13.2 Literature Search Methodology
In vitro analysis, in vivo experimentation, and human clinical studies which
explored the antibacterial and antiproliferative potency of phytoconstituent carvacrol, and its analogs by inhibiting various pathways were screened using
authentic databases, such as ScienceDirect, PubMed, Google Scholar, and Springer
reference. Relevant full articles published until April 2020 in peer-reviewed journals have been included. Conference abstracts and unpublished findings have not
been included. Only papers published in the English language have been considered
and included in this review. The keywords used for literature search included
carvacrol, antimicrobial, cancer, tumor, proliferation, phytochemicals, terpenoids,
in vivo, in vitro, and clinical studies.
13.3 Extraction and Isolation of Carvacrol
Like for most naturally occurring substances, the isolation and characterization of
carvacrol are based mainly on chromatographic approaches. Carvacrol is an aromatic chemical compound bearing a complex composition, isolated from the plant’s
raw material either by steam distillation, dry distillation, or a relevant automatic
process without heating. Carvacrol is extracted from an aqueous environment by a
physical hydro-distillation process which does not adversely impact their composition utilizing Clevenger equipment fitted with a microwave apparatus (Dhifi et al.
2016, Cáceres et al. 2020). Obeying to this information, many scientists processed
the isolation of the constituent carvacrol from the stems and leaves of many plants,
such as Origanum ehrenbergii, Origanum syriacum, Salvia fruticosa, and
Calamintha origanifolia. To immerse the whole plant in a flask, a specific amount
of water is added and boiled for 3 h. Carvacrol is driven with water vapor into a
condensed form owing to its volatile nature and later recollected which was purified
with anhydrous sodium bicarbonate. It is then stored in the dark at 4°C in a sealed
glass container for further utilization (Galehassadi et al. 2014, Cáceres et al. 2020).
Its quantification can be analyzed by high-performance liquid chromatography
(HPLC). Nonetheless, HPLC approach for carvacrol isolation has now become
commonly adopted. It is very sensitive and has the potentiality to identify extremely
small concentrations of a substance. Carvacrol is the major constituents of
Origanum vulgare with a concentration of 83.7% (Laothaweerungsawat et al.
2020). Another documented report revealed that carvacrol content is 48% in
Origanum vulgare (Bahmani et al. 2019)
Another method widely considered for carvacrol analysis is gas chromatography. While this approach is not as common as HPLC, both a qualitative and a
quantitative study of carvacrol were carried out. Excellent performance but with
small productivity and a basic process were the key reasons for its adoption. It was
identified and quantified using the gas chromatography-mass spectroscopic
13 Carvacrol (Origanum vulgare): Therapeutic Properties …
439
In vitro analysis, in vivo experimentation, and human clinical studies which
explored the antibacterial and antiproliferative potency of phytoconstituent carvacrol, and its analogs by inhibiting various pathways were screened using
authentic databases, such as ScienceDirect, PubMed, Google Scholar, and Springer
reference. Relevant full articles published until April 2020 in peer-reviewed journals have been included. Conference abstracts and unpublished findings have not
been included. Only papers published in the English language have been considered
and included in this review. The keywords used for literature search included
carvacrol, antimicrobial, cancer, tumor, proliferation, phytochemicals, terpenoids,
in vivo, in vitro, and clinical studies.
13.3 Extraction and Isolation of Carvacrol
Like for most naturally occurring substances, the isolation and characterization of
carvacrol are based mainly on chromatographic approaches. Carvacrol is an aromatic chemical compound bearing a complex composition, isolated from the plant’s
raw material either by steam distillation, dry distillation, or a relevant automatic
process without heating. Carvacrol is extracted from an aqueous environment by a
physical hydro-distillation process which does not adversely impact their composition utilizing Clevenger equipment fitted with a microwave apparatus (Dhifi et al.
2016, Cáceres et al. 2020). Obeying to this information, many scientists processed
the isolation of the constituent carvacrol from the stems and leaves of many plants,
such as Origanum ehrenbergii, Origanum syriacum, Salvia fruticosa, and
Calamintha origanifolia. To immerse the whole plant in a flask, a specific amount
of water is added and boiled for 3 h. Carvacrol is driven with water vapor into a
condensed form owing to its volatile nature and later recollected which was purified
with anhydrous sodium bicarbonate. It is then stored in the dark at 4°C in a sealed
glass container for further utilization (Galehassadi et al. 2014, Cáceres et al. 2020).
Its quantification can be analyzed by high-performance liquid chromatography
(HPLC). Nonetheless, HPLC approach for carvacrol isolation has now become
commonly adopted. It is very sensitive and has the potentiality to identify extremely
small concentrations of a substance. Carvacrol is the major constituents of
Origanum vulgare with a concentration of 83.7% (Laothaweerungsawat et al.
2020). Another documented report revealed that carvacrol content is 48% in
Origanum vulgare (Bahmani et al. 2019)
Another method widely considered for carvacrol analysis is gas chromatography. While this approach is not as common as HPLC, both a qualitative and a
quantitative study of carvacrol were carried out. Excellent performance but with
small productivity and a basic process were the key reasons for its adoption. It was
identified and quantified using the gas chromatography-mass spectroscopic
13 Carvacrol (Origanum vulgare): Therapeutic Properties …
439