, the composition of the culture medium, and the growth rate of the microorganism [107].

3. Materials and Methods

An assessment of the species richness of the Fabaceae family in the state of Tamaulipas was conducted based on documented records. Species records were obtained from Villaseñor’s Plantas vasculares de México [108], which reports 347 species for the region; these were used as the reference dataset for the present analysis.

Using these records, a detailed systematic review was performed through Google Scholar, Web of Science, PubMed, and SciELO. This review includes information generated in 16 countries. The search criteria applied to each of the 347 Fabaceae species were: (a) phytochemical extracts, (b) antimicrobial activity of extracts, (c) bioactive compounds, (d) phytocompounds, and (e) medicinal use. All studies combining these keywords and providing relevant information were included, regardless of publication year or language. Articles lacking essential information were considered non-relevant and excluded. In total, 109 publications were incorporated into the manuscript, approximately 44% of which were published within the last ten years (2015–2025). Most sources were journals indexed in the Journal Citation Reports (JCR), although additional publications containing relevant data were also considered. The review focused on the chemical composition of the species, their traditional uses, the microorganisms affected by the extracts, the plant organs used for extraction, and the solvents employed.

Tamaulipas is recognized for its great diversity of ecosystems, resulting from its varied topography—ranging from coastal areas to elevations of 3,100 m a.s.l.—and its position at the transition between the Nearctic and Neotropical biogeographic regions (Figure 5). The state’s climatic diversity includes dry and semi-dry climates, warm sub-humid conditions across most of the territory, and small areas with temperate sub-humid and warm humid climates toward the southwest. These conditions have supported substantial floristic richness, with 4,278 vascular plant species recorded, distributed across 218 families and 1,309 genera [10,108].

Validation of the scientific names of the 347 species was essential to ensure accurate identification and classification. For this purpose, The Plant List (plantlist.org) was used to confirm nomenclatural accuracy, and the names of the Fabaceae species were cross-checked using the Catalogue of Life (catalogueoflife.org) [109]. This procedure ensures nomenclatural authenticity and prevents potential synonymies that might generate confusion in scientific literature. The combined use of both tools strengthens the reliability and consistency of taxonomic information, ensuring that all names used are globally accepted and recognized.

4. Conclusions

The Fabaceae family stands out not only for its remarkable ecological diversity and species richness but also for its significant importance in traditional medicine worldwide. The literature search conducted across multiple databases revealed that 19% of the Fabaceae species native to Tamaulipas have undergone phytochemical studies, identifying phenols, flavonoids, alkaloids, tannins, and terpenoids, among other compounds. These metabolites are associated with antimicrobial, antifungal, antidiabetic, antispasmodic, anti-inflammatory, and tumor-cytotoxic activities. However, only 13.3% of the species have documented traditional therapeutic uses, mainly for digestive disorders, dermatological conditions, and parasitic infections.

The widespread use of Fabaceae across different cultures for purposes related to human health highlights the need to deepen research on their pharmacological and phytochemical properties. Moreover, the careful selection of extraction and analytical methods for bioactive compounds, along with rigorous evaluation of their activity against various microorganisms, is essential to scientifically validate their therapeutic potential and to promote their incorporation into modern medicine.

The integration of traditional knowledge with updated scientific research strengthens the importance of the Fabaceae family as a valuable source for the development of new treatments and natural products, reinforcing its relevance as a biological and cultural resource at a global level.