Effect of climate conditions on total phenolic content and antioxidant activity of Jatropha dioica Cerv. var. dioica

The aim of this work was to determine the antioxidant activity, total phenolic content (TPC) and total flavonoid content (TFC) in the rhizomes and stems of  Jatropha dioica and their relation to collection season, collection location, extraction solvent and their interactions to understand the effect of climate conditions on the synthesis of the antioxidant compounds in J. dioica . Plants were collected during different seasons at two locations in Mexico. A 3-factorial experimental design was used for the stems and rhizomes, using the extraction solvent, collection location and season as sources of variation. A Tukey’s test with a P≤0.05 significance level was used to perform the comparison of the means. Significant differences were found when comparing the three sources of variation separately for TPC and antioxidant activity in the stems and rhizomes. In terms of the interactions for the stems, there was a significant difference between the Morelos × 70% ethanol × dry interaction and Tetepango × water × rain interaction for the TPC and the antioxidant activity; however, no significant difference was found for the TFC. In terms of the rhizomes, a significant difference was found among the 4 variables analyzed. These results indicate that collection location, collection season and extraction solvent affect the TPC and antioxidant activity. In addition, the rhizomes presented higher antioxidant activity and TPC than that of the stems.