The Mining Of Nigerian Medicinal Plants For Cancer Therapy

Abstract

Tumour is an abnormal growth of cells which form a mass called neoplasm. When the tumor is slow growing and confined to a certain organ it is called benign. Sometimes the tumour can progress into a malignant phenotype while in some situations the cancer cells break away from a tumour mass and spread to other tissues or organs such as the brain and bones through the blood or lymph system. The tumour cells can settle in new places and form new masses. When this happens, the process is called metastasis. This type of neoplasm is called cancer. However certain tumours such as astrocytomas (brain tumors) even when malignant hardly metastasize outside the brain. In contrast breast, prostate and other cancers can metastasize to the brain.

Cancer occurs when cells in a part of the body begin to grow out of control. Normal cells divide and grow in an orderly fashion, but cancer cells do not. They continue to grow and crowd out normal cells. Although there are many kinds of cancers, they all have, in common, this out-of-control growth of cells. Other hallmarks of cancers include; sustained angiogenesis (increased blood vessel supply), high invasive and migratory rates, ability to overcome programmed cell death (apoptosis), limitless proliferative potential, insensitivity to anti-growth signals and self-sufficiency in growth signals (Hanahan and Weinberg, 2000). Different kinds of cancers do not behave in the same manner. For example, lung and breast cancers are very different diseases. Cancers grow at different rates and respond to different treatments. As a result of the heterogeneity of cancers, treatment strategies should be tailored to be patient and cancer-specific.