Abstract Grape plant (Vitis vinifera L.) is a species of the family Vitaceae. It is an economically
important fruit plant abundantly grown all over the world. Vitaceae comprised of 900 species distributed
across tropical, sub-tropical and partially temperate sorts of climatic zones. In the current
study we aimed to evaluate the antioxidant activities of grape leaves extract from different Pakistani
varieties.
We have analyzed the crude methanolic extract from the leaves of Pakistani grape varieties (i.e.
NARC Black, Sundar Khani, Shogran-1, Shogran-2, Haita, Sheghali, Perlette, and Sultania-C) cultivated
in various soil compositions. Total phenolic contents (TPC) of the extract were determind by
using Folin-ciocalteu reagent method. Total flavonoid contents (TFC) were determind by the
Aluminum Chloride Calorimetric method. Antioxidant activities of the extracts of different
concentration were evaluated using Phosphomolybdenum method, Reducing power and DPPH
(2, 2-disphenyl-1-picryl-hydrazyl) assays. Assays performed for grape varieties showed greatantioxidant potential. All varieties significantly depicted with variation in polyphenolic contents
and antioxidant potential with changes in the soil conditions. The highest TPC and TFC were quantified
in Shogran-1 97.58 ± 0.09 (GAE, g
1) and Sultania-C 97.47 ± 0.12 (mg QE/g DE) varieties
respectively which were grown in (T6) and (T5), while lower were recorded in Sundar khani
5.16 ± 0.23 in (T6). Likewise, Shogran-1 128.26 ± 0.23 (mg AAE/g extract) variety grown in
(T6) depicted highest total antioxidant capacity, NARC black 182.06 ± 0.24 (mg AAE/g extract)
variety grown in (T6) resulted in maximum reducing power while DPPH free radical scavenging
potential were determinded in Sultania-C 80.91 ± 0.10 (T4) equivalent mg/g. In the terms of bioassays,
the promising results were showed by compost + sand + clay (T4), compost + clay + dung
(T5) and sand + clay + dung (T6). Therefore, we conclude that variation in soil composition has a
significant contribution in the quantity of phytochemicals and antioxidants expression. Our study
further suggest that use of organic fertilizer (Compost) and loamy sort of soil enhance functioning
of most of the varieties in terms of important phytochemicals.