Comparative analysis of phenolic content and antioxidant power between parasitic Phoradendron californicum (toji) and their hosts from Sonoran Desert

Abstract

Parasitic plants, such as toji acquire nutrients through xylem of the host plants. To investigate the influence of parasitic-host interactions on phenolic composition and antioxidant activity from arid sites of Sonora, Mexico is the objective of this research. Organic and aqueous extracts from trees (stems) such as Prosopis glandulosa (Mesquite), Olneya tesota (Palo fierro), Parkinsonia aculeata (Palo verde), Acacia farnesiana (Vinorama), Quercus sp. (Encino o Oak), and Phoradendron californicum (toji) were collected in an arid zone. Each plant was analyzed for phytochemical screening, phenolic composition using Folin-Ciocalteu, AlCl3, DNP methods and reversed phase high performance liquid chromatography. In vitro the antioxidant properties were determined by 1,1-diphenyl-2- picryl hydrazyl radical scavenging (DPPH), ferric reducing antioxidant power (FRAP) and superoxide radical scavenging (O2). Pearson correlation was used for quantifying the relationship between phenolic content and antioxidant activity in toji compared to their non-parasitic hosts. The highest content of phenolic compounds and antioxidant capacity was found in the parasitic toji (Phoradendron californicum) compared to their hosts. Some correlations (r > 0.5, P < 0.01) between Mesquite or Vinorama (hosts) and toji secondary compounds (flavonoids and tannins) and between Oak and toji phenols and tannins could indicate that toji (parasite) might get some chemical compounds transferred from the host xylem.