Human beings have relied on herbs and medicinal plants as sources of food and remedy from time immemorial. Bioactive compounds from plants are currently the subject of much research interest, but their extraction as part of phytochemical and/or biological investigations present specific challenges. Herbalists or scientists have developed many protocols of extraction of bioactive ingredients to ensure the effectiveness and the efficacy of crude drugs that were used to get relief from sickness. With the advent of new leads from plants such as morphine, quinine, taxol, artemisinin, and alkaloids from Voacanga species, a lot of attention is paid to the mode of extraction of active phytochemicals to limit the cost linked to the synthesis and isolation. Thus, the extraction of active compounds from plants needs appropriate extraction methods and techniques that provide bioactive ingredients-rich extracts and fractions. The extraction procedures, therefore, play a critical role in the yield, the nature of phytochemical content, etc. This chapter aims to present, describe, and compare extraction procedures of bioactive compounds from herbs and medicinal plants.
Part of the book: Natural Medicinal Plants
Oxidative stress occurs when the body’s enzymatic or non-enzymatic antioxidants are outweighed by endogenous or exogenous free radicals. Oxidative radicals, reactive oxygen species, and other biomolecule-damaging free radicals can be generated during normal cellular metabolism and react with proteins, lipids, and DNA. In the domains of biology and medicine, free radicals have become increasingly important. They can accumulate in a variety of ways, both endogenously and exogenously. Mitochondria are the primary source of cell-level endogenous reactive oxygen species. In several chronic and degenerative disorders, this results in tissue destruction. In addition to being produced endogenously, antioxidants can also be delivered exogenously to the biological system, most frequently through nutrition. Antioxidants are generally used to counteract the effects of free radicals produced by metabolic processes. In this chapter, the crucial function of reactive oxygen species in human health, as well as exploring the functioning of antioxidative defense systems in reducing toxicity caused by excess reactive oxygen species were discussed.
Part of the book: Importance of Oxidative Stress and Antioxidant System in Health and Disease
Paclitaxel (Taxol) is potent natural anticancer drug that has evolved over the years. It has been useful in the management of many cancers. Hence, this review aims to appraise the pros and cons of paclitaxel in the management of cancers using literature. Paclitaxel acts by obstructing mitotic spindle formation attributed to clampdown of mitotic clampdown hence arresting the cell cycle at the G2/M phase. Some of the notable side effects of paclitaxel usage include: hair loss, numbness, bone marrow suppression, muscle pain, allergic reactions, diarrhea, etc. Among the mechanism of paclitaxel resistance are P-glycoprotein efflux pumps, mutation in tubulin and alterations in binding regions of β-tubulin, altered function of cytokine expression as well as apoptotic Bcl-2 and p53. Combination of paclitaxel with cisplatin clearly improves the duration of progression-free survival and of overall survival of breast cancer. Paclitaxel which is a valuable natural anticancer drug seems promising in the management of non-cancer diseases such as COVID-19, renal and hepatic fibrosis, inflammation, skin disorders, axon regeneration, limb salvage, and coronary artery restenosis. With the advancement of technology, it is expected that the biosynthesis, chemo-resistance as well as its targeted delivery would unfold and perhaps open new uses and vista to the old drug of about five decades ago.
Part of the book: Drug Repurposing