Physico-Chemical Parameters, Phenolic Profile, In Vitro Antioxidant Activity and Volatile Compounds of Ladastacho (Lavandula stoechas) from the Region of Saidona

Abstract

The aim of the present study was to characterize Lavandula stoechas (Ladastacho) from the region of Saidona by means of physico-chemical parameters, phenolic profile, in vitro antioxidant activity and volatile compounds. Physico-chemical parameters (pH, acidity, salinity, total dissolved solids, electrical conductivity and liquid resistivity) were determined using conventional methods. The phenolic profile was determined using high-performance liquid chromatography electrospray ionization mass spectrometry (HPLC/ESI-MS), whereas a quantitative determination was also accomplished using the total phenolics assay. In vitro antioxidant activity was determined using the 2,2-diphenyl-1-picryl-hydrazyl assay. Finally, volatile compounds were determined using headspace solid phase microextraction coupled to gas chromatography mass spectrometry (HS-SPME/GC-MS). The results showed that Lavandula stoechas aqueous extract had a slightly acidic pH, low salinity content and considerable electrochemical properties (electrical conductivity and liquid resistivity along with electric potential). In addition, aqueous fractions showed a significantly (p < 0.05) higher phenolic content and in vitro antioxidant activity, whereas phenolic compounds, such as caffeic acid, quercetin-O-glucoside, lutelin-O-glucuronide and rosmarinic acid, were identified. Finally, numerous volatile compounds were found to dominate the volatile pattern of this flowering plant, producing a strong, penetrating, cool and menthol-like odour.

Antioxidant Activity of Polyphenolic Plant Extracts

“…In general, the phytochemical and pharmacognostical studies of local plant varieties, especially those used as traditional medicinal plants, is considered currently important for drug and food supplement development [29]. Thus, Karabagias et al [30] examined the antioxidant properties of Lavandula stoechas grown in Greece. L. stoechas has been used in the traditional medicine since ancient times [30].…”

“…Thus, Karabagias et al [30] examined the antioxidant properties of Lavandula stoechas grown in Greece. L. stoechas has been used in the traditional medicine since ancient times [30]. Both methanolic and aqueous extracts of L. stoechas exhibited in vitro antioxidant activity, but the latter was the most potent [30].…”

“…L. stoechas has been used in the traditional medicine since ancient times [30]. Both methanolic and aqueous extracts of L. stoechas exhibited in vitro antioxidant activity, but the latter was the most potent [30]. The major polyphenols found in L. stoechas aqueous extract were caffeic acid, quercetin-O-glucoside, lutelin-O-glucuronide and rosmarinic acid [30].…”

“…Both methanolic and aqueous extracts of L. stoechas exhibited in vitro antioxidant activity, but the latter was the most potent [30]. The major polyphenols found in L. stoechas aqueous extract were caffeic acid, quercetin-O-glucoside, lutelin-O-glucuronide and rosmarinic acid [30]. Moreover, fifty volatile compounds belonging to alcohols, aldehydes, ketones, norisoprenoids, and numerous terpenoids were identified by using HS-SPME/GC-MS [30].…”

“…The major polyphenols found in L. stoechas aqueous extract were caffeic acid, quercetin-O-glucoside, lutelin-O-glucuronide and rosmarinic acid [30]. Moreover, fifty volatile compounds belonging to alcohols, aldehydes, ketones, norisoprenoids, and numerous terpenoids were identified by using HS-SPME/GC-MS [30]. In another study, Blando et al [31] assessed the antioxidant activity of polyphenolic extracts from cladodes of Opuntia ficus-indica (L.).…”