LC-MS/MS profiles and interrelationships between the enzyme inhibition activity, total phenolic content and antioxidant potential of Micromeria nervosa extracts.

The objective of this study was to quantify the phenolic compounds and to evaluate and compare the biological activities of the ethyl acetate (EtOAc), methanolic (MeOH) and aqueous extracts from the Micromeria nervosa aerial parts, based on their antioxidant activity and enzymatic inhibition. Total phenolic and flavonoid contents were calculated and individual compo3unds were detected using LC-ESI-MS/MS. The antioxidant activity was determined using six different assays while enzymatic activity was determined by α-amylase and tyrosinase enzyme inhibition. The main phenolic constituents detected in the extracts were rosmarinic acid. In the antioxidant assays the aqueous extract was shown to be more efficient than the others. The EtOAc and MeOH extracts presented higher inhibitory activity with respect to α-amylase and tyrosinase. Regardless of the solvent, the results suggest M. nervosa aerial extracts present a biological potential due to their antioxidant activity and enzymatic inhibition.

Ziziphora taurica subsp. taurica: Analytical Characterization and Biological Activities.

The Lamiaceae family comprises many flowering plants classified into about 236 genera. The genus Ziziphora is one of the well-known genera of this family and its species are important in different fields of pharmaceutical, chemical, traditional, and folk medicines. The phytochemicals present in Ziziphora include monoterpenic essential oils, triterpenes, and phenolic substances. The aim of this paper was to study the phytochemical profile of Ziziphora taurica subsp. taurica and compare and evaluate the biological activities of its ethyl acetate (ZTT-EtOAc), methanolic (ZTT-MeOH), and aqueous (ZTT-W) extracts based on their enzyme inhibition and antioxidant capacities. Determination of total phenolic (TPC) and total flavonoid (TFC) contents as well as biological activities were determined using spectrophotometric procedures. Subsequently, the individual phenolic compounds were detected by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). In total, twenty-two different phenolic compounds were identified, including apigenin, ferulic acid, and luteolin which were the most common. ZTT-MeOH extract showed the best antioxidant activity, whereas ZTT-EtOAc extract was the most effective against tyrosinase and α-amylase. Ziziphora taurica subsp. taurica represents a potential source of natural compounds with positive effects on human health.

Phenolic composition, enzyme inhibitory, and antioxidant activity of Bituminaria bituminosa.

This study aimed to evaluate the in vitro antioxidant and enzyme inhibitory activities of ethyl acetate, methanol, and water extracts of Bituminaria bituminosa. In phosphomolybdenum assay, the methanol extract showed the highest activity (166.78 µmol TEs/g dry plant). The water extract exhibited the highest scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH∙) and 2,2-azino-bis (3-ethylbenzothiazloine-6-sulphonic acid) (ABTS∙+). In addition, it exhibited the highest activity in cupric ion reducing (CUPRAC) and ferric reducing antioxidant power (FRAP) assays (41.26 and 46.82 µmol TEs/g dry plant). The extracts did not show cholinesterase and tyrosinase inhibitory activity. However, α-glucosidase inhibition assay resulted in the superiority of water extract (1233.86 µmol ACEs/g dry plant). In the case of α-amylase inhibitory assay, the ethyl acetate extract showed the highest activity (53.65 µmol ACEs/g dry plant). The water extract exhibited the highest phenolic content (31.70 µmol GAEs/g dry plant). In contrast, the methanol extract was found rich in flavonoid compounds (5.29 µmol REs/g dry plant). The water extract contained considerable amounts of rosmarinic acid, luteolin, quercetin, and rutin. Therefore, it can be used as a source of new and alternative antioxidant and enzyme inhibitory agents.