Differences in bioactivity of three endemic Nepeta species arising from main terpenoid and phenolic constituents

Abstract

Methanol extracts of three endemic Nepeta species were analyzed for their main secondary metabolites, terpenes and phenolics, and further investigated for antioxidant capacity and embryonic toxicity in zebrafish. UHPLC/DAD/(±) HESI-MS/MS analysis showed that the dominant compound in N. rtanjensis was trans,cis-nepetalactone, the cis,trans isomer of this monoterpene lactone was dominant in N. sibirica, while nepetalactone was detected only in traces in N. nervosa. In all investigated species, rosmarinic acid was the dominant phenolic compound, while other identified phenolic acids (chlorogenic, neochlorogenic and caffeic) were present in considerably lower amounts. ABTS and DPPH assays showed that the methanol extracts of N. rtanjensis, N. sibirica and especially N. nervosa possessed strong antioxidant activities, with the FRAP assay revealing high ferric-reducing abilities for all three tested species. Such a strong antioxidant potential, especially as manifested in the DPPH and FRAP assays, can be attributed to phenolic acids, and in the first place to rosmarinic acid. Increased lethality of zebrafish embryos in any of the treatments was not observed, but several toxic effects on embryonic development were recorded, such as pericardial and yolk sac edema. As in other Nepeta species, the three studied endemic species possessed a great potential for food conservation or as medicinal supplements if applied in optimized concentrations; however, alternative sources of plant material (e.g. field cultivation) should be established bearing in mind their vulnerability in nature.

Leaves micromorphology, chemical profile, and bioactivity of in vitro‐propagated Nepeta cyrenaica (Lamiaceae)

“…As we know, there are no literature data on the antioxidant potential of N. cyrenaica extracts and EO. However, there are several studies dealing with the antioxidant effects of other Nepeta taxa, 1,4,17,53,60,66,69 In contrast to the results of Zengin et al 4 and Patial et al, 60 the results of the current study showed that the extract obtained with DCM as the least polar solvent had the highest antioxidant capacity.…”

“…In general, Sharma et al 7 reported that more than 20 phenolic acid derivatives were isolated from the Nepeta species. The values presented in Table 4 were lower than in the studies performed by Dienaitė et al 59 and Nestorović Živković et al 66 These authors found that rosmarinic acid, ferulic acid, caffeic acid, and chlorogenic acid were the most abundant phenolic components of analysed Nepeta species. Rosmarinic acid was identified as one of major phenolic constituents of N. baytopii , while ferulic acid was not detected.…”

“…As we know, there are no literature data on the antioxidant potential of N. cyrenaica extracts and EO. However, there are several studies dealing with the antioxidant effects of other Nepeta taxa, 1,4,17,53,60,66,69 which highlighted that phenolic components are the most active antioxidant compounds of the Lamiaceae species. The results of the present study are in line with those of Nestorović Živković et al, 66 who found that methanolic extracts of Nepeta nervosa and N. rtanjensis had stronger DPPH neutralising activity than Nepeta sibirica , which is probably due to a 1.5–3.0 times higher content of rosmarinic acid.…”

“…64 The extracts of N. cyrenaica (Table 4) contained an over ten times lower amount of this iridoid than the in vitro-grown N. nuda. 64 Nestorovi c Živkovi c et al 66 found that amount of cis,trans-nepetalactone in two in vitro-grown Nepeta species was about 10 times higher than the levels of rosmarinic acid. The methanolic extracts of 12 Nepeta species studied by Miši c et al 14 also contained cis,trans-nepetalactone, as well as cis,cisnepetalactone, and dehydronepetalactone.…”

The impact of puffball autolysis on selected chemical and biological properties: Puffball extracts as potential ingredients of skin-care products

“…Phenolic compounds, α-tocopherol and ergosterol all possess antioxidant activity [24,[29][30][31] and are found in higher concentrations in the extracts of mature fruiting bodies; however, many other unknown metabolites are probably involved. Although phenolics may prevent lipid peroxidation [32], lipophilic compounds such are tocopherols and ergosterol may show a greater effect in the β-carotene bleaching assay.…”