Autoimmune Disorders and Secondary Plant Metabolites (Part 1)

From the very moment our heart starts to beat, and we take our first breath, there is an army of cells and tissues that make up organs and a system that stands in our defense called the ‘Immune system.’ The immune system responds to foreign molecules like viruses, bacteria, or any other organic molecule that is not familiar to the body and the extrinsic particles that, however, can cause us damage whilst not attacking its cells with specific identifiers. This remarkable and intricate network is called the immune system, and as complex as it is, it is fascinating. To study this system, we have a very delicate and integral part of the medical field called ‘Immunology.’ Several physiological processes are intertwined with the elaborate defensive system, like clotting, wound healing, maintenance of body temperature, and much more. This chapter will walk you through the fundamentals of immunology, like diverse types of immunities, and what can happen if the body attacks its own cells, such as accidental betrayal. The accident is medically called the ‘Autoimmune disorder,’ which occurs as a result of neglected self-tolerance, leading to attacking the body’s own tissues and network systems. Factors like genetics, environment, and lifestyle are generally taken into consideration to diagnose and further treat an autoimmune disorder. Though this is not an event that is often experienced in the body, it might occur sometimes, which leads us to study it and prevent it. Additionally, we will be talking about why and how this accidental betrayal usually happens.

Plants have been used as a source of medicine for the treatment of different diseases for thousands of years. Bioprospecting of medicinal plants aims at the development of commercially valuable therapeutic goods, which could be used for the treatment of different diseases. The therapeutic values of medicinal plants are due to the presence of different bioactive secondary metabolites. The exploration of phytochemicals from the medicinal plants via ethnopharmacological, chemotaxonomical and random selection approach. The phytochemical-based drug discovery was performed by extraction, isolation, identification, bioassay, which further goes for target identification, target validation, lead identification, lead optimization, and clinical trials. The crucial step in drug discovery from the medicinal plant is lead identification and optimization due to their complex structural organization. This problem of drug discovery can be resolved by employing the concept of virtual screening and databases like COCONUT, TCMPG, IMPPAT 2.0, PMDB, PMhub, etc. Each of these steps has its specificities, limitations, and advances. In this regard, knowledge about combinatorial biosynthesis, chemical synthesis, and the technique of acquiring drugs from medicinal plants was gathered for this chapter. This chapter concludes by discussing a few significant facets of current case studies in relation to the discovery of novel bioactive compounds from medicinal plants and the creation of affordable, safe, and effective medications to combat the world's expanding list of illnesses.

Plant Secondary Metabolites (PSM) are compounds vital for plant survival that play a pivotal role in their mechanisms of action, and possess various medicinal properties that can enhance human health. These bioactive substances, generated by plants as defense mechanisms against predators and to attract pollinating insects, are garnering increased attention for their potential pharmacological benefits. PSM encompassing alkaloids, flavonoids, terpenes, saponins, and more, exhibit diverse pharmacological activities such as antihypertensive, anticancer, and antimicrobial effects. Ancient civilizations practiced medicinal plant usage, with secondary metabolites primarily responsible for their therapeutic efficacy. Classified based on structure and biosynthetic derivation into primary and secondary metabolites, the latter category includes terpenoids, phenolics, alkaloids, and glycosides. They serve as crucial sources of bioactive ingredients in both nutraceuticals and modern pharmaceuticals. Secondary metabolites display diverse pharmacological activities, interacting with receptors, cell membranes, and nucleic acids. This comprehensive book chapter delves into their classification, phytochemistry, and pharmacological activities, shedding light on their application in modern medicine for human health enhancement and drug innovation. Understanding these compounds aids in identifying and isolating pharmacologically active lead compounds for drug discovery.

Type-1 Diabetes Mellitus (T1DM) poses major complications due to its autoimmune nature, which is characterized by pancreatic β-cell breakdown, resulting in a lack of insulin as well as dysregulated glucose metabolism. While insulin therapy remains the cornerstone of T1DM management, emerging research investigating adjunctive therapies includes natural compounds, such as terpenoids derived from plants. Regenerative medicine aims to generate new insulin-producing cells derived from various cell kinds to treat T1DM, which is caused by the loss of pancreatic β cells. Terpenoids, also known as isoprenoids, are natural chemicals derived from isoprene that play important functions in all species' metabolisms. Natural terpenoid compounds have been classified into five different categories based on their structure: monoterpenoids (Paeoniflorin, Catalpol, Geniposide), sesquiterpenoids (Curcumol, βPatchoulene), diterpenoids (Carnosic Acid, Ginkgolide), triterpenoids (Ginsenoside, Ursolic Acid), and tetraterpenoids (Lycopene, Astaxanthin). Terpenoids appear to have a therapeutic impact on non-alcoholic fatty liver disease, largely via insulin resistance, regulating lipid metabolism, inflammation, and oxidative stress. Terpenoids can help diagnose diabetic nephropathy by decreasing the production of pro-inflammatory cytokines (α-amylase and α-glucosidase), controlling glycolipid metabolism, and lowering renal inflammation. We look at some of the most beneficial and promising terpenoids that are now being employed in medicine and research, as well as the most recent information on their natural occurrence, biosynthesis, and mechanism of action in the body. Terpenoids promote the proliferation and development of osteoblast cells in high-glucose circumstances. These findings demonstrated that terpenoids stimulated glycogenesis via the PI3K/AKT pathway while inhibiting glucosamine-induced gluconeogenesis by downregulating gluconeogenesis enzymes. Despite these encouraging findings, the therapeutic potential of terpenoids in T1DM has to be further investigated through rigorous preclinical and clinical trials. 

 A complicated and long-lasting neurodegenerative illness, Multiple Sclerosis (MS) is characterized by lesions in the Central Nervous System (CNS). Although the exact etiology of MS and the processes behind this rise are yet unknown, complex gene-environment interactions most likely have a significant impact. Growing research indicates that certain symptoms of multiple sclerosis and spinal cord damage, such as pain and spasticity, are effectively suppressed by Cannabinoids. Natural cannabis products and single Cannabinoids are often smoked or taken orally, with different administration routes. Transdermal, sublingual, ocular, and aerosols have only been employed in a few studies and are not highly relevant in modern practice. This chapter focuses on novel approaches of Cannabinoids drugs with synthetic material, co-drug development, mechanism of action, and demonstrating the use of Cannabinoids receptor agonists in the treatment of multiple sclerosis. Furthermore, the chapter explains the preclinical and clinical approaches, suggesting that Cannabinoids CB1 and/or CB2 receptors may decrease some of the pathological alterations that lead to the signs and symptoms of multiple sclerosis in addition to alleviating them and using synthetically derived Cannabinoids, also explains how it reduces the effects of MS and prolongs 'patient's lifespan. Thus, the chapter delivers the potentiality of using Cannabinoids with advances to overcome the Pharmacokinetic and Pharmacodynamic pathways.

Systemic Lupus Erythematosus (SLE) is an inflammatory illness characterised by chronic inflammation and multi-organ dysfunction. Secondary plant metabolites have received attention as potential innovative treatment agents. These metabolites provide a variety of pharmacological actions that are effective in managing SLE. These metabolites include polyphenols, alkaloids, terpenoids, and glycosides. While their immune-modulatory activities can address the immunological dysfunction characteristic of the disease, their anti-inflammatory qualities improve in lowering the chronic inflammation observed in SLE. These substances additionally show strong antioxidant activity, which reduces oxidative stress, a major factor in the pathogenesis of SLE. These natural compounds have been shown in numerous studies to have the capacity to suppress pro-inflammatory cytokines, control lymphocyte proliferation, and alter the function of various immune cells. Compared to traditional manufactured medications, secondary plant metabolites have a lower potential for side effects due to their natural origin. For SLE patients, ongoing research and clinical trials are crucial in determining the therapeutic potential of these natural substances and developing effective treatment strategies. 

Autoimmune diseases are among the most challenging conditions to manage in healthcare practice because of the chronic and often multifactorial nature of their pathophysiology. This chapter focuses mainly on autoimmune disorders and begins by establishing the context of the immune system, as well as its components, with a description of its functions, antigen presentation, clonal selection, memory cells, and the key mechanisms of immune responses. Moving on, it discusses autoimmune disorders, outlining their classification and employing the pathophysiology, molecules involved, and genetic factors, including HLA genes and gene mutations. Diagnostic procedures involving hematological examination, radiological imaging, and fineneedle aspiration cytology are employed to portray the modern techniques used in the diagnosis of autoimmune disorders. An assessment of pharmacological and nonpharmacological treatment options currently available examines the former in terms of corticosteroids, immunosuppressing agents, biologics, and small-molecule inhibitors, while the latter includes lifestyle interventions and complementary medicine. This chapter also focuses on advanced research and new treatment directions, such as gene therapy, monoclonal antibodies, repurposing drug approaches, malaria transcription intervention factor targeting, immune checkpoint blockage, autophagy regulation, and biodegradable nanoparticles to build up antigen-specific tolerance. New treatment regimens are characterized by pharmacodynamics, evidence-based, side effects or complications, and improved benefits compared with earlier interventions. The chapter concludes with a summary of the key points, emphasizing the importance of advancing our understanding and treatment of autoimmune disorders through ongoing research and innovation.