Chemotherapy drug antitumor activity

Prevention of Cancer Chemotherapy Drug-Induced Adverse Reaction, Antitumor and Antimetastatic Activities by Natural Products... 

Cancer Chemotherapy Drug without Loss of Antitumor Activity. 

Most platinum compounds exist as coordination complexes the tetravalent compounds typically are more toxic than the hexavalent ones [10]. Certain neutral platinum complexes exhibit antitumor activity and therefore are used in chemotherapy drugs such as cisplatin. Speeiation is required to distinguish platinum chemotherapy drugs from their metabolites in patients blood and serum samples. 

The success of cisplatin and carboplatin in treating cancer, combined with the intrinsic and acquired resistance of many tumors to traditional platinum chemotherapy, has generated considerable interest in developing next-generation platinum drugs. Since the discovery of the antitumor activity of cisplatin, researchers have reported the synthesis, characterization, and antitumor activity of thousands of platinum compounds [1] [2]. The previous two chapters in this section describe the promising activity of novel multi-nuclear Ptn and orally active PtIV complexes [3] [4],... 

Reduction of cancer chemotherapy drug-induced side effects widiout loss of antitumor activity. 

Prevention by Natural Products and Foodstuffs of Side Effects Induced by Cancer Chemotherapy Drug without Loss of Antitumor Activity. 

Selection of agents for combination chemotherapy regimens involves consideration of drug-specific factors such as mechanism of action, antitumor activity, and toxicity profile. Drugs that possess minimally overlapping mechanisms of action and toxicities are combined, when possible. Myelosuppressive combinations are sometimes alternated with nonmyelosuppressive combinations to allow bone marrow re-... 

The next step from a cell line to animal experiments was done by Old and coworkers [13]. Antitumor activity was demonstrated in vivo in a dog model with spontaneous lymphosarcoma. In the same year Oettgen and collaborators were the first to show similar efficacy of 1-ASP in humans with leukemias [14]. Since then large numbers of clinical trials have been performed using the enzyme. It turned out that 1-ASP is not an anticancer drug in general but that it is effective against certain types of tumors. For these it has become an essential component of chemotherapy strategies. 

The glutamate transporter-mediated increase of antitumor activity caused by theanine is a novel mechanism, and it is hoped that this action will lead to the discovery of a useful cancer chemotherapy for drug-sensitive, drug-resistant, and metastatic tumors. It was expected that this study will greatly contribute to clinical cancer chemotherapy in the future. ... 

From the animal screens emerged the set of structure-activity relationships enumerated earlier (Section IV.E.l). Both cisplatin and carboplatin conform to these rules, and to date no compounds with demonstrably better antitumor activity have been tested in humans. The decision to move an experimental drug into the clinic is a difficult one, however, and it may be that molecules such as cis-[Pt(NH3)2(4-Br-py)Cl]Cl (see Section V.D.V.c) would be effective for tumors that are refractive to cisplatin chemotherapy. In any case, the foregoing chain of events, from studying the effects of a compound on cells in culture through animal screens and eventually to humans, constitutes the principal route for introducing a new anticancer drug. The process can take more than a decade. 

The bleomycins are fermentation products of Streptococcus verticillus. The drug currently employed clinically is a mixture of bleomycin Aj and B. The bleomycins differ only in their terminal amino acid, which can be altered by the amino acids added to the fermentation medium. Bleomycins have significant antitumor activity against squamous carcinoma of the cervix, and against lymphomas and testicular tumors. They are minimally myelo- and immunosuppressive but cause unusual cutaneous side effects and pulmonary fibrosis. Because their toxicities do not overlap with those of other drugs, and because of their unique mechanism of action, bleomycins maintain an important role in combination chemotherapy. 

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