Shielding effect on oxidative stress and immune modulating potential of Himalayan Musk Rose (Rosa brunonii Lindl.)

Abstract

Rosa brunonii Lindl., a wildly growing species of rose is used widely by the folklore of the Himalayan region for various food and traditional medicinal purposes. The present study aims to evaluate the protective effects against oxidative stress markers and immunomodulation of Rosa brunonii Lindl. The crude extracts (chloroform, methanol, and aqueous) and subsequent fractions (chloroform, ethyl acetate, acetone, methanol, and aqueous) of both the leaves and flowers were evaluated for antioxidant potential (DPPH free radicals scavenging, chelation capacity on ferrous ions, FRAP activity, and reducing activity), DNA protection (DNA strand nicking) and immunomodulatory potential (humoral antibody titre) and cell-mediated (DTH immune responses and lymphocytic proliferation). The antioxidant study indicated that among all, methanol fraction (leaves) possessed remarkable antioxidant potential with the highest DPPH free radical scavenging (IC₅₀ 32.3±1.15 µg/mL), chelation capacity on ferrous ions (66±0.22%), reducing power (EC₅₀124.4±0.17 µg/mL), FRAP (3996±2.17 µM/g dry wt.) as well as highest amounts of total phenols (250±0.54 GAE mg/g dry wt.) and flavonoids (344±1.76 QE mg/g dry wt.). Moreover, a significant reduction in plasmid DNA damage was also observed. Immunomodulatory results of methanol fraction (flowers) at 100 µg/mL showed maximum stimulation with 125% on humoral response, 166% on cell-mediated response and significant suppressive effect on mitogen-induced lymphocytic proliferation. The active constituent identified in methanol fraction (leaves) through RP-HPLC analysis was myricetin and from methanol fraction (flowers) was p-coumaric acid. This study concluded that the leaves of R. brunonii are a rich source of natural antioxidants and immune-modulating agents which can be further explored for establishing their pharmacological potential.