Phenolic content and antioxidant activity of Nepeta parviflora Bieb. species from wild populations in Republic of Moldova

CP Stefanache; T Adriana; C Nina; G Veaceslav; D Doina; M Anca

doi:10.1055/s-0035-1565800

Planta Medica, Table of Contents

Phenolic content and antioxidant activity of Nepeta parviflora Bieb. species from wild populations in Republic of Moldova

CP Stefanache ¹, T Adriana ², C Nina ³, G Veaceslav ³, D Doina ¹, M Anca ²

¹NIRDBS Bucharest/'Stejarul' Biological Research Center, Piatra Neamt, Romania
²”Gr. T. Popa” University of Medicine and Pharmacy, Faculty of Pharmacy, Iasi, Romania
³Botanical Garden (Institute) of ASM, Chisinau, Moldova

Abstract

The genus Nepeta includes species that are wildly distributed, several having a special conservation status. Many therapeutic properties of Nepeta species are due to the phenolic and terpenic compounds, mainly essential oils.

Within the three Nepeta species in the spontaneous flora of Republic of Moldova (N. cataria L., N. pannonica L. and N. parviflora Bieb), our study focused on N. parviflora, species threatened with extinction in the local flora. Our study aimed to assess the total phenolic content and antioxidant activity of N. parviflora methanolic extracts. In this respect, samples were harvested before the flowering stage and at full flowering, from Buceag natural reservation.

The qualitative phytochemical study was carried out by thin layer chromatography (TLC), and the quantification of total phenolic content by Folin-Ciocalteu assay. The antioxidant activity was tested by DPPH and ABTS assays.

The TLC analysis revealed the presence of the phenolic acids (chlorogenic, caffeic, rosmarinic acids) and flavonoids (luteolin-7-O-glucoside, apigenin-7-O-glucoside). Folin-Ciocalteu assay showed a higher phenolic content in the samples harvested at full flowering (104.31 ± 2.27 mg gallic ac. equiv./g dry extract) compared with the samples harvested before the flowering stage (68.19 ± 1.49 mg/g d.e.). The antioxidant activity was in correlation with the total phenolic content, the samples harvested at full flowering having a higher antioxidant capacity (EC₅₀ values of 40.7 ± 0.3 µg/mL in DPPH assay and 13.2 ± 0.1 µg/mL in ABTS assay) compared with the samples harvested before the flowering stage (EC₅₀ values of 50.7 ± 0.4 in DPPH assay and ± 0.4 in ABTS assay). The species is rich in phenolic compounds with antioxidant activity, thus development of cultures having potential both for its capitalization and conservation.

Acknowledgement: The work was sustained from the Bilateral Collaboration Project RO-MD (694/2013) and the project PN 09 – 360401 (BIODIV) financed by ANCSI, Romania.