Phenolic compounds are the main phytochemical constituents of many higher plants. They play an important role in synthesizing metal nanoparticles using green technology due to their ability to reduce metal salts and stabilize them through physical interaction/conjugation to the metal surface. Six pure phenolic compounds were isolated from licorice (Glycyrrhiza glabra) and employed in synthesizing gold nanoparticles (AuNPs). The isolated compounds were identified as liquiritin (1), isoliquiritin (2), neoisoliquiritin (3), isoliquiritin apioside (4), liquiritin apioside (5), and glabridin (6). The synthesized AuNPs were characterized using UV, zeta sizer, HRTEM, and IR and tested for their stability in different biological media. The phenolic isolates and their corresponding synthesized NP conjugates were tested for their potential in vitro cytotoxicity. The anti-inflammatory effects were investigated in both normal and inflammation-induced settings, where inflammatory biomarkers were stimulated using lipopolysaccharides (LPSs) in the RAW 264.7 macrophage cell line. LPS, functioning as a mitogen, promotes cell growth by reducing apoptosis, potentially contributing to observed outcomes. Results indicated that all six pure phenolic isolates inhibited cell proliferation. The AuNP conjugates of all the phenolic isolates, except liquiritin apioside (5), inhibited cell viability. LPS initiates inflammatory markers by binding to cell receptors and setting off a cascade of events leading to inflammation. All the pure phenolic isolates, except isoliquiritin, neoisoliquiritin, and isoliquiritin apioside inhibited the inflammatory activity of RAW cells in vitro.

Glycyrrhiza glabra L. is a plant commonly utilized in herbal medicine and stands out as one of the more extensively researched medicinal plants globally. It has been documented with respect to several pharmacological activities, notably, neuroprotective effects, among others. However, the neuroprotective activity of pure phenolic compounds has not been reported yet. The chromatographic of a methanolic extract yielded twenty-two compounds, viz.: naringenin 4′-O-glucoside (1), 3′,4′,7-trihydroxyflavanone (butin) (2), liquiritin (3), liquiritin apioside (4), abyssinone (5), glabrol (6), isoliquiritin (7), neoisoliquiritin (8), isoliquiritin apioside (9), licuraside (10). 3’[O], 4’-(2,2-dimethylpyrano)-3,7-dihydroxyflavanone (11), glabrocoumarin (12), glabrene (13), isomedicarpin (14), 7-hydroxy-4′-methoxyflavone (formononetin) (15), ononin (16), glycyroside (17), (3S)-7,4′-dihydroxy-2′-methoxyisoflavan (18), glabridin (19), neoliquiritin (20), 3,11-dioxooleana-1,12-dien-29-oic acid (21), and 3-oxo-18β-glycyrrhetinic acid (22). The results of the neuroprotection evaluation showed that G. glabra total extract (TE) and compounds 1, 7, 11, 16, and 20 protected SH-SY5Y cells by inhibiting the depletion of ATP and elevated caspase 3/7 activities induced by MPP+. Indeed, this study reports for the first time the structure and activity of compound 11 and the neuroprotective activity of some phenolic constituents from G. glabra.

Aizoon africanum (L.) Klak (Synonym Galenia africana L.) is traditionally used for a variety of medicinal purposes; however, it has been reported to cause liver damage and severe ascites, particularly in sheep and Angora goats in the arid regions of the Western Cape. This study explores its cytotoxic properties to identify potential cytotoxic compound(s) in the plant. The methanolic extract of A. africanum was re-investigated and subjected to various chromatographic techniques, including preparative HPLC, resulting in the isolation of eight compounds (1–8). Structural elucidation was primarily based on NMR data. Among the isolated compounds, four were flavanones, one was a flavonone, and three were chalcones. Notably, compound 8 was identified as a new chalcone, while compounds 2 and 3 were reported for the first time from this plant. The toxicity of these isolated compounds was evaluated against the HepG2 and SH-SY5Y cancer cell lines using the MTT assay. We further investigated markers of cell death using spectrophotometric and luminometric methods. Among the isolated compounds, 7 and 8 exhibited cytotoxic activities within the range of 3.0–20.0 µg/mL. Notably, the compounds demonstrated greater cytotoxicity towards liver-derived HepG2 cells compared to the neuronal SH-SY5Y cell line. Compound 7 (2′,4′-dihydroxychalcone) was identified as inducing apoptosis through the intrinsic pathway without causing overt necrosis. The findings indicate that the phytochemicals derived from A. africanum exhibit differential cytotoxic effects based on cell type, suggesting potential for developing novel anticancer agents, particularly compound 7. Additionally, the identification of compound 8 provides insight into the liver toxicity of this plant observed in sheep in South Africa.

Fusarium species are significant phytopathogens responsible for major crop losses and contamination of food products with harmful mycotoxins, posing serious risks to food security and public health. In response to the limitations of conventional agrochemicals, this study explores sustainable antifungal strategies based on plant-derived products and nanotechnology. The aqueous extract of Ocimum basilicum was investigated as a bioresource for both direct antifungal activity and the green synthesis of silver nanoparticles (OB-AgNPs). Liquid chromatography–mass spectrometry (LC-MS) analysis of the O. basilicum aqueous extract revealed the presence of key compounds, including rosmarinic and chicoric acids, which can reduce and stabilize AgNPs. The biosynthesized nanoparticles were characterized using standard analytical techniques, including UV–visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), high-resolution transmission electron microscopy (HRTEM), and powder X-ray diffraction (PXRD). The OB-AgNPs exhibited a surface plasmon resonance (SPR) peak at 437 nm, a zeta potential of ~–16.3 mV, an average size of 28 nm (TEM) while the average hydrodynamic size is ≈57 nm (DLS). The synthesized AgNPs demonstrated stability in potato dextrose broth (PDB) for up to 24 h. The nanoparticles alongside the aqueous extract were evaluated against selected mycotoxigenic Fusarium species including F. verticillioides, F. proliferatum, F. subglutinans, F. graminearum, and F. globosum, following 96 h of exposure. Results showed that the aqueous O. basilicum extract exhibited limited antifungal activity, with significant inhibition observed only against F. globosum MRC 6122 at the highest concentration tested (400 ng/µL). In contrast, the biosynthesized OB-AgNPs demonstrated potent antifungal activity against most of the tested Fusarium strains, except for F. proliferatum MRC 8549 and MRC 8550, indicating substantially greater efficacy than the crude extract. These findings highlight the potential of O. basilicum-mediated AgNPs as effective and eco-friendly antifungal agents. The study underscores the value of integrating plant-based phytochemicals with nanotechnology for controlling Fusarium pathogens, while emphasizing the need for future studies to determine their effects on mycotoxin production, as well as their safety and phytotoxicity for agricultural applications.