Chemometric Approach of Different Extraction Conditions on Scavenging Activity of Helichrisym italicum (Roth) G. Don Extracts

Helichrysum italicum (Roth) G. Don is widely used as a liver stimulant and diuretic, as well as an antioxidant, antiallergenic, antimicrobial, antiviral, choleric, and antihypertensive agent. Therefore, the purpose of this study was to analyze the different extracts of H. italicum and to determine the relationship between total phenolic/flavonoid content and antioxidant activity. Plant material was pulverized to be 0.3 and 2 mm, and the extraction was obtained with 5 mL of different ethanol concentrations (30, 40, 50, 60, 96%, v/v) and water during different periods (10, 30, 60 min and 24 h) and with concentrated methanol (95%, v/v), dichloromethane, acetone, chloroform, ethyl acetate, and hexane during 10 and 30 min due to solvents volatility. Extracts were evaporated on the rotary evaporator. Total phenolic and flavonoid content were determined via spectrophotometric measurement, and antioxidant capacity was investigated by the inhibitory activity of DPPH radicals. The group of 92 extracts described through their TPC, flavonoids, yield, and IC50 values were subjected to PCA and HCA analysis. PCA and HCA were performed using Statistica v 10.0 software. The number of phenolic compounds ranged from 2.58 ± 0.1 to 43.60 ± 0.3 mg GAE/g of dry extract, and total flavonoids content ranged from 0.25 ± 0.01 to 23.96 ± 0.19 mg QE/g of dry extract. All extracts showed good antioxidant activity with an IC50 value in the range from 4.92 ± 0.2 to 231.12 ± 1.9 μg/mL. PCA and HCA analysis were performed on the whole data set comprising 92 extracts for both particle sizes (s0.3 and s2) as well as heat map analysis. It was found that the increased time of extraction, concentration of ethanol, and degree of fragmentation enhances the quality of the extracts in terms of phenolic component content and antioxidant effects. Applied chemometric analysis contributed to the extraction conditions grouping, overview, and selection in order to distinguish the extracts with the promising TPC, flavonoids, yield, and IC50 values.