Antioxidant and Toxic Activity of Helichrysum arenarium (L.) Moench and Helichrysum italicum (Roth) G. Don Essential Oils and Extracts

Abstract

Helichrysum arenarium (L.) Moench (sandy everlasting) is the only species from genus Helichrysum Mill that grows spontaneously in Lithuania. The chemical composition of the essential oils (EOs) from inflorescences and leaves of H. arenarium wild plants was analysed by GC-MS. Palmitic (≤23.8%), myristic (≤14.9%) and lauric (6.1%) acids, n-nonanal (10.4%), and trans-β-caryophyllene (≤6.5%) were the major constituents in the EOs. For comparison, the main components in EO from flowers (commercial herb material) of H. italicum were γ-curcumene (21.5%), β-selinene (13.6%), α-selinene (8.1%), β-eudesmol (8.3%), and α-pinene (6.5%). Composition of H. arenarium methanolic extracts was investigated by HPLC-DAD-TOF. The main compounds were the following: luteolin-7-O-glucoside, naringenin and its glucoside, apigenin, chlorogenic acid, arenol, and arzanol. Antioxidant activity of EOs and extracts was tested by DPPH● and ABTS●+ assays. Sandy everlasting extracts exhibited significantly higher radical scavenging activities (for leaves 11.18 to 19.13 and for inflorescences 1.96 to 6.13 mmol/L TROLOX equivalent) compared to those of all tested EOs (0.25 to 0.46 mmol/L TROLOX equivalent). Antioxidant activity, assayed electrochemically by cyclic and square wave voltammetry correlated with total polyphenolic content in extracts and radical scavenging properties of EOs and extracts. The toxic activity of EOs of both Helichrysum species was evaluated using a brine shrimp (Artemia salina) bioassay. H. italicum inflorescence EO was found to be toxic (LC50 = 15.99 µg/mL) as well as that of H. arenarium (LC50 ≤ 23.42 µg/mL) oils.

Hydroxypropyl-β-Cyclodextrin-Based Helichrysum italicum Extracts: Antioxidant and Cosmeceutical Activity and Biocompatibility

“…Another compound presented in substantial amounts was neo -intermedeol ( 45 ) (1.86% in OPT-1 and 1.34%), a sesquiterpene, which has not been previously reported in H. italicum , but is quite abundant in an African species, H. umbraculigerum. Also relatively well represented in the extracts were β-selinene ( 37 ) (2.02 and 1.46 for OPT-1 and OPT-2, respectively), γ-curcumene ( 35 ) (1.17 and 1.22 for OPT-1 and OPT-2, respectively), 4,6,9-trimethyl-8-decene-3,5-dione, (italidione I) ( 27 ) (1.23 and 0.7 for OPT-1 and OPT-2, respectively), and nerol ( 19 ) (0.94 and 0.64 for OPT-1 and OPT-2, respectively) which have been reported before [ 5 , 15 ]. HP-β-CD was effective for the encapsulation of some non-polar molecules that may also be found in H. italicum essential oils such as, limonene, linalool, [ 24 ], and α-pinene [ 25 ].…”

“…In addition, arzanol, a prenylated heterodimeric phloroglucinyl pyrone from H. italicum [ 8 ] that OPT-1 and OPT-2 extracts are rich in [ 10 ], shows antioxidant activity and is able to protect linoleic acid against free radical attack in assays of autoxidation and EDTA-mediated oxidation [ 14 ]. The H. italicum essential oil also displayed notable antioxidant properties in several studies [ 6 , 15 , 16 ], thus contributing to the observed activities of the extracts. Interestingly, the solvents also displayed a degree of antioxidant activity.…”

“…The most probable cause of the observed quantitative discrepancies in this study is the method for the separation of lipophilic oil components. Namely, hydro-distillation is the most common technique for essential oil isolation, including H. italicum essential oils [ 15 ]. However, it is not suited for the separation of larger molecules from the plant matrix.…”

“…The influence of the prepared extracts on the free radicals (as modeled by DPPH free radicals), the reducing activity (as modeled by power in the reducing power assay), and the activity in heat-induced unsaturated fatty acid degradation in the β-carotene-linoleic acid system was investigated and compared with the activity of standard antioxidants, BHA and ascorbic acid. The essential oil and the extracts of H. italicum displayed notable antiradical activity in the DPPH assay [ 6 , 8 , 15 ]. However, the reducing power and the activity in the β-carotene-linoleic acid assay have not been described so far.…”

“…Other phenolic plant constituents, e.g., flavonoids, such as luteolin and apigenin derivatives, display anti-erythematous and photoprotective activities [ 4 ]. In addition, it has been repeatedly shown that H. italicum essential oil [ 6 , 15 , 16 ] and hydrosol [ 16 ] display antimicrobial and antioxidant properties.…”