Coriander or Coriandrum sativum (C. sativum), a member of the Apiaceae family, is a popular herb with versatile applications. The seeds and leaves are widely used for culinary and seasoning. The seeds and fruits are often used for cooking meat. As honey plant, coriander is highly attractive to honeybee workers. Additionally, coriander has been used in many traditional medicines, and its medicinal values has been widely recognized. Coriander extracts have a wide range of biological benefits including neuroprotective, anxiolytic, hypnotic, antioxidant, anti-inflammatory, and so on.
1. Introduction
People in modern society are under greater life and work pressures, which will affect their physical and mental health and even increase the risk of depression
[1,2][1][2]. Depression is a persistent and serious mental illness that affects over 120 million people worldwide
[2]. According to the World Health Organization statistics, depression will be the leading cause of death worldwide by 2030
[3,4][3][4]. According to the reports, the direct or indirect treatment costs of depression are more than $30 billion each year in the United States, which will lead to a significant social burden
[5]. Moreover, most of the treated depression patients often have residual symptoms that persist, leading to impaired social function of the patients. Therefore, the prevention of depression is particularly important
[6].
In stressful modern life, the relaxing effect of natural stimuli is considered beneficial compared with other stimuli
[1]. According to stress recovery theory, exposure to unthreatening nature can elicit positive emotions, restrict negative thoughts, and reduces stress
[7]. Many people are thus attracted to the physiological and psychological relaxing effect of exposure to plants. Field experiments in urban parks and forest bathing have proved the psychological and physical relaxing effects of contact with plants
[8,9][8][9]. Forest bathing also increased natural killer cell function and improved immune function
[10]. This effect was sustained for approximately 1 month. Indeed, urban residents were socially isolated during the outbreak of the Covid-19 virus outbreak, and the value of residential gardens as therapeutic landscapes was brought to the fore
[11]. These results suggest that contact with plants is a type of prophylaxis.
The color and volatile organic compounds (VOCs) of plants may play an important role in regulating emotions. People mainly achieve the color perception through light, and different colors of plants reflect different wavelengths of light
[12]. Intrinsically photosensitive retinal ganglion cells (ipRGCs) sense light and project it to the paraventricular nucleus of the hypothalamus. This area regulates the secretion of stress hormones by stimulating the adrenal gland
[13]. Stress hormone levels can reflect stressful, emotional conditions
[14]. Previous research has shown that the green color of plants can effectively restore workers’ brainwave and the mental state, reduce shoulders and back pain, and relieve their work pressure
[15]. The volatile organic compounds of plants are beneficial to people’s physiological and psychological health. They can relieve anxiety and depression and maintain the memory of patients with Alzheimer’s disease or other memory disorders
[16].
Coriander or
Coriandrum sativum (
C. sativum), a member of the Apiaceae family, is a popular herb with versatile applications. The seeds and leaves are widely used for culinary and seasoning. The seeds and fruits are often used for cooking meat
[17]. As honey plant, coriander is highly attractive to honeybee workers
[18]. Additionally, coriander has been used in many traditional medicines, and its medicinal values has been widely recognized
[19,20][19][20]. Coriander extracts have a wide range of biological benefits including neuroprotective, anxiolytic, hypnotic, antioxidant, anti-inflammatory, and so on
[21,22][21][22]. However, the current research about coriander medicinal values have been mainly focusing on its extracts while lacking on living coriander plants. Our previous study found that coriander plants had a potential role in regulating negative emotions
[12]. Therefore, this study aims to investigate the effects of coriander plants on human emotions and physiological activities and the correlation between emotional fluctuations and salivary secretion.
2. Main VOCs of Coriander Plants
Coriander plants VOCs was analyzed by GC-MS. Representative gas chromatography–mass spectrometry (GC–MS) total ion chromatograms (
Figure S1 could be found https://www.mdpi.com/2079-7737/10/12/1283#supplementary). From the main of 22 separated peaks, alcohols, terpenoids, and esters were the predominant class of compounds, with 2-ethyl-1-hexanol (15.60%) being the major component (
Table 21). 2-ethyl-1-hexanol was often found in the natural VOCs of many plants. Other important substances were: d-limonene (9.58%), eucalyptol (8.97%), benzyl alcohol (6.16%), isophorone (6.06%), dimethyl glutarate (5.03%), α-terpineol (4.45%), styrene (3.97%), methyl methacrylate (3.20%), α-pinene (3.17%). The concentration of VOCs per cm
3 of coriander plants in the test room was about 0.82 ng. The smell of d-limonene was described as a light lemon smell, α-pinene having a moderate resin scent.
Table 21. Main volatile components of coriander plants.
Compounds |
Chemical Formula |
RT (min) |
RI |
RC (%) |
CAS |
Longifolene |
C15H24 |
36.46 |
1417.58 |
2.20 |
475-20-7 |
1,3,5-Benzetriol, 3TMS derivative |
C15H30O3Si3 |
32.49 |
1265.55 |
1.66 |
10586-12-6 |
2-Ethylhexyl acrylate |
C11H20O2 |
30.82 |
1146.97 |
1.59 |
103-11-7 |
α-Terpineol |
C10H18O |
29.88 |
1136.51 |
4.45 |
98-55-5 |
Dimethyl glutarate |
C7H12O4 |
27.86 |
1114.01 |
5.03 |
1119-40-0 |
Lsophorone |
C9H14O |
27.59 |
1110.99 |
6.06 |
78-59-1 |
1,2,3,5-Tetramethylbenzene |
C10H14 |
27.37 |
1108.63 |
2.82 |
527-53-7 |
3-Hydroxymandelic acid, 3TMS derivative |
C17H32O4Si3 |
27.22 |
1106.86 |
2.69 |
68595-69-7 |
Linalool |
C10H18O |
26.66 |
1100.66 |
0.60 |
78-70-6 |
Acetophenone |
C8H8O |
25.58 |
987.55 |
1.95 |
98-86-2 |
γ-Terpinene |
C10H16 |
25.27 |
983.73 |
1.10 |
99-85-4 |
Benzyl alcohol |
C7H8O |
24.36 |
972.51 |
6.16 |
100-51-6 |
Eucalyptol |
C10H18O |
24.30 |
971.76 |
8.87 |
470-82-6 |
D-Limonene |
C10H16 |
24.16 |
870.37 |
9.58 |
5989-27-5 |
2-Ethyl-1-hexanol |
C8H18O |
24.07 |
968.90 |
15.60 |
104-76-7 |
α-Pinene |
C10H16 |
20.17 |
930.96 |
3.17 |
80-56-8 |
Styrene |
C8H8 |
18.11 |
805.88 |
3.92 |
100-42-5 |
Furfural |
C5H4O2 |
15.14 |
639.22 |
0.75 |
98-01-1 |
Methyl methacrylate |
C5H8O2 |
9.18 |
613.16 |
3.20 |
80-62-6 |
1-Butanol |
C4H10O |
7.59 |
692.01 |
1.45 |
71-36-3 |
1,2-Ethanediol, diformate |
C4H6O4 |
6.35 |
598.03 |
6.18 |
629-15-2 |
Ethyl Acetate |
C4H8O2 |
6.61 |
618.02 |
2.54 |
141-78-6 |
Other volatile components |
- |
- |
|
t |
- |