Pharmacognostic and pharmacological evaluation of Podranea ricasoliana (tanfani) sprague: Exploring its antimicrobial, antioxidant and anti-inflammatory properties

Abstract

The study investigated Podranea ricasoliana, a shrub with pinkish violet flowers known as “tecoma pink” or “pink trumpet,” from the Bignoniaceae family. It involved pharmacognostic profiling through macroscopic and microscopic characterization and evaluation of antimicrobial, antioxidant, analgesic and anti-inflammatory potential of ethanolic extracts of aerial parts of the plant in vitro and in vivo models. The extract's inhibitory activity was tested against bacteria (both gram-positive and gram-negative) and fungi using the cup-plate method. In vitro antioxidant potency was assessed through H₂O₂, DPPH, and NO scavenging methods. Anti-inflammatory and analgesic activities were evaluated using in vitro (protein denaturation inhibition assays and proteinase activity) and in vivo methods (via different animal models). The results demonstrated a dose-dependent and significant inhibitory activity, against B. subtilis and E. coli, with moderate inhibition against B. pumilus, P. aeruginosa, C. albicans, and A. niger. The extract exhibited strong antioxidant potential, scavenging H₂O₂, DPPH, and NO radicals with IC₅₀ values of 26.84 µg/mL, 524.28 µg/mL, and 99.84 µg/mL, respectively. In vitro studies indicated dose-dependent protein denaturation activity, showing potency comparable to the standard. In vivo studies revealed dose-dependent analgesic and anti-inflammatory effects, significantly reducing acid-induced writhing, rat paw edema, and formalin-induced nociception compared to the disease control (p < 0.001). This comprehensive examination of P. ricasoliana's pharmacognostic profile and bioactivity suggests its potential as a natural alternative to synthetic drugs.