Image: Vinayaraj via Wikimedia Commons
Last year, in the wake of COVID-19, the Ministry of AYUSH recommended ashwagandha as a prophylactic against the pandemic. This led to high sales and stocks were soon depleted.
The primary source of the medicine is the root of the plant, Withania somnifera. Thus, making more of the medicine depletes the primary source. Which implies raising new plants quickly to meet market demand.
However, scientists from the Central Institute of Medicinal and Aromatic Plants, Lucknow say that plants raised in summer have low medicinal properties. 
They sowed ashwagandha in two seasons, in March and October, and, six months later, harvested plant parts, such as leaves, berries and roots, to investigate the seasonal effect on withanolides. Using chromatography, they analysed two different withanolides, withaferin and withanolide A, at different stages of the leaf, root and berry.
Summer plants have longer and thicker roots and higher plant productivity. However, in winter, plant tissue expression is high with higher withanolide accumulation in leaves and roots. Berry yield and withanolide content was also higher in winter plants.
To understand why, the researchers also quantified the expression of different genes involved in withanolide production through transcriptome analysis. In summer, they found, genes responsible for withanolide synthesis were expressed in lower amounts.
“Low temperature and humidity seem to increase withanolide accumulation”, says Neelam S. Sangwan, CIMAP, Lucknow.
Does this mean we have to wait for winter to get more effective ashwagandha?
“Not necessarily”, says Natesan Selvaraj from the Periyar EVR College, Tiruchirapalli. Along with researchers from the Bharathidasan University, Tiruchirapalli and South Korea, he has succeeded in producing roots with higher amounts of withanolides, the pharmacologically active ingredients, in the lab. 
They grew roots using tissue culture and incorporated the gene for squalene synthase, responsible for the production of withanolides, in the roots through genetic transformation. The hairy root culture was capable of producing high amounts of withanolides.
“A 40-day culture produced about 2 milligrams of withanolide,” says Andy Ganapathi, Bharathidasan University, Tiruchirapalli.
It is challenging to ensure steady production of withanolides through conventional cultivation. Cultivating roots in the lab may be a good way to ensure a continuous supply of the compounds. And this also means that we do not have to wait for winter to get our dose of withanolides.
Pharmaceutical companies could use these tips to produce good quality ashwagandha irrespective of season.
 DOI: 10.1016/j.indcrop.2020.112508
 DOI: 10.1016/j.indcrop.2020.112706
Rekha R Warrier, IFGTB Coimbatore
Tahera Arjumand, SKUAST-K Srinagar
Editor’s Note: Ashwagandha may not be adequate protection against SARS-CoV-2, though it may raise the level of immunity and improve the general sense of well being.
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