Ephedrine causes liver toxicity in SD rats via oxidative stress and inflammatory responses

Toxicity Potential of Nutraceuticals

During the past few decades and especially during and after the COVID-19 pandemic, the use of nutraceuticals has become increasingly popular in both humans and animals due to their easy access, cost-effectiveness, and tolerability with a wide margin of safety. While some nutraceuticals are safe, others have an inherent toxic potential. For a large number of nutraceuticals, no toxicity/safety data are available due to a lack of pharmacological/toxicological studies. The safety of some nutraceuticals can be compromised via contamination with toxic plants, metals, mycotoxins, pesticides, fertilizers, drugs of abuse, etc. Knowledge of pharmacokinetic/toxicokinetic studies and biomarkers of exposure, effect, and susceptibility appears to play a pivotal role in the safety and toxicity assessment of nutraceuticals. Interaction studies are essential to determine efficacy, safety, and toxicity when nutraceuticals and therapeutic drugs are used concomitantly or when polypharmacy is involved. This chapter describes various aspects of nutraceuticals, particularly their toxic potential, and the factors that influence their safety.

A toxicological review of alkaloids

Alkaloids are naturally occurring compounds with complex structures found in natural plants. To further improve the understanding of plant alkaloids, this review focuses on the classification, toxicity and mechanisms of action, providing insight into the occurrence of alkaloid-poisoning events and guiding the safe use of alkaloids in food, supplements and clinical applications. Based on their chemical structure, alkaloids can be divided into organic amines, diterpenoids, pyridines, isoquinolines, indoles, pyrrolidines, steroids, imidazoles and purines. The mechanisms of toxicity of alkaloids, including neurotoxicity, hepatoxicity, nephrotoxicity, cardiotoxicity and cytotoxicity, have also been reviewed. Some cases of alkaloid poisoning have been introduced when used as food or clinically, including accidental food poisoning, excessive consumption, and poisoning caused by the improper use of alkaloids in a clinical setting, and the importance of safety evaluation was illustrated. This review summarizes the toxicity and mechanism of action of alkaloids and provides evidence for the need for the safe use of alkaloids in food, supplements and clinical applications.

Developing a Screening Strategy to Identify Hepatotoxicity and Drug Interaction Potential of Botanicals

Botanical supplements, herbal remedies, and plant-derived products are used globally. However, botanical dietary supplements are rarely subjected to robust safety testing unless there are adverse reports in post-market surveillance. Botanicals are complex and difficult to assess using current frameworks designed for single constituent substances (e.g. small molecules or discrete chemicals), making safety assessments costly and time-consuming. The liver is a primary organ of concern for potential botanical-induced hepatotoxicity and botanical-drug interactions as it plays a crucial role in xenobiotic metabolism. The NIH-funded Drug Induced Liver Injury Network noted that the number of botanical-induced liver injuries in 2017 nearly tripled from those observed in 2004-2005. New approach methodologies (NAMs) can aid in the rapid and cost-effective assessment of botanical supplements for potential hepatotoxicity. The Hepatotoxicity Working Group within the Botanical Safety Consortium is working to develop a screening strategy that can help reliably identify potential hepatotoxic botanicals and inform mechanisms of toxicity. This manuscript outlines the Hepatotoxicity Working Group's strategy and describes the assays selected and the rationale for the selection of botanicals used in case studies. The selected NAMs evaluated as a part of this effort are intended to be incorporated into a larger battery of assays to evaluate multiple endpoints related to botanical safety. This work will contribute to a botanical safety toolkit, providing researchers with tools to better understand hepatotoxicity associated with botanicals, prioritize and plan future testing as needed, and gain a deeper insight into the botanicals being tested.

Natural Sympathomimetic Drugs: From Pharmacology to Toxicology

Sympathomimetic agents are a group of chemical compounds that are able to activate the sympathetic nervous system either directly via adrenergic receptors or indirectly by increasing endogenous catecholamine levels or mimicking their intracellular signaling pathways. Compounds from this group, both used therapeutically or abused, comprise endogenous catecholamines (such as adrenaline and noradrenaline), synthetic amines (e.g., isoproterenol and dobutamine), trace amines (e.g., tyramine, tryptamine, histamine and octopamine), illicit drugs (e.g., ephedrine, cathinone, and cocaine), or even caffeine and synephrine. In addition to the effects triggered by stimulation of the sympathetic system, the discovery of trace amine associated receptors (TAARs) in humans brought new insights about their sympathomimetic pharmacology and toxicology. Although synthetic sympathomimetic agents are mostly seen as toxic, natural sympathomimetic agents are considered more complacently in the terms of safety in the vision of the lay public. Here, we aim to discuss the pharmacological and mainly toxicological aspects related to sympathomimetic natural agents, in particular of trace amines, compounds derived from plants like ephedra and khat, and finally cocaine. The main purpose of this review is to give a scientific and updated view of those agents and serve as a reminder on the safety issues of natural sympathomimetic agents most used in the community.

Antioxidant and Antihyperglycemic Effects of Ephedra foeminea Aqueous Extract in Streptozotocin-Induced Diabetic Rats

Background: Ephedra foeminea is known in Jordan as Alanda and traditionally. It is used to treat respiratory symptoms such as asthma and skin rashes as an infusion in boiling water. The purpose of this study was to determine the antidiabetic property of Ephedra foeminea aqueous extract in streptozotocin-induced diabetic rats. Methods: The aqueous extract of Ephedra foeminea plant was used to determine the potential of its efficacy in the treatment of diabetes, and this extract was tested on diabetic rats as a model. The chemical composition of Ephedra foeminea aqueous extract was determined using liquid chromatography–mass spectrometry (LC-MS). Antioxidant activity was assessed using two classical assays (ABTS and DPPH). Results: The most abundant compounds in the Ephedra foeminea extract were limonene (6.3%), kaempferol (6.2%), stearic acid (5.9%), β-sitosterol (5.5%), thiamine (4.1%), riboflavin (3.1%), naringenin (2.8%), kaempferol-3-rhamnoside (2.3%), quercetin (2.2%), and ferulic acid (2.0%). The antioxidant activity of Ephedra foeminea aqueous extract was remarkable, as evidenced by radical scavenging capacities of 12.28 mg Trolox/g in ABTS and 72.8 mg GAE/g in DPPH. In comparison to control, induced diabetic rats treated with Ephedra foeminea extract showed significant improvement in blood glucose levels, lipid profile, liver, and kidney functions. Interleukin 1 and glutathione peroxidase levels in the spleen, pancreas, kidney, and liver of induced diabetic rats treated with Ephedra foeminea extract were significantly lower than in untreated diabetic rats. Conclusions: Ephedra foeminea aqueous extract appears to protect diabetic rats against oxidative stress and improve blood parameters. In addition, it has antioxidant properties that might be very beneficial medicinally.

Ephedrine alleviates middle cerebral artery occlusion-induced neurological deficits and hippocampal neuronal damage in rats by activating PI3K/AKT signaling pathway

Inflammation and oxidative stress are crucial in ischemic stroke. Ephedrine (EPH) has been proven to have anti-inflammatory and anti-oxidative stress effects. The present study analyzes whether EPH possessed neuroprotective effects and explored the underlying mechanisms of EPH based on an experimental model of middle cerebral artery occlusion (MCAO). We found that intraperitoneal injection with EPH attenuated the neurological deficit, cerebral infarction, and cerebral edema induced by MCAO in rats. Besides, EPH treatment alleviated MCAO-induced brain tissue damage and morphological abnormality, as well as neuronal loss. Moreover, EPH treatment upregulated GPx and CAT activity and downregulated MDA and NO content. EPH also evidently decreased the levels of IL-6 and TNF-α but increased IL-4 and IL-10 levels. Of note, EPH treatment promoted the phosphorylation of PI3K and AKT proteins in MCAO rats. Furthermore, administration of PI3K/AKT pathway inhibitor LY294002 abolished the beneficial effects of EPH. These results confirmed that EPH alleviated brain injury induced by MCAO via activating PI3K/AKT signaling pathway.

Ephedrine ameliorates cerebral ischemia injury via inhibiting NOD-like receptor pyrin domain 3 inflammasome activation through the Akt/GSK3β/NRF2 pathway

Ischemic stroke is a leading cause of death and long-term disability worldwide. The aim of this study is to explore the potential function of ephedrine in ischemic stroke and the underlying molecular mechanism. A middle cerebral artery occlusion (MCAO) rat model was established. The potential effects of ephedrine on MCAO rats and LPS-stimulated BV2 microglial cells were evaluated. Ephedrine reduced the infarct volume, cell apoptosis, brain water content, neurological score, and proinflammatory cytokines (TNF-α and IL-1β) production in MCAO rats. Ephedrine treatment also suppressed TNF-α and IL-1β production and NOD-like receptor pyrin domain 3 (NLRP3) inflammasome activation in BV2 microglial cells. The expression of NLRP3, caspase-1, and IL-1β was suppressed by ephedrine. Moreover, ephedrine treatment increased the phosphorylation of Akt and GSK3β and nuclear NRF2 levels in LPS-treated BV2 microglial cells. Meanwhile, LY294002 attenuated the inhibitory effects of ephedrine on NLRP3 inflammasome activation and TNF-α and IL-1β production. In addition, the level of pAkt was increased, while NLRP3, caspase-1, and IL-1β were decreased by ephedrine treatment in MCAO rats. In conclusion, ephedrine ameliorated cerebral ischemia injury via inhibiting NLRP3 inflammasome activation through the Akt/GSK3β/NRF2 pathway. Our results revealed a potential role of ephedrine in ischemic stroke treatment.