The Indian thorny ash, Zanthoxylum armatum, called tejphal in most parts of India, is edible. Its fruit peel serves as a spice and its seed is used in the Chinese ‘five spice’ mixture. Studies show that tambulin, a flavanol from the plant, has analgesic, anti-inflammatory, antioxidant, anticancer, and hepatoprotective activities. Recently, a team from the CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow reported that tambulin is useful to retard the aging process too.
Rakesh Pandey and team from CIMAP, Lucknow extracted tambulin from Indian thorny ash fruit and tested its longevity-promoting and neuromodulatory activities on the worm, Caenorhabditis elegans. They used age-synchronised C. elegans and treated them with different doses of tambulin. Tambulin increased the lifespan of the worms by more than 16%. And a concentration of 50 micromoles of tambuline was adequate to produce this effect.
When they challenged the worms with an oxidative stressor, juglone, they found that the treated worms were more tolerant to stress. This, the researchers say, might be because tambulin reduced cellular damage by reactive oxygen free radicals. They also found that tambulin up-regulates the mRNA expression of genes associated with longevity and oxidative stress resistance.
When the worms age, usually lipofuscin, yellow brown granules found in tissues, increases. Lipofuscin is easy to recognise since it fluoresces spontaneously. The researchers found that lipofuscin is reduced in the treated worms. They also noticed reduced lipid levels in the worms treated with tambulin.
The treated worms moved around more, but exhibited lower pharyngeal pumping. Normally lower pharyngeal pumping is seen when diet is restricted and, in such cases, too, the lifespan had been shown to increase.
The impact of tambulin on the mobility of the worms led the scientists to test the neuromodulatory effects of tambulin on the worms. The treated worms had elevated levels of dopamine, the feel-good neurotransmitter. They also found elevated levels of α-synclein, a protein that disrupts cellular homeostasis, affects synaptic function and results in cognitive decline and impaired muscle movements. Elevated levels of the protein are a hallmark of Parkinson’s. So the team suggests that tambulin can perhaps prove to be useful in Parkinson’s disease.
Though for tambulin to emerge as a medicine may take more animal and clinical trials, tejphal as a spice and nutraceutical is a decision that you can take in a kitchen.
Experimental Gerontology, 120:50-61 (2019); DOI: 10.1016/j.exger.2019.02.016
G Sharath Chandra
Indian Institute of Horticultural Research, Bengaluru