Basella alba

Basella alba L. belongs to the family Basellaceae, the order Centrospermae. The plants belonging to Centrospermae contain specific pigments: red-violet beta-cyanins and yellow betaxanthins, which have a common name, betalains. The occurrence of betalains is restricted to ten families of this order. The remaining families contain exclusively anthocyanins.

Basella alba and its white and red varieties belong to the plants most extensively cultivated in Asia, Africa and the New World. This vegetable of the spinach type is known under names such as: Indian, Ceylon or Malabar spinach, nightshade, basella poi and nivithi in Sri Lanka. Van Epenhuijsen (1974) has given Basella alba the names used in Nigeria such as Gambian spinach, amunututu, seje-soro and alari-funfun.

Irvine (1969) stated that this vegetable is of American origin, and has been cultivated in the West Indies for a long time. Herklots (1972), on the other hand, asserted that the plant originated from the Indies.

Basella alba: Botanical and Chemical Characteristics

Morphology and Taxonomy. Basella alba is a herb, naked succulent with a branched, creeping stem. The leaves are simple and all arranged alternatively on the stem, oval in shape with short petiole, heart-shaped base and a pointed or gently rounded apex. The leaves attain about 10 cm in length and 7 cm in width. In particular varieties the leaves are green (B. alba), reddish (B. alba var. rubra, B. rubra var. alba) or red (B. rubra). The flowers are small, bisexual, pentamerous in the shape of fleshy tube. The perianth is undifferentiated, stamens five in number are arranged near the fused together apex of the perianth. The fruits are deep red drupes.

In botanical literature, there is a certain confusion in reports about Basella alba and B. rubra. In the Index Kewensis (1895-1953), B. alba is the synonym of B. rubra. Regarded as synonyms of B. rubra are also B. cananifolia, B. cordifolia, B. casifolia, B. japonica, B. lucida, B. nigra, B. ramosa and B. volubilis. Podbielkowski (1985) mentioned the following synonyms of B. alba: B. rubra, B. lucida, B. japonica, B. cordifolia, B. nigra, B. crassifolia, Gondola alba and Gondola nigra.

Hegnauer (1964) included B. alba into the tribe Eubasellae the family Basellaceae. For the genus Basella the author mentioned three species. Engler (1964) included in the tribe Basellae five species having their natural distribution range in Asia and Africa. Chadefaud and Emberger (1960), on the other hand, included only one species of B. alba into the genus Basella. Dalziel (1975) stated that B. rubra is the most widely distributed, stable race of B. alba.

Basella alba: Conventional Propagation

The plants can be propagated either from the seeds or vegetatively from the fragments of roots and stems. The seeds are sown from mid-February until mid-June. The implanted seedlings should be cut. The plant requires good humus-rich, richly watered soil. In tropical regions it is a perennial plant.

Progressive collection of the leaves stimulates the production of new ones. Kamath (1974) stated that the varieties of B. alba are sensitive to frost, and also recommended the shading of the plants on high light exposure.

Basella alba sprayed with gibberellic acid showed hyperelongation of shoots associated with characteristic twinning habit. Use of CCC to cultivate this plant causes the marked reduction of internodes which makes B. alba suitable for commercial planting.

As Schery (1972) reported, the varieties of B. alba are grown in gardens around the houses in the USA and the West Indies and as climbers are often trained over fences, arbours or trellises.

Basella alba: Importance

Basella alba and its varieties show high nutritional properties. Herklots (1972) reported additionally that the boiled leaves of this plants can be used as a mild laxative. Goswami and Dutta (1983) mentioned species of Basella as an agent strengthening heart activity and positively affecting disorders of the respiratory tract.

According to Murthy et al. (1981) Basella species contain compounds with antiviral properties. Extracts from the leaves of B. alba showed inhibiting activities in relation to tobacco mosaic virus. Kamath (1974) reported, that pigments obtained from the pericarp of Basella species were used for colouring jellies, cakes and sweets. He also mentioned the use of the juice in ancient China as a cosmetic dye (rouge) and ink for sealing.

The interest in natural pigments has increased in recent years, since it has been found that many of the synthetic products used in the food industry have harmful effects.

Red beet (Beta vulgaris) is, in fact, the only cultivated plant comprising large quantities of betacyanins used to dye food (desserts, beverages, protein substitutes).

Since 1960, the European producers of wine have increased the value of their red wine by intensifying its colour by the addition of juice of beetroot and berries of American scarlet beet (Phytolacca americana). Although especially rich in betacyanins, berries of American scarlet contain factors which are detrimental to health and saponins that are difficult to eliminate.

Basella alba: Chemistry

The term betalains was introduced in 1968 by Mabry and Dreiding and denoted the derivatives of betalamic acid. Betalains contain nitrogen in their molecule, have amphoteric properties, are basically unstable compounds and are sensitive to the activity of oxidizing agents and elevated temperature. Betacyanins are characterized by glycoside structure, whereas betaxanthins do not contain sugar in their molecule. The typical example of betacyanin is betanin, the crimson pigment of red beet (Beta vulgaris). Wyler and Dreiding (1961) isolated phytolaccacin (Phytolacca decandra) the predominant red pigment of pokeberry and determined that it was identical to betanin. Betanin is betanidine glycoside, whose structural formula was presented by Wyler et al. (1963).

Alard et al. (1985) identified orange derivates of betanin, which were named neobetanins considered by Wyler (1986) as artefacts, whereas Minale et al. (1967) isolated betacyanins containing aromatic hydroxyacids in their molecule.

Piatelli (1976) and Reznik (1980) noted the occurrence of betalains also in fungi, where they have been regarded as an example of biochemical transformation similar to those which take place in Centrospermae.

In the literature there have been few reports on the chemical characteristics of the pigments contained in the species and varieties of Basella.

From the pericarp of Basella alba and Basella rubra Reznik (1955) reported four beta-cyanin compounds were obtained of which three were in trace quantities. Wyler and Dreiding (1961a) found two betacyanins in B. rubra: violet baselain v and red-violet baselain r. Until recently, it has been thought that of all betalain compounds only betacyanins are biosynthesized by the species Basella. The first report on betaxanthin was published by Reznik (1975).

Takami and Miho (1978) found in B. rubra amino acids similar to those present in spinach (Spinacia oleracea). Similar results for this species cultivated in the West Indies were obtained by Vasi and Kalintha (1980), whereas the total quantity of protein in the leaves was determined by Mirajkar et al. (1984). Proteins, amino acids and carotenoid compounds in Basella sp. were examined by Hall et al. (1976), Absar et al. (1978), and Shimizu and Mori (1980). These authors noted a high amount of the compounds examined.

Fat and sterols in Basella rubra leaves were investigated by Sayeed and Ahmad.

Medicinal and Aromatic Plants II (1989)