Muthukrishnan Arun

In the contemporary era, nanotechnology has emerged as a transformative tool across multiple sectors, including agriculture, with the potential to support sustainable food production. Among metallic nanoparticles (NPs), zinc oxide nanoparticles (ZnO NPs) play a crucial role in supplying zinc, an essential micronutrient required for crop growth and development. Soybean (Glycine max (L.) Merr.) is a globally important legume cultivated to meet increasing food and nutritional demands, and adequate zinc availability is vital for optimizing its growth and yield. Although conventional zinc fertilizers can enhance crop productivity, excessive application may exert phytotoxic effects, particularly within the rhizosphere environment. To mitigate these limitations, ZnO NPs are increasingly synthesized via biogenic approaches or conjugated with organic compounds to improve their environmental compatibility and reduce adverse impacts on plants and soil ecosystems. N-Acetyl-D-glucosamine (GlcNAc), an amino sugar and a monomer of chitin and chitosan, is known for its diverse commercial applications, including the stimulation of beneficial soil microbial communities. The present study investigates the growth-promoting potential of GlcNAc-conjugated ZnO NPs (GlcNAc–ZnO NPs) in soybean. The results demonstrate that GlcNAc–ZnO NPs exert a pronounced, concentration-dependent effect on soybean growth, physiology, and molecular regulation. Notably, an optimal dose of 75 mg/L GlcNAc–ZnO NPs significantly enhanced plant growth promotion compared with unmodified ZnO NPs and untreated controls, highlighting the importance of surface conjugation of organic compounds in improving plant growth performance.

Isoflavonoids are key secondary metabolites in leguminous plants that play essential roles in plant physiology and provide significant health benefits to humans. In the isoflavone biosynthetic pathway, isoflavone synthase (IFS) catalyzes the conversion of naringenin and liquiritigenin into the bioactive isoflavones genistein and daidzein. This study aimed to enhance genistein and daidzein accumulation in soybean seeds through genetic engineering. Agrobacterium tumefaciens strain EHA105 harboring the binary vector pCAMBIA1301 containing GmIFS under the control of a seed-specific promoter (Gmβ-conglycinin) was used to transform modified half-seed explants of soybean cv. JS335. Hygromycin-B-resistant plants were regenerated, hardened, and confirmed by histochemical GUS assay. Molecular analysis by PCR validated the presence of the GmIFS transgene, yielding a 700 bp amplicon. Biochemical analysis revealed that seeds of T₀ transgenic plants showed a 1.53-fold increase in total phenolic content and a 3.67-fold increase in flavonoid content compared to non-transformed controls. Antioxidant assays demonstrated significantly higher DPPH radical-scavenging activity and ferric-reducing antioxidant power (FRAP) in GmIFS-overexpressing plants. HPLC analysis further indicated that transgenic seeds accumulated, on average, 4.07-fold higher daidzein and 1.75-fold higher genistein levels relative to control plants. qRT-PCR analysis showed significantly elevated GmIFS expression in immature cotyledons, mature cotyledons, and seeds of transgenic plants. Overall, these results demonstrate that GmIFS overexpression effectively enhances isoflavone production in soybean seeds, highlighting the potential of metabolic engineering of biosynthetic pathway genes to improve nutritional quality.

Background: Cyclin-dependent kinases 4 and 6 (CDK4/6) are pivotal regulators of the cell cycle, whose dysregulation is closely linked to cancer progression. While synthetic CDK4/6 inhibitors such as Palbociclib and Ribociclib are clinically effective, their use is limited by significant adverse effects. Methods: In this study, the aqueous root extract of Thottea siliquosa, a traditionally used medicinal plant, was evaluated for its potential as a natural CDK4/6 inhibitor. Phytochemical profiling using GC-MS identified bioactive compounds, which were subsequently subjected to molecular docking, ADME prediction, and in vitro cell-based assays using HCT116 and L929 cells. Results: The docking results revealed that Isocorydine (−7.4 kcal/mol for CDK4 and −7.2 kcal/mol for CDK6) and Thunbergol (−6.5 kcal/mol for CDK4 and −7.0 kcal/mol for CDK6) exhibited promising binding affinities comparable to standard CDK inhibitors, Palbociclib (−7.2, −8.3 kcal/mol) and Ribociclib (−7.1, −8.1 kcal/mol). Among the other tested natural compounds, Squalene (−7.1 kcal/mol for CDK4) and 2-palmitoylglycerol (−5.2 kcal/mol for CDK4, −4.9 kcal/mol for CDK6) demonstrated moderate binding affinities. ADME analysis confirmed favorable drug-like properties with minimal toxicity alerts. The extract displayed dose-dependent cytotoxicity with an IC₅₀ of 140 μg/mL and reduced cell migration in HCT116 cells, indicating potential anti-proliferative effects. These findings suggest that T. siliquosa root extract, through synergistic phytochemical interactions, holds promise as a multi-targeted, plant-based therapeutic candidate for CDK4/6-associated cancers, warranting further in vitro and in vivo validation.

Vitex negundo is a traditional medicinal plant known for its anticancer properties, particularly its effectiveness in targeting apoptosis-related cancer pathways. Colorectal cancer is the most prevalent malignancy worldwide, often requiring alternative therapies involving plant-derived bioactive compounds. This study aimed to synthesize zinc oxide nanoparticles using V. negundo leaves (VnZnONP) and confirm their formation through characterization studies. Further, the anticancer efficacy of VnZnONPs was also evaluated in HT-29 colorectal cancer cells. Zinc oxide nanoparticles were synthesized using methanolic leaf extract of V. negundo (MeVn), which contained nearly 39 phytocompounds, identified in gas chromatography-mass spectrometry (GC-MS). UV-vis spectroscopy showed a prominent peak at 374 nm, while dynamic light scattering (DLS) revealed a size distribution peaking at 452.5 nm. In SEM analysis, the spherical-shaped morphology with random distribution was observed. EDX analysis confirmed the presence of zinc and oxygen, and zeta potential analysis showed a + 41.4 mV charge, indicating stable nanoparticles. FTIR analysis identified functional groups such as aliphatic, aromatic compounds, alkenes, alcohols, and amides. In the DPPH assay, VnZnONP at 100 µg/ml exhibited 87.96% antioxidant activity, significantly higher than MeVn (39.89%). VnZnONPs showed dose-dependent cytotoxicity against HT-29 cells with an IC₅₀ value of 60.56 µg/ml. In addition, DAPI staining confirmed nuclear damage, and acridine orange/ethidium bromide staining indicated early and late apoptosis. RT-PCR analysis revealed downregulation of Jab1 and Bcl2, and upregulation of Bax, Caspase-3, and Caspase-9. This study demonstrates that V. negundo-based ZnO nanoparticles can promote apoptosis and can serve as a promising therapeutic agent for colorectal cancer. The online version contains supplementary material available at 10.1007/s10616-025-00775-x.