Malva sp. (Mallow)

2015

Distribution and Importance of the Plant

Although about 1000 species are designated with the common name of mallow, approximately 30 species belonging to the genus Malva (of the Malvaceae family) are known for their medicinal value, mostly in a traditional sense.

The common (blue or high) mallow (Malva sylvestris L.) is a biennial to short-lived perennial with prostrate to semi-erect stems (10-80 cm long) and long-stalked rounded leaves with a heart-shaped base and five to seven broad shallow-toothed lobes. The leaves of M. sylvestris var. incanescens Gris are hairy. The flowers (appearing from May to September) are pale lilac to bright mauve-purple and the seeds are flat button-like nutlets. The plant is found naturally in marginal or waste lands, hedgerows and roadsides and is approximately 1 m high, with stalked, roundish, five- to seven-lobed leaves. Plant parts abound with a mild mucilage.

Malva aegyptia (Egyptian mallow) is an annual species, endemic in the Mediterranean countries, 20-50 cm high with purple-blue flowers.

Malva cretica (Crecian mallow) is another Mediterranean species, which is an annual, 10-30 cm high with rose-coloured leaves.

Malva ambigua Guss (M. sylvestris var. ambigua) is a perennial with hairy roots and purple leaves.

Malva neglecta is also known as common mallow or ‘cheeses’. It has white to pale lilac flowers (appearing from May to September) with five slightly notched petals. Leaves are wavy up and down, their edges having rounded teeth. Plants (10-100 cm high) are covered with hairs and are branched at the base. M. neglecta has similar pharmacological properties to common mallow. The dwarf mallow (Malva rotundifolia L.) is a similar but smaller species with prostrate stems and pale lilac flowers.

Malva pussila is an annual weed with white-purple flowers.

Malva parviflora is also an annual, with white-blue flowers. It is a poisonous plant for various animal species ()

The musk mallow (Malva moschata L.) is a related perennial species with light-green leaves and rose-coloured flowers, which are considerably larger than those of the common mallow. It is one of the few mallow species that are cultivated, even on a marginal level.

Mallows are abundantly distributed in temperate and tropical regions and virtually worldwide.

Common mallow has been traditionally used both as a food source and a remedy for various diseases. The young leaves and shoots of this plant (gathered in July and August) have been eaten since at least the 8th century B.C. Pliny called common mallow ‘the food of the poor’. The seeds are also edible and the boiled foliage can be consumed as a vegetable, making a good soup. M. neglecta is used for the preparation of fresh or cooked’panerak’in Pakistan. Country people have traditionally used flowers for decorative purposes.

The medicinal value of the plant is reflected in the Spanish adage,’A kitchen garden and mallow, sufficient medicines for a home’. The leaves and flowers are the main plant parts used, although from musk mallow the white root is mostly used. Traditional uses of the species include the treatment of coughs and throat infections and other bronchial problems, as well as stomach and intestinal irritations. The flowers and leaves are emollient and used for the softening of sensitive areas of the skin. It is applied as a poultice to reduce swelling and draw out toxins. Taken internally, the leaves reduce gut irritation and have a laxative effect. Combined with eucalyptus, it makes a good remedy for coughs and other chest ailments. The mucilage has an anti-complementary activity. M. rotundifolia is a potential vasodilator (i.e., a blood pressure-lowering agent).

Based on ethnomedical information gathered from surveys at clinics and hospitals as well as interviews with traditional healers and rural dwellers, Gri-erson and Afolayan revealed that M. parvifolia is among the most commonly used plants for the treatment of wounds in the eastern Cape Province, South Africa, although extracts from this species did not show any antibacterial activity.

Huang et al. used short-term in vivo and in vitro tests to further confirm the anti-tumour activities of Malva crispa powder, a vegetable powder, prepared from Malva crispa L. In cancer cell culture systems, the Malva crispa powder fat-soluble extract revealed inhibitory effects on the growth and proliferation of the human hepatoma and the gastric cancer cells in a dose-response manner. In the colony formation test, Malva crispa powder also altered the morphology of human gastric cancer cells. It was suggested that Malva crispa powder could be consumed not only by healthy subjects for cancer prevention but also by patients with cancer as a supplementary treatment in combination with anti-carcinogenic drugs such as 5-FU or cyclophosphamide (CP).

In Box Reported pharmacological properties of common mallow and indicative dosages of herbal preparations, reported pharmacological properties of different common mallow species are presented cumulatively, along with indicative dosages of herbal preparations.

Box Reported pharmacological properties of common mallow and indicative dosages of herbal preparations

Pharmacological property → Indicative dose

Malva sp. (Mallow): Conclusion and Prospects

Although documented research with tissue culture of Malva sp. is limited to a small number of reports, the successful induction of callus and somatic embryos from this species allows for a discernible potential for the further application of biotechnological techniques on this species for various purposes, such as the in vitro production of useful metabolites and the expression of genes related to the induction of somatic embryogenesis. Mallow petiole culture could be exploited as a reliable, fast-responding model system for investigating the effect of various chemical factors on the induction of callus or somatic embryogenesis from dicotyledonous plant species. Indeed, this system is being currently used for evaluating the growth regulatory potential of oligosaccharide fractions derived from various Malvaceae species (Research Project PENED 1999). Further progress in somatic embryogenesis and other advanced aspects of cell culture (e.g. protoplast culture and fusion) could lead to a significant involvement of biotechnology to the utilisation of mallow as a modern medicinal and/or fodder plant species.

 

Selections from the book: “Medicinal and Aromatic Plants XII” (2002).