Vanadium—Speciation Chemistry Can Be Important When Assessing Health Effects on Living Systems

Debbie C. Crans

Colorado State University

Kahoana Postal

Colorado State University Universidade Federal do Parana

Judith A. MacGregor

Toxicology Consulting Services

CONTENTS

  • 12.1 Introduction..........................................................................................................................183
  • 12.2 Speciation of Vanadium........................................................................................................184
  • 12.3 Mining and Industrial Applications of Vanadium................................................................186
  • 12.4 Environmental Presence of Vanadium.................................................................................187
  • 12.5 Therapeutic and Biomedical Developments with Vanadium Compounds...........................187
  • 12.6 Toxicity Studies Assessing Adverse Health Effects.............................................................188
  • 12.7 Regulation of Vanadium in the Foods and the Environment...............................................190
  • 12.8 Conclusion and Future..........................................................................................................191

Acknowledgments..........................................................................................................................191

References......................................................................................................................................191

Introduction

Vanadium has been reported to have many biological effects, some beneficial and others detrimental (Trevino et al. 2019, Crans et al. 2018). Vanadium is a first-row transition metal that is present on the earth’s surface as a trace metal. For the last couple of decades, vanadium compounds have continued to be developed for therapeutic applications, including applications for the treatment of several cancers and diabetes mellitus (Trevino et al. 2019, Crans et al. 2004, Evangelou 2002). Although the mode of action of many vanadium compounds is not well understood, the effects of many different vanadium salts and compounds have been reported (Evangelou 2002, Crans, LaRee et al. 2019).

While these beneficial applications of vanadium compounds are developed, regulatory bodies are interested in assessing their safety because of the concerns regarding the toxicity of vanadium compounds (Ghosh, Saha, and Saha 2015, Cooper 2007), such as V205 (Figure 12.1) which is used

Structure representation of vanadium pentoxide (V0 also referred to as V0) and a generic VO-porphyrin, where R represents possible organic substitutes

Figure 12.1 Structure representation of vanadium pentoxide (V205 also referred to as V4010) and a generic VO-porphyrin, where R represents possible organic substitutes.

primarily in the production of the iron alloy ferrovanadium and as an industrial catalyst. Here, we present a mini-review describing some of these biological effects, in the context of important chemistry concepts relevant to this first-row transition metal.

Since vanadium is a metal, it forms a range of different metal ions depending on conditions. The existence of these different species is a phenomenon referred to as speciation, conferring this element fundamental properties to be significantly different from that of a non-metal element such as carbon (Crans and Smee 2003). Vanadium is naturally occurring in several minerals and in coal and crude oil as a V=0-porphyrin derivative (Zhao et al. 2014, Dechaine and Gray 2010) (Figure 12.1). Considering these fundamental differences, it is therefore not surprising that drugs containing vanadium are very different from the typical organic drugs. Although biological responses of different vanadium compounds are commonly attributed to “vanadium,” this language is not properly reflecting the effects of the different vanadium compounds that have biological activities. Such imprecise language is problematic and is strongly discouraged particularly because it creates biases for the non-expert, which can be problematic regarding the development of beneficial uses of the vanadium compounds, as well as for the management and efforts to reduce undesirable environmental effects of different vanadium compounds. Because measurement of the vanadium species is rarely done, and elemental vanadium and total vanadium is typically analyzed instead, this creates difficulty in the assessment of health effects, which can vary with the specific vanadium compound.

In the following, we will briefly summarize concepts relating to understanding the beneficial and toxic effects of vanadium beginning with the speciation chemistry of this element. We will also describe the natural occurrence of vanadium, occupational studies, and industrial activities relating to vanadium as well as some safety assessments associated with vanadium compounds. We will also summarize some of the potential applications of vanadium compounds in medicine.

 
Source
< Prev   CONTENTS   Source   Next >