Phenolic profile and in vitro bioactive potential of Saharan Juniperus phoenicea L. and Cotula cinerea (Del) growing in Algeria

Abstract

The aim of this study was to characterize the individual phenolic profile and antioxidant, anti-inflammatory, cytotoxic, and antimicrobial activities of hydroethanolic and infusion extracts prepared from Algerian Saharan Juniperus phoenicea L. and Cotula cinerea (Del). The phenolic profile was determined using a liquid chromatograph coupled to a diode array detector and an electrospray ionization mass spectrometer (LC-DAD-ESI/MS). A total of thirteen and nine individual phenolic compounds were identified in J. phoenicea and C. cinerea, respectively. 3-p-Coumaroylquinic acid, quercetin- and myricetin-O-pentoside were the major compounds present in J. phoenicea; on the other hand, C. cinerea presented luteolin-7-O-glucoside, luteolin-O-malonylhexoside, and 5-O-caffeoylquinic acid as the main molecules. In general, all samples exhibited interesting antioxidant activity when compared to the standard Trolox, but J. phoenicea extracts presented the highest bioactivity. Likewise, all the samples exhibited anti-inflammatory activity; thus J. phoenicea hydroethanolic extracts showed the highest potential (88 ± 8 μg mL-1). In addition, their cytotoxicity was evaluated towards a panel of four selected cell lines (HeLa, NCI-H460, MCF-7 and HepG2), and all the extracts showed cytotoxic effects, with J. phoenicea extracts being the most effective. The in vitro antimicrobial activity of the plant extracts was moderate, Gram-positive bacteria thus being more sensitive than the Gram-negative strains (MIC values between 5 and 20 mg mL-1). The present work suggests that J. phoenicea and C. cinerea are sources of bioactive ingredients with potential use in the food and pharmaceutical industries.

Structural characterization of bioactive compounds in Cotula cinerea extracts by ultra‐high‐performance liquid chromatography with photodiode array and high‐resolution time‐of‐flight mass spectrometry detectors

“…The presence of phenolic acids in Cotula cinerea has been previously reported, including neochlorogenic acid, chlorogenic acid, and cryptochlorogenic acids, in addition to several derivatives of caffeoylquinic acids . The results presented herein confirm the occurrence of phenolic acid derivatives in Cotula cinerea.…”

“…Among the non‐glycosylated detected flavonoids, the quercetin derivatives chrysospenol‐D ( 6 ), chrysosplenetin ( 7 ), oxyayanin‐B ( 8 ), axillarin ( 9 ) and 3‐methylquercetin ( 10 ), which have all been previously reported in Cotula cinera extracts, were also detected in these samples. The structures of these compounds were readily assigned through a combination of their UV–vis spectra and high‐resolution mass spectra in addition to the subsequent MS/MS product ions which were in agreement with the proposed structures and the previously reported data for the proposed compounds . The [M − H] − ions of each compound, in addition to those corresponding to product ions involving cleavage of the C‐ring, were in agreement with the proposed structures (Table , Figure ) …”

“…The [M − H] − ion of compound 17 was observed at m/z 447, and its mass spectrum also showed a peak at m/z 285 corresponding to the [M − H − 162] − ion, indicating the glycosylated nature of this compound which was concluded to be luteolin 7‐ O ‐glucoside in agreement with previously reported data . Luteolin and its 7‐ O ‐glucosylated derivative have already been reported in Cotula cinerea samples . Their presence in the investigated sample was also confirmed by MS in the extracted ion current mode.…”

“…The results discussed above indicated that Cotula cinerea extracts contained several phenolic phytochemicals including phenolic acids, flavonoids, and sulfated flavonoids. While the occurrence of phenolic acid derivatives and flavonoids has been previously reported, to the best of our knowledge, this is the first report of sulfated flavonoids in Cotula cinerea extracts. Given the various biological activities attributed to such compounds in the last decade, including anticoagulant, antiplatelet, antiviral, anti‐inflammatory, immunomodulatory and antitumor properties, their presence in this plant will obviously play an important positive role in its biological activities and will make this plant an open research area for further investigations.…”

“…From a phytochemical point of view, Cotula cinerea was reported to contain a wide range of phytochemical compounds such as saponins, alkaloids, phenolic acids, tannins, flavonoids, steroids, and terpenoids . Although the phytochemical and the biological activities of Cotula cinerea have been reported in previous studies, the secondary metabolites of the Moroccan plant have not been thoroughly investigated and will be explored in the present work.…”