Physalis (PROSEA)
 |
Introduction |
Physalis L.
- Protologue: Sp. pl. 1: 182 (1753); Gen. pl. ed. 5: 85 (1754).
- Family: Solanaceae
- Chromosome number: x= 12; P. angulata: 2n= (24), 48, P. minima: 2n= 48
Major species
- Physalis angulata L.,
- P. minima L.
Vernacular names
- Husk tomato, ground cherry (En).
- Coqueret (Fr).
Origin and geographic distribution
Physalis consists of about 100 species, mainly distributed in tropical and temperate America, but some of the species have a worldwide distribution. P. angulata and P. minima are widely spread as weeds in the Old World, probably as post-Columbian introductions.
Uses
In Malesia, P. angulata and P. minima have the same use. In Peninsular Malaysia and Java, the leaves are used for a poultice to treat headache, and an infusion is taken for intestinal pains and as an antihypertensive. The leaves are smeared with oil, gently heated, and applied to ulcers, or together with limestone powder to wounds and skin diseases. A decoction of the plant together with the leaves of Plantago major L. is taken to cure gonorrhoea, and as a diuretic. In Indonesia, the fruits are considered diuretic, alterative, purgative and aperient, and are used for curing epileptic attacks, dysuria, jaundice, bleeding gums, dropsy, urinary diseases, and gout. In Java and Thailand, the root is eaten as a vermifuge and an extract of the root is taken for fevers. In Sulawesi, an infusion of the herb is used to cure hepatitis, influenza, bronchitis, throat infections and orchitis. In the Philippines, a decoction of the roots is used to treat diabetes and hypoglycaemia. In the Solomon Islands, the seeds are reportedly a remedy for sterility. In Thailand, the dried whole plant of P. minima in decoction is taken as an antipyretic, diuretic and antidiarrhoeal, while the fresh whole plant is crushed with a little water and slowly swallowed for abscesses in the mouth or topically applied to swellings.
P. angulata is used to treat malaria in Peru, toothache in Puerto Rico, liver ailments and rheumatism in Brazil, and is considered a diuretic and relaxant. In Curaçao and Jamaica, the infusion of the plant used to be taken for gonorrhoea, and in Trinidad for indigestion, nephritis and fever.
The leaves and fruit of P. angulata are consumed raw in several countries, but are bitter. Eating too many of the fruits causes dizziness. In larger quantities the plant is poisonous to cattle and sheep, and it makes the meat smell like musk.
Several Physalis species are cultivated for their edible fruits, in particular P. peruviana L. (Cape gooseberry), P. philadelphica Lamk and P. ixocarpa Brot. ex Hornem. (Mexican husk tomato or tomatillo). P. minima is cultivated in India and South Africa for its edible fruits. P. alkekengi L. (Chinese lantern) is cultivated as an ornamental, for its bright orange husks, and is the only Physalis from the Old world.
Production and international trade
Chinese herbalists in Peninsular Malaysia stock Physalis plants green, and the fruits in their husks are widely sold in local markets.
Properties
Phytochemically, P. angulata and P. minima are well distinguished by the presence of several steroidal lactones, in general belonging to the physaline- and withanolide type. P. angulata contains the physalins A-I, as well as the withanolides physagulin A-G, withangulatin A and withanolide T, and several vitasteroids (sometimes also mentioned as withasteroids) e.g. vamonolide. P. minima contains the physalins physalin D, withaphysalin D and E, and dihydroxyphysalin B, and the withanolide withaminimin.
The pyrrolidine alkaloid phygrine (bis-hygrine) was isolated from the roots and aerial parts of both species, as well as from several other Physalis.
The isolated physalins B and F were found to inhibit the growth of several human leukaemia cells in vitro: K562 (erythroleukaemia), APM1840 (acute T lymphoid leukaemia), HL-60 (acute promyelocytic leukaemia), KG-1 (acute myeloid leukaemia), CTV1 (acute monocytic leukaemia) and B cell (acute B lymphoid leukaemia). In general, physalin F was found to be the most active one. Physalin F also showed cytotoxicity in vitro on 5 other human cancer cell lines, HA22T (hepatoma), HeLa (cervix uteri), KB (nasopharynx), Colo-205 (colon) and Calu-1 (lung), and 3 animal cancer cell lines, H1477 (melanoma), Hep-2 (laryngeal) and 8401 (glioma). The anti-hepatoma and anti-HeLa actions were found to be the strongest. In addition, physalin F had an antitumour effect in mice in vivo, against P388 lymphocytic leukaemia, whereas physalin D was inactive, both in vitro and in vivo.
Isolated withangulatin A, was found to be a topoisomerase II inhibitor in vitro, and a cytotoxic, capable of suppressing general protein synthesis and of inducing the synthesis of a small set of proteins, including those generated by heat-shock treatment, in vivo, in 9L rat brain tumour cells.
Vitanolides, isolated from the aerial parts of P. angulata, showed anti-inflammatory activity in rat and mice induced inflammation models, although they were less potent than hydrocortisone as reference. Furthermore, the crude leaf extract of P. minima contains hyperoside (quercetin-3-O-galactoside), which shows a marked anti-inflammatory activity in the rat paw oedema test.
Other biological effects of Physalis extracts include a marked activity against human African sleeping sickness, caused by Trypanosoma brucei rhodesiense by petroleum ether-, dichloromethane-, methanol- and water extracts from the aerial parts of P. angulata, as well as for cytotoxicity for the human fibroblast cell-line WI-38. The tincture of aerial parts macerated in 50% alcohol also showed a marked in vitro inhibitory effect against Neisseria gonorrhoeae strains isolated from symptomatic patients. The ethanol extract of entire plants showed immunomodulating effects via blastogenesis stimulation in cell cultures. However, immunosuppressive activity was observed when administered intraperitoneally to mice.
Finally, the bright orange colour of several Physalis fruits is due to the presence of characteristic xanthophylls, e.g. zeaxanthin and cryptoxanthin.
Adulterations and substitutes
Some Solanum species are used in a similar way as Physalis to cure digestive and intestinal problems, including stomach-ache and diarrhoea, and for various skin problems such as sores, boils and cuts. Many Physalis species are also employed to treat fever and malaria, headache and rheumatism. Several other Solanaceae also contain series of withanolides, e.g. the genera Withania Pauquy and Nicandra Adans.
Description
- Annual or perennial herbs, small or large, soft stemmed, angular, often much branched, taproot short.
- Leaves alternate to subopposite, simple, usually ovate, sometimes linear, margins toothed to entire, usually hairy, often with trichomes; petiole present; stipules absent.
- Flowers axillary, solitary or few together in a fascicle, nodding, actinomorphic, pedicel present; calyx campanulate, 5-toothed; corolla plicate, often open campanulate to rotate, slightly 5-lobed, normally yellowish, often with 5 more or less clear, brownish spots at the throat, varying amounts of hair usually present at the throat; stamens 5, implanted at the base of the corolla tube, anthers 2-celled, opening by a longitudinal slit; style filiform, stigma capitate.
- Fruit a biloculed pulpy berry, usually sessile, nodding, enclosed in the persistent, inflated bladdery calyx (husk), 5-10 angled or ribbed.
- Seeds numerous, orbicular to reniform, small.
- Seedling with epigeal germination.
Growth and development
Physalis has a zoo- and hydrochorous dispersion. It can be found flowering throughout the year when sufficient water is available. In the United States, P. angulata plants grow to 80-100 cm tall before flowering, when free of competition, but where competition pressure is high flowering starts when the plants are 25-30 cm tall. Physalis is cross-pollinated. In Malaysia, plants raised from seeds start flowering after 6 weeks, and fruits are ripe 6 weeks later. Dormancy starts 8 weeks after flowering.
Other botanical information
Physalis is variable and taxonomically confusing, and no comprehensive study of the genus exists. It is closely related to Margaranthus and Nicandra. Intermediate specimens are found between related species, such as P. angulata and P. minima in South-East Asia. Both might be varieties of the same species. In America, P. angulata is morphologically also very similar to P. philadelphica, of which a larger-fruited, cultivated type and a smaller-fruited, wild type exist.
Ecology
Physalis can be found up to 3000 m altitude at temperatures above 10 °C, although light frost does not kill them. At high temperatures the plants do not develop well. They grow best in moist, fertile soils and are tolerant of partial shade. P. angulata and P. minima occur widely as weeds of annual and perennial crops, in waste areas and pastures.
Propagation and planting
In a germination test of P. angulata seeds, temperatures of 20, 25 and 30 °C gave about 5, 40 and 45% germination respectively, but at constant temperatures of 10 or 40 °C no germination occurred. Alternating temperatures for 10 h at 21 °C and for 14 h at 30 °C gave about 95% germination. Emergence decreased from about 85% for seeds planted 0-1.2 cm deep to 60% at 5 cm deep, and no seedlings emerged when seeds were planted 10 cm deep. Seeds germinate both in the light and the dark, and germination is optimal when pH is 6-8. Tillage promotes germination slightly compared with no tillage, but germination in both cases is low (about 15% and lower). Irrigation diminishes emergence to less than 5%.
Diseases and pests
Physalis is sensitive to many fungal diseases, caused e.g. by Albugo, Alternaria, Bipolaris, Cercospora, Curvularia, Odium, Oidiopsis, Pseudocercospora, Pyricularia grisea and Pythium. P. angulata is also a host of the causal agent of tomato bacterial spot (Xanthomonas campestris pv. vesicatoria). Physalis hosts viruses found in tobacco, potato, okra, Capsicum pepper, beans and several other crops, as well as physalis mottle virus, and also several root-knot nematodes (Meloidogyne spp.). P. minima hosts the parasitic weed Orobanche indica Buch.-Ham. ex Roxb.
The inflated calyx of Physalis protects the fruit-eating larvae of Heliothis subflexa and H. virescens (Lepidoptera) (which are also pests on cotton, soyabean and tobacco) against parasitism by the braconid Cardiochiles nigriceps. P. angulata is a host for the caterpillar Diacrisia obliqua, and several plant mites.
Harvesting
Physalis is picked from the wild whenever needed, and used fresh or dried.
Yield
Single plants of P. angulata may produce 13 100-31 000 seeds. In a field test in Indonesia, the average number of fruits/plant was about 130, and the average number of seeds/fruit was about 130, so about 17 000 seeds per plant were produced.
Handling after harvest
The fruits of Physalis will keep for 3 months if stored in their husks under dry conditions.
Genetic resources and breeding
Physalis is widespread, and P. angulata and P. minima are pantropical weeds, and not liable to genetic erosion. Large germplasm collections of Physalis exist in Mexico and Guatemala. P. angulata and P. minima are kept in gene banks in Germany and the Netherlands.
Prospects
Withanolides and physalins isolated from Physalis show very interesting activities e.g. in the field of tumour inhibition. More research on their toxicity toward non-malignant cells is, however, needed to fully evaluate their possibilities as lead compounds in cancer research.
Literature
- Caceres, A., Menendez, H., Mendez, H., Cohobon, E., Samayoa, B.E., Jauregui, E., Peralta, E. & Carrillo, G., 1995. Antigonorrhoeal activity of plants used in Guatemala for the treatment of sexually transmitted diseases. Journal of Ethnopharmacology 48(2): 85-88.
- Chiang, H.C., Jaw, S.M., Chen, C.F. & Kan, W.S., 1992. Antitumor agent, physalin F from Physalis angulata L. Anticancer Research 12(3): 837-843.
- Chiang, H.C., Jaw, S.M. & Chen, P.M., 1992. Inhibitory effects of physalin B and physalin F on various human leukemia cells in vitro. Anticancer Research 12(4): 1155-1162.
- Nee, M., 1991. The systematics of lesser known edible Solanaceae of the New World. In: Hawkes, J.G., Lester, R.N., Nee, M. & Estrada, N. (Editors): Solanaceae III: taxonomy, chemistry, evolution. Royal Botanic Gardens Kew & Linnean Society of London, United Kingdom. pp. 365-368.
- Waterfall, U.T., 1967. Physalis in Mexico, Central America, and the West Indies. Rhodora 69: 82-120, 203-239, 319-329.
- Young Menzel, M., 1951. The cytotaxonomy and genetics of Physalis. Proceedings of the American Philosophical Society 95(2): 132-183.
Selection of species
Authors
- Slamet Sutanti Budi Rahayu
