Solid tumor is one of the highly prevalent cancers among humans and the treatment is often restricted by drug resistance to chemotherapeutics. One of the main reasons might be attributed to the limited penetration ability of drugs through tumor tissues due to heterogeneity within the tumor microenvironment. Over the recent years, so much research has been carried out for developing phytochemicals as cancer therapeutic agents. These are well-established as potential candidates for preventing and treating cancer, especially solid tumors, but have limited clinical applications due to their large molecular size, low bioavailability, stability, and target specificity, along with other side effects when used at high concentrations. There has been a widely proposed nano delivery system of bioactive constituents to overcome these obstacles. This nanostructured system might be able to potentiate the action of plant constituents, by reducing the side effects at a lesser dose with improved efficacy. Indeed, nanosystems can deliver the bioactive constituents at a specific site in the desired concentration and avoid undesired drug exposure to normal tissues. Furthermore, these nanoparticles demonstrate high differential absorption efficiency in the target cells over normal cells by preventing them from interacting prematurely with the biological environment, enhancing the cellular uptake and retention effect in disease tissues, while decreasing the toxicity. This review discusses various treatment stratagems used for the management of solid tumors with special emphasis on nanocarrier systems as a potential treatment strategy for herbal drugs. This also covers a wide list of plants that are used for the treatment of solid tumors and cancers along with their mechanisms of action and enlists various nanocarrier systems used for different phytoconstituents. This review gives a brief idea about different plants and their constituents exploited for their anticancer/antitumor potential along with several nanocarrier systems employed for the same and gives future directions to stress the nanotechnology platform as a valuable approach for the prevention and treatment of solid tumors.

中文翻译：

---

结合纳米技术在实体瘤中递送生物活性成分

实体瘤是人类中高发的癌症之一，治疗通常受到化疗药物耐药性的限制。主要原因之一可能是由于肿瘤微环境内的异质性导致药物通过肿瘤组织的渗透能力有限。近年来，为开发植物化学物质作为癌症治疗剂进行了大量研究。这些药物已被公认为预防和治疗癌症，尤其是实体瘤的潜在候选药物，但由于其分子大、生物利用度低、稳定性和靶标特异性低，以及在高浓度下使用时会产生其他副作用，因此临床应用受到限制。已经广泛提出生物活性成分的纳米递送系统来克服这些障碍。这种纳米结构系统可能能够通过以较低剂量减少副作用并提高功效来增强植物成分的作用。事实上，纳米系统可以在特定部位以所需浓度递送生物活性成分，并避免不希望的药物暴露于正常组织。此外，这些纳米颗粒通过防止靶细胞过早地与生物环境相互作用，增强疾病组织中的细胞摄取和保留作用，同时降低毒性，从而在靶细胞中表现出比正常细胞更高的吸收效率。本综述讨论了用于治疗实体瘤的各种治疗策略，特别强调纳米载体系统作为草药的潜在治疗策略。这还涵盖了广泛的用于治疗实体瘤和癌症的植物及其作用机制，并包括用于不同植物成分的各种纳米载体系统。这篇综述简要介绍了不同植物及其成分的抗癌/抗肿瘤潜力，以及用于相同用途的几种纳米载体系统，并给出了强调纳米技术平台作为预防和治疗实体瘤的有价值方法的未来方向。