Investigation of the phytochemical and antimicrobial activity of Primula veris L. extracts

Methanol, ethanol (50%) and aqueous extracts were prepared from the roots, leaves and flowers of Primula veris collected and dried under natural conditions in meadows near Marosludas in April 2018. The polyphenol contents of the plant parts, as well as the antioxidant capacity were measured by ABTS spectrophotometric methods. For the microbiology section, aqueous and ethanolic extracts (100 mg/ml) were prepared from the roots, leaves and flowers of Primula veris followed by testing of their antimicrobial activity against human pathogenic yeasts (Candida albicans, Candida parapsilosis, Candida glabrata) and bacteria (Gram negatives:, Escherichia coli, Acinetobacter sp., Pseudomonas aeruginosa, Enterobacter cloacae; Gram-positive: Enterococcus faecalis, Listeria monocytogenes, Staphylococcus aureus) by agar well diffusion method.

Ethanol proved to be the most effective solvent for all three drugs to determine the polyphenol content. The flower drug contains the highest amounts of polyphenols. With the ABTS method of antioxidant measurement, ethanolic extracts are more effective than aqueous extracts.

Agar well diffusion studies showed that all extracts caused complete inhibition within the inhibition zone in the yeasts tested. The inhibitory effect of aqueous extracts was stronger than that of ethanolic extracts in the case of all three plant parts. The greatest inhibition was caused by extracts of the roots with ethanol. The three yeasts tested showed similarly high sensitivity to roots extracts, while the inhibitory effect was weaker for leaf extracts. Candida parapsilosis was resistant to leaf and flower extracts. Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus aureus, like fungi, showed good sensitivity to extracts, while other bacteria showed little or no inhibitory effect.