Scientific studies on Terminalia chebula
In animal studies, T. chebula has been shown to speed up gastric emptying and to have a significant prokinetic effect on intestinal motility.

Extracts of the fruit pericarp have demonstrated cardiotonic activity in isolated frog hearts.10 The extracts had a positive inotropic action, increasing the force of contraction and cardiac output, without increasing heart rate. These studies suggested that the calcium content of the extracts were not responsible for the cardiac effects, which appeared to result from a direct action on the heart muscle rather than being mediated by the b1-receptors of the heart.

T. chebula inhibited the development of experimental duodenal ulcers and appeared to exert a cytoprotective effect on the gastric mucosa in vivo.

An aqueous extract of T. chebula has been investigated as a potential anti-caries and anti-plaque agent.13 The growth of Streptococcus mutans, which is directly involved in the development of dental caries through the production of enamel degrading acids, was strongly inhibited by the extract.

Terminalia Bellirica
An up to 40 meter tall deciduous tree found throughout large parts of India at elevations up to 900 meters above sea level, except in arid regions. It also occurs in Nepal, Sri Lanka, South-east Asia and Malaysia. The glabrous leaves are broadly elliptic to obovate, 10-24cm x 5-8cm, clustered at the ends of the branchlets. The flowers are small, yellowish-green and occur in axillary spikes. The fruit is a drupe, almost globular, 2.5 x 2 cm, covered in soft hairs and obscurely 5-angled.6;9

The dried fruit contains about 20% tannins of both condensed and hydrolysable type. Other constituents identified in the fruit include lipids, b-sitosterol, saponins, gallic and ellagic acids and their derivatives, glycosides and various carbohydrates. It is unclear whether T. bellirica contains anthraquinones. An earlier report of the presence of a novel cardiac glycoside has not been confirmed by subsequent investigations.6

Terminalia Bellirica in Ayurveda
The fruit rind (pericarp) of T. bellirica constitutes the Ayurvedic drug vibhitaki. It is described as bitter, acrid, astringent, laxative, germicidal and antipyretic and is applied in a diverse range of conditions including cough, tuberculosis, eye diseases, dyspepsia, diarrhoea, dysentery, inflammation of the small intestine, biliousness, flatulence, liver disease and leprosy. It is also said to cleanse the blood and the voice and to promote hair growth.9;14

The ripe fruit is used as an astringent, whereas the half ripe fruit is used as a purgative.

T. bellirica fruit is also used in Egyptian folk medicine.12

Scientific studies on Terminalia Bellirica
Fruit extracts have anti-bacterial activity against Micrococcus pyogenes and Escherichia coli.6

Oral administration of a water soluble fraction of the fruit demonstrated significant hepatoprotective activity in vivo against experimental liver injury induced by carbon tetrachloride.15 The carbon tetrachloride-induced elevation of lipid peroxidation in the liver was significantly suppressed by the extract. Likewise, the accumulation of triglycerides in the liver following exposure to the liver toxin was inhibited, suggesting the plant extract may prevent the development of fatty liver.

An alcoholic extract of the fruit was found to have a marked stimulant effect on the secretion of bile in vivo. The total solid content of the bile was also increased. An aqueous extract had poor activity in the same test model.14

An open clinical study in 93 patients suffering from respiratory conditions found that vibhitaki (T. bellirica) had anti-asthmatic, anti-spasmodic, expectorant and anti-tussive effects.16

Phyllanthus Emblica
A deciduous tree with small, 15mm x 3mm, oblong, simple leaves, arranged on branchlets so as to resemble the presence of large, bipinnate leaves. The flowers are tiny, greenish-yellow, in the leaf axils. The fruit is about 3cm across, somewhat depressed globular in shape and shining yellowish green when ripe. The species occurs in tropical parts of India, Pakistan, Bangladesh, China, Sri Lanka and the Malayan Peninsula.9;17;18

P. Emblica contains a range of tannins and other phenolic compounds. These include hydrolysable tannins (10-12%) with a molecular weight of less than 1000, including Emblicanins A and B, punigluconin, pedunculagin,17;18 and an ellagitannin, putranjivain A.12 It also contains the flavonoid quercetin.19

Most literature makes reference to the high content of vitamin C in the fruits of Phyllanthus Emblica. This has been given as being in the range 3.25-4.5% (dry weight) for the dried fruit and 0.1-0.7% (wet weight) for the fresh.17;20 However, a study published in 1996 claims to have conclusively demonstrated that P. Emblica fruit does not contain L-ascorbic acid (vitamin C) in either free or conjugated form, using chromatographic and spectroscopic methods including high-performance liquid chromatography (HPLC), mass spectroscopy (MS) and nuclear magnetic resonance (NMR).17

Phyllanthus Emblica in Ayurveda
The ripe fruit of Phyllanthus Emblica is the third component of Triphala. Known as amalaki in sanskrit, amla in Hindi and emblic myrobalan or Indian gooseberry in English, it is an important rasayana drug in its own right, used for the treatment of diseases caused by morbid vata, pitta and kapha and regarded as being able to impart youthful vigour and strength. It is considered astringent, bitter, digestive, aphrodisiac, laxative, diuretic and tonic. It has been used in the treatment of vomiting, haemorrhage, fever, coughs, dyspnoea, eye inflammation, ulceration, anorexia, emaciation, scurvy, diabetes, jaundice, menorrhagia, leucorrhoea, and toxicosis. It is also said to relieve thirst, burning sensations, impurity of the blood and to promote abundant hair growth and has been used for the treatment of the common cold, scurvy, cancer and heart disease.9;20;21

P. Emblica fruit is a major constituent of many Ayurvedic tonics prescribed for rejuvenation, recuperation and vitality.22

Scientific studies on Phyllanthus Emblica
Antioxidant activity
An extract of fresh P. Emblica fruits was found to inhibit lipid peroxidation induced by gamma radiation in rat liver microsomes.20 The same extract also inhibited radiation-induced damage to the antioxidant enzyme superoxide dismutase in rat liver mitochondria. The observed effects were dose-dependent.

In another in vitro study, two low-molecular weight hydrolysable tannins, Emblicanin A and B, were shown to provide dose-dependant protection against rat peripheral blood erythrocyte haemolysis induced by oxygen radicals.17

An extract containing hydrolysable tannins (Emblicanin A 37%, Emblicanin B 33%, punigluconin 12% and pedunculagin 14%) has demonstrated antioxidant activity in an animal model.18 Administered intraperitoneally to rats for 7 days, the extract caused marked dose-dependent increases in the activities of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase in the rat brain. Lipid peroxidation of brain tissues was also significantly inhibited in a dose-dependent manner by the plant extract.

Anti-cancer activity
Numerous studies have suggested that P. Emblica fruit possesses anti-cancer activity.

A simple aqueous extract of P. Emblica fruit was shown to protect mice against the chromosome-damaging effects of the well known carcinogen 3,4-benzo(a)pyrene.23 This carcinogen causes genotoxicity at least in part because it is an electrophilic reactant, which causes the formation of oxygen-derived free radicals with DNA-damaging potential. The protective effect against this type of damage therefore most likely involves the antioxidant activities of the P. Emblica fruit extract.

An anti-cancer effect may also be mediated by the immune system. An anti-tumour effect of a P. Emblica aqueous fruit extract was demonstrated in tumour-bearing mice, resulting in a 35% increase in life span.22 The anti-tumour activity was shown to be meditated primarily through enhanced natural killer cell activity and antibody-dependent cellular cytotoxicity.

Another study showed an aqueous extract of P. Emblica to significantly reduce induced solid tumours in mice in a manner suggesting interaction with cell cycle regulation.24

Extracts of P. Emblica fruit inhibited the proliferation of four human tumour cell lines in vitro.25 Pyrogallol was identified as an active component of the extracts.

An aqueous extract of the dried fruits of P. Emblica protected mice against the effects of nickel chloride.26 Nickel is a major environmental pollutant with carcinogenic potential.

Lipid-lowering and anti-atherosclerotic effects
The lipid-lowering and anti-atherosclerotic effects of the fresh fruit juice of P. Emblica were studied in rabbit.27 Rabbits were hyperlipidaemic following an atherogenic diet. The fruit juice was administered to the rabbits at a dose of 5mL/kg body weight for a period of 60 days. Serum cholesterol, triglycerides, phospholipid and LDL levels were reduced by 82%, 66%, 77% and 90%, respectively. Also, tissue lipid levels were significantly reduced and aortic plaques regressed. Compared with untreated controls, rabbits treated with the fruit juice excreted higher levels of cholesterol and phospholipids, suggesting that the juice inhibited the absorption of these.

Hepatoprotective activity
An extract of P. Emblica fruit and the flavonoid constituent quercetin were shown to provide significant protection against liver toxicity caused by ethanol and paracetamol in vivo.19 Quercetin was more potent than the plant extract, suggesting that it may be the main hepatoprotective constituent in the fruit. The hepatoprotective mechanism may involve decreased glutathione depletion and prevention of cytochrome P450 stimulation by the hepatotoxic agents.

An aqueous extract of P. Emblica fruit protected mice against the hepatotoxic and nephrotoxic effects of lead and aluminium salts.21

Anti-HIV activity
The fruit of P. Emblica was shown to contain a number of compounds with potent inhibitory activity against human immunodeficiency virus (HIV) reverse transcriptase.12 Because reverse transcriptase plays a key role in the replication of retroviruses, this enzyme is an important potential target for the development of therapeutic agents for the treatment of HIV/AIDS. The most potent compound from P. Emblica in terms of inhibition of reverse transcriptase was an ellagitannin, putranjivain A (IC50=3.9mcM). Other isolated compounds with potent inhibitory activity included several phenolic compounds derived from gallic acid and two flavonoid glycosides.

Safety of Triphala
Crude alcoholic extracts of T. chebula, T. bellirica and P. Emblica were found to lack cellular toxicity in an assay using fresh sheep erythrocytes.28

The aqueous extract of T. bellirica fruit was found to be non-toxic when administered orally to mice, whereas the LD50 of the alcoholic extract was equivalent to 4.25g crude drug per kilo body weight.14

A water soluble fraction of T. bellirica showed no signs of toxicity in mice at oral doses up to 3.2g/kg bodyweight.15

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