**1. Introduction**

*Ericaceae* is a cosmopolitan family, represented by 124 genera and 4100–4250 species that are widely distributed around the world, particularly in the Mediterranean area, in deficient and non-calcic soils, as well as in high mountains [1–4]. Within this family, *Erica* and *Calluna* are the most abundant and widely spread genera. In Northern Morocco, *E. multiflora*, *E. scoparia*, and *C. vulgaris* are traditionally consumed by local people

**Citation:** Bekkai, D.; Oulad El

Majdoub, Y.; Bekkai, H.; Cacciola, F.; Miceli, N.; Taviano, M.F.; Cavò, E.; Errabii, T.; Laganà Vinci, R.; Mondello, L.; et al. Determination of the Phenolic Profile by Liquid Chromatography, Evaluation of Antioxidant Activity and Toxicity of Moroccan *Erica multiflora, Erica scoparia*, and *Calluna vulgaris* (*Ericaceae*). *Molecules* **2022**, *27*, 3979. https://doi.org/10.3390/ molecules27133979

Academic Editor: Nour Eddine Es-Safi

Received: 1 June 2022 Accepted: 18 June 2022 Published: 21 June 2022

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in the form of infusions, and are well known for their therapeutic properties [5–7]. In Morocco, *Erica multiflora* L. and *Erica scoparia* L. are considered among the most well-known species of the *Erica* genus [1,8]. According to popular knowledge, both species might have anti-inflammatory and analgesic properties when it comes to urinary diseases [5,6]. Moreover, *E. multiflora* has shown antihyperlipidemic and liver function repair effects [8,9], and effective antilithiatic activity [10].

*Calluna vulgaris* (L.) Hull belongs to the monotypic genus of *Calluna*, also known for its powerful bioactive compounds. It is widely used to treat kidney and urinary system disorders, particularly inflammatory diseases of the bladder, prostate, and urinary tract [7,11–15]. It is also important to note that heather honey obtained from *C. vulgaris* nectar is a special type of honey that is highly appreciated by consumers, not only for its distinctive flavor and dietary value but also for its therapeutic purposes [12,15].

These biological effects are closely related to their composition in bioactive compounds such as flavonoids, tannins, anthocyanins, vitamins C and E, triterpenoids, saponins, proteins, steroids, coumarins, ascorbic acid, hydroquinone, etc. [4,16–19]. In the human body, the accumulation of free radicals induces numerous illnesses and health issues. Therefore, research within plants for natural antioxidant sources might be a promising alternative to lower the incidence of multiple diseases that are due to oxidative stress [20,21]. Polyphenols are an important class of secondary metabolites in plants, characterized by one or more hydroxyl groups binding to one or more aromatic rings, and are divided into two groups: flavonoids and non-flavonoids [22]. The biological and medicinal proprieties of antioxidant compounds such as plant polyphenols have been widely reported in the scientific literature [23]. Indeed, the protective role of polyphenols, especially as free radical scavengers, has been well established, and these molecules may play a prominent role in the prevention and/or the treatment of oxidative stress-induced diseases [24].

In the current study, *E. multiflora*, *E. scoparia*, and *C. vulgaris*, collected from Northern Morocco, were investigated for their phenolic composition and were further tested for their antioxidant properties as well as for their potential toxicity. In particular, the qualitative–quantitative profile of the phenolic constituents contained in the hydroalcoholic extracts obtained from the leaves and aerial parts of both *Erica* species and from the leaves of *C. vulgaris* was determined by LC–DAD/ESI–MS analyses. In order to provide a comprehensive view of the antioxidant profiles, the in vitro antioxidant effectiveness of the extracts was assessed by using three different methods: the DPPH (1,1-diphenyl-1-picrylhydrazyl) test and the reducing power and ferrous ion chelating assays. Moreover, the brine shrimp (*Artemia salina* Leach) lethality bioassay was utilized to evaluate the toxicity.

The phenolic content of *E. multiflora* has been already evaluated in other works [2,8,25,26]; however, either the leaves [2,8] or flowers [25]/entire plant [26] have been investigated. Notably, ref. [2] refers to an Algerian species, whereas ref. [25] refers to a Tunisian species. No data are available in the literature on the chemical composition and biological properties of *E. scoparia*; on the other hand, for *C. vulgaris*, only the inflorescences of a Portuguese species [27] have been reported so far.
