Comparative Pharmacological Analysis of Certain Secondary Metabolite-Containing Fractions from Georgian Flora Species of Primula

Abstract

Background: The genus Primula L., comprising approximately 577 species worldwide, includes 22 species recorded in Georgia. Notably, Primula saguramica Gavr. is a Georgian endemic, while Primula woronowii Losinsk. Phytochemical investigations of Primula species have revealed a variety of bioactive compounds, including flavonoids, saponins, and phenolic compounds, which are known to possess antioxidant, anti-inflammatory, antimicrobial, expectorant, and antirheumatic properties. Objectives: This study aimed to conduct a preliminary pharmacological evaluation of secondary metabolite-containing fractions of different polarities obtained from three Primula species growing in Georgia: P. macrocalyx Bunge, P. woronowii Losinsk., and P. saguramica Gavr. Methods: Based on recent TLC screening, in vitro analyses, and literature data, the analgesic and anti-inflammatory potential of crude extracts and their corresponding fractions were assessed in vivo using the "hot plate" and carrageenan-induced paw edema models, respectively. All animal studies were conducted by the 3Rs principles and were approved by the TSMU Ethics Committee on Animal Research (Approval # AP-56-22). Results: The in vivo experiments demonstrated analgesic and anti-inflammatory efficacy of the fractions, with activity ranging from 22% to 120% and 26% to 84%, respectively, compared to the control group. Variability in pharmacological activity is presumed to be influenced by the flavonoid-to- terpenoid ratio within specific fractions. These findings support the rationale for a detailed investigation of the most active fractions to isolate and identify the individual compounds responsible for the observed effects. Conclusions: The study confirms the analgesic and anti-inflammatory potential of secondary metabolite-rich fractions from Primula species. Activity differences appear to be influenced by the flavonoid-to-terpenoid ratio, suggesting the need for further phytochemical analysis to isolate and characterize the active constituents.