ANTI TUMOR DRUGS Presentation Transcript:
1.TUMOR INHIBITING DRUGS
2.INTRODUCTION OF CANCER AND TUMOR
3. INTRODUCTION OF ANTI TUMOR DRUGS
4. Plant-derived compounds have been an important source of several clinically useful anti-cancer agents. Anti cancer or Anti tumor agents are those agents which are used in the treatment of cancer or tumor.
5.Plants are an enormously rich source of peptides with the potential to be developed as anticancer agents, e.g. Violaceae, Rubiaceae, and Cucurbitaceae families and some marine plants.
Most peptides isolated from plants are cyclic peptides, so-called cyclopeptides.
Peptides, including those isolated from plants, have a potential antitumor effect.
6.How Cancer Drugs Work?
All cancer drugs on the whole show the same mechanism of action:
“They block the growth of living cells”.
But the way by which they achieve this goal differs on the basis of cellular functions on which each drug acts. The characteristics that lead to cell growth can be used against the cell, and this advantage is used in chemotherapy.
7.The Mechanism Of Action Of Peptides Act As Anti Tumor Agent
Peptides from plants exhibit marked inhibitory effects on the proliferation of various tumor cell lines,
Condensing and dissociation of
the cellular microtubules are important processes for cell proliferation. Interruption of such processes can stop division during cell mitosis, which results in either the prolongation of the cell cycle or cell apoptosis.
Mitotic inhibitors causes the crystallization of microtubules during mitosis causing mitotic arrest and apoptosis.
Enzymes that act by inhibiting protein synthesis thereby depriving tumor cell and inhibit cell replication.
9.BY CURBING BLOOD SUPPLY TO TUMOR CELLS
By reducing the blood flow to the tumor cells. Thus, acting as an antivascular targeting agent, which blocks tumour blood supply.
It is reported that these agents cause the shutdown of blood flow in many animal tumors leading to extensive tumour necrosis.
10.Apoptosis is an important process for eliminating cancer cells. Induction-apoptosis is a key mechanism by which anticancer compounds show their action.
6. ENZYME INHIBITORS
such as Topoisomerase inhibitors resulting DNA damages that interferes with cell replication and transcription.
11.HISTORY OF ANTITUMOR DRUGS
12.Natural origin is defined as natural products, derivatives of natural products or synthetic pharmaceuticals based on natural product models
The search for anti-cancer agents from plant sources started in earnest in the 1950s with the discovery and development of the vinca alkaloids, vinblastine and vincristine, and the isolation of the cytotoxic podophyllotoxins.
These plants are used against various types of tumors/cancers such as sarcoma, lymphoma, carcinoma and leukemia
The first agents to advance into clinical use were the isolation of the vinca alkaloids, vinblastine and vincristine from the Madagascar periwinkle, Catharanthus roseus (Apo-cynaceae)
Vinblastine and vincristine are primarily used in combination with other cancer chemotherapeutic drugs for the treatment of a variety of cancers, including leukemias, lymphomas, advanced testicular cancer, breast and lung cancers, and Kaposi’s sarcoma.
14.Podophyllotoxin (abbreviated as PPT), otherwise known as podofilox, is a non-alkaloid toxin lignan extracted from the roots and rhizomes of American Mayapple (Podophyllum peltatum). Another common source of podophyllotoxin is the rhizomes of Podophyllum hexandrum Royle (Berberidaceae).
Podophyllotoxin's anticancer property can be attributed to the inhibition of tubulin polymerization. As podophyllotoxin binds to the tubulin, microtubule formation is prevented. Consequently, podophyllotoxin arrests the cell cycle in the metaphase
Etoposide and teniposide are well known anti tumor agents are the semisynthetic products of Podophyllotoxin they are used for the treatment of small lung cell cancer, testicular cancer neuroblastoma and hepatoma.
A racemic mixture of harringtonine and homoha-rringtonine has been used successfully in China for the treatment of acute myelogenous leukemia and chronic myelogenous leukemia.
15.The discovery of paclitaxel from the bark of the Pacific Yew, Taxus brevifolia Nutt. (Taxaceae), is another evidence of the success in natural product drug discovery.
Taxus baccata was reported to use in the Indian Ayurvedic medicine for the treatment of cancer. Paclitaxel is significantly active against ovarian cancer, advanced breast cancer, small and non-small cell lung cancer.
The extract of Camptotheca acuminate (Nyssaceae) was the only one of 1000 of the plant extracts tested for anti-tumor activity which showed efficacy and camptothecin was isolated as an active constituent
Topotecan and irinotecan are semi-synthetic derivatives of camptothecin and are used for the treatment of ovarian and small cell lung cancers, and colorectal cancers, respectively.
Tabebuia (Bignoniaceae) have a history of use in the treatment of cancers started in the 1960s.