Herbal remedies to combat cancers in humans and animals – A Review

Cancer is considered as one of the leading cause of death worldwide, especially in the economically developed countries. Over 12.7 million cancer cases with the death tolls reaching up to 7.6 million were in 2008 throughout globe. The situation is no any different in a country like India where death toll per year reaches upto 5.8 lakhs out of the 8.5 lakhs diagnosed clinical cases. Conventional therapies based on surgery, radiation therapy, chemotherapy, hormone therapy, immunoadjuvant therapy, cryotherapy, apoptin therapy and nanoparticles (to facilitate better drug delivery) are widely used but are having side effects, resulting in fatal outcome. Under such circumstances, herbal therapy forms an integral part of the alternative approach as they are cheaper and are without having any toxic effect. More than 50% of all modern drugs in clinical use are herbal products, many of them having the ability to control cancer and importantly, over 60% of cancer patients use them. Plants are used against various types of tumors/cancers such as sarcoma, lymphoma, carcinoma and leukemia. Natural non-steroidal anti-inflammatory substances and their roles to prevent cancer need to be explored. Broadly, the anticancer mechanisms of herbs have been divided into two distinct categories viz. direct cytotoxicity and immunomodulation. Several herbs add to the versatility of cancer management by boosting up the immune system and thereby, preparing the body to defend against future or existing cancer and include Morinda citrifolia, Catharanthus roseus, Taxus brevifolia, Camptotheca acuminate, Podophyllum species, Tinospora cordofolia, Glycyrrhiza glabra etc. having promising anticancer properties. India is an abode of several botanical plants effective against tumours of brain and uterus; abdomen and glandular organs; throat and breast cancer. Thus, it is anticipated that plants can provide potential bioactive compounds for the development of new therapies to combat cancer. But their efficacy in humans and animals need to be evaluated. Thus, rigorous safety and quality evaluation, comparative clinical studies using modern techniques, proper standardization methods, and good manufacturing practices are extremely important. Isolation and purification of biologically active components from the bulk extracts need to be carried out side by side to understand the basic mechanisms of the drug action. All these form the topic of discussion of this review in order to find out solution to this grave disease of mankind and animals without causing much stress and side effects.