In vitro safety pharmacology evaluation of 2-hydroxybenzylamine acetate

J. Scott Daniels,Olivier Boutaud,John A. Oates,Naji N. Abumrad,Ryan D. Morrison,John C. Fuller,Lisa M. Pitchford,Charles R. Flynn,John A. Rathmacher

doi:10.1016/j.fct.2018.09.047

Abstract

2-hydroxybenzylamine (2-HOBA), a compound found in buckwheat, is a potent scavenger of reactive γ-ketoaldehydes, which are increased in diseases associated with inflammation and oxidative stress. While the potential of 2-HOBA is promising, studies were needed to characterize the safety of the compound before clinical trials. In a series of experiments, the risks of 2-HOBA-mediated mutagenicity and cardio-toxicity were assessed in vitro. The effects of 2-HOBA on the mRNA expression of select cytochrome P450 (CYP) enzymes were also assessed in cryopreserved human hepatocytes. Further, the distribution and metabolism of 2-HOBA in blood were determined. Our results indicate that 2-HOBA is not cytotoxic or mutagenic in vitro and does not induce the expression of CYP1A2, CYP2B6, or CYP3A4 in human hepatocytes. The results of the hERG testing showed a low risk of cardiac QT wave prolongation. Plasma protein binding and red blood cell distribution characteristics indicate low protein binding and no preferential distribution into erythrocytes. The major metabolites identified were salicylic acid and the glycoside conjugate of 2-HOBA. Together, these findings support development of 2-HOBA as a nutritional supplement and provide important information for the design of further preclinical safety studies in animals as well as for human clinical trials with 2-HOBA.

Highlights

While reactive oxygen species (ROS) play critical signaling roles in cells and tissues, excessive ROS production and/or inadequate antioxidant activity results in oxidative stress, which can lead to cell damage and inflammation
Many types of ROS drive lipid peroxidation, which results in the generation of reactive carbonyl species, such as γketoaldehydes. γKA are highly reactive lipid aldehydes that form via non-enzymatic rearrangement of intermediates created during either prostaglandin formation by cyclooxygenase (Iyer et al, 1989; Murthi et al, 1993) or free radical-catalyzed arachidonic acid oxidation (Brame et al, 1999; Morrow et al, 1990; Salomon and Miller, 1985). γKA rapidly react with lysine residues (Davies et al, 2002) and phosphatidylethanolamine (Bernoud-Hubac et al, 2009; Sullivan et al, 2010) to form adducts that have been linked to loss of protein function, mitochondrial and endoplasmic reticulum stress, and inflammation
Additional beneficial effects of 2-HOBA have been identified in animals, including increased lifespan in C. elegans (Nguyen et al, 2016), improved hypertension in mice (Wu et al, 2016), and protection from memory deficits in a mouse model of Alzheimer’s disease (Davies et al, 2011). These results provide promising data supporting a potential benefit of 2-HOBA supplementation in humans; additional data on the safety of 2-HOBA are necessary

Summary

Introduction

While reactive oxygen species (ROS) play critical signaling roles in cells and tissues, excessive ROS production and/or inadequate antioxidant activity results in oxidative stress, which can lead to cell damage and inflammation. 2-HOBA is a potent γKA scavenger (Davies et al, 2002; Zagol-Ikapitte et al, 2010a), scavenging γKAs 980-fold faster than the rate of formation of γKA protein adducts and protecting cells from the detrimental effects of γKA adducts. This nutritional compound has the potential to attenuate the damaging effects of oxidative stress in multiple tissues. Additional beneficial effects of 2-HOBA have been identified in animals, including increased lifespan in C. elegans (Nguyen et al, 2016), improved hypertension in mice (Wu et al, 2016), and protection from memory deficits in a mouse model of Alzheimer’s disease (Davies et al, 2011)

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