Carthamus tinctorius leaves were extracted with methanol and distilled water. The extracts were evaluated for their potential free radical scavenging capacity using four different in vitro methods (DPPH, metal chelation, radical removal and hydrogen peroxide scavenging methods). The total phenolic content obtained for aqueous (112. 2±1.708 GAE mg/g) and for methanolic extract (89.66±2.00 GAE mg/g). In DPPH, IC50 values was found to be 176.66±2.08 and 278.33±1.52 and 310.33±1.52 for the ascorbic acid, aqueous and methanolic extract respectively. In superoxide radical scavenging IC50 values are 381.27±1.43, 544.42±2 and 606.78±3.02 µg/ml for the ascorbic acid, aqueous and methanolic extract respectively. In the metal chelating activity, IC50 values are 385.94±3.00, 337±1 and 487±0.984 µg/ml for the EDTA, aqueous extract and methanolic extract respectively. In hydrogen peroxide scavenging, IC50 values were 261±1, 278±3.52 and 370±1 µg/ml for the ascorbic acid, aqueous extract and methanolic leaf extract of Carthamus tinctorius respectively. The correlation suggests that phenolic compounds are responsible for the antioxidant activities of leaves.

No abstract

Cordia macleodii, an important medicinal plant traditionally used for the treatment of various disorders, including wound healing, jaundice, gastric ulcer, hepatoprotective activity and antivenom potential, thus the plant showed the high antioxidant properties. Successive extraction of leaf and barks powder with methanol and water was tested for quantitative determination of total phenolics, total flavonoids and various in vitro antioxidant activities. Phytochemical screening of crude plant extracts revealed the presence of sterols, alkaloid, flavonoid, phenolic, Reducing sugar, glycosides, tannins and saponins. All extracts showed the significant total phenolic and flavonoid contents and as well as radical scavenging and iron-chelating activities. Among all, methanol leaf extract was observed to be higher antioxidant activity than that of other extract. The methanol extracts showed greater antioxidant activity by DPPH scavenging the free radical with IC50 values of 7.63 ± 0.38 μg gm-1 along with scavenged free radical in a concentration depended manner, which is compare to the standard ascorbic acid.  Our results revealed that the presence of grater antioxidant activity of C. macleodii extract may be due to the high level of flavonoid and phenolic content in the plant. These results clearly indicated that C. macleodii is an effective natural antioxidant. Key words: Cordia macleodii, antioxidant, radical scavenging, phenolics, flavonoid, phytochemical.

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Natural antioxidant capacity of five important folk medicinal plants measured in vitro. Total phenolic content (TPC), flavonoid content (FC) and free radical scavenging capacity of ethanolic, methanolic and aqueous leaf extracts of Lippia alba (LA), Annona squamosa (AS), Hyptis suaveolens (HS), Commiphora wightii (CW) and Milletia pinnata (MP) was assessed using spectrophotometric method. Folin ciocalteu and aluminium chloride method employed to optimise TPC and FC. Free radical scavenging potentiality of leaf extracts was assessed using Ferrous ion chelation (FIC), 2, 2'-diphenyl-1-picrylhydrazyl (DPPH•) scavenging, Hydroxyl (OH•) radical scavenging (HRS) and Superoxide (O- 2) radical scavenging (SRS) methods. Results revealed that the TPC (96.22±5.85 to 519.23±34.90 μg GAE/gm dry weight) were found significant in aqueous extracts from all the plants except AS (p<0.05). For FC (μg QCE/gm dry weight), ethanol was found optimum for LA (463.94±6.49), CW (289.99±2.70) and MP (347.47±4.50) whereas, aqueous was found more appropriate for rest two plants were found significant instead of ethanol and methanol (all p<0.05). The lowest IC50 (μg/ml) were recorded from A. squamosa (27.72±8.95), H. suaveolens (27.78±0.88), C. wightii (27.18±0.16) and M. pinnata (27.30±0.03). All plants have reflected a high antioxidant capacity; however, the highest antioxidant activity was reported from ethanolic extract of H. suaveolens followed by L. alba, A. squamosa, C. wightii and M. pinnata. Hence, these studies show that all folk medicinal plants contain potential antioxidant bioactive compounds.