186

12(1): Medicinal and poisonous plants 1

Cassia L.

Sp. pl. 1: 376 (1753); Gen. pl. ed. 5: 178 (1754).

LEGUMINOSAE

x = 12, 14; Cassia fistula: 2n = 24, 28, Cassia grandis: 2n = 28

Major species Cassia fistula L., Cassia grandis L.f.

Cassia comprises about 30 species and is pantropical. There is probably only one indigenous species in Malesia (Cassia javanica) and three other species have been introduced from mainland Asia or South America, originally for ornamental purposes: Cassia bakeriana Craib, Cassia fistula and Cassia grandis. The medicinal use of Cassia fistula dates from ancient times and has been the main factor in its spread.

The ripe pods and seeds of Cassia fistula, Cassia grandis and Cassia javanica are used as a laxative. Other plant parts (root-bark, leaves, flowers) of Cassia fistula also have purgative properties, but to a lesser extent. A decoction of the roots may be used to purify wounds and ulcers. The bark of the trunk is reported to be used in Java and India to treat skin problems, whereas in the Philippines the leaves are applied on fungal skin infections. In India, the roots are used to treat fever. Fresh juice of the leaves of Cassia grandis is used externally in the treatment of ringworm. Leaf decoctions are also used as laxative and to treat lumbago. In Panama, Cassia fistula is used in folk medicine for the treatment of diabetes.
In modern medicine, the pulp of Cassia fistula is sometimes used as a mild laxative in pediatrics. However, laxative drugs of this type should be used with caution, because daily and prolonged use may lead to dependence and 'cathartic colon'. Apart from its medicinal properties, Cassia has many other uses. Cassia bakeriana, Cassia fistula, Cassia grandis and Cassia javanica are all planted as ornamentals. The latter three species and especially Cassia javanica provide hard multipurpose timber. In Thailand, the heartwood of Cassia fistula is used as a masticatory. The bark of Cassia fistula and Cassia javanica is also used for tanning, but the latter species is less valued. The seeds of Cassia fistula, Cassia grandis and Cassia javanica are a potential commercial source of gums. Seed gum is a potential binder for the pharmaceutical industry.

Although Cassia fistula pods have been traded to Europe for centuries, no recent trade information is available.

The fruit pulp of Cassia fistula is rich in pectins and mucilages. Furthermore, the laxative properties of fruit pulp and leaves are mainly due to the content of anthraquinone derivatives (about 2%), e.g. rhein (an anthraquinone), the sennidins (dianthrones) and the sennosides (the corresponding dianthrone-glycosides). In a study in Mexico, sennoside contents were found up to 1.5% in the leaves, and up to 1.9% in the fruits. Anthraquinone drugs are used as laxatives. The sugar moiety in the glycosides increases water solubility of the molecule, and thus facilitates transport to the site of action: the colon. In the colon, bacteria hydrolyse the glycosides and dianthrones to anthraquinones, a reaction which is immediately followed by the local reduction of the anthraquinones to their corresponding anthrones. The latter compounds act directly on the large intestine, to stimulate peristalsis. Anthraquinones are also found in Cassia javanica (anthraquinone glycosides) and Cassia grandis (aloe-emodin).
In an Indian study, fatty acids in Cassia fistula were found to consist mainly of linoleic acid (52.5%), oleic acid (18.1%) and palmitic acid (16%). Other fatty acids were: vernolic acid (6.1%), stearic acid (3.4%), sterculic acid (2%) malvalic acid (1.5%) and myristic acid (0.4%).
Compounds isolated from Cassia grandis include centaureidine, catechin, myristicin, 2,4-dihydroxybenzaldehyde, 3,4,5-trimethoxybenzaldehyde, 2,4,6-trimethoxybenzaldehyde, 'BETA'-sitosterol, kokusaginine (6,7-dimethoxyfuroquinoline) and fabioline (1,1'-bipiperidine).
In vitro and in vivo tests showed that seed powder of ripe Cassia fistula fruits has amoebicidal and cysticidal properties against Entamoeba histolytica and that it could cure intestinal and hepatic amoebiasis of laboratory animals and intestinal amoebiasis of humans. Cassia fistula also exhibits further anti-amoebic, insecticide and anthelmintic activities.
The hypocholesterolaemic effect of Cassia fistula has been investigated using hypercholesterolaemic male albino rats. Hypercholesterolaemia was induced by feeding on a mixture of cholesterol plus cholic acid for a 12-week period. Hypercholesterolaemia was characterized by significant increase in the average levels of total lipids, total cholesterol and triglycerides, and significant decrease in phospholipid content. Administration of Cassia fistula significantly reduced blood and liver total lipids. Brain, spleen, kidneys and heart followed nearly the same trend but with moderate effect. Blood, liver, kidneys, spleen and heart total cholesterol were significantly reduced, while that of the brain was not affected. The level of triglycerides was markedly improved. There was a moderate rise, however, in phospholipid content in all organs studied; that is, there was marked progress in the correction of lipid metabolism. Administration of Cassia fistula also induced a significant decrease in the high activities of serum GOT, GPT, alkaline and acid phosphatase; the values nearly returned to the initial values. Total serum protein, albumin (A), globulin (G), A/G, free amino acids, uric acid and creatinine were also determined. Their values were improved and nearly attained the normal values of the control group.
The aqueous fraction of Cassia fistula produced a significant decrease in glycaemia in mice (p < 0.001) at 4 and 24 hours with doses of 300 and 500 mg/kg, and at 1 and 4 hours after the dose of 1000 mg/kg (p < 0.001). In the glucose tolerance test, the aqueous fraction of Cassia fistula produced a significant decrease (p < 0.05) in glucose tolerance at a dose of 500 mg/kg, but a significant increase (p < 0.001) at a dose of 1000 mg/kg.
The ethanol extract of the leaves and bark of Cassia grandis showed in vitro antifungal activity against Epidermophyton floccosum, Microsporum gypseum and Trichophyton rubrum in pure culture at a minimal inhibitory concentration of 50 µg/ml.

Anthraquinone glycosides and sennosides are also found in Senna species, which are also used for their laxative and purgative properties.

Large shrubs or small to medium-sized trees up to 30(-40) m tall; bole up to 60 cm in diameter. Leaves arranged spirally, often distichous, paripinnate, without extrafloral nectaries; stipules present. Inflorescence terminal on main shoots or short side shoots or axillary, racemose. Flowers having pedicels with 2 bracteoles at or just above the base; hypanthium present but variable; calyx 5-merous, sepals reflexed at anthesis; corolla 5-merous, zygomorphic; androecium zygomorphic, 10-merous, filaments of 3 abaxial stamens sigmoidally curved, generally longer than their anthers, the other 7 filaments straight and short; ovary superior, style variable. Fruit an elongated pod, cylindrical or compressed, indehiscent, many-seeded. Seeds 1- or 2-seriate, funicle filiform. Seedling with epigeal germination; cotyledons emergent, semi-fleshy.

Cassia fistula is a slow growing, deciduous tree. Generally, it takes 8-10 years from sowing to flowering. This can be reduced by vegetative propagation. In Singapore, Cassia fistula sheds its leaves at 9-10 months' intervals and the inflorescences develop with the new leaves. At the beginning of flowering, the whole crown is covered with flowers; sporadic flowering continues up to 3 months. Experiments have shown that pollen is still viable after 4 weeks of storage.
Seedling development in Cassia grandis is initially rapid, but slows down after 2 months. It is reported evergreen in Java and deciduous in northern Malaysia and Indo-China, where the leaves fall at the beginning of the dry season. The tree flowers before new leaves appear. In Costa Rica, fruit takes 10-12 months to mature.
The roots of Cassia fistula and Cassia javanica lack nodulating ability, but for Cassia grandis this is not clear. The concentration of sennoside in the leaves of Cassia fistula was highest soon after the onset of the rainy season, when new leaves had appeared and flowering started. The sennoside content of the pods was highest at the midstage of fruit maturation, when the pods were pale brown.

Until the beginning of the 1980s Cassia was considered to be a very large genus of over 500 species, but then it was split into 3 genera: Cassia sensu stricto, Senna and Chamaecrista. Cassia now has only about 30 species, whereas Senna and Chamaecrista comprise about equal numbers of species (about 260 and 270 respectively). Cassia fistula is able to hybridize with Cassia javanica.

Cassia is found in forests at low altitudes. Cassia fistula occurs in Java in light forest below 400 m altitude, in the Philippines in open grasslands at low and medium altitudes. It seems to favour calcareous and red, volcanic soils, but in Thailand it is also found on sandy and loamy soils. Cassia javanica occurs in moist evergreen forest, deciduous monsoon forest and in more open or even savanna-like habitats. The various subspecies of Cassia javanica show preferences for either dry or moist habitats on a wide variety of soils.

Cassia fistula, Cassia grandis and Cassia javanica can be propagated by seed and vegetatively through cuttings and layering. They have a hard seed-coat and germination is improved considerably by mechanical scarification or treatment with concentrated sulphuric acid for at least 45 minutes. Seed can be stored for prolonged periods without loss of viability. Cassia fistula seed should be sown in full light, and adequate water supply is required for optimal germination. The seed can increase three times in weight by absorbing water. Direct sowing is practised in Asia, but preliminary weeding is important. In Costa Rica, Cassia grandis is propagated by means of large cuttings ('apicormic shoots'). Vertical shoots of 15 cm in diameter are cut, trimmed to a length of 2.5 m. These are laid out in the shade for a week and then stacked vertically for three weeks. Then they are planted, with the lower ends buried 50 cm deep. Cassia javanica is usually propagated by seed, with 50% of the seed producing healthy plants.

Colletotrichum gloeosporioides causes brown pinhead spot disease in Cassia fistula in Malaysia. In the Philippines, Cassia fistula is attacked by the psyllid Heteropsylla cubana. Symptoms include leaf curling, defoliation, stunted shoot growth and death.

Pods of Cassia are harvested when mature, and in general simply collected from the ground.

For domestic use of Cassia fistula, the pulp is scraped from the fresh pods. Pods intended for trade are dried. Prolonged boiling of the pulp leads to loss of the purgative properties.

In view of their wide distribution Cassia fistula, Cassia grandis and Cassia javanica are not endangered or liable to genetic erosion.

Cassia fistula, Cassia grandis and Cassia javanica may be interesting multipurpose trees for South-East Asian farmers, and have a high ornamental value. With regard to the frequent use of Cassia as laxative, caution seems to be justified. The hypocholesterolaemic, antifungal and anti-amoebic properties warrant further research.

Asseleih, L.M.C., Hernandez, O.H. & Sanchez, J.R., 1990. Seasonal variations in the content of sennosides in leaves and pods of two Cassia fistula populations. Phytochemistry 29: 3095-3099.
Bruneton, J., 1995. Pharmacognosy, phytochemistry, medicinal plants. Lavoisier Publishing, Paris, France. pp. 349-366.
Caceres, A., Lopez, B., Juarez, X., del Aguila, J. & Garcia, S., 1993. Plants used in Guatemala for the treatment of dermatophytic infections. 2. Evaluation of antifungal activity of seven American plants. Journal of Ethnopharmacology 40(3): 207-213.
El-Saadany, S.S., el-Massry, R.A., Labib, S.M. & Sitohy, M.Z.A.D., 1991. The biochemical role and hypocholesterolaemic potential of the legume Cassia fistula in hypercholesterolaemic rats. Nahrung 35(8): 807-815.
Esposito-Avella, M., Diaz, A., de Gracia, I., de Tello, R. & Gupta, M.P., 1991. Evaluacion de la medicina tradicional: efectos de Cajanus cajan L. (Guandu) y de Cassia fistula L. (canafistula) en el metabolismo de los carbohidratos en el raton [Evaluation of traditional medicine: effects of Cajanus cajan L. and of Cassia fistula L. on carbohydrate metabolism in mice]. Revista Medica de Panama 16(1): 39-45.
Gonzalez, A.G., Bermejo, J. & Valencia, E., 1996. A new C6-C3 compound from Cassia grandis. Planta Medica 62(2): 176-177.
Irwin, H.S. & Barneby, R.C., 1982. The American Cassiinae. A synoptical revision of Leguminosea tribe Cassieae subtribe Cassiinae in the New World. Memoirs of the New York Botanical Garden 35(2): 64-635.
Larsen, K. & Ding Hou, 1996. Cassia. In: Kalkman, C., Kurkop, D.W., Nooteboom, H.P., Stevens, P.F. & de Wilde, W.J.J.O. (Editors): Flora Malesiana. Series 1, Vol. 12(2). Rijksherbarium/Hortus Botanicus, Leiden University, the Netherlands. pp. 556-565.
Monif, T., Malhotra, A.K. & Kapoor, V.P., 1992. Cassia fistula seed galactomannan: potential binding agent for pharmaceutical formulation. Indian Journal of Pharmaceutical Sciences 54(6): 234-240.
Shukla, S.C. & Das, S.R., 1988. Cure of amoebiasis by seed powder of Cassia fistula. International Journal of Crude Drug Research 26(3): 141-144.

Anny Victor Toruan-Purba

Cassia fistula
Cassia grandis

Toruan-Purba, A.V., 1999. Cassia L.. In: de Padua, L.S., Bunyapraphatsara, N. and Lemmens, R.H.M.J. (Editors): Plant Resources of South-East Asia No 12(1): Medicinal and poisonous plants 1. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea

The following species in this genus are important in this commodity group and are treated separatedly in this database:
Cassia fistula
Cassia grandis