Joel E López-Meza

• PhD
• Principal Investigator at Universidad Michoacana de San Nicolás de Hidalgo

Aim: To identify peptides derived from bovine lactoferricin (LfcinB) as potential therapeutics for colon cancer treatment. We systematically modified dimeric peptides to enhance their selectivity against colon cancer cells and reduce toxicity. We examined the effects of specific changes, such as substituting L-arginine (Arg) with L-ornithine (Orn)...

The Verbesina gender represents the second most diverse group from the Asteraceae family in Mexico; Verbesina sphaerocephala is one of the most distributed species along the Mexican territory. This species has been poorly studied, reporting the presence of some bioactive compounds with antioxidant and antibacterial activity. In this study, phenolic...

Luminal breast cancer has a high incidence worldwide and poses a severe health threat. Estrogen receptor alpha (ER-α) is activated by 17β-estradiol (E2), and its overexpression promotes cancerous characteristics. Luminal breast cancer is an epithelial type; however, the cytokine IL-6, secreted by cells within the tumor microenvironment, stimulates...

Luminal breast cancer has a high incidence worldwide and is a severe health threat. Estrogen receptor alpha (ER-α) is activated by 17β-estradiol (E2), and its overexpression promotes cancerous characteristics. Luminal breast cancer is an epithelial type; however, the cytokine IL-6 secreted by cells from the tumor microenvironment stimulates the epi...

Estrogens and their role in cancer are well-studied, and some cancer types are classified in terms of their response to them. In recent years, a G protein-coupled estrogen receptor (GPER) has been described with relevance in cancer. GPER is a pleiotropic receptor with tissue-specific activity; in normal tissues, its activation is related to correct...

Anticancer peptides are increasingly being considered as alternative treatments for cancer due to their potency, selectivity, and low toxicity. Previously, the peptide LfcinB (21–25)Pal showed in vitro anticancer effects against the Caco-2 colon cancer cell line (half-maximal inhibitory concentration (IC50): 86 μM). In this study, we developed modi...

Cancer is a relevant health problem worldwide. In 2020, leukemias represented the 13th most commonly reported cancer cases worldwide but the 10th most likely to cause deaths. There has been a progressive increase in the efficacy of treatments for leukemias; however, these still generate important side effects, so it is imperative to search for new...

Different ethnomedicinal studies have investigated the relationship between various phytochemicals as well as organic extracts and their bioactive aspects. Studies on biological effects are attributed to secondary metabolites such as alkaloids, phenolic compounds, and terpenes. Since there have been no reviews in the literature on the traditional,...

We observed how a change of specific residues in LfcinB dimeric and palindromic sequences caused a notable increase in the cytotoxic activity against CaCo-2 cells while maintaining or even diminishing the level of the cytotoxic effect against normal fibroblast and HEK-293 cells. In both cases, the IC50 of the peptides was reduced by more than half...

In recent years, it has been recognized that epigenetic alterations play an important role in the development and maintenance of cancer, including leukemias. Furthermore, it is known that these alterations are involved in the emergence of resistance to conventional chemotherapeutics. Consequently, molecules with an anticancer activity whose activit...

The aim of this study was to evaluate the cytotoxic potential of Aristolochia foetida Kunth. Stems and leaves of A. foetida Kunth (Aristolochiaceae) have never been investigated pharmacologically. Recent studies of species of the Aristolochiaceae family found significant cytotoxic activities. Hexane, dichloromethane, ethyl acetate and methanol extr...

Cancer is a health problem in global and national levels because of high rates of mortality. In Mexican women, breast cancer is the main type of cancer with 25 % of cases. However, disinformation about prevention and detection of breast cancer represents a crucial challenge for Mexican society. Therefore, the aim of this work is the review of the m...

Osteosarcoma is the most common malignant bone tumor in both children and dogs. It is an aggressive and metastatic cancer with a poor prognosis for long-term survival. The search for new anti-cancer drugs with fewer side effects has become an essential goal for cancer chemotherapy; in this sense, the bioactive compounds from avocado have proved the...

Avocado (Persea americana Mill.) is a tree native from central and eastern México that belongs to the Lauraceae family. Avocado has three botanical varieties known as Mexican (P. americana var. drymifolia), West Indian (P. americana var. americana), and Guatemalan (P. americana var. guatemalensis). It is an oil-rich fruit appreciated worldwide beca...

Background Butyrate is a histone deacetylases inhibitor that induces apoptosis and inhibits cell proliferation of colorectal cancer cells. To improve its anticancer activity, butyrate has been evaluated mixed with drugs and different molecules. Plant antimicrobial peptides are attractive anticancer alternative molecules because they show selective...

Intracellular lipid droplets (LD) provide the oil storage mechanism of plants. They are found within seeds as individual structures, even under conditions of cold stress and dehydration, due to the protein that covers them. This protein, called oleosin, is found exclusively in plants and has been widely studied in seeds. Avocado fruits (Persea amer...

The palindromic nonapeptide H‐¹RWQWRWQWR⁹‐NH2 (LfcinB (21–25)Pal) was synthetize and scaled following the good manufacturing practices (GMP) guidelines to obtained batches up to 1 g of pure peptide which evidencing their synthetic viability. Its cytotoxic effect was tested against breast cancer cell lines MDA‐MB‐231 and MCF‐7 and was dependent on c...

Defensins are an important group of host defense peptides. They have immunomodulatory properties, which have been mainly described for mammal defensins, but similar effects for plant defensins remain unknown. Previously, we showed that the defensin γ-thionin (Capsicum chinense) reduces Staphylococcus aureus internalization into bovine mammary epith...

Bacterial vaginosis is one of the most frequent vaginal infections. Its main etiological agent is Gardnerella vaginalis, which produces several virulence factors involved in vaginal infection and colonization, in particular, sialidase (SLD), a potential clinical biomarker that participates in immune response modulation and mucus degradation. The ma...

Changes in the levels of reproductive hormones compromise the bovine innate immune response (IIR). Changes in 17β-estradiol (E2) and prolactin (bPRL) levels affect the IIR of bovine mammary epithelial cells (bMECs), the target tissue of these hormones. In this work, we explored the effect of the combined hormones on bMEC IIR during Staphylococcus a...

The effect on the cytotoxicity against breast cancer cell lines of the substitution of ²⁶Met residue in the sequence of the Bovine Lactoferricin-derived dimeric peptide LfcinB (20-30)2: (²⁰RRWQWRMKKLG³⁰)2-K-Ahx with amino acids of different polarity was evaluated. The process of the synthesis of the LfcinB (20-30)2 analog peptides was similar to th...

Background: The most common ocular disease affecting cattle worldwide is infectious bovine keratoconjunctivitis (IBK), which has been associated with Moraxella bovis bacterium. Objective: To report the molecular characterization of the ocular bacterial microbiota and its relation to IBK in cattle in two dairy regions in Michoacán, Mexico. Methods...

Avocado fruit oil ( Persea americana ), mainly cultivar Hass, has excellent medicinal properties as antioxidant and anti‐inflammatory activities. However, these properties have not been evaluated in the seed oil of the native Mexican avocado ( P. americana var. drymifolia). This study investigated the antioxidant and anti‐inflammatory activity of n...

Plant diseases with a negative impact on strawberry yield (Fragaria  ananassa), such as anthracnose and fruit rot, are mainly controlled using pesticides, which can cause harmful effects; thus, new control alternatives for fruit decay are needed. Chitosan is a compound already evaluated for fungal disease control at post-harvest. The aim of this s...

Pyrolytic products have been historically used as a therapeutic treatment for psoriasis, a dermatological inflammatory disease. However, little is known about the mechanisms involved in their pharmacological activity. The main goals of this work were to characterize pyrolytic fractions derived from Amphipterygium adstringens bark, a plant used in M...

Colorectal cancer (CRC) is the third most common type of cancer worldwide. Chemotherapy used in CRC patients has severe side effects. As an alternative, the search to identify natural compounds increases the opportunity to select therapeutics. In this work, the cytotoxic effect of a lipid extract (LEAS) from Mexican native avocado seed (Persea amer...

Bovine mammary epithelial cells (bMECs) are capable of initiating an innate immune response (IIR) to invading bacteria. Staphylococcus aureus is not classically an intracellular pathogen, although it has been shown to be internalized into bMECs. S. aureus internalizes into nonprofessional phagocytes, which allows the evasion of the IIR and turns an...

The cytotoxic effect of the tetrameric peptide LfcinB (20-25)4 against breast cancer cell line ATCC® HTB-22™ (MCF-7) was evaluated. The tetrameric peptide exhibited a concentration-dependent cytotoxic effect against MCF-7 cancer cells. The peptide at 22 µM had the maximum cytotoxic effect against MCF-7 cancer cells, reducing their cell viability to...

Satureja macrostema is a Mexican medicinal plant known as nurite, it is used in decoctions and infusions for the treatment of stomach pain and liver and intestinal diseases, which present inflammatory processes and oxidative stress. In our working group, the in vitro antioxidant activity of the essential oil of aerial parts of S. macrostema obtaine...

The overuse of antibiotics has facilitated the selection of multidrug-resistant bacteria, many of which are pathogenic to humans. Research on new materials to confront this problem is a public health challenge. Chitosan is a biopolymer produced by the deacetylation of chitin. Because it is recognized by the FDA as a safe compound with antimicrobia...

The overuse of antibiotics has facilitated the selection of multidrug-resistant bacteria, many of which are pathogenic to humans. Research on new materials to confront this problem is a public health challenge. Chitosan is a biopolymer produced by the deacetylation of chitin. Because it is recognized by the FDA as a safe compound with antimicrobial...

Introducción El moho gris es una de las principales causas de pudrición en poscosecha del fruto de fresa (Fragaria x ananassa Duch.), la cual es ocasionada por el hongo Botrytis cinerea Pers.:fr. El tratamiento con fungicidas químicos es el método principal de su control; no obstante, su uso ocasiona problemas de salud y contaminación. Lo anterior...

The innate immune system can function under hormonal control. 17 β -Estradiol (E2) is an important sexual hormone for the reproductive cycle of mammals, and it has immunomodulatory effects on epithelial cells, which are the first line of defense against incoming bacteria. E2 regulates various pathophysiological processes, including the response to...

Cancer represents a worldwide problem, in 2012 about 8.2 million deaths were reported. Colorectal cancer (CRC) is the third most common type of cancer and the fourth leading cause of death in the world, accounting for about 700,000 deaths a year. Chemotherapy currently used in patients with CRC is associated with severe side effects. The use of nat...

Cellular homeostasis is regulated by genetic and epigenetic mechanisms controlling cell proliferation and differentiation; dysregulation in these functions has been associated to cancer. Breast cancer is considered the first worldwide cause of cancer death in women. Antimicrobial peptides (AMPs) have showed cytotoxic activity against diverse cancer...

Antimicrobial peptides (AMPs) are key elements of plant defense mechanisms, resembling conserved protection strategies also present in mammals. Among the AMPs, plant thionins are particularly interesting due that display antibacterial and antifungal activities. In Arabidopsis thaliana have been described four thionins: Thi2.1, Thi2.2, Thi2.3 and Th...

Background: The aim of this study was to investigate the in vitro antioxidant activity of Satureja macrostema (Moc. and Sessé ex Benth.) Briq. (Lamiaceae) essential oil, a Mexican medicinal plant known as nurite. Materials and Methods: Fresh aerial parts of S. macrostema plants cultivated in greenhouse for 3 months were subjected to hydrodistillati...

Background The aim of this study was to investigate the in vitro antioxidant activity of Satureja macrostema (Moc. and Sessé ex Benth.) Briq. (Lamiaceae) essential oil, a Mexican medicinal plant known as nurite. Materials and Methods Fresh aerial parts of S. macrostema plants cultivated in greenhouse for 3 months were subjected to hydrodistillatio...

Aims: The objective of this study was to show whether the edible part of broccoli has antibacterial and antifungal activity against microorganism of importance in human health and vegetable spoilage, and to test if this effect was partially due to antimicrobial peptides. Methods and Results: Crude extracts were obtained from florets and stems of b...

Background: The aim of this study was to investigate the in vitro antioxidant activity of Satureja macrostema (Moc. and Sessé ex Benth.) Briq. (Lamiaceae) essential oil, a Mexican medicinal plant known as nurite. Materials and Methods: Fresh aerial parts of S. macrostema plants cultivated in greenhouse for 3 months were subjected to hydrodistillati...

Proteins of the Split ends (Spen) family are characterized by an N-terminal domain, with one or more RNA recognition motifs and a SPOC domain. In Arabidopsis thaliana, the Spen protein FPA is involved in the control of flowering time as a component of an autonomous pathway independent of photoperiod. The A. thaliana genome encodes another gene for...

Sucrose is synthesized from UDP-Glc and Fru-6-phosphate via the activity of sucrose-phosphate synthase (SPS) enzymes, which produce Suc-6-phosphate. Suc-6-phosphate is rapidly dephosphorylated by phosphatases to produce Suc and inorganic phosphate. Arabidopsis has four sps genes encoding SPS enzymes. Of these enzymes, AtSPS1F and AtSPS2F have been...

Bovine mammary epithelial cells (bMECs) contribute to mammary gland defense against invading pathogens, such as Staphylococcus aureus (intracellular facultative), which is recognized by TLR2. In a previous report, we showed that sodium octanoate [NaO, a medium chain fatty acid (C8)] induces (0.25 mM) or inhibits (1 mM) S. aureus internalization int...

- Analysis of growth and development in A. thaliana lines.

Antimicrobial peptides (AMPs) are cytotoxic to cancer cells; however, mainly the effects of AMPs from animals have been evaluated. In this work, we assessed the cytotoxicity of PaDef defensin from avocado (Persea americana var. drymifolia) on the MCF-7 cancer cell line (a breast cancer cell line) and evaluated its mechanism of action. PaDef inhibit...

Satureja macrostema is a Mexican medicinal plant known as nurhitini té or nurite, whose antioxidant properties are mainly attributed to the volatile compounds from aerial part. Therefore, the goal of the present study was to investigate the in vitro cytotoxic and antioxidant potential of essential oil and some related terpenes of S. macrostema. Ess...

17 β -Estradiol (E2), the predominant sexual hormone in females, is associated with the modulation of the innate immune response (IIR), and changes in its levels at parturition are related to intramammary infections, such as mastitis. In bovine mammary epithelial cells (bMECs), E2 regulates differentiation and proliferation, but its immunomodulator...

Defensins are members of the antimicrobial peptide superfamily that are produced in various species from different kingdoms, including plants. Plant defensins exhibit primarily antifungal activities, unlike those from animals that exhibit a broad-spectrum antimicrobial action. Recently, immunomodulatory roles of mammal-defensins have been observed...

Background: Low protein digestibility and lysine content of white sorghum grain limit its use as foodstuff. The increase in γ-kafirin cross-linking, has an important role in the reduction of protein digestibility. The objective of this study was to characterize the γ-kafirin gene in 12 Mexican tannin-free white sorghum genotypes and its relationsh...

Staphylococcus aureus is an etiological agent of human and animal diseases, and it is able to internalize into non-professional phagocytic cells (i.e. bovine mammary epithelial cells, bMECs), which is an event that is related to chronic and recurrent infections. bMECs contribute to host innate immune responses (IIR) through TLR pathogen recognition...

Staphylococcus aureus has the ability to invade mammary epithelial cells (bMECs) causing mastitis. This event depends primarily on the α5β1 integrin in the host cell. In addition, bMECs are a target for the hormone prolactin (PRL), which can regulate β1 integrin-dependent actions related to differentiation and lactation. Previously, we demonstrated...

The Pseudomonas aeruginosa plasmid pUM505 contains the umuDC operon that encodes proteins similar to error-prone repair DNA polymerase V. The umuC gene appears to be truncated and its product is probably not functional. The umuD gene, renamed umuDpR, possesses an SOS box overlapped with a Sigma factor 70-type promoter; accordingly, transcriptional...

We would like to express our appreciation to all the authors for their informative contributions and the reviewers for their support and constructive critiques in making this special issue possible.

Antimicrobial peptides (AMPs) are part of the innate immune defense mechanism of many organisms and are promising candidates to treat infections caused by pathogenic bacteria to animals and humans. AMPs also display anticancer activities because of their ability to inactivate a wide range of cancer cells. Cancer remains a cause of high morbidity an...

The articles contained in the present issue include both reviews and basic scientific studies focused on characterizing AMPs from different sources to evaluate their numerous biological activities. This issue comprises the description of effects of naturally occurring AMPs from bacteria, plants, humans, and pigs as well as the effect of synthetic A...

Staphylococcus aureus is a successful human and animal pathogen. The majority of infections caused by this pathogen are life threatening, primarily because S. aureus has developed multiple evasion strategies, possesses intracellular persistence for long periods, and targets the skin and soft tissues. Therefore, it is very important to understand th...

A reduction of dopaminergic (DAergic) activity with increased prolactin levels has been found in obese and hypertensive patients, suggesting its involvement as a pathophysiological mechanism promoting hypertension. Similarly, leptin action increasing sympathetic activity has been proposed to be involved in mechanisms of hypertension. The aim of thi...

Avocado is one of the most important fruits in the world. Avocado "native mexicano" (Persea americana var. drymifolia) seeds are widely used in the propagation of this plant and are the primary source of rootstocks globally for a variety of avocado cultivars, such as the Hass avocado. Here, we report the isolation of 5005 ESTs from the 5' ends of P...

Patients with chronic kidney disease (CKD) have signs of genomic instability and, as a consequence, extensive genetic damage, possibly due to accumulation of uraemic toxins, oxidative stress mediators and other endogenous substances with genotoxic properties. We explored factors associated with the presence and background levels of genetic damage i...

Bovine mammary epithelial cells (bMECs) are capable of initiating an innate immune response to invading bacteria. Short chain fatty acids can reduce Staphylococcus aureus internalization into bMEC, but it has not been evaluated if octanoic acid (sodium octanoate, NaO), a medium chain fatty acid (MCFA), has similar effects. In this study we determin...

Antimicrobial therapy is a useful tool to control infectious diseases in general and rising antibiotic resistant microorganisms in particular. Alternative strategies are desirable, and antimicrobial peptides (AMP) represent attractive control agents. Mexican avocado (Persea americana var. drymifolia) is used in traditional medicine; however, the AM...

Bovine mammary epithelial cells (bMECs) are capable of initiating an innate immune response to invading bacteria. Short chain fatty acids can reduce Staphylococcus aureus internalization into bMEC, but it has not been evaluated if octanoic acid (sodium octanoate, NaO), a medium chain fatty acid (MCFA), has similar effects. In this study we determin...

Naturally occurring cationic antimicrobial peptides (CAMPs) have been considered as promising candidates to treat infections caused by pathogenic bacteria to animals and humans. This assumption is based on their mechanism of action, which is mainly performed through electrostatic membrane interactions. Unfortunately, the rise in the reports that de...

Vitamin D has immunomodulatory functions regulating the expression of host defense genes. The aim of this study was to determine the effect of cholecalciferol (vitamin D3) on S. aureus internalization into bovine mammary epithelial cells (bMEC) and antimicrobial peptide (AP) mRNA expression. Cholecalciferol (1-200nM) did not affect S. aureus growth...

Bacillus thuringiensis is characterized by the synthesis of parasporal crystals during sporulation; these are composed of one or more highly specific insecticidal or nematocidal endotoxin proteins. Genetic manipulation of B. thuringiensis has been achieved due to the development of stable shuttle vectors and the establishment of efficient transform...

Background: The actions of plant antimicrobial peptides (PAP) against intracellular pathogens are poorly known. It has been reported that wheat puroindolines show antibacterial activity against Staphylococcus epidermidis endocyted by macrophages. In this work, we evaluated the intracellular antimicrobial activity of PAP gamma-thionin and thionin Th...

Short chain fatty acids (SCFAs) are critical nutrients for ruminants and are mainly obtained from bacterial fermentation of carbohydrates. In addition to their nutrimental function, SCFAs have antimicrobial and anti-inflammatory properties, as well as immunomodulatory roles. It has been reported that sodium butyrate reduces Staphylococcus aureus in...

The hormone prolactin (PRL) regulates differentiation and lactation in the bovine mammary epithelium. This tissue is especially prone to contracting mastitis, a disease characterized by an inflammatory response in the mammary gland. Staphylococcus aureus is the infectious agent primarily responsible for mastitis. In a previous study, we have shown...

Helenium mexicanum (Asteraceae) is used in traditional Mexican medicine. Several studies have shown its insecticidal activity but its antibacterial properties have not been studied. The aim of this work was to assess the antibacterial activity of flowers extracts from H. mexicanum on ten human pathogen bacteria by disc-diffusion, broth dilution and...

Prolactin (PRL) hormone has been considered as a cytokine able to modulate immune response in mammals. In addition, particular effects of this hormone on inflammatory response have been documented in autoimmune diseases, whereas its effects on innate immune response during infectious diseases are in general, unknown. The objective of this review is...

Crude root extracts from Mexican avocado trees (Persea americana) were screened for antioomycete activity against Phytophthora cinnamomi. Forty-eight accessions from Mexican avocado trees were selected with potential resistance to P. cinnamomi according to environmental and site descriptors. Crude root extracts from these accessions were obtained a...

A distinctive feature of bovine milk fat is the presence of butyrate, molecule with recognized antimicrobial and antiinflammatory properties. Bovine mastitis is a pathology characterized by inflammatory and infectious processes; however, the role of sodium butyrate on Staphylococcus aureus infection in mammary epithelium has not been studied. In th...

Antimicrobial therapy is a useful tool to control bovine mastitis caused by Staphylococcus aureus, as consequence an increase in staphylococci resistant cases has been registered. Alternative strategies are desirable and bacteriocins represent attractive control agents to prevent bovine mastitis. The aim of this work was to evaluate the activity of...

The production of antimicrobial peptides is an important key of innate immunity. Tracheal antimicrobial peptide (TAP) expression has been reported in bovine tracheal epithelial cells and it can be modulated by bacterial infection or bacterial components. In mammary gland TAP expression has been reported, but the cell type that produces it is unknow...

For bean (Phaseolus vulgaris L.) anthracnose control under greenhouse and field conditions, the effect of crude extract and the mixture of bioactive afinina (A) compounds and bornyl decatrién (DB) obtained from Heliopsis longipes 'A. Gray' Blake root was assessed. Besides, the effect on bean root colonization by shrub vesicle mycorrhizal fungi (HMV...

Fifteen (15) backyard farms were investigated to determine the antimicrobial susceptibility and invasion ability of S. aureus isolates from cows with subclinical mastitis in México. A total of 106 cows were sampled and 31 S. aureus isolates were recovered. S. aureus isolates were resistant to penicillin class antibiotics and susceptible to gentamic...

For bean (Phaseolus vulgaris L.) anthracnose control under greenhouse and field conditions, the effect of crude extract and the mixture of bioactive afinina (A) compounds and bornyl decatrién (DB) obtained from Heliopsis longipes ‘A. Gray’ Blake root was assessed. Besides, the effect on bean root colonization by shrub vesicle mycorrhizal fungi (HMV...

Thionins are plant antimicrobial peptides with antibacterial and antifungal activities. Thionin Thi2.1 cDNA from Arabidopsis thaliana was expressed in BVE-E6E7 bovine endothelial cell line and its activity was evaluated against Escherichia coli, Staphylococcus aureus, Candida albicans and different mammal cell lines. Total protein (2.5 microg) from...

Bovine mastitis is mainly caused by Staphylococcus aureus and antimicrobial therapy, commonly used for its control, has resulted in an increase in the frequency of resistant staphylococci in recent years. Thus, alternative therapies are desirable and the antimicrobial peptides represent attractive control agents. In this work, we expressed the anti...

The incidence of mastitis in dairy cattle is highest at the drying off period and parturition, which are characterized by high levels of the lactogenic hormone prolactin (PRL). One of the most frequently isolated contagious pathogens causing mastitis is Staphylococcus aureus. However, the role of PRL on S. aureus infection in mammary epithelium has...