Mast tree, the medicinal masquerade

Polyalthia longifolia (Sonn.) Thwaites (PL) (Family: Annonaceae) is a tall evergreen tree cultivated throughout India. It is commonly known as the false ashoka, cemetery tree, mast tree, masquerade tree and Buddha tree. It is widely recognised as an excellent avenue or street tree because of its ability to reduce noise pollution.

Constituents

Different parts of the mast tree contain proteins, lipids, fibre, carbohydrates, ash and moisture. The principal phytochemical constituents include clerodane-type diterpenes (incensole, serratol and neophytadiene), protoberberine alkaloids, flavonoids (including quercetin derivatives), tannins, saponins, steroids and essential oils. Analyses have also shown the presence of appreciable quantities of minerals such as sodium, potassium, calcium and magnesium.

Preparations

The plant may be used in the form of fresh or dried leaves, bark, roots or seeds. It is also available as dried powder or in capsule form. Traditionally, it may be prepared as a decoction.

Pharmacological actions and medicinal uses

Different parts of the plant are valued in traditional medicine for their antimicrobial, anti-inflammatory, antioxidant and antidiabetic properties. They have long been used to manage fever, skin disorders and digestive ailments. Studies have shown that leaf extracts inhibit the growth of pathogenic bacteria, including Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as well as fungi such as Candida albicans. The bioactive compounds present in the leaves have also demonstrated analgesic activity, which may be attributable to their anti-inflammatory effects. Pharmacological studies further suggest that leaf extracts may help lower and regulate blood glucose levels. In addition, the leaves are rich in antioxidant secondary metabolites that help protect cells against oxidative damage and may support the management of gastric ulcers.

Longifolia has also been reported as a traditional remedy for the treatment of gonorrhoea, snakebites and scorpion stings. The aqueous bark extract has been shown to reduce blood pressure and heart rate. Traditionally, the bark has also been used as a febrifuge and in the management of septic infections, hepatomegaly, hepatosplenomegaly, cough, diarrhoea and certain cancers. Furthermore, P. longifolia has demonstrated anticancer, gastroprotective, hypotensive, corrosion-inhibiting and bioadsorbent properties. Experimental studies on leaf extracts have shown that some of their constituents can induce cell death in various cancer cell lines.

Adverse effects

1. longifolia may cause gastrointestinal disturbances, including nausea and mild diarrhoea, dizziness resulting from reduced blood pressure, and skin irritation when the essential oil is applied undiluted. It may also interact with sedatives and anticoagulant medications.

Economic uses and potential

In Nigeria, live Polyalthia longifolia seedlings typically sell for between N1,500 and N5,000 at local nurseries. Specialised health retailers also market dried bark powder or capsules for traditional medicinal use at approximately N7,000 to N9,000 per 100 g.

The mast tree is widely cultivated as an ornamental plant, for landscaping and as a living fence. Historically, its timber was used in the construction of ship masts. Today, the lightweight, straight-grained and easily worked wood is used as fuelwood, for shuttering-grade plywood, and in the manufacture of small wooden items such as pencil cases.

Seed extracts have potential for commercial production of organic pesticides, fungicides and mite repellents, while leaf extracts are increasingly being investigated as phytobiotic feed supplements to replace conventional antibiotics in broiler and ruminant production. Consequently, the mast tree possesses considerable potential for both the pharmaceutical and agricultural industries.

Reference

Shinde, P. K., Kokate, R. H., & Gawade, G. S. (2023). Physicochemical, phytochemical, biological and chromatographic evaluation of Polyalthia longifolia plant leaves: A review. Research Journal of Science and Technology, 15(1), 41–48.

By Pharm. Ngozika Okoye MSc, MPH, FPCPharm

(Nigeria Natural Medicine Development Agency)

Email: ngozikaokoye@yahoo.com