Search Results (8)

The growing threat of antibiotic-resistant Gram-negative bacteria highlights the urgent need for innovative, non-bactericidal therapeutic strategies. Quorum-sensing (QS) inhibition has emerged as a promising approach to attenuate bacterial virulence without exerting selective pressure. This study evaluated the antimicrobial, anti-QS, and antibiofilm properties of aqueous extracts from five medicinal plants native to northeastern Mexico: Gymnosperma glutinosum, Ibervillea sonorae, Larrea tridentata, Olea europaea, and Tecoma stans. Disk diffusion and violacein quantification assays using Chromobacterium violaceum demonstrated significant QS inhibition by G. glutinosum and T. stans, with violacein reductions of 60.02% and 52.72%, respectively, at 40 mg/mL. While L. tridentata and O. europaea exhibited antibacterial activity, I. sonorae showed no growth or pigment inhibition but achieved the highest biofilm disruption (89.89%) against Salmonella typhimurium. UPLC-MS analysis identified chlorogenic acid, kaempferol, and D-(−)-quinic acid as major constituents, compounds previously associated with QS modulation. These findings highlight the potential of traditional Mexican plant species as sources of QS inhibitors and bio-film-disrupting agents, supporting their further development as alternatives to conventional antibiotics. Full article

Tecoma stans belongs to the Bignoniaceae family and possesses various pharmacological activities, including antimicrobial, anti-inflammatory, antifungal, antioxidant, and wound-healing activities. Although numerous studies have highlighted the beneficial effects of T. stans extracts, the impacts of different solvents on its biological activities, particularly its inhibitory effect on skin degradation enzymes (collagenase, elastase, and hyaluronidase assay), have not been reported. This study aims to explore the effects of different solvent extractions on the total phenolic and total flavonoid contents, antioxidant and anti-aging activities, and cytotoxicity. The most suitable extract was selected for incorporation into an anti-aging product. T. stans flowers were extracted using hexane, ethyl acetate, absolute ethanol, and deionized water through maceration. The aqueous extract yielded the highest extraction efficiency (40.73%), followed by absolute ethanol, ethyl acetate, and hexane. The phytochemical screening results revealed that all T. stans flower extracts contained phenolics, flavonoids, terpenoids, and alkaloids. Among the various solvents tested for T. stans flower extraction, absolute ethanol demonstrated the highest total phenolic content (24.10 ± 2.07 mg gallic acid equivalents (GAE)/g extract), followed by deionized water (20.83 ± 1.28 mg GAE/g extract). The highest total flavonoid content was observed in the ethyl acetate extract (205.11 ± 7.83 mg catechin equivalents (CE)/g extract), with ethanol showing a significantly lower concentration (140.67 ± 1.92 mg CE/g extract). In terms of antioxidant activity, the aqueous extract exhibited the most potent effects, with IC₅₀ values of 0.600 ± 0.005 mg/mL for the DPPH^• assay and 0.207 ± 0.001 mg/mL for the ABTS^•+ assay. For anti-aging assays, the absolute ethanolic extract demonstrated the highest enzyme inhibition activity at 1 mg/mL, with collagenase, elastase, and hyaluronidase inhibition rates of 89.49% ± 2.96%, 94.61% ± 2.33%, and 82.56% ± 2.27%, respectively. Moreover, at a concentration of 50 µg/mL, the absolute ethanolic extract exhibited lower cytotoxicity, with human keratinocyte (HaCaT) cell viability of 78% ± 8.47%, which was significantly higher than that of the other extracts. An anti-aging gel containing 0.05% w/w of the ethanolic T. stans extract demonstrated physical and physicochemical stability during three months of storage at ambient temperatures, 4 °C, 45 °C, as well as after six cycles of heating/cooling tests. These findings suggest that the ethanolic extract of T. stans flower has potential as a safe and effective anti-aging agent for cosmeceutical products. Full article

Bioactive compounds from medicinal plants have applications in the development of functional foods. However, since they are unstable, encapsulation is used as a conservation alternative. This work aimed to assess the bioactive properties (antioxidant and hypoglycemic) of different extracts, including the infusion, as well as their spray-dried microencapsulates from Tecoma stans leaves. A factorial design was proposed to determine the best extraction conditions, based on ABTS and DPPH inhibition. Maltodextrin (MD), arabic gum (AG), and a 1:1 blend (MD:AG) were used as encapsulating agents. Moreover, characterization through physicochemical properties, gas chromatography/mass spectrometry (GC-MS) and scanning electron microscopy (SEM) of the best two powders based on the bioactive properties were analyzed. The results showed that the combination of stirring, water, and 5 min provided the highest inhibition to ABTS and DPPH (35.64 ± 1.25 mg Trolox/g d.s. and 2.77 ± 0.01 g Trolox/g d.s., respectively). Spray drying decreased the antioxidant activity of the extract while preserving it in the infusion. The encapsulated infusion with MD:AG had the highest hypoglycemic activity as it presented the lowest glycemic index (GI = 47). According to the results, the microencapsulates could potentially be added in foods to enhance nutritional quality and prevent/treat ailments. Full article

Tecoma stans is an ornamental perennial tropical and subtropical plant belonging to the Bignoniaceae family with green leaves and yellow attractive fragrance flowers and commonly known as yellow trumpetbush or yellow bells. The plant originated in the tropical areas of South America and Mexico and has been cultivated in many countries such as Egypt, Iraq, and the United Arab Emirates (UAE). T. stans has been found in different parts of the UAE such as Ras Al Khaimah, Abu Dhabi, and Dubai, where it can be seen in public parks, side roads, and home gardens. The Flash Chromatography System is used in different aspects of drug discovery studies because of its ability to purify secondary metabolites from crude plant extracts. A method was developed using the Flash Chromatography System to isolate three components from the ethanolic extract of T. stans leaves that showed in vitro antioxidant activity. In vitro evaluation of the antioxidant activity of the isolated components of T. stans was conducted using 1,1-diphenyl-2-picryl hydrazyl and 2, 2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid methods. Isolated components A-4, A-3, and A-2 had antioxidant activity when compared to ascorbic acid. Component A-3 showed antioxidant activity using the DPPH and ABTS methods; antifungal activities when tested against Candida albicans; and more than 80% inhibitions in the third dilution when compared to itraconazole and nystatin as positive controls. This rapid and efficient method using flash chromatography was used for the isolation and purification of an isolated component A-3 that showed both antioxidant and antifungal activities. Full article

Metabolic syndrome is a constellation of abnormalities related to insulin resistance with an unfortunately high prevalence worldwide. Tecoma stans (L.) Juss. Ex Kunth. is a well-known medicinal plant that has been studied in several biological models related to diabetes mellitus. The aim of this study was to evaluate the effects of T. stans on a hypercaloric diet-induced metabolic syndrome model. An organic fraction obtained using liquid–liquid separation from the hydroalcoholic extract of T. stans and four subfractions of this organic fraction were administered for ten weeks to C57BL6J male mice previously fed with a hypercaloric diet. The hypercaloric diet caused changes in glucose levels (from 65.3 to 221.5 mg/dL), body weight (31.3 to 42.2 g), triglycerides (91.4 to 177.7 mg/dL), systolic (89.9 to 110.3 mmHg) and diastolic (61.6 to 73.7 mg/dL) blood pressure, and insulin resistance (4.47 to 5.16). Treatment with T. stans resulted in improvements in triglycerides (83.4–125.0 mg/dL), systolic blood pressure (75.1–91.8 mmHg), and insulin resistance (4.72–4.93). However, the organic fraction and hydroalcoholic extract produced a better response in diastolic blood pressure (52.8–56.4 mmHg). Luteolin, apigenin, and chrysoeriol were the major constituents in the most active subfractions. Treatment with T. stans, particularly a luteolin-rich organic fraction, achieved an improvement in metabolic syndrome alterations. Full article

Urban areas with trees provide several ecosystem services to citizens. There is a growing interest in ecosystem services for the removal of air pollutants such as particulate matter. The objective of this paper is to show a study on the variation of intercepted particulate matter concentration (IPMC) by tree leaves in the megacity of Bogotá (Colombia). The relationship between IPMC and PM_2.5 concentrations observed in air quality stations in two urban zones with different air pollutions was studied. Influences of climate and leaf morphology variables on IPMC were also analyzed. The species under study were Ligustrum-lucidum, Eucalyptus-ficifolia, Tecoma-stans, Callistemon-citrinus, Lafoensia-acuminata, and Quercus-humboldtii. The results showed that leaf IPMC decreased as the PM_2.5 concentration increased. Species that best described this trend were Ligustrum-lucidum and Lafoensia-acuminata. These two species also showed the largest IPMC in their leaves. Indeed, species that showed the largest leaf area were those with the highest IPMC. On average, it was observed that for each 5.0 µg/m³ increase in PM_2.5 concentration the IPMCs of the species Ligustrum-lucidum and Lafoensia-acuminata decreased by 33.6% and 23.1%, respectively. When wind speed increased, there was also an increase in PM_2.5 concentrations and a reduction in the leaf IPMCs. Full article

Knowledge on alien species is needed nowadays to protect natural habitats and prevent ecological damage. The presence of new alien plant species in Italy is increasing every day. Calabria, its southernmost region, is not yet well known with regard to this aspect. Thanks to fieldwork, sampling, and observing many exotic plants in Calabria, here, we report new data on 34 alien taxa. In particular, we found three new taxa for Europe (Cascabela thevetia, Ipomoea setosa subsp. pavonii, and Tecoma stans), three new for Italy (Brugmansia aurea, Narcissus ‘Cotinga’, and Narcissus ‘Erlicheer’), one new one for the Italian Peninsula (Luffa aegyptiaca), and 21 new taxa for Calabria (Allium cepa, Asparagus setaceus, Bassia scoparia, Beta vulgaris subsp. vulgaris, Bidens formosa, Casuarina equisetifolia, Cedrus atlantica, Chlorophytum comosum, Cucurbita maxima subsp. maxima, Dolichandra unguis-cati, Fagopyrum esculentum, Freesia alba, Juglans regia, Kalanchoë delagoënsis, Passiflora caerulea, Portulaca grandiflora, Prunus armeniaca, Prunus dulcis, Solanum tuberosum, Tradescantia sillamontana, and Washingtonia filifera). Furthermore, we provide the first geolocalized record of Araujia sericifera, the confirmation of Oxalis stricta, and propose a change of status for four taxa (Cenchrus setaceus, Salpichroa origanifolia, Sesbania punicea, and Nothoscordum gracile) for Calabria. The updated knowledge on the presence of new alien species in Calabria, in Italy and in Europe could allow for the prevention of other new entries and to eliminate this potential ecological threat to natural habitats. Full article

Background and Objectives: Teeth decay and plaque are complicated problems created by oral pathogens. Tecoma stans (L.) and Cassia javanica (L.) are two ornamental evergreen plants widely distributed in Egypt. These plants are traditionally used for oral hygienic purposes. This study aims to elucidate the volatile oil constituents obtained from the flowers of these plants and evaluate the antimicrobial activity of these volatile oils against specific oral pathogens in comparison to chlorhexidine. Materials and Methods: The flowers obtained from both plants were extracted by n-hexane. GC-MS spectrometry was used to identify the constituents. Minimum inhibitory concentrations (MICs) were measured using tetrazolium salt (2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) (XTT). Results: GC-MS analysis revealed the presence of 32 and 29 compounds, representing 100% of the volatile constituents of Tecoma stans and Cassia javanica, respectively. The GC-MS analysis showed more than 60% of the volatile oil constituents are represented in both plants with different proportions. Chlorhexidine exerted stronger activity than tested plants against all microorganisms. Cassia javanica flower extract was more active against all tested microorganisms than Tecoma stans. Of note was the effect on Streptococcus mutans, which was inhibited by 100% at 12.5 and 25 µg/mL of Cassia javanica and Tecoma stans, respectively. The growth of Lactobacillus acidophilus was also completely inhibited by 25 µg/mL of the Cassia javanica extract. MIC90 and MIC were also calculated, which revealed the superiority of Cassia javanica over Tecoma stans against all tested oral pathogens. Conclusion: Cassia javanica flower volatile oils showed a potential anti-oral pathogen activity at relatively low concentrations. Also, Cassia javanica and Tecoma stans demonstrated a strong activity against tooth decay’s notorious bacteria Streptococcus mutans. Both plants can be potential substituents to chlorhexidine. Formulating the constituents of these plants in toothpastes and mouthwashes as anti-oral pathogen preparations can be an interesting future plan. Full article