Free radicals or reactive oxygen species (ROS) generated from various sources in the environment as well as from cellular processes in the body are of serious health challenges. Overwhelming levels of these free radicals disrupt the antioxidant defense system in the body thereby damaging cell membranes and cellular macromolecules such as proteins, lipids and nucleic acids leading to cell death or causing mutations leading to uncontrolled cell division. Once the cellular antioxidant system is disrupted and becomes deficient, oxidative stress emerges thereby promoting several diseases such as diabetes, arthrosclerosis, cancer, cardiovascular diseases, etc. Better management of oxidative stress requires antioxidants from external sources to supplement the body’s antioxidant defense system. Because of their natural origin and therapeutic benefits, plants have been considered as a major source of antioxidants. Certain non-enzymatic plant phytochemicals such as glutathione, polyphenols, bioflavonoids, carotenoids, hydroxycinnamates as well as some vitamins have shown to possess antioxidant properties in vitro and in vivo. These plant phytochemicals are now been used in the prevention and management of oxidative stress-related diseases.
Part of the book: Phytochemicals
Ebola virus disease is one of the most deadly emerging infectious diseases in the world which causes severe haemorrhagic fever, with a mortality rate of 50–90%. Following the largest outbreak in West Africa in 2014 which was the most deadly of all time challenging global health, so much concern has been tilted towards the management of the disease. Some of the major global challenges that prolonged and escalated the gravity of the 2014 outbreak were the lack of prompt, reliable and affordable diagnostic tools, but most importantly no specific treatment and vaccines were available to manage the infection. Though certain non-licensed experimental drugs as well as vaccines were introduced during the 2014 outbreak that contributed towards the control of the epidemic, their efficacy was yet to be confirmed in randomized trials. Presently, a few rapid diagnostic test kits have been approved by FDA and WHO. Also, several experimental drugs and vaccines are undergoing randomized clinical trials with a few currently at phase III. Thus, it is our hope that most of these drugs and vaccines will be available in future to better manage re-emerging Ebola infections or outbreaks.
Part of the book: Current Topics in Tropical Emerging Diseases and Travel Medicine
Several heavy metals are found naturally in the earth crust and are exploited for various industrial and economic purposes. Among these heavy metals, a few have direct or indirect impact on the human body. Some of these heavy metals such as copper, cobalt, iron, nickel, magnesium, molybdenum, chromium, selenium, manganese and zinc have functional roles which are essential for various diverse physiological and biochemical activities in the body. However, some of these heavy metals in high doses can be harmful to the body while others such as cadmium, mercury, lead, chromium, silver, and arsenic in minute quantities have delirious effects in the body causing acute and chronic toxicities in humans. The focus of this chapter is to describe the various mechanism of intoxication of some selected heavy metals in humans along with their health effects. Therefore it aims to highlight on biochemical mechanisms of heavy metal intoxication which involves binding to proteins and enzymes, altering their activity and causing damage. More so, the mechanism by which heavy metals cause neurotoxicity, generate free radical which promotes oxidative stress damaging lipids, proteins and DNA molecules and how these free radicals propagate carcinogenesis are discussed. Alongside these mechanisms, the noxious health effects of these heavy metals are discussed.
Part of the book: Poisoning in the Modern World