Phytosynthesis, Characterization, Phenolic and Biological Evaluation of Leptadenia pyrotechnica-Based Zn and Fe Nanoparticles Utilizing Two Different Extraction Techniques.

Introduction: Phyto-nanotechnology offers a sustainable method for synthesizing biocompatible metal nanoparticles (NPs) with therapeutic potential. The diverse medicinal flora in the UAE, particularly Leptadenia pyrotechnica (LP), provides a vital resource for advancing this research area. This plant is historically valued in the region for its wide medicinal applications due to its abundance of bioactive compounds.

Methods: In this study, eco-friendly, straightforward, and low-temperature hydrothermal synthesis methods were applied to synthesize potentially therapeutic Zn and Fe NPs using LP extracts. The generated NPs were characterized using UV-VIS, FT-IR, SEM, EDX, XRD and DLS. Moreover, they were investigated for their total phenolic and flavonoid contents, along with their antioxidant and skin anticancer effects.

Results: The UV-Vis spectra disclosed absorption band at about 275 nm, and the FT-IR confirmed the successful coating of the NPs with the plants' phytochemicals, thus ensuring the successful bio-fabrication of the proposed NPs. SEM/EDX outcomes suggest a more potent reducing effect of the aqueous extract, while a more effective coating of the alcoholic extract. DLS revealed monodispersed NPs, with average sizes ranging from 43.82 to 207.8 nm. LFeC demonstrated the highest phenolic and flavonoid contents (49.96±4.76 μg of GAE/mg of DW and 43.89±2.89 μg of Qu/mg of DW, respectively) and the greatest potency against skin cancer cell lines (IC₅₀=263.56 µg/mL). However, LZnC exhibited the strongest radical scavenging effect against DPPH and ABTS radicals (IC₅₀=139.45µg/mL and 35.1µg/mL, respectively).

Discussion: The results of this study demonstrated that both extracts of LP are effective in the green synthesis of Fe and Zn nanoparticles for biomedical applications, with alcoholic extracts providing superior coating, capping, and stabilizing properties, leading to lower agglomeration, higher carbon content, total phenolic and flavonoid contents, along with enhanced anticancer and antioxidant effects. This work gives a showcase of sustainable materials that are promising for therapeutic applications.