Fighting Multidrug Resistance With Herbal Extracts Essential Oils And Their Components

Fighting Multidrug Resistance with Herbal Extracts, Essential Oils and their Components offers scientists a single source aimed at fighting specific multidrug-resistant (MDR) microorganisms such as bacteria, protozoans, viruses and fungi using natural products. This essential reference discusses herbal extracts and essential oils used or under investigation to treat MDR infections, as well as those containing antimicrobial activity that could be of potential interest in future studies against MDR microorganisms. The need to combat multidrug-resistant microorganisms is an urgent one and this book provides important coverage of mechanism of action, the advantages and disadvantages of using herbal extracts, essential oils and their components and more to aid researchers in effective antimicrobial drug discovery Addresses the need to develop safe and effective approaches to coping with resistance to all classes of antimicrobial drugs Provides readers with current evidence-based content aimed at using herbal extracts and essential oils in antimicrobial drug development Includes chapters devoted to the activity of herbal products against herpes, AIDS, tuberculosis, drug-resistant cancer cells and more

High prevalence of multidrug-resistant microorganisms in the etiologic structure of different infectious processes significantly decreases the effectiveness of the treatment and enhances the probability of an unfavorable outcome from the infection. Combinations between antibiotics and other antimicrobial agents represent one of the most promising approaches for combating multidrug-resistant bacteria. A high therapeutic potential exists for combinations of antibiotics and natural antimicrobial substances with complex mechanisms of action and multiple healing properties, such as plant essential oils. The purpose of the present chapter is to review published studies on antibiotic-essential oil combinations and discuss the prospects for future studies. In general, many studies have shown the potential for essential oils to act synergistically with antibiotics in vitro. The main proposed mechanism of this beneficial effect is through inhibition of efflux pumps by some essential oils, which restores the activity of the antibiotic. Future efforts should be directed into further studies of antibiotic-essential oil combinations against multidrug-resistant bacteria, with an emphasis on understanding the mechanisms of the produced effect. Combinations of essential oils with different types of antimicrobial agents, such as bacteriophages, nanoparticles, and quorum-sensing inhibitors, require greater attention and are worthy of future investigations.

In the search for successful antitubercular treatments, investigators have often turned their efforts to ethnobotany, ethnopharmacology, and phytochemistry. Since many of the world’s peoples have well-developed systems of traditional medicine with plants and their extracts as a major component and many of these plants have been used to treat tuberculosis, indigenous herbal medicine is a logical starting point for a research program. The major aims in this chapter are to summarize current antitubercular treatments; look for structural patterns in molecules that have been used successfully in the therapeutics of tuberculosis; examine published evidence of natural products derived principally from macrophytic species with an anecdotal reputation as antitubercular treatments or that have been deliberately tested for antitubercular activity; and identify promising structural classes of plant metabolites that can serve as lead compounds. Finally, I would like to indicate some of the directions being followed by leading researchers in the field and suggest ways forward in drug discovery to treat multidrug-resistant tuberculosis.

Antibiotics are antimicrobial agents that are used to treat infectious diseases. The outbreak of pathogenic antibiotic-resistant strains illustrates our urgent need to search for new alternative sources of treatment. Hence, an attempt has been made in this review to list some plant extracts, essential/volatile oils, and their antimicrobial activity against different microorganisms using different methods, as well as synergistic effects (plant extract-plant extract, plant extract-essential oils, plant extract-conventional antibiotics, phytochemical-antibiotics, and essential oil-essential oil). Plant products and their active constituents are useful in the treatment of infectious diseases caused by multidrug-resistant microbes, food borne diseases caused by food spoiling microbes, and oral pathogens. Products derived from plants have the potential to control microbial growth in diverse situations, and specifically in the treatment of disease. The various aspects of this review may be helpful for the food, cosmetic, and pharmaceutical industries.

The development of vancomycin resistance by some microbial strains has made the treatment of some infections more difficult and, in many cases, impossible. Although the search for new drugs against vancomycin-resistant organisms has been very successful, resistance can arise against many of these compounds. Natural products are an invaluable source of a diversity of biologically active compounds for addressing the challenges facing drug development initiatives to combat vancomycin-resistant enterococcal infections. Despite the fact that scientific data on plant metabolites active against vancomycin-resistant enterococci remain scarce, some compounds (including terpenoids and phenolics) have been reported to have inhibitory effects at various levels. This chapter describes the state of the art of research into plant bioactive metabolites against vancomycin-resistant enterococci, highlighting the hit compounds.

Infectious diseases are responsible for one in every two deaths in many developing countries, but people in sub-Saharan Africa are particularly vulnerable, as poverty is rampant and access to health care is limited. Additionally, the unregulated use of antibiotics in some parts of Africa has led to the emergence of resistance in pathogens. Indeed, one of the biggest pandemics is malaria, which kills millions annually. Currently, artemisinin (effective against chloroquine-resistant Plasmodium) is the only weapon available to fight this pandemic, yet the World Health Organization has reported with concern that some countries in Southeast Asia are beginning to witness resistance to artemisinin. As a consequence, increasing attention is being drawn to botanicals, as they have the potential to provide alternative and complementary therapies, as well as potential leads to address emerging infections and resistance. This chapter will review some medicinal plants from the African Herbal Pharmacopoeia that show promise for containing existing and emerging infectious diseases.

Herpes simplex virus (HSV) infections comprise one of the most important health problems worldwide. HSV-1 and HSV-2 that are the types most frequently seen in disease, manifested by sores and blisters on the mouth, tongue, skin, and genitals of infected individuals. Moreover, herpetic infections can reach life-threatening levels; for instance, HSV-2 prevalence has increased greatly in human immunodeficiency virus-positive patients. This indicates that the herpetic infection could be a major cause of morbidity in immunosuppressed patients. Unfortunately, resistance against antiherpetic drugs has recently been reported. Therefore there is an immediate need to search for new antiviral agents in order to cope with HSV infections. Recently, it has been demonstrated that traditional medicinal plants have strong antiviral activity and some are already being used in the treatment of viral infections, including herpes simplex infections. Accordingly, this chapter aims to present published information on various herbal compounds, investigate the antiherpetic effectiveness of these compounds, and determine the potential of plants as herpetic treatments in the future.

The genus Candida comprises more than 200 species, but few of them have been associated with human infections. C. albicans is the most important cause of disease. Other species such as C. dubliniensis, C. glabrata, C. guilliermondii, C. krusei, C. parapsilosis, and C. tropicalis are also being increasingly recognized as significant human pathogens. In recent years, the number of clinical infections caused by Candida species worldwide has risen considerably, and the incidence of resistance to traditional antifungal therapies is also increasing. There is an exigent need for novel antifungal remedies, and plants remain a vital source of these new substances, especially in low-resource countries. Natural compounds are potential antimycotic agents either in their nascent form or as template structures for more effective derivatives. The data and studies described in this chapter document the antimicrobial activity of plant extracts and essential oils against Candida species and show that medicinal plants can be a rich source of potential antifungal compounds.