## 4 Limitations of Using Plant Products as Bioherbicides
### Enhancement of Bioactivity Using Nanotechnology  
To address limitations such as the high volatility, instability, and rapid degradation of specialized metabolites in EOs and the extracts, solutions, and water emulsions of EOs under environmental conditions, [PERSON] et al. [266] highlight the benefits of using polysaccharides as raw materials for encapsulating natural chemicals in nanoparticles as novel crop protection products. Polysaccharides can be derived from various natural sources, including plants (hyaluronic acid, pectin, cellulose, lignin, \(\beta\)-glucan, starch, and guar gum), animals (chitosan and chitin), algae (agar, alginate, and carrageenan), and microorganisms (pullulan, xanthan gum, dextran, and bacterial cellulose). These materials offer many advantages, including biocompatibility, biodegradability, and the controlled release of active compounds. As the authors point out, various natural substances, such as EOs, plant extracts, antimicrobial compounds, and microRNA, can be incorporated into these nanoparticles and delivered to target sites in plants, easily passing through cell walls and membranes due to their small size range of 10 to 1000 nm. In addition, bioactive compounds can mediate hormone signaling and gene expression in various physiological aspects of plants and increase their tolerance to abiotic stress conditions. In addition, this type of treatment can support sustainable agriculture by properly developing food safety through the production of non-toxic nanoparticles, low-cost industrial scalability, and the use of biodegradable materials. To date, no results have been reported on the encapsulation and use of nanoparticles for iridoid compounds in _Nepeta_ species for potential biotherbicide applications. However, [PERSON] et al. [267] encapsulated EOs from \(N\). _hormozganica_ and \(N\). _dschuprensi_s into chitosan using a simple ionic gelation method with tripolyphosphate. The synthesized nanocapsules were evaluated for antifungal activity and demonstrated that encapsulated EOs increased antifungal efficiency by up to 100%. [PERSON] et al. [268] showed that the encapsulation of \(N\). _cataria_ EO in a chitosan nanocomposite had a lethal effect against _Toxoplasma gondii_. [PERSON] et al. [269] investigated the encapsulation of \(N\). _bianludensis_ extracts and their release kinetics under laboratory conditions. Extracts were encapsulated using maltodextrin and gum arabic and the release kinetics of the microencapsulated phenolic compounds were studied. The results revealed that combining maltodext with dextrose and gum arabic yielded superior efficiency in assessing antioxidant activity. [PERSON] et al. [270] prepared microcapsules containing EOs from _Nepeta_ sp. species through electro-atomization and complex coaervation, using sodium alginate and gelatin as wall materials. The results indicated that the microcapsules enabled stable release over 15 days and maintained a mosquito repellency rate above 80% for 48 h, suggesting potential applications in mosquito repellent formulations. [PERSON] et al. [271] demonstrated that cyclodextrin inclusion complexes successfully encapsulated and enhanced the properties of \(N\). _cataria_ EO, extending its potential use in tick control formulations. [PERSON] al. [272] investigated the in vivo activity of biosynthesized silver nanoparticles with \(N\). _cataria_ extract in a rat excision wound model, where the treatment significantly improved wound healing. [PERSON] et al. [273] presented an eco-friendly approach for managing disease-transmitting vectors and bacterial pathogens by rapidly synthesizing copper nanoparticles using \(N\). _cataria_ leaves. Encapsulation and nanoparticle formulations of EOs and extracts from _Nepeta_ species have demonstrated enhanced stability and improved biological and pharmacological responses in various studies. These advancements underline their potential and will be a focus of future research, particularly in evaluating their efficacy as bioherbicides under agricultural conditions.