Bioactive compounds and antioxidant potential of Viola cinerea and Pseudogaillonia hymenostephana from Surghar Range, Pakistan

Medicinal plants are key source of bioactive compounds possessing antioxidant potential. The current research work was conducted to evaluate the bioactive compounds and antioxidant potential of two plants viz. Viola cinerea (V. cinerea) and Pseudogaillonia hymenostephana (P. hymenostephana) collected from Surghar Range, Pakistan in 2020. For determination of bioactive compounds, the extracts of both plants were evaluated for total phenolic, flavonoids and tannin content. For antioxidant potential three assays were applied viz. FRAP, DPPH and ABTS method. The results depicted that total phenolic content (TPC) for V. cinerea was found to be 38.65 ± 0.93 GAE mg g−1. Total flavonoid content (TFC) was 17.37 ± 0.87 Catechin eq. mg g−1 and total tannin content (TTC) for V. cinerea was 2.88 ± 0.32 Catechin eq. mg g−1. The results for P. hymenostephana indicated 33.16 ± 1.32 GAE mg g−1 (TPC), 15.21 ± 0.73 Catechin eq mg g−1 (TFC), while 3.12 ± 0.11 Catechin eq mg g−1 of total tannin contents (TTC) were observed. The results of DPPH, ABTS and FRAP assay for V. cinerea were 38.21 ± 2.37, 38.34 ± 2.87 Trolox equivalent µmol g−1 and 19.57 ± 1.05 µmol g−1 respectively. The value of DPPH assay for P. hymenostephana was 43.41 ± 3.34, ABTS assay valued at 39.21 ± 2.22 Trolox equivalent µ mol g−1 and FRAP assay analysis showed the value 18.23 ± 1.11 µmol L−1 g−1 for P. hymenostephana. The results indicated that like other violets and medicinal plants of family Rubiaceae both the plants which were under consideration shown good antioxidant potential.