With the progression in the field of bioinorganic chemistry, the role of transition metal complexes as the most widely used therapeutics is becoming a more and more attractive research area. The ...complexes of transition metals possess a great variety of attractive pharmacological properties, including anticancer, anti-inflammatory, antioxidant, anti-infective, etc., activities. Transition metal complexes have proven to be potential alternatives to biologically active organic compounds, especially as antitumor agents. The performance of metal coordination compounds in living systems is anticipated to differ generally from the action of non-metal-containing drugs and may offer unique diagnostic and/or therapeutic opportunities. In this review, the rapid development and application of metallocenes and metal complexes of elements from Groups 4 to 7 in cancer diagnostics and therapy have been summarized. Most of the heavy metals discussed in the current review are newly discovered metals. That is why the use of their metal-based compounds has attracted a lot of attention concerning their organometallic and coordination chemistry. All of this imposes more systematic studies on their biological activity, biocompatibility, and toxicity and presupposes further investigations.
The field of medicinal (organic, bioinorganic, and coordination) chemistry as well as the interdisciplinary studies related to medicine is a rapidly developing area of study ....
Cancer is one of the major cases of death in the world. Current treatment of cancer is limited to surgery, radiotherapy, and the use of cytotoxic agents, despite their well known side effects and ...problems associated with the development of resistance. For most forms of disseminated cancer, however, no curative therapy is available, and the discovery and development of novel active chemotherapeutic agents is largely needed. Since the development of cisplatin, an inorganic platinum complex, numerous platinum and non-platinum metal complexes were synthesized and tested for anticancer activity. Very few match the clinical efficacy of cisplatin. Ruthenium complexes were prepared to ameliorate cisplatin activity, particularly on resistant tumours, or to reduce host toxicity at active doses. Since many years a lot of scientific groups have actively worked in the field of inorganic antitumor drugs and have developed a number of Ru(II) and Ru(III) complexes, which were shown to possess good antitumor and, above all, antimetastatic properties against animal models. Ruthenium complexes are presently an object of great attention in the field of medicinal chemistry, as antitumor agents with selective antimetastatic properties and low systemic toxicity. Ruthenium compounds appear to penetrate reasonably well the tumor cells and bind effectively to DNA. In this review, the achievements in the field of medicinal chemistry, DNA binding modes, and the development status of Ru(II) and Ru(III) complexes as anticancer agents are discussed. The aim of this review is therefore that of critically examining the past and the actual work on ruthenium compounds with emphasis on their proposed role in cancer therapy.
A series of complexes containing titanium and vanadium as a metal centers have shown to possess a wide spectrum of antitumor properties. These series belong to the non-platinum metal antitumor agents ...that appear to offer a different alternative for cancer chemotherapy which do not follow mechanism of action of the platinum complexes. The antitumor activity of both titanocene and vanadocene complexes has been established against various animal and xenografted human tumors. The exact mechanism of action for these compounds has not been determined, the target is unknown and even the exact chemical nature of the formulated solutions is still unknown. It has been proposed that these species interact with DNA, inhibiting the cell cycle. However, the antitumor mechanism of the titanocenes is most likely a complex pathway, probably involving a number of different biological molecules related to the transport and delivery of Ti species into cancer cells, and, after hydrolysis, subsequent interaction with nucleic acids and/or proteins and/or other potential coordinating constituents present in the intracellular environment. The tendency to hydrolyze seems to be one of the hypotheses for the tumor-inhibiting potency of the titanocene dihalides. Vanadium compounds exert preventive effects against chemical carcinogenesis on animals, by modifying, mainly, various xenobiotic enzymes, inhibiting, thus, carcinogen-derived active metabolites. The anticarcinogenic effects of vanadium, in combination to its low toxicity, established also, by its administration in humans, suggest vanadium as a candidate antineoplastic agent against human cancer. New complexes being more potent and less toxic favor this perspective. The use of these species as chemotherapeutic agents remains relatively unexplored and waits for future investigation. Research proceeded during the recent decades, enriched our knowledge on the chemical and biochemical properties, as well as the mechanisms of systemic, cellular and molecular antitumor effects of titanium and vanadium compounds.
Biogenic metals and their various inorganic, organometallic, and coordination compounds are comprehensively studied and extensively used in medical practice. Since the biogenic metals have various ...chemical properties corresponding to their position in the periodic table, their biological functions are different. Almost all of the discussed biogenic elements have an ability to form coordination complexes. Furthermore, the different accessible oxidation states occupied by most of these elements enables the body to catalyze oxy-reduction interactions, depending on the biological conditions. As they are biogenic in nature, their deficiency or their excess in the body leads to numerous pathological obstructions. The application of metal-based compounds as medications is connected with the oxy-reduction properties and the capability to form coordination complexes, which are involved in many bioreactions. The usefulness of these metals as therapeutic and diagnostic agents is also pointed out.
Cancer is one of the leading causes of human death among all major diseases. Metal-based complexes are considered as the most promising vital part in the existing arsenal of cytotoxic candidates used ...in cancer therapy and diagnostics. The efforts of many scientific groups resulted in the development of numerous metal-based compounds featuring different biologically active organic ligands in order to modulate their bioactivity. Along with the main representatives as potential therapeutic agents, such as the complexes Pt(II)/Pt(IV), Pd(II), Ru(II)/Ru(III), Ag(I), Au(I)/Au(III), Ti(IV), V(IV) and Ga(III), many other transition metal and lanthanide complexes possessing antiproliferative activity are widely discussed in the literature. However, such drugs remain outside the scope of this review. The main purpose of the current study is to review the potential activity of main group metal- and metalloid-based complexes against the most common cancer cell types, such as carcinomas (lung, liver, breast, kidney, gastric, colorectal, bladder, ovarian, cervical, prostate, etc.); sarcomas; blastomas; lymphomas; multiple myeloma; and melanoma. Overcoming the long disregard of organometallic compounds of metals and metalloids from the main groups, a growing number of emerging anticancer agents remarkably prove this field offers an extensive variety of new options for the design of innovative unexplored chemopharmaceutics. Moreover, some of the metal complexes and organometallic compounds from these elements can exhibit entirely different, specific modes of action and biological targets. Obviously, exploitation of their distinct properties deserves more attention.
Since the accidental discovery of the anticancer properties of cisplatin more than half a century ago, significant efforts by the broad scientific community have been and are currently being invested ...into the search for metal complexes with antitumor activity. Coordination compounds of transition metals such as platinum (Pt), ruthenium (Ru) and gold (Au) have proven their effectiveness as diagnostic and/or antiproliferative agents. In recent years, experimental work on the potential applications of elements including lanthanum (La) and the post-transition metal gallium (Ga) in the field of oncology has been gaining traction. The authors of the present review article aim to help the reader "catch up" with some of the latest developments in the vast subject of coordination compounds in oncology. Herewith is offered a review of the published scientific literature on anticancer coordination compounds of Pt, Ru, Au, Ga and La that has been released over the past three years with the hope readers find the following article informative and helpful.
The search for metal-derived antioxidants has received much attention and effort in order to identify the compounds having high capacity in scavenging free radicals related to various disorders and ...diseases associated with oxidative damage, caused by reactive oxygen species (ROS). Presently, synthetic antioxidants are widely used because they are effective and cheaper than natural antioxidants. Currently a number of Schiff-base metal complexes have been investigated as effective scavengers of ROS, acting as antioxidants. The aim of this review is to highlight specific characteristics of Schiff-based compounds capable of chelating metal ions and their antioxidant activity. Schiff bases form an important class of organic compounds with a wide variety of biological properties. Schiff bases have often been used as chelating ligands in the field of coordination chemistry, and their metal complexes have been of great interest to researchers for many years. The activity is usually increased by complexation therefore to understand the properties of both ligands and metal can lead to the synthesis of highly active compounds. The influence of certain metals on the biological activity of these compounds and their intrinsic chemical interest as multidentate ligands has prompted a considerable increase in the study of their coordination behavior. Development of a new chemotherapeutic Schiff bases and their metal complexes is now attracting the attention of medicinal chemists.
Metal ions are known to bind with nucleic acids and thereby alter their conformation and biological function. The metal ion-base interaction depends on the nature of both metal and bases; a certain ...site of coordination is preferred. One of the most notable successes for inorganic drugs has been the effectiveness of platinum complexes against cancer. These advances have spurred a surge of investigations to identify new inorganic agents for use in chemotherapy with improved specificity and decreased toxic side effects. Gold(I) and gold(III) complexes, the last isostructural and isoelectronic with platinum(II) complexes, are potentially attractive as anticancer agents. The design of an effective anticancer agent is a complicated game that must encompass not only the drug's inherent inhibitory properties but also its delivery, dosage, and residence time in vivo. Gold(I) and gold(III) complexes overcome some of these challenges by forming strong covalent attachments to targets. Au(III) isoelectronic with Pt(I1)-d8 system usually forms square planar complexes in solution. Since the square planar geometry of Pt(II) is important for its action as an anticancer drug, Au(III) compounds also can be used for the same purpose with the added advantage of decreased toxicity. This, together with the recent finding that certain transitional metal complexes like Au and Pt complexes have been found to be potentially useful in cancer chemotherapy, created a renewed interest in the study of the interactions of metal ions with respect to the site of binding and the structure and stability of the complexes. This work was motivated by the thought that information on the variety of Au(III) complexes and their effects can be obtained by studying the properties of Au complexes with various ligands. Various studies in the past have shown that Au complexes are very attractive in view of their application as anticancer agents.
