Effect of contrasting climates on antioxidant and bioactive constituents in five medicinal herbs in Western Himalayas

To understand the effect of climate change on constitutive antioxidant and biochemical metabolites in Western Himalayas, five medicinal herbs were selected and grown at two altitudes in Jammu (305 m) and Srinagar (1730 m) with subtropical and temperate climates, respectively. Significant variations were observed in phenols and flavonoids in Hypericum perforatum L., Matricaria chamomilla L., Thymus vulgaris L., Cynara cardunculus L. and Echinacea purpurea L. growing at two locations. High altitude temperate site show variable (up to 13 fold) increase in their content. Proteins (1.3 – 1.8 times), sugars (2.8 – 4.1 times) and free amino acid (1.04 – 1.22 times) were also higher at Srinagar (1730 m). Within these plants, H. perforatum and M. chamomilla have shown higher accumulation of phenols, xanthophylls and proline even at subtropical environment in Jammu (305 m) suggesting potential for increasing their geographical area. The results demonstrate that changing environmental conditions significantly affect the bioactive constituents, which accumulate as a defence strategy by these temperate plants. Their medicinal significance during climate change scenario has also been discussed.