Phytopharmacological overview of Terminalia chebula Retz

Phytotherapy is the traditional method used to cure many diseases. Various medicinal plants found in many parts of India are well known for their various medicinal values. The Terminalia chebula Retz. a native plant of Asia is found to have various properties like anti-oxidant and free radical scavenging activity, anti-carcinogenic activity, ant-imutagenic activity, anti-bacterial activity, anti-fungal activity, anti-viral activity, anti-diabetic, renoprotective activity, cardio-protective activity, anti-inflammatory and anti-arthritic activity. These properties of T. chebula discussed in this review are mainly due to the presence of various types of phytoconstituents.


INTRODUCTION
The Siddha and Ayurveda treatments use plants to cure various diseas es; 1 they are the traditional method adopted in India before 5000 years.The use of plants in various treatments has drawn attention in recent years due to their accuracy in treatment and their reduced or absence of side effects.Treatments involving the use of chemically synthesized compounds have more severe side effects to patients other than cur ing the disease effectively.Terminalia chebula Retz. is one of the many traditional medicinal trees used to treat many diseased conditions.T. chebula under the family Combretaceae, a native plant in India and Southeast Asia, is widely cultivated in Taiwan.Its dried ripe fruit, also called as medicinal Terminalia fruit, has traditionally been used as a way to treat various ailments in Asia. 2 T. chebula possesses a large num ber of different types of phytoconstituents which exhibits a number of medicinal activities.The fruit of the tree provides diverse health benefits and is a traditional medicine for household remedy against various human ailments over decades. 3T. chebula has been widely used in Ayurveda, Unani and Homoeopathic medicine and has become an important part of modern medicine.The presence of the various phyto chemicals like polyphenols, terpenes, anthocyanins, flavonoids, alka loids and glycosides makes them a potent antioxidant, antifungal, anti bacterial, antiviral agents.

BOTANICAL DESCRIPTION
T. chebula is a native plant of Asia, found predominantly in Srilanka, Bangladesh, Egypt, Turkey, Tibet, Pakistan and various parts of India.This is a deciduous tree that grows up to 30 m in height with a crown shaped like a broad disk. 4This tree grows at the height of 15002000 m.They have subopposite or alternate leaves elliptic blades of 718×4.410cm.They have veins which are lateral and they occur as 612 pairs.T. chebula have monoecious flowers with unpleasant smell and are pale yellow in color.The unripen fruit is green in color and the ripe fruit is yellowish grey in color with the size of 12 inches.May to June is the time the flowers appear and July to December the fruits appear.

ANTI-OXIDANT AND FREE RADICAL SCAVENGING ACTIVITY
Compounds that can scavenge excessive free radicals in the body can hinder the process of carcinogenesis.The leaves, bark and fruit of T. chebula possessed high antioxidant activity due to the presence of phenolics which is responsible for this activity. 5Aqueous form of the extract of T. chebula inhibited xanthine/xanthine oxidase activity and was also a scavenger of DPPH radicals. 5The polyherbal formulation of T. chebula (Aller7/ NRA2) is found to inhibit the hemolysis and makes the lipopolysaccharide to release nitric oxide in an inhibited form. 6cetone extract has stronger antioxidant activity than alphatocopherol and HPLC analysis with diode array detection indicated the presence of phenolic compounds such as hydroxybenzoic acid derivatives, hydroxyl cinnamic acid derivatives, flavonol aglycones and their glycosides. 7

ANTI-CARCINOGENIC ACTIVITY
A group of researchers have reported the phenolics of T. chebula fruit have inhibitory action on cancer cell growth and found that tannic acid, ellagic acid and chebulinic were the growth inhibitory phenolics of T. chebula. 8Ethanol extract of T. chebula fruit inhibited cell proliferation and induce the death of the cell in a dose dependent manner in many malignant cell lines including breast cancer cell line of mouse (S115) and human (MCF7), human osteosarcoma cell line (HOS1), a nontu morigenic immortalized human prostate cell line (PNT1A) and human prostate cancer cell (PC3). 9Besides, acetone extract of bark and fruit powder of T. chebula have constituents with promising anticarcinogenic activity. 9

ANTI-MUTAGENIC ACTIVITY
Antimutagenic activity of aqueous extract and hydrolyzable tannins from T. chebula in Salmonella typhimurium has been well documented. 10he aqueous extract of T. chebula inhibits gamma radiation induced strand breaks formation in plasmid PBR322 DNA. 11The administration of aqueous extract of T. chebula prior to whole body irradiation of mice resulted in a reduction of peroxidation of membrane lipids in the mice liver and a decrease in radiation induced errors to DNA.It also protected the human lymphocytes from the harmful gamma radiationinduced damage to DNA exposed in vitro. 12T. chebula showed chemo preventive effects on toxicity, nickel chloride induced renal oxidative stress, and cell proliferation response in male Wistar rat.

ANTI-BACTERIAL ACTIVITY
T. chebula showed antibacterial activity against both Grampositive and Gramnegative human pathogenic bacteria. 13,14Ethanedioic acid and ellagic acid isolated from T. Chebula fruit extract had strong antibacterial activity against intestinal bacteria, Clostridium perfingens and Escherichia coli. 15It is effective against Helicobactor pyroli by inhibiting the urease activity, and ubiquitous bacterium which cause stomach cancer, ulcers and gastritis. 14The methicillinresistant Staphylococcus aureus when treated with the extract of T. chebula showed decreased growth and activity thereby confirming the antibacterial activity.The ripe seeds of T. chebula also have strong antibacterial activity against S. aureus.The aqueous extract of T. chebula strongly inhibited the growth of Streptococcus mutants, salivary bacteria. 16

ANTI-FUNGAL ACTIVITY
An aqueous extract of T. chebula showed antifungal activity against a number of dermatophytes and yeasts.It's activity is effective against the pathogenic yeast Candida albicans and dermatophytes Epidermophyton floccosum, Microsporumgy pseum and Trichophyton rubrum. 17Methanol extract of T. chebula have anticandidal activity which acts against clotrimazole resistant Candida albicans.Antifungal activity against Trichophyton glabrata exhibited by seed extracts. 18

ANTI-VIRAL ACTIVITY
T. chebula fruits used for four immunodeficiency virus HIV1 (type 1) integrase inhibitors, GA (I) and three galloyl glucoses (IIIV).Their galloyl moiety plays an important role for inhibition of 3'processing of HIV1 integrase of the compounds. 19T. chebula also exhibit retroviral reverse transcriptase inhibitory activity. 20It protects epithelial cells against influenza a virus; supporting its use for aiding in treatment of acute respiratory infections. 21It also showed the therapeutic activity against herpes simplex virus both in vitro and in vivo tests. 22These find ings encouraged a team of Japanese researchers to investigate T. chebula effect on human cytomegalovirus (CMV).The replication of human cytomagalo virus in AIDS is found to be inhibited by the extract of T. chebula and also in preventing CMV disease.

ANTI-DIABETIC AND RENOPROTECTIVE ACTIVITY
In streptozotocin induced diabetic rats T. chebula fruit and seeds showed dose dependent reduction in blood glucose both in short term and long term study and also had renoprotective activity.The high blood sugar level is reduced to normal by using the extract of T. chebula. 23,24

CARDIOPROTECTIVE ACTIVITY
Pretreatment with the extract of T. chebula was found to ameliorate the consequence of isoproterenol on the formation of lipid peroxide and also retained the activities of the diagnostic marker enzymes in iso proterenol induced myocardial damage in rats. 25Its pericap has been reported to have cardioprotective activity which is showed in isolated frog heart model.

ANTI-INFLAMMATORY AND ANTI-ARTHRITIC ACTIVITY
Aqueous extract of dried fruit of T. chebula demonstrated inhibition of inducible nitric oxide synthesis which shows antiinflammatory activity. 26hebulagic acid obtained from immature seeds of T. chebula significantly suppressed the onset and progression of collagen induced arthritis in mice. 27Polyherbal formulation (Aller7) containing T. chebula exhibited a dose dependent antiinflammatory activity against Freund's adjuvant induced arthritis in rats. 28

CONCLUSION
Among all the rapidly healing chemical medicines available, a large number of populations in the whole world are still using plants to cure disease.The T. chebula with its numerous pharmacological activities found its rightful place in traditional medicine.More biochemical tests are yet to be conducted to find more uses and potential value of T. chebula.This can lead to a rapid emergence of the use of plant extracts to cure many diseases without causing any harm to the patient thereby leading to a healthy environment.