In Silico and In Vitro Insights into the Pharmacological Potential of Pouzolzia zeylanica

TL;DR

This study identifies compounds from Pouzolzia zeylanica with antioxidant and anti-inflammatory properties, supported by in vitro and in silico experiments.

Contribution

The study combines in vitro and in silico methods to evaluate the pharmacological potential of eight isolated compounds from Pouzolzia zeylanica.

Findings

Compound 3 showed the strongest antioxidant activity with low IC50 values in DPPH and TBARS assays.

Compound 8 exhibited the most potent anti-inflammatory effect by inhibiting NO, TNF-α, and IL-6.

In silico results confirmed the compounds' antioxidant and anti-inflammatory potential, aligning with experimental data.

Abstract

The present study involves the isolation, structural elucidation, and biological evaluation of eight compounds from Pouzolzia zeylanica. From the n-hexane and ethyl acetate extracts of the plant, eight compounds were successfully isolated and identified: oleanolic acid (1), ursolic acid (2), 2α-hydroxyursolic acid (3), 3β-O-acetyl-12-oleanen-28-oic acid (4), 5-hydroxy-6,7-dimethoxyflavanone (5), 4′-methoxytectochrysin (6), 3,4′,5,7-tetrahydroxyflavanone-3-O-L-rhamnopyranoside (7), and 3,3′,5,5′,7-pentahydroxyflavanone-3-O-L-rhamnopyranoside (8). These compounds were evaluated for in vitro antioxidant activity using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and lipid peroxidation inhibition (TBARS) assays, as well as anti-inflammatory activity via inhibition of nitric oxide (NO) production and the secretion of pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in RAW 264.7 macrophages. It was observed that compound 3 exhibited the strongest antioxidant activity with IC50 values of 18.52 ± 1.50 µM (DPPH) and 10.34 ± 0.93 µM (TBARS), whereas compounds 2, 5, and 6 showed moderate to weak effects. Meanwhile, compound 8 demonstrated the most potent anti-inflammatory effect with IC50 values of 16.25 ± 0.95 µM (NO inhibition), 12.97 ± 0.88 µM (TNF-α inhibition), and 22.52 ± 1.98 µM (IL-6 inhibition). Furthermore, in silico approaches were employed, including density functional theory (DFT) calculations to predict the antioxidant mechanisms of compounds 1 and 3 and molecular docking to assess the cyclooxygenase-2 (COX-2) and phosphodiesterase-4B (PDE4B) inhibitory potentials of compounds 4, 7, and 8. Computational results aligned well with experimental data, supporting the potential of these compounds as natural antioxidant and anti-inflammatory agents.

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