Hypericum Essential Oils—Composition and Bioactivities: An Update (2012–2022)

Abstract

Hypericum genus, considered to comprise over 500 species that exhibit cosmopolitan distribution, has attracted human interest since ancient times. The present review aims to provide and summarize the recent literature (2012–2022) on the essential oils of the title genus. Research articles were collected from various scientific databases such as PubMed, ScienceDirect, Reaxys, and Google Scholar. Scientific reports related to the chemical composition, as well as the in vitro and in vivo pharmacological activities, are presented, also including a brief outlook of the potential relationship between traditional uses and Hypericum essential oils bioactivity.

Constituents, Enantiomeric Content, and ChE Inhibitory Activity of the Essential Oil from Hypericum laricifolium Juss. Aerial Parts Collected in Ecuador

“…The chemical profiles of Hypericum EOs exhibit extensive qualitative and quantitative variability, including the distribution of the main constituents [ 5 ]. In general, the various parameters affecting the content, composition, and yields of Hypericum EOs could be related to the effect of variables such as genetic factors, developmental stages, and seasonal variation phenological cycle, types of plant material and specific organs studied, methods of extraction, environmental conditions, and geographic distribution [ 5 ]. The main constituents of the EO from H. laricifolium aerial parts collected in Ecuador were limonene (about 26.5%), ( E )-β-ocimene (about 24.5%), ( Z )-β-ocimene (about 14.5%).…”

“…The most frequently reported major constituents of Hypericum EOs are the monoter-pene hydrocarbons α- and β-pinenes, the sesquiterpene hydrocarbons ( E )- β-caryophyllene and germacrene D, and the oxygenated sesquiterpenes spathulenol and caryophyllene oxide; however, in some cases, major constituents are n -alkanes, such as n -undecane and n -nonane [ 5 ]. The EO of Ecuadorian H. laricifolium belongs to the “terpenoid” type; however, α- and β-pinenes, and germacrene D are only minor components (<3%), while the high content (>12%) of β-ocimene stereoisomers and limonene, accounting for more than 65% of the oil, is unprecedented among Hypericum EOs [ 5 ]. Such characteristic can thus be considered a reliable identification marker of the EO from Ecuadorian H. laricifolium aerial parts.…”

“…Several Hypericum spp. are used throughout the world in folk medicine, as astringent, febrifuge, diuretic, antiphlogistic, analgesic, antispasmodic, antimigraine, antiepileptic, cholagogue, and antidepressant agents, and to treat diarrhea, dyspepsia, parasite, neuralgia, sciatic, and rheumatism [ 3 , 4 , 5 , 6 ]. As a typical example, H. perforatum has become one of the most extensively studied herbs and is probably the best-known medicinal herb on the market today [ 7 , 8 , 9 ].…”

“…Several contents of Hypericum EOs show an extensive qualitative and quantitative variability, even within the same species, depending on different factors, including environmental conditions and geographic distribution [ 5 ]. Therefore, we were interested in characterizing the EO from H. laricifolium aerial parts collected in Ecuador and in comparing it with the EO from Venezuela [ 3 ].…”

“…In this context, the essential oils have become of great interest, due to their availability, good penetration of the blood–brain barrier, and few side effects or toxicity, as well as their biodegradability [ 37 , 39 ]. Some extracts of Hypericum species, for example, those of H. perforatum , H. humifusum , H. neurocalycinum , and H. malatyanum , have exhibited high potential for the treatment of AD [ 20 , 40 , 41 ]; however, the ChE inhibitory effects of volatile fractions isolated from Hypericum species have not yet been tested [ 5 ].…”