Antifungal Essential Oils of Lamiaceae: History
Subjects: Biology
Contributors:

The incidence of fungal infections has been steadily increasing in recent years. Systemic mycoses are characterized by the highest mortality. At the same time, the frequency of infections caused by drug-resistant strains and new pathogens e.g., Candida auris increases. An alternative to medicines may be essential oils, which can have a broad antimicrobial spectrum. Rich in the essential oils are plants from the Lamiaceae family. 

  • Labiatae
  • fungi
  • Aspergillus
  • Cryptococcus
  • Penicillium
  • dermatophytes
  • β-caryophyllene
  • sesquiterpene
  • monoterpenes
  • minimal inhibitory concentration (MIC)

1. Introduction

Fungal infections belong to the most often diseases of humans. It is estimated that about 1.7 billion people (25% of the population) have skin, nail, and hair fungal infections [1]. The development of most of these infections is affected by dermatophytes, namely Trichophyton spp., Microsporum spp., and Epidermophyton spp. [2]. Simultaneously, mucosal infections of the oral and genital tracts caused by Candida spp. are very common. About 0.13 billion of women suffer from vulvovaginal candidiasis. On the other hand, oral candidiases are common in babies and denture wearers. Fungi also cause life-threatening systemic infections, with mortality reaching >1.6 million, which is >3-fold more than malaria [3]. Among life-threatening fungal infections prevail cryptococcosis (Cryptococcus neoformans) with >1,000,000 cases and mortality rate 20–70%, candidiasis (Candida albicans) with >400,000 cases and mortality rate 46–75%, pneumocystosis (Pneumocystis jirovecii) with >400,000 cases and mortality rate 20–80%, and aspergillosis (Aspergillus fumigatus) with >200,000 cases and mortality rate 30–95% [1,4,5]. In Table 1 are presented diseases caused by some of the most often fungal pathogens among people.
Table 1. Fungal pathogens of humans and most often observed mycoses (based on [6,7]).
Superficial mycoses
  • Hortae werneckii (Tinea nigra)
  • Malassezia furfur (Pityriasis versicolor)
  • Piedraia hortae (Black piedra)
  • Trichosporon spp. (White piedra)
Cutaneous and subcutaneous mycoses
  • Aspergillus spp. (Onychomycosis, Keratitis)
  • Candida spp. (Tinea pedis, Tinea cruris, Onychomycosis, Keratitis)
  • Chaetomium spp. (Subcutaneous phaeohyphomycosis)
  • Curvularia spp. (Subcutaneous phaeohyphomycosis)
  • Epidermophyton spp. (Tinea pedis, Tinea cruris, Onychomycosis)
  • Exophiala spp. (Chromoblastomycosis, Subcutaneous phaeohyphomycosis)
  • Fonsecaea spp. (Chromoblastomycosis)
  • Fusarium spp. (Onychomycosis, Keratitis, Eumycotic mycetoma)
  • Geotrichum spp. (Onychomycosis)
  • Microsporum spp. (Tinea corporis, Tinea capitis)
  • Phaeoacremonium spp. (Eumycotic mycetoma)
  • Phialophora spp. (Chromoblastomycosis, Subcutaneous phaeohyphomycosis)
  • Scopulariopsis brevicaulis (Onychomycosis)
  • Sporothrix schenckii (Lymphocutaneous sporotrichosis)
  • Trichophyton spp. (Tinea pedis, Tinea corporis, Tinea cruris, Tinea capitis, Onychomycosis)
  • Trichosporon spp. (Onychomycosis)
Endemic mycoses
  • Blastomyces dermatitidis (Blastomycosis)
  • Histoplasma capsulatum (Histoplasmosis)
  • Coccidioides immitis/posadasii (Coccidioidomycosis)
  • Penicillium marneffei (Penicilliosis)
  • Paracoccidioides brasiliensis (Paracoccidioidomycosis)
Opportunistic mycoses
  • Acremonium spp. (Hyalohyphomycosis-cutaneous, disseminated infection)
  • Alternaria spp. (Phaeohyphomycosis-subcutaneous, sinusitis, disseminated infection)
  • Aspergillus spp. (Allergic reactions, Aspergillosis-nasal, sinusitis, bronchial, pulmonary, systemic dissemination)
  • Bipolaris spp. (Phaeohyphomycosis-subcutaneous, sinusitis, brain abscess)
  • Candida spp. (Candidiasis-superficial mucosal, cutaneous, widespread hematogenous distribution involving target organs)
  • Cryptococcus spp. (Cryptococcosis-cutaneous, pulmonary, meningitis)
  • Curvularia spp. (Phaeohyphomycosis-subcutaneous, sinusitis, disseminated infection)
  • Fusarium spp. (Hyalohyphomycosis-cutaneous, disseminated infection)
  • Lichtheimia spp. (Mucormycosis-cutaneous, invasive)
  • Mucor spp. (Mucormycosis-cutaneous, invasive)
  • Paecilomyces spp. (Hyalohyphomycosis-cutaneous, disseminated infection)
  • Pneumocystis jirovecii (Pneumocystosis-pneumonia, extrapulmonary manifestations)
  • Rhizomucor spp. (Mucormycosis-cutaneous, invasive)
  • Rhizopus spp. (Mucormycosis-cutaneous, invasive)
  • Scedosporium spp. (Hyalohyphomycosis-cutaneous, disseminated infection)
  • Trichosporon spp. (Trichosporonosis-invasive disease)
  • Wangiella spp. (Phaeohyphomycosis-subcutaneous, sinusitis, brain abscess)
The big problem is growing drug-resistance amid fungi. Among Candida and Aspergillus species is observed resistance to azoles, e.g., to fluconazole, voriconazole, and posaconazole. Some Candida species, especially C. glabrata and C. parapsilosis, can be echinocandin- and multidrug-resistant [8,9]. Acquired resistance to echinocandins has also been reported for yeasts C. albicansC. tropicalisC. kruseiC. kefyrC. lusitaniae, and C. dubliniensis [10]. More than 3% of Aspergillus fumigatus isolates are resistant to one or more azoles [11]. Polyene resistance mainly concerns amphotericin B. Resistance to this drug is observed in Fusarium spp., Trichosporon spp., Aspergillus spp., and Sporothrix schenckii [12,13]. Resistance to amphotericin B has also been reported for C. albicansC. glabrata, and C. tropicalis [14,15,16]. Cultures of some Candida species and Cryptococcus neoformans are presented in Figure 1.
Figure 1. Cultures of selected yeast fungi on Sabouraud agar (Author of photos: Tomasz M. Karpiński).
The new epidemiological problem is C. auris, a multidrug-resistant organism first described in Japan in 2009 [17]. Recently, C. auris has been reported from 36 countries from six continents [18]. About 30% of isolates demonstrate reduced susceptibility to amphotericin B, and 5% can be resistant to the echinocandins [19,20]. The estimated mortality from C. auris fungemia range from 28% to 60% [21].
Fundamental issues are also the costs of treatment and hospitalization of patients with invasive fungal diseases. According to Drgona et al., all costs range from around €26,000 up to over €80,000 per patient [5].

2. Components of Essential Oils of Lamiaceae Family

The family Lamiaceae or Labiatae contains many valuable medicinal plants. In the family are 236 genera and between 6900 and 7200 species. To the most abundant genera belong Salvia (900 species), Scutellaria (360), Stachys (300), Plectranthus (300), Hyptis (280), Teucrium (250), Vitex (250), Thymus (220), and Nepeta (200). Lamiaceae plants rich in essential oils have great worth in natural medicine, pharmacology, cosmetology, and aromatherapy [25]. The essential oils are mostly present in leaves, however, they can be found in flowers, buds, fruits, seeds, rind, wood, or roots [26]. Essential oils are mixtures of volatile compounds, which are secondary plant metabolites. They play a role in the defense system of higher plants [27]. Essential oils may contain over 300 different compounds, mainly of molecular weight below 300 [28]. Some oils, e.g., obtained from LavandulaGeranium, or Rosmarinus, contain 450 to 500 chemicals [29]. Among the active compounds of essential oils are various chemical classes, e.g., alcohols, ethers, aldehydes, ketones, esters, phenols, terpenes (monoterpenes, sesquiterpenes), and coumarins [30,31].
To the chemical components most commonly found as the main ingredients in essential oils, among plants presented in Table 2, include β-caryophyllene (41 plants), linalool (27 plants), limonene (26), β-pinene (25), 1,8-cineole (22), carvacrol (21), α-pinene (21), p-cymene (20), γ-terpinene (20), and thymol (20) (Figure 2). Sesquiterpene β-caryophyllene seems particularly important antifungal component in the Lamiaceae family. Its activity and its derivatives, such as caryophyllene oxide is well known [134,135,136]. According to Bona et al. [137], essential oils containing high concentrations of phenolic monoterpenes (e.g., carvacrol, p-cymene, thymol) have great antifungal activities. Rich in these substances are, among others Origanum and Thymus plants. Important antifungal chemicals often presented in Lamiaceae are also other monoterpenes as alcohol linalool and cyclic 1,8-cineole, limonene, pinenes, and terpinenes [138,139,140,141,142,143,144,145,146]. Table 1 shows that all of these antifungal substances are common in presented plants.
Figure 2. Chemical formulas of ten substances the most commonly found in essential oils of Lamiaceae plants presented in Table 1.

3. Antifungal Activity of Essential Oils of Lamiaceae Family

In Table 3 are shown the antifungal activities of selected Lamiaceae essential oils. More than half of the essential oils have good activity (<1000 µg/mL) against fungi. In some cases are observed significant discrepancies between different studies. An example could be the action of essential oils from Italian Calamintha nepeta against Candida albicans. In the work of Marongiu et al. [39], minimal inhibitory concentrations amounted to 1.25–2.5 µg/mL, while in Božović et al. [40] MICs were between 780 to 12,480 µg/mL. Differences may be related to the different biochemical composition of the examined essential oils. In results presented by Marongiu et al. [39] the main components of essential oils were pulegone (39.9–64.4%), piperitenone oxide (2.5–19.1%) and piperitenone (6.4–7.7%), while in Božović et al. [40] three main substances were pulegone (37.7–84.7%), crysanthenone (1.3–33.9%) and menthone (0.5–35.4%). Some authors have described that the content of active substances varies depending on the season. In studies of Gonçalves et al. [60] in Mentha cervina during the flowering phase in August amount of isomenthone and pulegone in essential oil amounted 8.7% and 75.1% respectively. Simultaneously, in the vegetative phase in February, the content of both components changed significantly and amounted to 77.0% for isomenthone and 12.9% for pulegone. Similarly, Al-Maskri et al. [75] presented essential changes in some compounds of Ocimum basilicum essential oil between winter and summer. In the summer essential oil, there is significantly more of linalool, p-allylanisole and β-farnesene, and at the same time much less content of limonene and 1,8-cineole. In this work, a seasonal variation of chemical composition is directly related to other antifungal activities. It is particularly evident in action against Aspergillus niger, which was lower in the summer season. Zone of growth inhibition (ZOI) for winter essential oil was 21 mm and MIC > 50 µg/mL, while for summer essential oil-ZOI was 13 mm and MIC > 100 µg/mL [75]. Influence on the content of chemical substances in essential oils also has a method of obtaining them. Ćavar et al. [40] compared the composition of oils obtained from Calamintha glandulosa using three methods: Hydrodistillation (HD), steam distillation (SD) and aqueous reflux extraction (ARE). For example, the level of menthone was 3.3% in ARE, 4.7% in HD, and 8.3% in SD method, while for shisofuran was only 0.1% in HD and SD, and even 9.7% in ARE [40]. Additionally, many other factors can affect antimicrobial activity, such as amount and concentration of inoculum, type of culture medium, pH of the medium and incubation time. All these factors can affect the value of MIC [145]. Differences are visible in Table 2. Generally, it can be assumed that the best activity (MICs < 100) have essential oils from Clinopodium spp. (excluding C. nepeta subsp. glandulosum and C. umbrosum), Lavandula spp., Mentha spp. (excluding M. piperita), Thymbra spp., and Thymus spp. (excluding T. migricus and T. vulgaris). The highest values of MICs are presented among others for Aeollanthus suaveolensAgastache rugosaLepechinia muticaMentha × piperita, and Salvia sclarea. Simultaneously, some essential oils have a very different activity, and MIC values differ depending on the region, chemical composition, research methodology, etc. Significant variations can be observed even in Ocimum basilicum (MICs 1–10,000), O. sanctum (MICs 0.1–500), Origanum majorana (MICs 0.5–14,400) or in Thymus vulgaris (MICs 0.08–3600).
Table 3. Minimal inhibitory concentrations (MICs) of essential oils against fungi.
Source of the Essential Oil Targeted Fungus MICs (µg/mL; µl/mL) Reference(s)
Aeollanthus suaveolens Mart. ex Spreng. = A. heliotropioides Oliv. Candida albicans 1200–5000 [34]
Candida glabrata 5000 [34]
Candida krusei 2500 [34]
Candida parapsilosis 2500 [34]
Candida tropicalis 1200 [34]
Cryptococcus neoformans 600–5000 [34]
Agastache rugosa (Fisch. and C.A.Mey.) Kuntze Aspergillus flavus 10,000 [153]
Aspergillus niger 5000 [153]
Blastoschizomyces capitatus 5000 [153]
Candida albicans 28–5000 [153,154]
Candida utilis 5000 [153]
Candida tropicalis 5000 [153]
Cryptococcus neoformans 10,000 [153]
Trichoderma viride 5000 [153]
Trichophyton erinacei 780 [153]
Trichophyton mentagrophytes 3120 [153]
Trichophyton rubrum 1560 [153]
Trichophyton schoenleinii 1560 [153]
Trichophyton soudanense 1560 [153]
Trichophyton tonsurans 10,000 [153]
Trichosporon mucoides 5000 [153]
Ballota nigra subsp. foetida (Vis.) Hayek Alternaria solani 750 [37]
Botrytis cinerea 600 [37]
Fusarium coeruleum 350 [37]
Fusarium culmorum 300 [37]
Fusarium oxysporum 300 [37]
Fusarium solani 350 [37]
Fusarium sporotrichioides 350 [37]
Fusarium tabacinum 350 [37]
Fusarium verticillioides 300 [37]
Clinopodium dalmaticum (Benth.) Bräuchler and Heubl = Micromeria dalmatica Benth. Aspergillus niger 0.4 [38]
Aspergillus ochraceus 0.4 [38]
Cladosporium cladosporioides 0.4 [38]
Fusarium tricinctum 0.4 [38]
Penicilium ochrochloron 0.4 [38]
Phomopsis helianthi 0.2 [38]
Trichoderma viride 0.4 [38]
Clinopodium nepeta subsp. glandulosum (Req.) Govaerts = Calamintha glandulosa (Req.) Bentham = Calamintha officinalis Moench Aspergillus niger 1250 [39]
Candida albicans 2500 [39]
Clinopodium nepeta (L.) Kuntze = Calamintha nepeta (L.) Savi Aspergillus flavus 1.25–10 [41]
Aspergillus fumigatus 0.64–5 [41]
Aspergillus niger 0.32–10 [41]
Candida albicans 1.25–12,480 [41,42]
Candida guillermondii 1.25–2.5 [41]
Candida krusei 1.25–2.5 [41]
Candida parapsilosis 1.25–2.5 [41]
Candida tropicalis 1.25–2.5 [41]
Cryptococcus neoformans 0.32–1.25 [41]
Epidermophyton floccosum 0.64–2.5 [41]
Microsporum canis 0.64–2.5 [41]
Microsporum gypseum 1.25–5 [41]
Trichophyton mentagrophytes 0.64–5 [41]
Trichophyton rubrum 0.64–5 [41]
Clinopodium thymifolium (Scop.) Kuntze = Micromeria thymifolia (Scop.) Fritsch Aspergillus niger 2 [38]
Aspergillus ochraceus 2 [38]
Cladosporium cladosporioides 2 [38]
Fusarium tricinctum 2 [38]
Penicillium ochrochloron 2 [38]
Phomopsis helianthi 0.4 [38]
Trichoderma viride 2 [38]
Clinopodium umbrosum (M.Bieb.) Kuntze = Calamintha umbrosa Benth. Alternaria solani 3000 [43]
Fusarium oxysporum 2000 [43]
Helminthosporium maydis 1500 [43]
Dracocephalum heterophyllum Benth. Alternaria solani 625 [155]
Candida albicans 625–1000 [44,155]
Epidermophyton floccosum 2500 [155]
Fusarium semitectum 313 [155]
Hymenocrater longiflorus Benth. Aspergillus niger 480 [45]
Candida albicans 240 [45]
Hyptis ovalifolia Benth. Microsporum canis 15.6–1000 [46,156]
Microsporum gypseum 7.8–1000 [46,156]
Trichophyton mentagrophytes 15.6–1000 [46,156]
Trichophyton rubrum 7.8–1000 [46,156]
Hyssopus officinalis L. Aspergillus niger 52,200 [47]
Aspergillus ochraceus 26,100 [47]
Aspergillus versicolor 10,440 [47]
Candida albicans 128–1000 [44,48]
Candida glabrata 512–1024 [48]
Candida krusei 128–256 [48]
Candida parapsilosis 256–512 [48]
Candida tropicalis 512–1024 [48]
Cladosporium cladosporioides 10,440 [47]
Cladosporium fulvum 26,100 [47]
Penicillium funiculosum 52,200 [47]
Penicillium ochrochloron 26,100 [47]
Trichoderma viride 10,440 [47]
Lavandula angustifolia Mill. Candida albicans 0.125–512 [50,51,157]
Malassezia furfur >4 [49]
Trichophyton rubrum 1–512 [49,51]
Trichosporon beigelii 2 [49]
Lavandula multifida L. Aspergillus flavus 0.64 [52]
Aspergillus fumigatus 0.32 [52]
Aspergillus niger 0.32 [52]
Candida albicans 0.32 [52]
Candida guilliermondii 0.32 [52]
Candida krusei 0.64 [52]
Candida parapsilosis 0.32 [52]
Candida tropicalis 0.32 [52]
Cryptococcus neoformans 0.16 [52]
Epidermophyton floccosum 0.16 [52]
Microsporum canis 0.16 [52]
Microsporum gypseum 0.16 [52]
Trichophyton mentagrophytes 0.16 [52]
Trichophyton mentagrophytes var. interdigitale 0.16 [52]
Trichophyton rubrum 0.16 [52]
Trichophyton verrucosum 0.16 [52]
Lavandula pedunculata (Miller) Cav. Aspergillus flavus 5–10 [53]
Aspergillus fumigatus 2.5–5 [53]
Aspergillus niger 5 [53]
Candida albicans 2.5 [53]
Candida guillermondii 1.25 [53]
Candida krusei 1.25–2.5 [53]
Candida parapsilosis 2.5–5 [53]
Candida tropicalis 1.25–2.5 [53]
Cryptococcus neoformans 0.32–1.25 [53]
Epidermophyton floccosum 0.32–0.64 [53]
Microsporum canis 0.32–1.25 [53]
Microsporum gypseum 0.64–2.5 [53]
Trichophyton mentagrophytes 0.64–1.25 [53]
Trichophyton rubrum 0.32–1.25 [53]
Lavandula stoechas L. Aspergillus flavus 1.25–10 [54]
Aspergillus fumigatus 0.64–1.25 [54]
Aspergillus niger 0.32–1.25 [54]
Candida albicans 0.64–512 [51,54]
Candida guillermondii 1.25 [54]
Candida krusei 2.5 [54]
Candida parapsilosis 2.5 [54]
Candida tropicalis 2.5 [54]
Cryptococcus neoformans 0.64 [54]
Epidermophyton floccosum 0.16–0.32 [54]
Microsporum canis 0.16–0.64 [54]
Microsporum gypseum 0.32–0.64 [54]
Trichophyton mentagrophytes 0.32–0.64 [54]
Trichophyton mentagrophytes var. interdigitale 0.16–0.64 [54]
Trichophyton rubrum 0.16–256 [51,54]
Trichophyton verrucosum 0.32 [54]
Lavandula viridis L’Her. Aspergillus flavus 5 [55]
Aspergillus fumigatus 2.5 [55]
Aspergillus niger 2.5 [55]
Candida albicans 1.25–2.5 [55]
Candida guillermondii 0.64–1.25 [55]
Candida krusei 1.25–2.5 [55]
Candida parapsilosis 1.25 [55]
Candida tropicalis 1.25–2.5 [55]
Cryptococcus neoformans 0.64 [55]
Epidermophyton floccosum 0.32 [55]
Microsporum canis 0.32 [55]
Microsporum gypseum 0.64 [55]
Trichophyton mentagrophytes 0.32–0.64 [55]
Trichophyton mentagrophytes var. interdigitale 0.32–0.64 [55]
Trichophyton rubrum 0.32 [55]
Trichophyton verrucosum 0.32 [55]
Lepechinia mutica (Benth.) Epling Candida albicans >9000 [56]
Fusarium graminearum >9000 [56]
Microsporum canis 2200–4500 [56]
Pyricularia oryzae >9000 [56]
Trichophyton rubrum 2200–4500 [56]
Marrubium vulgare L. Aspergillus niger >1180 [58]
Botrytis cinerea >1100 [58]
Fusarium solani >1190 [58]
Penicillium digitatum >1120 [58]
Melissa officinalis L. Aspergillus niger 313 [158]
Candida albicans 30–313 [59,158]
Cryptococcus neoformans 78 [158]
Epidermophyton floccosum 30 [59]
Microsporum canis 30 [59]
Penicillium verrucosum 125 [159]
Trichophyton mentagrophytes var. mentagrophytes 15 [59]
Trichophyton rubrum 15 [59]
Trichophyton tonsurans 15 [59]
Mentha cervina L. Aspergillus flavus 2.5–5 [60]
Aspergillus fumigatus 1.25–2.5 [60]
Aspergillus niger 1.25–2.5 [60]
Candida albicans 1.25–2.5 [60]
Candida guillermondii 1.25–2.5 [60]
Candida krusei 1.25–2.5 [60]
Candida parapsilosis 1.25–2.5 [60]
Candida tropicalis 1.25–2.5 [60]
Cryptococcus neoformans 1.25 [60]
Epidermophyton floccosum 0.64–1.25 [60]
Microsporum canis 1.25 [60]
Microsporum gypseum 1.25–2.5 [60]
Trichophyton mentagrophytes 1.25–2.5 [60]
Trichophyton rubrum 1.25 [60]
Mentha × piperita L. Aspergillus flavus 1450–5000 [62,64]
Aspergillus niger 625–10,000 [64,158]
Aspergillus parasiticus 2500 [64]
Candida albicans 225–1125 [63,158,160]
Candida glabrata 225 [62]
Candida tropicalis 225–230 [62]
Cryptococcus neoformans 313 [158]
Fusarium oxysporum 125 [161]
Penicillium chrysogenum 1250 [64]
Penicillium minioluteum 2050–2200 [62]
Penicillium oxalicum 1300–2050 [62]
Penicillium verrucosum 2500 [90]
Mentha pulegium L. Aspergillus niger 0.25–1.25 [65,162]
Aspergillus flavus 1.25 [162]
Aspergillus fumigatus 1.25 [162]
Candida albicans 0.94–3.75 [65,66,162,163]
Candida bracarensis 3.75 [163]
Candida guillermondii 1.25 [162]
Candida krusei 0.94–1.25 [162,163]
Candida parapsilosis 1.25 [162]
Candida tropicalis 1.25 [162]
Cryptococcus neoformans 0.64 [162]
Epidermophyton floccosum 1.25 [162]
Microsporum canis 1.25 [162]
Microsporum gypseum 1.25–2.5 [162]
Saccharomyces cervisiae <0.3–0.94 [66,163]
Trichophyton mentagrophytes 1.25–2.5 [162]
Trichophyton mentagrophytes var. interdigitale 2.5 [162]
Trichophyton rubrum 1.25 [162]
Trichophyton verrucosum 1.25 [162]
Mentha requienii Bentham Alternaria spp. >40 [67]
Aspergillus fumigatus >60 [67]
Candida albicans 0.94–40 [67,163]
Candida bracarensis 3.75 [163]
Candida krusei 0.94 [163]
Fusarium spp. >40 [67]
Penicillum spp. >60 [67]
Rhodotorula spp. 45 [67]
Saccharomyces cerevisiae 0.94 [163]
Mentha spicata L. Aspergillus flavus 1.25 [162]
Aspergillus fumigatus 0.64 [162]
Aspergillus niger 0.64–313 [158,162]
Candida albicans 1.25–625 [51,158,162]
Candida guillermondii 1.25 [162]
Candida krusei 1.25 [162]
Candida parapsilosis 1.25 [162]
Candida tropicalis 1.25 [162]
Cryptococcus neoformans 0.32–313 [158,162]
Epidermophyton floccosum 0.64 [162]
Fusarium graminearum 2.5 [164]
Fusarium moniliforme 2.5 [164]
Malassezia furfur >4 [49]
Microsporum canis 0.64–2 [68,162]
Microsporum gypseum 0.64–3 [162]
Penicillium corylophilum 0.625 [165]
Penicillium expansum 2.5 [164]
Trichophyton erinacei 3 [68]
Trichophyton mentagrophytes 0.64–3 [68,162]
Trichophyton mentagrophytes var. interdigitale 0.64 [162]
Trichophyton rubrum 0.25–512 [49,51,162]
Trichophyton terrestre 3 [68]
Trichophyton verrucosum 0.32 [162]
Trichosporon beigelii 0.25 [49]
Mentha suaveolens Ehrh. Candida albicans 0.34–1250 [69,71,166]
Candida glabrata 0.69–2.77 [69]
Cryptococcus neoformans 300 [167]
Microsporum canis 1250 [167]
Microsporum gypseum 1250 [167]
Trichophyton mentagrophytes 600–1250 [167]
Trichophyton rubrum 5000 [167]
Trichophyton violaceum 600 [167]
Micromeria albanica (Griseb. ex K. Maly) Silic Aspergillus niger 0.2 [38]
Aspergillus ochraceus 0.2 [38]
Cladosporium cladosporioides 0.2 [38]
Fusarium tricinctum 0.4 [38]
Penicilium ochrochloron 0.2 [38]
Phomopsis helianthi 0.2 [38]
Trichoderma viride 0.4 [38]
Moluccella spinosa L. Aspergillus niger 50 [72]
Candida albicans 100 [72]
Fusarium oxysporum 100 [72]
Nepeta ciliaris Benth. = Nepeta leucophylla Benth. Alternaria solani 3000 [43]
Candida albicans 0.78 [168]
Fusarium oxysporum 1000 [43]
Trichophyton rubrum 0.19 [168]
Helminthosporium maydis 1500 [43]
Nepeta clarkei Hook. f. Alternaria solani 3000 [43]
Fusarium oxysporum 2000 [43]
Helminthosporium maydis 2000 [43]
Ocimum basilicum L. Aspergillus flavus 10,000 [64]
Aspergillus fumigatus >50 [75]
Aspergillus niger >50–10,000 [64,75,158]
Aspergillus parasiticus 5000 [64]
Candida albicans 30–625 [73,74,158]
Candida guilliermondii 3.125–6.25 [76]
Cryptococcus neoformans 313–1250 [158,169]
Debaryomyces hansenii 6.25 [76]
Epidermophyton floccosum 15 [74]
Microsporum canis 1–15.2 [68,74]
Microsporum gypseum 3 [68]
Penicillium chrysogenum 10,000 [64]
Penicillium italicum >50 [75]
Rhizopus stolonifer >50 [75]
Rhodotorula glutinis 86 [73]
Trichophyton erinacei 2.5 [68]
Trichophyton mentagrophytes 2.5–8.3 [68,74]
Trichophyton terrestre 3 [68]
Saccharomyces cerevisiae 28 [73]
Schizosaccharomyces pombe 86 [73]
Trichophyton rubrum 8.3 [74]
Trichophyton tonsurans 8 [74]
Yarrowia lypolytica 57 [73]
Ocimum × africanum Lour. = Ocimum × citriodorum Candida guilliermondii 3.125 [76]
Debaryomyces hansenii 1.56 [76]
Ocimum campechianum Mill. = Ocimum micranthum Willd. Candida albicans 69 [73]
Rhodotorula glutinis 139 [73]
Saccharomyces cerevisiae 69 [73]
Schizosaccharomyces pombe 104 [73]
Yarrowia lypolytica 69 [73]
Ocimum forskolei Benth. Candida albicans 35.3–8600 [77,170]
Ocimum gratissimum L. Aspergillus fumigatus >1000 [78]
Candida albicans 350–1500 [78,171]
Candida krusei 750 [171]
Candida parapsilosis 380 [171]
Candida tropicalis 1500 [171]
Cryptococcus neoformans 250–300 [78,79]
Fusarium oxysporum f. sp. cubense 62.5 [80]
Fusarium oxysporum f. sp. lycopersici 31.25 [80]
Fusarium oxysporum f. sp. tracheiphilum 62.5 [80]
Fusarium solani 62.5 [80]
Macrophomina phaseolina 62.5–125 [80]
Malassezia pachydermatis 300 [78]
Microsporum canis 200–500 [78,172]
Microsporum gypseum 150–250 [78,172]
Rhizoctonia solani 31.25 [80]
Scopulariopsis brevicaulis 400 [78]
Trichophyton interdigitale 250 [78]
Trichophyton mentagrophytes 200–250 [78,172]
Trichophyton rubrum 150–250 [78,172]
Ocimum tenuiflorum L. = Ocimum sanctum L. Aspergillus flavus 300 [83]
Candida albicans 0.1–300 [81,82]
Candida glabrata 0.15–300 [81,82]
Candida krusei 0.35–450 [81,82]
Candida parapsilosis 0.25–500 [81,82]
Candida tropicalis 0.1–300 [81,82]
Origanum compactum Benth. Alternaria alternata 300 [84]
Bipolaris oryzae 300 [84]
Fusarium equiseti 300 [84]
Fusarium graminearum 300 [84]
Fusarium verticillioides 300 [84]
Origanum majorana L. Aspergillus flavus 450–650 [62]
Aspergillus niger 625 [158]
Botrytis cinerea 5000 [87]
Candida albicans 625 [158]
Cryptococcus neoformans 313 [158]
Fusarium delphinoides 1800–14,400 [85]
Fusarium incarnatum-equiseti 450–3600 [85]
Fusarium napiforme 3600–14,400 [85]
Fusarium oxysporum 900–3600 [85]
Fusarium solani 900–3600 [85]
Fusarium verticillioides 14,400 [85]
Microsporum canis 0.5 [68]
Microsporum gypseum 2 [68]
Penicillium expansum 10,000 [87]
Penicillium minioluteum 400–500 [62]
Penicillium oxalicum 350–400 [62]
Sporothrix brasiliensis ≤2250–9000 [86]
Sporothrix schenckii ≤2250–9000 [86]
Trichophyton erinacei 1 [68]
Trichophyton mentagrophytes 1.5 [68]
Trichophyton terrestre 2 [68]
Origanum vulgare L. Aspergillus flavus 0.64–2500 [64,89,91]
Aspergillus fumigatus 0.32–0.64 [89]
Aspergillus niger 0.32–623 [62,89,91,158]
Aspergillus ochraceus 470 [91]
Aspergillus parasiticus 2500 [64]
Candida albicans 0.32–700 [74,88,89,91,158]
Candida glabrata 350 [88]
Candida guillermondii 0.64–1.25 [89]
Candida krusei 0.64–700 [88,89]
Candida parapsilosis 0.64–170 [88,89]
Candida tropicalis 0.32–700 [88,89]
Cladosporium sp. 0.05–0.3 [173]
Cryptococcus neoformans 0.16–78 [89,158]
Epidermophyton floccosum 0.32–2 [74,89]
Fusarium sp. 0.1–0.5 [173]
Malassezia furfur 1–780 [49,174]
Microsporum canis 0.025–2 [68,74,89]
Microsporum gypseum 0.025–1.25 [68,89]
Penicillium sp. 0.1–0.5 [173]
Penicillium chrysogenum 625 [64]
Penicillium corylophilum 0.625 [165]
Penicillium funiculosum 610 [91]
Penicillium ochrochloron 710 [91]
Penicillium verrucosum 1.1719 [90,91]
Trichophyton mentagrophytes 0.32–1.25 [74,89]
Trichophyton rubrum 0.16–1.25 [49,74,89]
Trichophyton tonsurans 1 [74]
Trichosporon beigelii 0.25 [49]
Trichophyton erinacei 0.5 [68]
Trichophyton mentagrophytes 0.5 [68]
Trichophyton terrestre 0.25 [68]
Pogostemon cablin (Blanco) Benth. Aspergillus flavus >1500 [92]
Aspergillus niger 156 [158]
Aspergillus oryzae >1500 [92]
Candida albicans 32–625 [158,175]
Candida krusei 64–257 [175]
Candida tropicalis 32–257 [175]
Cryptococcus neoformans 20 [158]
Pogostemon heyneanus Benth. Candida albicans 6000 [176]
Candida glabrata 6000 [176]
Candida tropicalis 10,000 [176]
Premna microphylla Turcz. Aspergillus niger >500 [94]
Candida albicans >500 [94]
Fusarium oxysporum >500 [94]
Rosmarinus officinalis L. Aspergillus flavus 330 [91]
Aspergillus ochraceus 590 [91]
Aspergillus niger 380–10,000 [91,98,158]
Botrytis cinerea 2500 [87]
Candida albicans 30.2–1000 [51,91,96,98,158]
Cryptococcus neoformans 313 [158]
Epidermophyton floccosum 30 [96]
Microsporum canis 2.5–30.2 [68,96]
Microsporum gypseum 2.5 [68]
Penicillium expansum 5000 [87]
Penicillium ochrochloron 470 [91]
Penicillium funiculosum 570 [91]
Trichophyton erinacei 1.5 [68]
Trichophyton mentagrophytes 5–15.3 [68,96]
Trichophyton rubrum 15–256 [51,96]
Trichophyton terrestre 5 [68]
Trichophyton tonsurans 15.2 [96]
Salvia fruticosa Miller Candida albicans 512 [51]
Fusarium oxysporum f. sp. dianthi >2000 [99]
Fusarium proliferatum >2000 [99]
Fusarium solani f. sp. cucurbitae >2000 [99]
Malassezia furfur >4 [99]
Rhizoctonia solani >2000 [99]
Sclerotinia sclerotiorum >2000 [99]
Trichophyton rubrum 2–256 [49,99]
Trichosporon beigelii 4 [49]
Salvia mirzayanii Rech. f. and Esfand Candida albicans 0.5–2 [100]
Candida krusei 1 [100]
Candida dubliniensis 0.06–0.5 [100]
Candida glabrata 0.06–1 [100]
Candida parapsilosis 0.25–1 [100]
Candida tropicalis 0.25–2 [100]
Trichosporon sp. 1 [100]
Salvia officinalis L. Aspergillus flavus 5–10 [101]
Aspergillus fumigatus 2.5–5 [101]
Aspergillus niger 5–1250 [101,158]
Candida albicans 2.5–2780 [96,101,158,177]
Candida guillermondii 1.25–2.5 [101]
Candida krusei 2.5–5 [101]
Candida parapsilosis 5 [101]
Candida tropicalis 5 [101]
Cryptococcus neoformans 0.64–625 [101,158]
Epidermophyton floccosum 0.64–100 [96,101]
Microsporum canis 1.25–100.2 [96,101]
Microsporum gypseum 1.25–2.5 [101]
Trichophyton mentagrophytes 1.25–60 [96,101]
Trichophyton mentagrophytes var. interdigitale 1.25 [101]
Trichophyton rubrum 0.64–60 [96,101]
Trichophyton tonsurans 60 [96]
Trichophyton verrucosum 1.25–2.5 [101]
Salvia sclarea L. Aspergillus niger 1250 [158]
Candida albicans 1250 [158]
Cryptococcus neoformans 313 [158]
Fusarium delphinoides 1800–3600 [85]
Fusarium incarnatum-equiseti 1800–3600 [85]
Fusarium napiforme 1800–3600 [85]
Fusarium oxysporum 1800–3600 [85]
Fusarium solani 3600–7200 [85]
Fusarium verticillioides 1800 [85]
Satureja hortensis L. Alternaria alternata 62.5 [103]
Aspergillus flavus 31.25–500 [103,104,117]
Aspergillus niger 471 [117]
Aspergillus ochraceus 423 [117]
Aspergillus parasiticus 373 [117]
Aspergillus terreus 389 [117]
Aspergillus variecolor 125 [103]
Candida albicans 200–400 [103,178]
Fusarium culmorum 125 [103]
Fusarium oxysporum 250 [103]
Microsporum canis 62.5 [103]
Moniliania fructicola 31.25 [103]
Penicillium spp. 125 [103]
Rhizoctonia solani 125 [103]
Rhizopus spp. 250 [103]
Sclerotinia minor 250 [103]
Sclerotinia sclerotiorum 125 [103]
Trichophyton mentagrophytes 62.5 [103]
Trichophyton rubrum 31.25 [103]
Satureja montana L. Microsporum canis 0.5 [68]
Microsporum gypseum 2 [68]
Trichophyton erinacei 2 [68]
Trichophyton mentagrophytes 2 [68]
Trichophyton terrestre 3 [68]
Satureja thymbra L. Aspergillus flavus 25 [105]
Aspergillus fumigatus 1.25–25 [105,179]
Aspergillus niger 2.5–25 [105,179]
Aspergillus ochraceus 2.5–25 [105,179]
Aspergillus versicolor 1.25 [179]
Candida albicans 25–128 [51,105]
Penicillium funiculosum 2.5–25 [105,179]
Penicillium ochrochloron 1–1.25 [105,179]
Trichoderma viride 1.25–25 [105,179]
Trichophyton rubrum 128 [51]
Stachys cretica L. Candida albicans 625 [106]
Stachys officinalis (L.) Trevis Aspergillus niger 2500 [107]
Candida albicans 5000 [107]
Stachys pubescens Ten. Alternaria alternata 1 [108]
Aspergillus flavus 0–5 [108]
Fusarium oxysporum 1 [108]
Teucrium sauvagei Le Houerou Aspergillus fumigatus >1000 [109]
Candida albicans >1000 [109]
Cryptococcus neoformans >1000 [109]
Epidermophyton floccosum 850 [109]
Microsporum canis 800 [109]
Microsporum gypseum 900 [109]
Scopulariopsis brevicaulis >1000 [109]
Scytalidium dimidiatum >1000 [109]
Trichophyton mentagrophytes var. interdigitale 950 [109]
Trichophyton mentagrophytes var. mentagrophytes 900 [109]
Trichophyton rubrum 800 [109]
Trichophyton soudanense 800 [109]
Teucrium yemense Deflers. Aspergillus niger 313 [77]
Botrytis cinerea 313 [77]
Candida albicans 1250 [77]
Thymbra capitata (L.) Cav. = Thymus capitatus (L.) Hoffmanns. and Link = Coridothymus capitatus (L.) Rchb.f. Solms Aspergillus flavus 0.32 [111]
Aspergillus fumigatus 0.16–0.32 [111]
Aspergillus niger 0.1–0.16 [111,180]
Aspergillus oryzae 0.2 [180]
Candida albicans 0.16–128 [51,110,111,112]
Candida glabrata 0.32 [111,112]
Candida guilliermondii 0.16–0.32 [111,112]
Candida krusei 0.32 [111]
Candida parapsilosis 0.32 [111,112]
Candida tropicalis 0.32 [111,112]
Epidermophyton floccosum 0.08 [111]
Fusarium solani 0.2 [180]
Microsporum canis 0.08 [111]
Microsporum gypseum 0.08 [111]
Penicillium digitatum 0.5 [180]
Trichophyton mentagrophytes 0.08 [111]
Trichophyton rubrum 0.16–64 [51,111]
Thymbra spicata L. Aspergillus fumigatus 0.3 [179]
Aspergillus niger 0.6 [179]
Aspergillus versicolor 0.3 [179]
Aspergillus ochraceus 0.6 [179]
Candida albicans 1.12–3750 [51,113,114]
Candida krusei 1.12 [114]
Candida parapsilosis 0.6–1.12 [114]
Penicillium funiculosum 0.3 [179]
Penicillium ochrochloron 0.3 [179]
Trichoderma viride 0.3 [179]
Trichophyton rubrum 64 [51]
Thymus bovei Benth. Candida albicans 250 [115]
Thymus daenensis Celak. Alternaria alternata >8 [108]
Aspergillus flavus 1 [108]
Fusarium oxysporum 4 [108]
Thymus kotschyanus Boiss. and Hohen. Alternaria alternata 1 [108]
Aspergillus flavus 0.5 [108]
Fusarium oxysporum 0–5 [108]
Thymus mastichina (L.) L. Candida albicans 1.25–2.5 [116]
Candida glabrata 1.25–1.5 [116]
Candida guilliermondii 1.25 [116]
Candida krusei 1.25–2.5 [116]
Candida parapsilosis 2.5–5 [116]
Candida tropicalis 2.5–10 [116]
Thymus migricus Klokov et Des.-Shost. Aspergillus flavus 452 [117]
Aspergillus niger 460 [117]
Aspergillus ochraceus 430 [117]
Aspergillus parasiticus 581 [117]
Aspergillus terreus 447 [117]
Thymus pulegioides L. Aspergillus flavus 0.32 [119]
Aspergillus fumigatus 0.16 [119]
Aspergillus niger 0.32 [119]
Candida albicans 0.32–0.64 [119]
Candida glabrata 0.32–0.64 [119]
Candida guilliermondii 0.32 [119]
Candida krusei 0.32–0.64 [119]
Candida parapsilosis 0.64 [119]
Candida tropicalis 0.32–0.64 [119]
Epidermophyton floccosum 0.16 [119]
Microsporum canis 0.16 [119]
Microsporum gypseum 0.16 [119]
Trichophyton mentagrophytes 0.16 [119]
Trichophyton rubrum 0.32 [119]
Thymus schimperi Ronninger Aspergillus minutus 0.512–2 [120]
Aspergillus niger 0.16 [181]
Aspergillus tubingensis 1–4 [120]
Beauveria bassiana 0.128–1 [120]
Candida albicans 0.16 [181]
Microsporum spp. 0.08 [181]
Microsporum gypseum 0.128–1 [120]
Penicillium chrysogenum 0.512–2 [120]
Rhodotorula spp. 0.08 [181]
Tricophyton spp. 0.08–0.31 [181]
Verticillium sp. 0.512–2 [120]
Thymus serpyllum L. Aspergillus carbonarius 1.25 [182]
Aspergillus ochraceus 0.625 [182]
Aspergillus niger 2.5 [182]
Microsporum canis 0.025 [68]
Microsporum gypseum 0.25 [68]
Trichophyton erinacei 0.1 [68]
Trichophyton mentagrophytes 0.2 [68]
Trichophyton terrestre 0.1 [68]
Thymus striatus Vahl. Alternaria alternata 1 [121]
Aspergillus flavus 1.5 [121]
Aspergillus niger 1 [121]
Aspergillus ochraceus 1 [121]
Aspergillus terreus 1 [121]
Aspergillus versicolor 1 [121]
Cladosporium cladosporioides 0.5 [121]
Epidermophyton floccosum 1 [121]
Microsporum canis 1.5 [121]
Penicillium funiculosum 2 [121]
Penicillium ochrochloron 2 [121]
Phomopsis helianthi 0.5 [121]
Trichoderma viride 2 [121]
Trichophyton mentagrophytes 1 [121]
Thymus vulgaris L. Absidia spp. 7 ± 4 [122]
Alternaria spp. 9.4 ± 4.5 [122]
Alternaria alternata 4.7–500 [122,183]
Aspergillus spp. 3.2 [122]
Aspergillus flavus 9.35–1500 [64,104,122,125,184]
Aspergillus fumigatus 144–1000 [124,184]
Aspergillus niger 9.35–1250 [64,122,158,184]
Aspergillus ochraceus 2.5–750 [164,184]
Aspergillus parasiticus 1250 [64]
Aspergillus sulphureus 10.88 ± 3.1 [122]
Aspergillus versicolor 9.6 ± 9.25 [122]
Botrytis cinerea 312 [87]
Candida albicans 0.16–313 [73,74,116,158]
Candida glabrata 0.16–0.32 [116]
Candida krusei 0.08–0.16 [116]
Candida guillermondii 0.16 [116]
Candida parapsilosis 0.16–0.32 [116]
Candida tropicalis 0.16–0.32 [116]
Chaetomium globosum 1.6 [122]
Cladosporium spp. 12.8 [122]
Cladosporium sphaerospermum 19.6 [122]
Cryptococcus neoformans 78 [158]
Epidermophyton floccosum 4 [74]
Fusarium spp. 62.5 [185]
Fusarium delphinoides 900–1800 [85]
Fusarium incarnatum-equiseti 450–3600 [85]
Fusarium napiforme 900 [85]
Fusarium oxysporum 5–900 [85,126]
Fusarium solani 1800–3600 [85]
Fusarium verticillioides 900 [85]
Malassezia furfur 920 [174]
Microsporum canis 2.2 [74]
Mortierella spp. 250 [185]
Mucor spp. 50.2 ± 8.4 [122]
Penicilium spp. 18.95–500 [122,185]
Penicilium brevicompactum 19.6 [122]
Penicillium chrysogenum 312.5–1750 [64,184]
Penicilium chrysogenum 19.6 [122]
Penicillium citrinum 1250 [184]
Penicillium expansum 625 [87]
Penicillium griseofulvum 19.6 [122]
Rhizopus spp. 12.6 [122]
Rhodotorula glutinis 72 [73]
Rhizopus oryzae 256–512 [123]
Saccharomyces cerevisiae 72 [73]
Schizosaccharomyces pombe 36 [73]
Stachybotrys chartarum 6.2 [122]
Trichoderma spp. 16.8 [122]
Trichophyton mentagrophytes 2.2 [74]
Trichophyton rubrum 2–72 [74,124]
Trichophyton tonsurans 2.2 [74]
Ulocladium spp. 5.45 ± 1.5 [122]
Yarrowia lypolytica 36 [73]
Thymus zygis L. Candida albicans 0.16–0.32 [116]
Candida glabrata 0.32 [116]
Candida krusei 0.16–0.32 [116]
Candida guillermondii 0.16 [116]
Candida parapsilosis 0.32 [116]
Candida tropicalis 0.16–0.32 [116]
Penicillium corylophilum 0.3125–0.625 [165]
Vitex agnus-castus L. Candida albicans 0.53–512 [51,129]
Candida dubliniensis 0.27 [129]
Candida famata 2.13 [129]
Candida glabrata 0.27 [129]
Candida krusei 0.27 [129]
Candida lusitaniae 2.13 [129]
Candida parapsilosis 1.06 [129]
Candida tropicalis 0.13 [129]
Epidermophyton floccosum 0.64–2.5 [128]
Microsporum canis 0.64–5 [128]
Microsporum gypseum 1.25–10 [128]
Trichophyton mentagrophytes 1.25–10 [128]
Trichophyton rubrum 0.64–512 [51,128]
Zataria multiflora Boiss. Aspergillus flavus 358 [117]
Aspergillus niger 358 [117]
Aspergillus ochraceus 341 [117]
Aspergillus parasiticus 367 [117]
Aspergillus terreus 447 [117]
Microsporum canis 0.125–0.25 [130]
Microsporum gypseum 0.03–0.06 [130]
Trichophyton mentagrophytes 0.03 [130]
Trichophyton rubrum 0.03–0.06 [130]
Trichophyton schoenleinii 0.125–0.6 [130]
Ziziphora clinopodioides Lam. Aspergillus flavus 48.82 [184,186]
Aspergillus fumigatus 1750 [184]
Aspergillus niger 3000 [184]
Aspergillus ochraceus 1500 [184]
Aspergillus parasiticus 48.82 [186]
Penicillium chrysogenum 3000 [184]
Penicillium citrinum 1750 [184]
Ziziphora tenuior L. Aspergillus flavus 1.25 [133]
Aspergillus fumigatus 0.64 [133]
Aspergillus niger 0.64 [133]
Candida albicans 1.25 [133]
Candida guillermondii 1.25 [133]
Candida krusei 1.25 [133]
Candida parapsilosis 1.25 [133]
Candida tropicalis 1.25 [133]
Cryptococcus neoformans 0.16 [133]
Epidermophyton floccosum 0.64 [133]
Microsporum canis 0.64–1.25 [133]
Microsporum gypseum 1.25 [133]
Trichophyton mentagrophytes 1.25 [133]
Trichophyton mentagrophytes var. interdigitale 1.254 [133]
Trichophyton rubrum 0.64 [133]
Trichophyton verrucosum 0.64 [133]
The mode of action of essential oils is multidirectional. Essential oils lead to disruption of the cell wall and cell membrane through a permeabilization process. The lipophilic compounds of essential oils can pass through the cell wall and damage polysaccharides, fatty acids, and phospholipids, eventually making them permeable [146,147]. Change of the permeability for H+ and K+ cations affects cellular pH and damage of cellular organelles [148,149]. Additionally, essential oils inhibit the synthesis of fungal DNA, RNA, proteins, and polysaccharides [150]. Essential oils can also disintegrate mitochondrial membrane [151,152]. It has also been shown that essential oil from Thymus vulgaris inhibits the production of aflatoxins by Aspergillus flavus and leads to the reduction of ergosterol production [123].

This entry is adapted from the peer-reviewed paper 10.3390/biom10010103