HPTLC Fingerprinting of Phenolic Acids and Assessment of Antioxidant Potential of Pouzolzia bennettiana Wight a Medicinal Plant from Nilgiri Hills

Aim: To screen the secondary metabolites, evaluate the antioxidant potential and identify phenolic acids of methanolic extract of leaf and stem of Pouzolzia bennettiana Wight.

Study Design: The study aimed to determine the antioxidant potential using various assays and to identify the secondary metabolites using HPTLC fingerprinting.

Place and Duration of Study: KMCH college of Pharmacy, between April 2015 and December 2015.

Methodology: The methanolic leaf and stem extract of Pouzolzia bennettiana Wight was screened for its phytochemical components, quantitative analysis of phenols and flavonoids, antioxidant activity by DPPH, ABTS, FRAP and TAC assay. Few phenolic acids responsible for antioxidant activity was identified by HPTLC fingerprinting.

Results: The important secondary metabolites such as flavonoids, tannins, terpenoids, saponins and sterols were identified in the methanolic leaf and stem extract along with primary metabolites such as carbohydrates and proteins. The total phenol and flavonoid content of leaf extract was found to be 34.65 µg and 33.36 µg/100 µg of extract respectively whereas stem extract possessed 31.74 µg and 12.58 µg/100 µg of extract respectively. The antioxidant potential of the methanol extract of leaf and stem was evaluated and the leaf extract showed significant activities in all antioxidant assays compared to the reference antioxidant whereas the stem possessed less antioxidant activity. The HPTLC fingerprinting of leaf extract revealed the presence of the following phenolic acids orcinol, ferulic acid, benzoic acid and resorcinol. The stem extract identified phloroglucinol, ferulic acid and resorcinol.

Conclusion: These results suggest that Pouzolzia bennettiana Wight may act as a potential natural antioxidant offering effective protection from free radicals. The antioxidant effect may be due to the presence of phenolic acids. The phenolic acids identified possess various other applications along with antioxidant activity.