Polyphenolic contents and antioxidant potential in Nasturtium officinale

The present study was conducted with the aim to assess the impact of environmental conditions on polyphenolic content and free radical scavenging ability in the leaves of N. officinale used as food and medicine in the Himalayan region of Pakistan. Samples were gathered from six different sites located in Himalaya, Hindukush, and Karakorum ranges. Polyphenolic profiling, and in vitro antioxidant potential were determied using standard analytical techniques. The samples collected from Abbottabad had significnat levels (p≤0.05) of total phenolic (331.43±41.43 mg GAE/100g DW) and total flavonoid contents (8.45±1.53 mg RutE/100g DW). Whereas, rutin, quercitin and kaempferol were maximum in samples collected from Dir(132.46±0.31, 8.80±0.05 and 0.95±0.04 µg/g, respectively). Likewise, Gallic and caffeic acids were highest in Haripur and Swat samples, whereas ferulic and p-coumaric acids were maximum in samples taken from Dir. The percentage scavenging of DPPH was maximum in samples collectded from Chitral (69.57±3.39%) and that of H2O2 at Dir (57.24±8.05%), whereas samples collected from Abbottabad depicted maximum inhibition of ferric and molybdate ions. Total phenolic and total flavonoids contents exhibited highly significant positive correlations (p≤0.01) with ferric and molybdate ions reduction capacity. Cluster and principal component analyses also depicted significant associations among samples collected from Abbottabad-Haripur, Dir-Swat, and Mansehra-Chilas. Our findings contribute in understanding the antioxidant potential of N. officinale leaves, and highlights the importance of polyphenolic composition and environmental factors in future investigations related to its nutraceutical applications. Further research on detailed phytochemcial profiling, their in vitro and in vivo mechanisms of action could unveil the potential of this plant as a functional food.