Search Results (6)

In the face of evolving healthcare challenges, the utilization of silver nanoparticles (AgNPs) has emerged as a compelling solution due to their unique properties and versatile applications. The aim of this study was the synthesis and characterization of novel AgNPs (SB-AgNPs and SG-AgNPs, respectively) using Salvia blepharophylla and Salvia greggii leaf extracts and the evaluation of their antimicrobial, antioxidant, and antidiabetic activities. Several analytical instrumental techniques were utilized for the characterization of SB-AgNPs and SG-AgNPs, including UV–visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transmission infrared (FT-IR) spectroscopy, energy-dispersive X-ray analysis (EDX), and X-ray diffraction (XRD). FTIR analysis identified various functional groups in the leaf extracts and nanoparticles, suggesting the involvement of phytochemicals as reducing and stabilizing agents. High-resolution TEM images displayed predominantly spherical nanoparticles with average sizes of 52.4 nm for SB-AgNPs and 62.5 nm for SG-AgNPs. Both SB-AgNPs and SG-AgNPs demonstrated remarkable antimicrobial activity against Gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes and Gram-negative bacteria Salmonella typhimurium and Escherichia coli. SB-AgNPs and SG-AgNPs also exhibited 90.2 ± 1.34% and 89.5 ± 1.5% DPPH scavenging and 86.5 ± 1.7% and 80.5 ± 1.2% α-amylase inhibition, respectively, at a concentration of 100 μg mL⁻¹. Overall, AgNPs synthesized using S. blepharophylla and Salvia greggii leaf extracts may serve as potential candidates for antibacterial, antioxidant, and antidiabetic agents. Consequently, this study provides viable solutions to mitigate the current crisis of antibiotic resistance and to efficiently combat antimicrobial infections and Type 2 diabetes. Full article

A plant can combine physical and chemical tools to interact with other organisms. Some are designed for pollinator attraction (i.e., colors and volatile organic compounds-VOCs); others can act to discourage herbivores (i.e., non-glandular trichomes). Few studies fully address available tools in a single species; notwithstanding, this information can be pivotal in understanding new interactions out of the home range. We characterized flower traits, emission profiles of constitutive compounds from flowers and leaves, micro-morphology of the glandular trichomes, and listed flower visitors of two Mexican bird-pollinated Salvia species (S. blepharophylla and S. greggii), growing in an Italian botanical garden. Flowers were highly variable in their morphometric characteristics. In both species, four trichome morphotypes with similar histochemistry and distribution were documented for leaves and flowers except the calyx abaxial side. The vegetative emission profiles were qualitatively more complex than the floral ones; however, common compounds occurring in high relative percentages were β-caryophyllene and germacrene D. Floral bouquets were dominated by limonene and β-pinene in S. greggii and by 1,8-cineole in S. blepharophylla. Two potential (non-bird) pollinators were especially abundant: small bees belonging to the genus Lasioglossum and large bees belonging to the species Xylocopa violacea. Our study highlights the plasticity of these plants, as well as tools that can be conveniently used to establish novel interactions. Full article

Sage species belong to the family of Labiatae/Lamiaceae and are diffused worldwide. More than 900 species of sage have been identified, and many of them are used for different purposes, i.e., culinary uses, traditional medicines and natural remedies and cosmetic applications. Another use of sage is the application of non-distilled sage extracts and essential oils to control phytopathogenic bacteria and fungi, for a sustainable, environmentally friendly agriculture. Biocidal propriety of non-distilled extracts and essential oils of sage are w documented. Antimicrobial effects of these sage extracts/essential oils depend on both sage species and bacteria and fungi species to control. In general, it is possible to choose some specific extracts/essential oils to control specific phytopathogenic bacteria or fungi. In this context, the use of nanotechnology techniques applied to essential oil from salvia could represent a future direction for improving the performance of eco-compatible and sustainable plant defence and represents a great challenge for the future. Full article

Species of Colletotrichum are considered important plant pathogens, saprobes, and endophytes on a wide range of host plants. In Italy, several Colletotrichum species have been reported in glasshouse environments. In this study, we have explored the occurrence, diversity, and pathogenicity of Colletotrichum spp. associated with aromatic and ornamental plants belonging to the Lamiaceae family. Surveys were carried out during the 2011–2018 period in Liguria and Piedmont, Italy. A total of 19 Colletotrichum isolates were collected from symptomatic leaves and seeds of Ocimum basilicum (basil), Origanum vulgare (oregano) and different Salvia spp. A multi-locus phylogeny was established based on the basis of four genomic loci (ITS, GAPDH, ACT and TUB2). The aggressiveness of selected, representative isolates were tested. Colletotrichum isolates were identified as being members of three major species complexes: C. acutatum, C. destructivum, and C. gloeosporioides. Colletotrichum fioriniae, C. bryonicola, and C. fructicola were found in association with leaf lesions on Salvia leucantha, S. nemorosa, and S. greggii, respectively. Colletotrichum nigrum was isolated from twig lesions of S. greggii. Moreover, C. fioriniae and C. ocimi were found to be responsible for causing leaf anthracnose of oregano and basil, respectively. All the tested isolates were pathogenic and reproduced identical symptoms to those observed in commercial glasshouses. The present study improves our understanding of Colletotrichum species associated with several hosts belonging to the Lamiaceae family, which are cultivated extensively throughout Italy for different purpose, and provides information that may be useful for an effective disease management program. Full article

Salvia elegans Vahl., Salvia greggii A. Gray, and Salvia officinalis L. decoctions were investigated for their health-benefit properties, in particular with respect to antioxidant activity and inhibitory ability towards key enzymes with impact in diabetes and obesity (α-glucosidase, α-amylase and pancreatic lipase). Additionally, the phenolic profiles of the three decoctions were determined and correlated with the beneficial properties. The S. elegans decoction was the most promising in regard to the antioxidant effects, namely in the scavenging capacity of the free radicals DPPH^•, NO^• and O₂^•–, and the ability to reduce Fe³⁺, as well as the most effective inhibitor of α-glucosidase (EC₅₀ = 36.0 ± 2.7 μg/mL vs. EC₅₀ = 345.3 ± 6.4 μg/mL and 71.2 ± 5.0 μg/mL for S. greggii and S. officinalis, respectively). This superior activity of the S. elegans decoction over those of S. greggii and S. officinalis was, overall, highly correlated with its richness in caffeic acid and derivatives. In turn, the S. officinalis decoction exhibited good inhibitory capacity against xanthine oxidase activity, a fact that could be associated with its high content of flavones, in particular the glycosidic forms of apigenin, scutellarein and luteolin. Full article

The chemical composition of the essential oils of Salvia africana L., Salvia elegans Vahl, Salvia greggii A. Gray, Salvia mellifera Green and Salvia munzii Epling, cultivated in Eboli (Salerno, Southern Italy), was studied by means of GC and GC-MS analyses. In all, 88 compounds were identified, 54 for S. africana, accounting for 95.4% of the total oil, 55 for S. elegans (92.9%), 50 for S. greggii (96.9%), 54 for S. mellifera (90.4%) and 47 for S. munzii (97.5%), respectively. In S. africana,the amount of monoterpenoids and sesquiterpenoids is very similar. For other species, the monoterpenoid percentage is greater than the amount of sesquiterpenoids. The oils of S. elegans, S. greggii and S. munzii were active inhibitors of germination and radical elongation of Raphanus sativus L. and Lepidium sativum L. Full article