Using ankur to fight diseases


Nandkumar M Kamat

Land use changes and reclamation of swamps are destroying some very ancient wild edible resources in Goa. Many of these have provided local people powerful protection against several ailments such as chronic
constipation and viral diseases.

This is the month when one can see bunches of fiddleheads of handpicked greenish yellow local wild edible fern ‘ankor’ or ‘ankur’ scientifically known as Acrostichum aureum being marketed. One can see these bunches sold at roadside stalls close to estuarine and mangrove swamp areas.

Goa is rapidly destroying its biological resources especially plants, mushrooms and ferns which have powerful antiviral compounds. There was a lot of excitement when a team from Bangladesh and Australia found novel phthalate
compounds in Acrostichum aureum fern which showed antiviral activity against dengue virus, human parainfluenza virus and chikungunya. This fern has been used as a traditional medicine in Bangladesh and various other countries for a variety of diseases including infections. This edible fibrous local fern Acrostichum aureum or ankur is Goa’s challenge to asparagus in texture, taste and flavour. It has tremendous potential in artificial cultivation and processing and in the pharmaceutical industry.

In May 2014 when MSc (Botany) student Valerie Lorraine Dias from Moira approached me to guide her for a dissertation project, I immediately drew her attention to the neglect of research on this fern growing close to her area on the way to Mapusa. Later she completed her dissertation on ‘Pioneer studies on the endophytic yeasts and calcium biominerals from Goa’s mangrove fern Acrostichum aureum’. But later very little follow-up research could be undertaken. Recently I noticed human interference destroying this fern along Mapusa and Moira river where she had done her field work. Since this fern has not been artificially cultivated it is important to conserve and protect its remaining habitats. Sustainable exploitation of this fern is possible but if major habitats get destroyed then people would have to import it from other states. From June to October at least one thousand people in Goa get their income from selling this fern.

Several road construction projects have endangered the habitat of Acrostichum aureum. People use it as a seasonal vegetable delicacy but being a fern it’s not like any other vegetable. It is a pteridophyte belonging to the division pteridophyte in the order polypodiales. We find more than 9000 species in the world in this order ranging from small structures to tall tree-like ferns. In genus Acrostichum we find three species, Acrostichum aureum, Acrostichum daneaifolium and Acrostichum speciosum. Among these only A aureum is used for consumption. The fern locally gathered from wild Acrostichum aureum is popularly known in the world as the golden fern, mangrove fern or the swamp fern. It grows to almost two metres and one can see large stands at Guirim, near Mapusa river and on the way to Nachinola from Mapusa. It grows luxuriantly at Sirigao, Banastarim, Amone, Khandola, etc, but it is risky to venture into these muddy areas. The width of the fern matches its height. Acrostichum fern produces an erect stem known as the rhizome with long upstanding pinnate fronds.

Just before the arrival of the south west monsoon the local people familiar with mangrove habitat using traditional knowledge keep an eye on sprouting of the young fronds known as fiddleheads. These tender fiddleheads need to be handpicked. These are abundant in June-July but sometime we see the crops marketed up to September due to asynchronous growth in different locations. It grows from minute spores – the sporophytes in saline soil. It needs a lot of light and comes up in areas conducive to mangrove colonisation

There are dozens of ways people in Goa cook different recipes from ankur. While processing they would not fail to observe that it produces a peculiar polysaccharide. This fern has a lot of digestible fibre which improves the tone of gastrointestinal system and is favoured by the gut microbiome. Besides acting as an antidote for constipation and piles, seasonal use of such fibre can prevent gastric and intestinal cancers. Perhaps its probiotic and medicinal properties were discovered centuries ago but were not properly documented.

A recent phytochemical study (Badhsheeba and vadivel, 2020) titled ‘Physicochemical and phytochemical contents of the leaves of Acrostichum aureum l’ published in the journal of global biosciences concluded that the detection of steroids, saponins, flavonoids, phenols, proteins, glycosides and terpenoids in methanolic extracts of A aureum leaf signals their therapeutic potential. Ankur bioaccumulates a lot of calcium, phosphorus and iodine from the saline soil. These are essential in nutrition. Valerie Dias discovered some beneficial endophytic yeasts in this fern but their exact role is not understood. She had also found iron containing minerals called sideroliths for the first time in the leaves which store iron in biomass.

As global research and interest in pharmacological properties of this fern picks up it would be a big mistake to destroy the last remaining local habitats of ankur. Therefore bio entrepreneurs and organic farmers must come forward to cultivate it artificially under greenhouse conditions and thus make it available for fresh consumption and value addition. Such probiotic immunity enhancing edible ferns hold huge promise to fight off future viral diseases. Those who exploit it from the wild must not cause total plunder. The local biodiversity management committees need to protect the last remaining ankur habitats in Goa.