Comparative assessment of active compounds in Solidago species from the flora of the Republic of Moldova

Abstract

Introduction. Solidago virgaurea (European goldenrod) and Solidago canadensis (Canadian goldenrod) are two plant species that have been extensively investigated for their complex phytochemical profiles, particularly represented by flavonoids, phenolic acids, saponins, and essential oils with notable antioxidant and anti-inflammatory properties. Material and methods. Goldenrod plants were collected during the flowering period (2019–2024), S. virgaurea obtained from spontaneous flora and S. canadensis from the Scientific-Practical Center in the Domain of Medicinal Plants of Nicolae Testemitanu State University of Medicine and Pharmacy. The macroscopic analysis was performed using specific morphological indices of the Herba vegetal product, while the microscopic examination was performed on superficial preparations and cross-sections of vegetal material using a Micros microscope equipped with a digital imaging system. Dry extracts were prepared using repeated maceration, followed by phytochemical investigations employing qualitative color and sedimentation tests, ultraviolet-visible spectrophotometry (for total polyphenolic compounds, flavonoids, hydroxycinnamic acids, carotenoids, and saponins), and gas chromatography-mass spectrometry for essential oils. The antioxidant potential was assessed in vitro using the 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay and the metal chelation method. In vivo pharmacological studies included antimicrobial activity, assessed via serial dilution in liquid nutrient media, and anti-inflammatory activity, evaluated using the xylene-induced ear edema model in mice and the carrageenan- induced paw edema model in rats. Results. The biological, macroscopic, and microscopic investigations established reliable diagnostic criteria for the clear differentiation and identification of Herba-type vegetal products derived from the two Solidago species from the Moldovan flora. Qualitative phytochemical screening using specific color and sedimentation reactions confirmed the presence of flavonoids and triterpenic saponins in the examined vegetal products. Quantitative ultraviolet-visible spectrophotometric analysis revealed that S. canadensis contained relatively higher levels of bioactive compounds–flavonoids, hydroxycinnamic acids, saponins, and carotenoids–and exhibited greater antioxidant activity compared to S. virgaurea. Gas chromatography- mass spectrometry analysis showed that the essential oils of both species differ more quantitatively than qualitatively. Both Solidago species exhibited moderate anti-inflammatory and antibacterial activities. Conclusions. The results of this complex study support the selection of the vegetal product Solidaginis canadensis herba as a promising candidate for the local pharmaceutical industry, serving as a valuable source of new local plant-derived antioxidant, anti-inflammatory, and antibacterial drugs.