Bionanotechnology is a branch of science that has revolutionized modern science and technology. Nanomaterials, especially noble metals, have attracted researchers due to their size and application in different branches of sciences that benefit humanity. Metal nanoparticles can be synthesized using green methods, which are good for the environment, economically viable, and facilitate synthesis. Due to their size and form, gold nanoparticles have become significant. Plant materials are of particular interest in the synthesis and manufacture of theranostic gold nanoparticles (NPs), which have been generated using various materials. On the other hand, chemically produced nanoparticles have several drawbacks in terms of cost, toxicity, and effectiveness. A plant-mediated integration of metallic nanoparticles has been developed in the field of nanotechnology to overcome the drawbacks of traditional synthesis, such as physical and synthetic strategies. Nanomaterials′ tunable features make them sophisticated tools in the biomedical platform, especially for developing new diagnostics and therapeutics for malignancy, neurodegenerative, and other chronic disorders. Therefore, this review outlines the theranostic approach, the different plant materials utilized in theranostic applications, and future directions based on current breakthroughs in these fields.

Zinc Oxide Nanoparticles (ZnONPs) are one of the most widely used metal oxide nanoparticles in biological applications because of their outstanding biocompatibility, affordability, and low toxicity. In biomedicine, ZnONPs have shown promise, particularly in the disciplines of anticancer and antibacterial fields. In comparison to other standard synthesis methods, the environmentally-friendly synthesis of metallic nanoparticles utilizing various plant extracts is a good option. The current research focuses on the synthesis of zinc oxide nanoparticles (ZnONPs) from R. sativus leaf extract under various physical conditions (Precipitation method). Analytical methods were used to confirm and characterize the produced ZnONPs. The spherical nature of the produced nanoparticles was established by SEM analysis. The generation of very pure ZnONPs was confirmed by EDS data. The crystalline nature of the produced nanoparticles, with a particle size of 66.47 nm, was confirmed by XRD. The XRD graphs’ presence of the (100), (002), and (101) planes strongly suggest the production of wurtzite ZnO. The visual and infrared area exhibits transmissions of 84 percent in the pH 10 nanoparticles. The band gap of the nanoparticles increases from 3.34 to 3.38 eV when the pH increases. These nanoparticles were effective against both Gram-positive and Gram-negative bacteria. The effect of several process parameters such as pH and temperature were investigated, and the best conditions were discovered to be pH 12 and 80 °C, respectively. The effect of ZnONPs was tested with human breast cancer cells (MCF-7), and they showed significant cytotoxic results. Collectively, our data suggest that ZnONPs of R. sativus leaf extract inhibit breast cancer cell lines. The ZnONPs are, therefore, a prospective source of chemopreventive drugs that merit additional exploration in order to uncover lead compounds with cancer chemotherapeutic potential.

The applications of bioactive compounds from medicinal plants as therapeutic drugs are largely increasing. The present study selected the bioactive compounds from Acacia concinna (A. concinna) and Citrus limon (C. limon) to assess their phytochemicals, proteins, and biological activity. The plant material was collected, and extraction performed as per the standard procedure. Qualitative analysis was undertaken, and identification of functional organic groups was performed by FTIR and HPLC. Antibacterial, anticancer, antioxidant, antihyperglycemic, antihyperlipidemic, and inhibition kinetics studies for enzymes were performed to assess the different biological activities. Flavonoids and phenols were present in a significant amount in both the selected plants. A. concinna showed significant antimicrobial activity against Z. mobilis, E. coli, and S. aureus, with minimum inhibition zones (MIZ) of 24, 22, and 20 mm, respectively. C. limon strongly inhibited all the tested pathogenic bacteria with maximum and minimum MIZ of 32 and 17 mm. A. concinna silver nanoparticles also exhibited potent antimicrobial activity. Both extracts showed substantial antioxidant, antihyperlipidemic, antidiabetic, anticancer (MCF-7), and anti-urease (antiulcer) properties. To conclude, these plants can be used to treat hyperlipidemia, diabetes, cancer, and gastrointestinal ulcers. They can also serve as antimicrobial and antioxidant agents. Thus, the studied plants must be exploited cost-effectively to generate therapeutic drugs for various diseases.

Objective: The Illicium verum is an evergreen Chinese plant, from which a culinary spice named star anise is obtained and is predominantly used in Asian countries. Besides its flavor, it possess high medicinal value. Illicium verum possesses good antimicrobial properties and in the past utilized to treat versatile ailments of microbial origin. Illicium verum is commonly known as star anise. Methods: This study is an attempt to resurrect the ancient forgotten traditional spice Illicium verum by analyzing its essential oils (EOs) for the phyto-biochemical properties using GC–MS, IR studies and various standard biochemical tests to record the presence of the chemical compounds based on its test reactions and also to measure its anti-microbial vulnerability testing towards the MRSA clinical isolates, by deploying the standard anti-microbial assay in the aseptic microbiological laboratory conditions. Results: The data procured from the standard antimicrobial assay of Illicium verum essential oil were compared with that of the standard antibiotic e-strips towards the same set of MRSA clinical isolates. The antimicrobial assay test results of Illicium verum essential oil against the clinical isolates of the MRSA showed promising results when compared to that of standard antibiotic e-strips. The results showed that all the MRSA clinical isolates were susceptible to the tested drug with inhibition zone diameter ranging from 18 mm to 28 mm (Mean 24.05 mm). The MBC and MIC results confirmed that the tested extract was potent against the highly virulent Methicillin-Resistant Staphylococcus aureus (MRSA) clinical isolates with MBC and MIC of 0.97 µg/mL and 0.70 µg/mL, which was lower compared to MBC and MIC values of the standard antibiotics. Conclusion: The results obtained from this study is a motivation to rediscover the ancient phytochemical compounds as an added asset to the standard available drugs in dealing with the upcoming hazardous diseases and pandemics. Thus, it relishes us to perform more of such studies to enhance the phyto-pharmacological industry.

In the present work, characterization of water soluble colloidal MnO₂ nanoflakes which act as an oxidizing agent was carried out using UV–visible spectroscopy. Transmission electron microscopy microstructure of colloidal MnO₂ nanoflakes confirms the shape and nature of these particles. Selected area electron diffraction ring indicated that colloidal nanoflakes were amorphous in nature. Surface morphology of synthesized colloidal MnO₂ nanostructure was determined by field emission scanning electron microscopy indicating a crumpled net like arrangement.