Salacia chinensis Seeds | Chinese Salacia
LATIN NAME: Salacia chinensis
COMMON NAME: Chinese Salacia
Plant Profile
Salacia chinensis is a climbing shrub with opposite leathery leaves, greenish flowers in small clusters and round orange fruit. It scrambles over trees and rocks in the forests of India, Sri Lanka and South-East Asia, and it is one of several species sold under the name saptarangi.
The root is the part that is traded. It is dug from the wild in India and Sri Lanka, sliced and dried, and sold in the herbal market for diabetes, often mixed with the roots of related species. The plant is a liana rather than a tree, and it is not cultivated on any scale. The bark is grey and warty, and the stems climb by twining rather than by tendrils.
Science & Biotechnology
The root contains salacinol and kotalanol, two sulphur-containing sugar analogues that inhibit alpha-glucosidase, the enzyme that breaks starch into glucose in the gut. The mechanism is the same as that of the drug acarbose, and the compounds were isolated and characterised in the 1990s in Japanese and Sri Lankan laboratories.
The clinical evidence is much thinner than the laboratory work. Small trials in India and Japan have reported reductions in post-meal blood glucose, but the numbers are small, the products are not standardised and the trials are mostly of short duration. Mangiferin, another constituent, is also under study for its antioxidant activity. The root also contains mangiferin, a xanthone that is being studied for its effect on blood lipids, again with limited human data.
Uses & Benefits
The dried root is sold as a powder and as a decoction for type 2 diabetes, usually alongside conventional treatment rather than instead of it. It is also used in Sri Lanka for skin complaints and for rheumatism, and the timber is used for small turnery.
Wild collection is destructive, since the whole root is dug and the plant is slow to regenerate. Some suppliers now buy from planted stock, but the trade is not well regulated and the identity of the material is rarely checked. There is no food use.
Growing from Seed
Sow fresh seed in a moist, free-draining mix at twenty-five degrees, and expect germination in four to eight weeks. Cuttings of half-ripe wood also root in a humid frame, and they are the faster route to a plant of known sex.
Plant out in a frost-free climate in light shade, with a trellis or a tree to climb on, and water through the dry season. The plant needs humidity and does not tolerate cold, and it is slow to establish. It is grown in a few collections in India and Sri Lanka rather than in gardens. The plant is also grown from root cuttings in India, which is faster than seed for a crop plant.
Our Take
A tropical liana whose root is the source of a real alpha-glucosidase inhibitor, and one whose evidence is far ahead of its cultivation. Do not substitute it for treatment.
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