Medicinal plants have a long history of usage in traditional medicine to ancient times. These plants have been utilized in diverse fields, including traditional medicine, agriculture and human treatment, owing to the potential of plant bioactive components such as barks, leaves, flowers, roots, fruits and seeds, have been possess inhibitory properties [1]. In recent years, the field of nanotechnology has significant advancements in green chemistry processes and environmentally friendly synthesis methods [2]. These approaches have been developed with the goal of reducing the production of toxic substances and the synthesized nanoparticles (NPs) using these green approaches, with their sizes typically falling within the range of 1–100 nm [3]. Green synthesis offers several advantages, including sustainability, cost-effectiveness, biocompatibility, versatility and the potential for industrial scalability [4]. Recent days, synthesis of zinc oxide nanoparticles, which have shown great promise in various biomedical fields such as pharmaceuticals, cosmetics, photonics and photocatalysis [5].

ZnO nanoparticles have been extensively studied for their antibacterial properties, demonstrating the ability to inhibit the growth of various pathogenic microbes Antioxidants play a crucial role in effectively protecting cells from damage caused by oxidants, including reactive oxygen species, reactive nitrogen species, unstable ions and molecules [6]. The presence of flavonoids in the extract was confirmed to be incorporated into the ZnO nanoparticles. This incorporation was attributed to the interaction between the functional groups of flavonoids and phenols present in the extract, leading to the reduction of zinc ions (Zn2+ to Zn+1) and the formation of zinc (Zn0) [7]. Reactive oxygen species are formed during the metabolic processes of living organisms and are composed of reactive oxygen ions and peroxides. However, when produced in excessive amounts of ROS can have harmful effects on biomolecules such as DNA, RNA, proteins, lipids and various pathological diseases [8].

Current years, cancer becoming a major global health concern, scientists are actively exploring nanoparticle based treatments to target cancer cells [9]. Zinc oxide nanoparticles have emerged as a promising option due to their ability to selectively target and eliminate cancer cells [10]. The biomedical field recognizes the potential of zinc oxide (ZnO) nanoparticles, as they exhibit inherent cytotoxicity against cancer cells, making them valuable for targeted chemotherapy across different types of cancer cell lines [11]. Recent studies have provided compelling evidence of the selective elimination of tumor cells and the cytotoxic effects of ZnO nanoparticles on various cancer types [12]. Moreover, advancements in smart nanomaterials based on the cancer theranostic methodologies have shown promise in enhancing drug delivery and minimizing side effects. Current research has focused on the potential of zinc oxide nanoparticles for cancer treatment, including their effects on the A431 and MCF-7 cancer cell lines. ZnO nanoparticles have demonstrated cytotoxic properties and the ability to induce apoptosis in cancer cells, showing higher cytotoxicity compared to free polyphenol drugs, particularly in human epidermoid carcinoma (A431) cells [13,14]. Zinc oxide nanoparticles have been found to have several potential applications in the field of cancer treatment. Studies have shown that ZnO nanoparticles can induce cell cycle arrest and apoptosis in MCF-7 breast cancer cells. These nanoparticles have unique physicochemical attributes and biocompatibility, which make them suitable for drug delivery and cancer treatment. They have been extensively explored for their potential in fighting against cancer and other diseases [15].

The scarlet sage plant, scientifically known as Salvia coccinea Buc'hoz ex Etl., belongs to the Salvia genus in the Lamiaceae family. With approximately 900 species distributed worldwide, the Salvia genus has a long history of use in traditional medicine [16]. Salvia coccinea, also known as scarlet sage or blood sage, is a herbaceous perennial in the mint family (Lamiaceae) with bright red flowers. It is native to Mexico and the southeastern United States and is widespread throughout the Southeastern US, Central America and northwestern South America [17]. It is the only native US sage with red flowers. It grows best in full sun to partial shade and prefers sandy, fertile soil with good drainage. Scarlet sage is known to tolerate drought but will flower more abundantly with watering during dry spells. It reseeds easily and is attractive to hummingbirds and butterflies [18]. The Salvia genus, including Salvia coccinea, has been extensively studied for its medicinal properties. The genus name Salvia is derived from the Latin term “Salveo" which means “be well" and refers to the plant traditional medicinal uses. Scientific research has identified Salvia coccinea as a valuable source of antioxidant polyphenols, which have significant therapeutic potential, including antioxidant, anti-inflammatory and antitumor effects [19,20]. This study is the first to report on the promising bio-functional potential of green ZnO nanoparticles synthesized using Salvia coccinea leaf extract. This innovative approach opens up new possibilities of nanoparticles in various fields such as biomedical applications.