Christopher E. Ekpenyong

Ethnopharmacology, phytochemistry, and biological activities of Cymbopogon citratus (DC.) Stapf extracts.

Cymbopogon citratus is a widely distributed perennial herb belonging to the Poaceae family and has been extensively consumed for its medicinal, cosmetic, and nutritional effects for centuries. A large number of reports have been published describing the pharmacological, biological, and therapeutic actions of this herb. In this review, we summarized the literatures on related studies (up to January, 2014) that highlighted the pharmacologic and biological effects of the major phytochemicals isolated from C. citratus extracts and its essential oil. The components of the essential oils found in C. citratus have a similar pharmacokinetic properties, including absorption, distribution, metabolism, and excretion. They are quickly absorbed following oral, pulmonary, and dermal administration. Based on the published reports, it can also be inferred that, after absorption from the small intestine, some phytochemicals in C. citratus can undergo oxidation, glucuronidation, sulfation, and/or O-methylation. Excretion is through urine, feces and/or expired volatiles. The biotransformation reactions of C. citratus bioactive constituents are essential for its relatively safe consumption and therapeutic applications. The data available so far warrant further studies evaluating C. citratus pharmacokinetics. Reliable pharmacokinetic data in humans would be critical for a better understanding of the the systemic handling of C. citratus.

Recent advances in occupational and environmental health hazards of workers exposed to gasoline compounds

The impact of health and environmental hazards, associated with the constituents of gasoline, on occupationally exposed workers has been recorded over the past few decades. However, the scientific literature on their pathogenic potential remains incomplete, which could affect the current understanding of the associated health risks. This review provides current information based on recently improved research techniques to evaluate gasoline toxicity profiles for humans. Our current knowledge provides insight into the intricate mechanism of gasoline-induced adverse effects, including the formation of reactive metabolites via bio-activation and subsequent generation of reactive oxygen species (ROS) and oxidative stress, which are involved in multiple mechanisms that are central to the aetiology of gasoline-induced toxicity. These mechanisms include covalent binding to deoxyribonucleic acid (DNA), leading to oxidative damage, tumor-suppression gene activity, and activation of pro-oncogenes. Furthermore, it results in induction of autoimmunity and local inflammatory responses, disruption of multiple neurotransmitters and immune cell function, derangement of various enzyme activities (e.g., sodiumpotassium adenosine triphosphate (Na+/K+/ATPase) activity, cytochrome P450 (CYP450), nitric oxide synthase (NOS), antioxidant enzyme activities, etc.), conjugation of bile, and non-specific cell membrane interaction, leading to damage of the membrane lipid bilayer and proteins. Available data suggests that exposure to gasoline or gasoline constituents have the potential to cause different types of illnesses. The data highlights the need to maintain safety measures via suitable research, medical surveillance, regulatory control, life style modification, early detection, and intervention to minimize exposure and manage suspected cases. They also present novel opportunities to design and develop effective therapeutic strategies against gasoline-induced detrimental effects. Int J Occup Med Environ Health 2017;30(1):1-26.

Use of Cymbopogon citratus essential oil in food preservation: Recent advances and future perspectives

ABSTRACT The economic burdens and health implications of food spoilage are increasing. Contamination of food sources by fungi, bacteria, yeast, nematodes, insects, and rodents remains a major public health concern. Research has focused on developing safer natural products and innovations to meet consumers acceptance as alternatives to synthetic food preservatives. Many recent novel preservative techniques and applications of both natural and synthetic origin continue to proliferate in food and chemical industries. In particular, some essential oils of plant origin are potent food preservatives and are thus attractive alternatives to synthetic preservatives. This paper provides an overview of recent advances and future prospects in assessing the efficacy of the use of Cymbopogon citratus (lemongrass) essential oil in food preservation. The possible mechanisms of action and toxicological profile as well as evidence for or against the use of this essential oil as an alternative to synthetic food preservatives in domestic and industrial applications are discussed.