A comprehensive review on traditional applications, phytochemistry, pharmacology, and toxicology of Thymus serpyllum

Abstract

Thymus serpyllum L. from the Lamiaceae family is an underexplored perennial medicinal shrub with traditional usage in treating respiratory and gastrointestinal issues in the upper foothills of India. This review aims to provide a comprehensive assessment of current knowledge concerning the traditional uses, phytochemistry, and pharmacology of T. serpyllum. The primary objective is to collect updated information on this plant and encourage further in vivo and in vitro research to validate local claims. Notably, the essential oil derived from T. serpyllum has gained significant attention as a plant-derived product due to its diverse pharmacological properties, including antioxidative, antimicrobial, anti-inflammatory, and anticancer activities. Ethnomedicinal research revealed a vast scope of T. serpyllum in developing new drugs to address numerous health sector challenges. While T. serpyllum has been used widely, pharmacological studies are not enough. Most studies are either in vivo or in vitro. More studies are required to assess these medicinal claims through well-planned pharmacological experiments. This review will provide the groundwork for future research. While T. serpyllum has been put to considerable conventional use, pharmacological studies are insufficient; most studies are either in vivo or in vitro. More compound isolation, comprehensive pharmacological analysis, and exploration of food applications are vital areas to investigate.

Introduction

The modern world is liable for using medicinal plants to achieve better immune responses and high reproduction efficiency to attain good health. Traditional medicines are known to be budget-friendly and attainable sources to cure diseases as they have been used for decades (4000–5000 B.C.). Chinese obtained the first natural herbal preparation of medication. Plant utilization as drugs in India was initially written in Rig-Veda (1600–3500 B.C.). In India, using medicinal plants came from traditional physicians.[1] Plants act as a supply for developing new medicine directly or indirectly. According to the WHO reports, around 80% of developed countries’ population depends on traditional medications for good well-being.[2] There is an increment in demand for therapeutic plants in developed and developing countries.

Thyme holds a prominent position within the Lamiaceae family, one of its most significant genera. This versatile herb is a widely utilized spice documented all over the world. According to the World Checklist (http://apps.kew.org/wcsp/incfamilies.do), the Thyme genus contains 7534 species, involving 220 species of Thymus L.[3] Identification of different varieties of Thymus have been made by Richard all over the world.[4] The Thyme genus is widely used in the food, cosmetics, perfumery, and pharmaceutical industries.[5]

Thyme is a home remedy for various issues, including colds, flu, indigestion, nausea, renal diseases, ulceration, headache, diabetes, and asthenia.[6] The primary area of investigation for researchers revolves around thyme oil, which comprises terpenes, esters, and phenolic compounds. Thyme oil is classified as one of the most popular herbs globally, primarily due to its aromatic and therapeutic qualities. It is widely recognized as one of the top ten essential oils (EOs) worldwide.[7] Hence, this review aims to furnish current data about the pharmacological properties, phytochemical constituents, traditional applications, and safety profile of T. serpyllum. The review provides pharmacological and phytochemical information that can be utilized to investigate potential therapy alternatives, address gaps in scientific understanding, and develop successful intervention techniques.

Botanical Description and Geographic Distribution

T. serpyllum is a miniature, scented shrub forming a clump of sharp, shiny blue-green leaves that turns tanned with time. It is called Breckl and thyme, wild thyme, or creeping thyme. It is distributed in Asia, Africa, Europe, North America, and some areas of East Africa. In India, it is found in Jammu and Kashmir, Himachal Pradesh, and Uttarakhand.[8]

T. serpyllum is a perennial shrub that can grow up to 5–7 cm. It has a hairy and creeping appearance, with clusters of trifling, pink-purple flowers.[8] The oval-shaped leaves measure around 4–6 mm in length and 2–4 mm in width, having a smooth texture on both sides and covered in long trichomes. The central vein is robust, while the lateral veins at the base along the margin are less noticeable. These leaves persist throughout the year. T. serpyllum exhibits hermaphroditic characteristics and relies on pollinators like butterflies, bees, and flies, attracted by its distinctive aroma. It thrives in loose, sandy, rocky, and nutrient-poor soil, showing its best growth under medium to dry moisture content and well-drained conditions. The species displays remarkable tolerance to drought and strong winds but tends to diminish in shady areas.[9] It can be quickly grown in average humid soil and requires more daylight. It can be easily propagated through stem cuttings.

Traditional Applications of Thymus serpyllum

For decades, T. serpyllum has been used for dietary and medicinal purposes. Apart from their traditional application in medicine, they also found an essential place in our culture and diet.[10] In addition to psychological perception, it is also traditionally used by warriors and martyrs to achieve physical strength and has the fastest healing and valor properties.[11] According to Greek physicians, whole plant juice is used against cough and asthma,[12] while its paste is used externally to treat arthritis and disinfect wounds and scrapes.[13]

Based on the knowledge of Greek physicians, the juice derived from the entire plant is traditionally used to alleviate cough and asthma,[12] and its paste is applied externally to treat arthritis and disinfect wounds and scrapes.[13] Furthermore, the leaves and floral shoots address cramps, menstrual pain, and various skin issues, including eruptions and itching.[14] Moreover, an infusion made from the leaves of T. serpyllum, when combined with “jaggery,” is known for its diuretic properties.[15] T. serpyllum aerial parts have been used as an antiseptic, antiplasmodic, deodorant, and disinfectant, and help treat the respiratory and gastrointestinal systems.[16] In the Western Balkans, T. serpyllum has improved blood circulation and is an immunostimulant.[17] T. serpyllum has a long history of traditional use in India for treating menstrual disorders.[18] In addition, it has been employed to alleviate swelling, inflammation, and eczema[13] Furthermore, its antidiarrheal properties have been recognized in ethnoveterinary practices.[19] The British Pharmacopoeia, Commission Secretariat of the Medicines, and Healthcare Products Regulatory Agency (2015) reported that combining T. serpyllum and blackberry leaves effectively treat acute pharyngitis. Moreover, T. serpyllum is frequently used to prepare herbal tea.[20] T. serpyllum EO has various disinfectant and relaxing characteristics that help combat different infections and is also used for mouthwashes and gargles.[21]

Phytochemistry

Numerous research has examined the phytoconstituents composition of the T. serpyllum EO during the past two decades [Table 1].[22] Several chemical compounds, such as germacrene thymol, carvacrol, α-terpinyl acetate, linalool, geraniol, citral, and (E)-caryophyllene, have been found to classify plant species of the genus Thymus.[23] The thymol content varied from 0% to 0.4% in the essential of thyme grown in Estonia, whereas thyme grown in India exhibited comparatively higher thymol content (60%–64.6%).

Table 1.

Various classes of phytocompounds present in Thymus serpyllum

Category of phytocompounds	Phytoconstituents
Phenolic acids and flavonoids	Gallic acid, rosmarinic acid, caffeic acid, ferulic acid, rosmarinic acid-glucoside, protocatechic acid, protocatechic acid-hexoside, chlorogenic acid, naringin, luteolin-o-diglucuronide, kaempferol-o-glucuronide, rutin, luteolin-o-glucuronide, apigenin- o-glucuronide, methyl kaempferol-o- rutinoside, luteolin, luteolin-7-o-rutinoside, luteolin-7-o-glucoside, apigenin-7-o-glucoside, apigenin, quercetin, eriodictyol-7-o-glucuronide, 8-prenylnaringenin, taxifolin, catechin, apigenin 6,8-di-c-glucoside[28,29]
Triterpenic acid	Oleanolic acid, betulinic acid, ursolic acid, corosolic acid[29]
Monoterpene hydrocarbon	Tricyclene, 𝛼-Pinene, o-cymene, camphene, sabinene, 𝛽-pinene, 𝛽-cymene, α-phellandrene, myrcene, thymol, α-terpinene, p-cymene, limonene, α-thujene, terpinene, thymol acetate[30,31]
Monoterpene oxidized	1,8-Cineole, linalool, δ3-carene, terpenolene, α-thujone, cis-sabinene hydrate, camphor, α-campholene, sabinene hydrate, trans-sabinene hydrate, borneol, isoborneol, p-mentha-3,8-diene, terpinen-4-ol, cis-sabinol, p-cymen-8-ol, cis-chrysanthenol, carvacrol acetate, geranial, methyl carvacrol, methyl thymol, thymol methyl ether, menthol, nerol, carvone, fenchyl alcohol, carvacrol methyl ether, thymoquinone, geraniol, bornyl acetate, 𝛽-citronellol, carvacrol, geranyl acetate, linalyl acetate, terpinyl acetate[30,31]
Sesquiterpene hydrocarbons	Copaene, 𝛽-bourbonene, 𝛼-elinene, 𝛿-cadinene, calamenene, 𝛿-cadinene, 𝛼-cadinene, germacrene D, 𝛽-abolene, epi-sesquiphellandrene, bicyclogermacrene, valencene, 𝛼-bisabolol, cis-bisabolene, 𝛼-cymene, 𝛽-cymene, 𝛽-ocinene, 𝛼-ylangene, 𝛽-longipinene, longifolene, cubebene, 𝛽-elemene, muurolene, amorphene, aromadendrene, 𝛼-humulene, allo-aromadendrene, (E)-𝛽-farnesene, 𝛽-caryophyllene, isoledene, iso-caryophyllene, trans-caryophyllene, spathulenol, elemol, trans-nerolidol, caryophyllene oxide, cadrol, 𝛼-campholene aldehyde, linalyl propanoate, isopulegone, tetra decanal, trans-carbyl propionate, ethyl cinamate, geranyl butyrate, bicyclogerma, piperitol, cadrol, crene, p-mentha-1-(7),8-diene, isoborneol, cubebene, longkyclene, longifolene, isovaleric acid, cis-dihydrocarvone, p-cymene-2,5-diol, β-bisabolene, heptanoic acid, hexadecanoic acid, 2-nonanone, caffeic acid ethyl ester[30]
Others	1-octen-3-ol, 3-octanol, 3-octanone, 3-penten-2-ol, 4-methyl-2-pentanol, 6-methyl-5-hepten-2-one[31]

Aziz et al.[24] reported thymol (16.5%–18.8%), 4,8-cineole (14.0%–18.0%), thymoquinone (2.6%), 1,8-cineole (14.0%–18.0%), and spathulenol (1.3%–2.1%) in T. serpyllum EO grown in Muzaffarabad, Jammu and Kashmir, India. Aziz et al.[24] reported the presence of spathulenol, cyclohexane and safrole in T. serpyllum essential oil. They also reported a higher amount of thymol (58.25%), followed by transgeraniol (55.93%), lavandulyl acetate (28.51%), nerol (2.76%) and E-citral (2.58%) from Northern Kazakhstan. Trans-geraniol, lavandulyl acetate, nerol, and E-citral were found to be the main components of essential oil of T. serphyllum from different regions of Southern Italy.[25] As confirmed by the WHO food additives guidelines, thymol and carvacrol are widely recognized food additives known for their safety and high concentrations, driving significant commercial interest.[26]

T. serpyllum plants and thymol can be used as spices, in compliance with the Food and Drug Administration (FDA) standard (www.fda.gov/downloads/ICECI/ComplianceManuals/CompliancePolicyGuidanceManual/UCM142644.pdf; accessed July 5, 2019). However, nonvolatile secondary metabolites, especially oleanolic acid, ursolic acid, and rosmarinic acid from T. serpyllum, are also getting tremendous interest in recent years.[27] Various phytoconstituents reported in T. serpyllum essential are shown in Table 1, and two-dimensional structures of phytocompounds are shown in Figures 1-4.

Figure 1.

2-dimensional structures Thymus serpyllum phytocompounds: (a) Monoterpene hydrocarbons present in Thymus serpyllum and (b) Oxidized monoterpenes

Figure 4.

2-dimensional structure of triterpenic acids and other phytocompounds in Thymus serpyllum

Figure 2.

2-dimensional structures of phenolics and flavonoids present in Thymus serpyllum

Figure 3.

2-dimensional structures of sesquiterpene hydrocarbons present in Thymus serpyllum

Pharmacological Applications of Thymus serpyllum

Scientists are now gaining interest in the biological activities of T. serpyllum. Many studies have shown that the extracts and compounds derived from T. serpyllum exhibited various biological activities, e.g., anticancer, antimicrobial, antioxidative, and anti-inflammatory effects. The action of thymol and carvacrol against COVID-19 nucleocapsid phosphoprotein was also recently investigated.[32] In another study, 25 phytocompounds of EO of T. serpyllum were found to show weak binding with SARS coronavirus 2 (PDB ID: 6VYO).[32] However, these studies are only in silico, which can be further verified through appropriate in vitro and in vivo experiments.

Some of the important biological applications of T. serpyllum are discussed in detail below.

Antioxidant property

Several studies evaluated the T. serpyllum extracts for antioxidant potential.[33] Kulisic et al.[33] reported the antioxidant activity of EO of T. serpyllum flower tops and stalks using the 2,2-diphenylpicrylhydrazyl (DPPH) method with IC₅₀-0.40 ± 0.05 g/L). Similarly, aqueous and ethanolic extracts of T. serpyllum also showed antioxidant properties with DPPH assay showing IC₅₀ values of 31.6 ± 0.8 μg/ml and 13.2 ± 0.3 μg/ml, respectively.[34] Antioxidant activity of water extract of T. serpyllum using Ferric ion reducing antioxidant power (FRAP) [IC₅₀-16.59 ± 1.06 mM Fe (II) equivalents] and ABTS assay (IC₅₀-8.60 ± 0.05 mM Trolox) was also reported by Mihailovic-Stanojevic et al.[22] Ultrasound-assisted extractions from T. serpyllum showed the free radical scavenging activity with IC₅₀-3.00–3.17 mg/mL.[35] Nikolic et al.[15] also showed antioxidant potential of T. serpyllum EO extracted from whole plants (IC₅₀ 0.96 g/mL) by the DPPH method. The antioxidant potency of this herb was due to the presence of rosmarinic and caffeic acids[22] and phenolic content.[36]

Antimicrobial effect

Several studies have shown the potency of extracts and EOs from various T. serpyllum plants as antibacterial agents.[15,28,30,37,38,39,40] Antibacterial and antifungal activities are summarized in Table 1. Research has shown that the antimicrobial potential of T. serpyllum was attributed to its thymol and carvacrol content.[15] Carvacrol and p-cymene disturb the cell membrane after interaction with intracellular sites and help kill the pathogens.[41]

Antibacterial and antifungal potential of T. serpyllum methanolic and ethyl acetate extracts against Pseudomonas aeruginosa, Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli, Aspergillus fumigatus, Candida albicans, Candida parapsilosis, and Aspergillus niger with minimum inhibitory concentration (MIC) ranging from 2000 g/ml to 4000 g/ml reported by Farrukh et al.[42] Exposure of T. serpyllum EO for 30 min resulted in a 100% bactericidal effect against all tested strains. Varga et al.[28] have reported thymol (32.2%) and carvacrol (25.8%) in the EO of T. serpyllum, and EO in concentrated (100%) and diluted form (50%) showed complete cell death of Cronobacter sakazakii, P. aeruginosa, Streptococcus pyogenes, Listeria innocua, C. albicans, and Saccharomyces cerevisiae in agar well diffusion assay. Verma et al.[30] evaluated the chemical and antimicrobial potentials of primary EO and dissolved oil (secondary EO) of T. serpyllum L. The secondary EOs of T. serpyllum had 92.5% phenolic phytocompounds compared to a primary EO (42.1%). Interestingly secondary EO showed antimicrobial solid activity with Ferric ion reducing antioxidant power (ZOI) ranging between 20 and >35 mm, and MIC ranging between 1/3200 and 1/6400 against all tested bacterial and fungal strains. Ouedrhiri et al.[38] have studied the combined effect of EO of T. serpyllum (wild thyme) with EOs of Origanum compactum (oregano), and O. majorana (marjoram) and reported practical antibacterial synergistic effect (P < 0.001) of EO of marjoram and wild thyme against S. aureus. In contrast, combining oregano with wild thyme EO showed significant synergistic activity against S. aureus and E. coli. Recently, Salaria et al.[40] have also reported the synergistic potential ability of EO from T. serpyllum with antifungal agents to treat candida infections. Erci and Torlak[39] demonstrated the antibacterial efficacy of silver nitrate nanoparticles (AgNPs) extracted from T. serpyllum aqueous extracts. The inhibition zone of AgNPs against B. cereus was 12.23 ± 0.54 mm. In contrast, the zone of inhibition was 13.86 ± 0.58 mm when treated against S. aureus. The inhibition zone diameters of AgNPs were 9.98 ± 1.02 mm and 10.60 ± 0.53 mm for E. coli and S. typhimurium, respectively. These studies clearly showed the importance of EO and extracts from wild thyme in the therapeutic industry to treat microbe-borne diseases. Table 2 shows the antimicrobial activities exhibited by EO or different extracts of T. serpyllum.

Table 2.

Antimicrobial activity of extracts and Thymus serpyllum essential oil against different bacterial and fungal species

Part used	Extracts/EO	Method	Tested strains	Key results
Aerial parts	EO	Agar well diffusion and broth dilution	K. pneumoniae P. aeruginosa E. coli S. aureus B. subtilis	15–40 mm, 100% bactericidal after 30 min exposure. In effective against P. aeruginosa[43]
Aerial part	Ethanol, butanol, methanol, hexane, ethyl-acetate, and aqueous extracts	Micro dilution method	E. coli, P. aeruginosa, S. aureus, S. epidermidis, C. albicans, C. parapsilosis A. fumigatus A. niger	Only ethyl-acetate and methanolic extracts exhibited significant activity against all tested bacteria and fungi, displaying MIC values ranging from 2000–4000 µg/mL[42]
Whole plant	EO	Micro dilution method	Ochratoxin a producing strains: A. ochraceus, A. ochraceus, A. carbonarius, and A. niger	MIC ranged between 0.625 and 2.5 µL/mL[37]
Aerial parts	EO	Agar diffusion method	P. aeruginosa, C. sakazakii, L. innocua and S. pyogenes, C. albicans, S. cerevisiae	Complete inhibition of the growth of all the strains by 50% and 100% EO[28]
Aerial parts	Primary EO and secondary EO	Disk diffusion method and micro dilution method	S. aureus, S. epidermidis, E. faecalis, S. mutans, E. aerogenes, K. pneumoniae and pathogenic fungi: C. neoformans and C. albicans	Φ - 20–>35mm MIC ranged between 1/3200 and 1/6400[30]
Aerial parts	EO of T. serpyllum in combination with EO of O. compactum (oregano), and O. majorana (marjoram)	Micro dilution method and checkerboard assay	B. subtilis, S. aureus and E. coli	Antibacterial synergistic effect was observed with combination of EO of T. serpyllum with EO of marjoram against S. aureus, while combination of EO of oregano and EO of T. serpyllum showed significant synergistic activity against S. aureus and E. coli[38]
Aerial parts	EO of T. serpyllum in combination with EO of O. majorana (marjoram)	Micro dilution method and checkerboard assay	E. coli and S. aureus	Synergistic antibacterial effect of EO of O. majorana and T. serpyllum with FIC index of 0.725[38]
Leaves	AgNPs of aqueous extracts	Agar well diffusion	B. cereus S. aureus E. coli S. typhimurium	Φ - 12.23±0.54 mm Φ - 13.86±0.58 mm Φ - 9.98±1.02 mm Φ - 10.60±0.53 mm

K. pneumoniae=Klebsiella pneumoniae, P. aeruginosa=Pseudomonas aeruginosa, E. coli=Escherichia coli, S. aureus=Staphylococcus aureus, B. subtilis=Bacillus subtilis, S. epidermidis=Staphylococcus epidermidis, C. albicans=Candida albicans, C. parapsilosis=Candida parapsilosis, A. fumigatus=Aspergillus fumigatus, A. niger=Aspergillus niger, A. ochraceus=Aspergillus ochraceus, A. carbonarius=Aspergillus carbonarius, C. sakazakii=Cronobacter sakazakii, L. innocua=Listeria innocua, S. pyogenes=Streptococcus pyogenes, S. cerevisiae=Saccharomyces cerevisiae, E. faecalis=Enterococcus faecalis, S. mutans=Streptococcus mutans, E. aerogenes=Enterobacter aerogenes, C. neoformans=Cryptococcus neoformans, B. cereus=Bacillus cereus, S. typhimurium=Salmonella typhimurium, T. serpyllum=Thymus serpyllum, O. majorana=Origanum majorana, O. compactum=Origanum compactum, Φ=Zone of inhibition in mm, MIC=Minimum inhibitory concentration, FIC=Fractional inhibitory concentration, EO=Essential oil, AgNPs=Silver nitrate nanoparticles

Anti-inflammatory effect

The anti-inflammatory response of T. serpyllum was analyzed by inhibiting the Src tyrosine kinase and interleukin-6 production in Balb/c mice splenocytes in vitro by Kindl et al.[44] A weak dose-dependent inhibition of Src kinase was observed with T. serpyllum methanolic extract (IC₅₀-115–167 μg/ml) as compared to polyphenols such as luteolin (IC₅₀-8 μM), luteolin-7-O-glucoside (IC₅₀-40 μM) and rosmarinic acid (IC₅₀-61 μM) and staurosporine (Src tyrosine kinase inhibitor) (IC₅₀-0.005 μg/ml at 0.01 μM). Furthermore, cytotoxic activity of T. serpyllum extract and polyphenols was evaluated using MTS test. T. serpyllum extract and polyphenols (200–0.8 μg/ml) restricted IL-6 production. More than 95% reduced cytokine production in the treated cells at high concentration (200 μg/ml) of T. serpyllum and IC₅₀ value for IL-6 production was found to be 49.5 ± 9.6μg/ml. No cytotoxicity was observed with T. serpyllum extract (200–0.8 μg/ml).

Anticancer and cytotoxic activity

Various research has demonstrated cytotoxic and anticancer potential of solvent extracts, EO, and phytocompounds of Thymus sp. Jaafari et al.[45] reported the cytotoxic and Hep-2 activity against leukemia model in mice. According to Nikolic et al.,[15] T. serpyllum essential showed anticancer activity against MCF-7 (Inhibition of growth by 50% (GI₅₀-52.69 ± 3.28 μg/ml), NCI-H460 (GI₅₀-37.17 ± 3.18 μg/ml), HCT-15 (GI₅₀-7.02 ± 0.07 μg/ml), HeLa (GI₅₀-17.71 ± 3.23 μg/ml), and HepG2 (GI₅₀-34.96 ± 2.90 μg/ml). T. serpyllum EO was found to be cytotoxic to MCF-7, LNCaP, and NIH3T3 fibroblast cell lines. According to research, compounds such as β-caryophyllene, a sesquiterpene, contribute to the EO’s antiproliferative properties.[46] Lazarevic et al.[47] discovered that the EO of T. serpyllum had limited antiproliferative activity against oral squamous cell carcinoma cultures and the SCC-25 cell line. The oil also had similar results against MCF-7, LNCaP, and NIH-3T3 cell lines, with IC₅₀ values of 95.8, 105.0, and 105.0 mg/ml, respectively.[46] According to Berdowska et al.,[48] the T. serpyllum water extract was analyzed for its cytotoxicity against wild-type MCF-7/wt and cancer cells (MCF-7/Adr). Thymol, one of the main components of T. serpyllum EO, also showed antiproliferative activity against HL-60 (acute promyelotic leukemia) cells.[49] Thymol and carvacrol showed dose-dependent cytotoxicity against breast cancer, colorectal cancer, and P815 mastocytoma cell line. Similarly, the correlation of the cytotoxic activity of T. serpyllum EO with carvacrol content was reported by Jaafari et al.[45] Thus, EO and phytocompounds of T. serpyllum and other species of thyme can be studied for clinical efficacy in humans for treating cancer.

Antimalarial activity

Hussain et al.[31] studied the antimalarial activity of EO of T. serpyllum using antihem biocrystallization assay. The higher antimalarial activity was observed in T. serpyllum oil (46.1%) at 10 mg/ml concentration. Further detailed studies with varying concentrations and model systems are required to explore the potential of T. serpyllum EO and its components as an antimalarial agent.

Toxicity Studies

Thyme has received the “food safe” classification from the U.S. FDA if it is used in recommended therapeutic quantities. Xie et al.[50] revealed that sustained inhalation of thymol in mice over a 6-month treatment period, at concentrations ranging from 0.1% to 0.5% thymol hydrofluoroalkane, did not result in any harmful effects on their lungs or respiratory systems. However, there is a lack of reports on the toxic effects of administering T. serpyllum EO. It is crucial to conduct detailed studies focusing on the toxicity aspects of T. serpyllum EO with various doses and model systems to understand its safety profile better.

Other Biotechnological Applications

Food preservative activity

Thymol, carvacrol, terpenoids, and other phytocompounds found in T. serpyllum EO have also demonstrated the importance of enhancing food quality and safety by halting the growth of food microbes. These phytocompounds prevent the deteriorative activity of microbes in food products or act as antimicrobials against food pathogens.[51] Wild thyme is an essential medicinal plant due to its antimicrobial and antioxidant properties.[15] In research by Hagan et al.[52] in baking, T. serpyllum EO was used as an antifungal agent to ferment cakes.

Insecticidal property

According to research, thymol, the main active ingredient in T. serpyllum’s EO, has shown to be resistant to common housefly (Musca domestica) larvae and pupae. Recent research has shown that T. serpyllum thymol has fumigant and contact toxic effects. This finding suggests that thymol and T. serpyllum EO both have toxic effects on housefly larvae and pupae, suggesting their potential as tools for controlling the population of this species. Szczepanik et al.[53] have also reported the insecticidal properties of carvacrol and thymol from T. vulgare. However there is no research done so far on the insecticidal properties of T. serpyllum EO. However, there is no research done so far on the insecticidal property of T. serpyllum EO.

Conservation

T. serpyllum has various pharmacological properties. Researchers and common people are showing very high interest in T. serpyllum to develop herbal products. T. serpyllum is mainly used in India, China, Nepal, Pakistan, North America, and East Africa.[8] Due to its high medicinal properties and limited sources, researchers are trying to cultivate T. serpyllum by in vitro tissue culture techniques. Er. Rajan Rolta, Scientific Advisor at Tridev Aushadhi Utpadhan Society, Rohal, Chirgaon, District Shimla, Himachal Pradesh, India, is also trying to cultivate the T. serpyllum in its natural habitat to fulfill the industrial demand for this herb.

Future Perspectives and Conclusions

The aerial part of T. serpyllum has been utilized for treating respiratory, digestive, and urogenital tract issues. Due to its pharmacological importance, EO derived from this species has gained popularity in the modern medicinal system. The composition of phytocompounds and the yield of T. serpyllum EO depend on various factors, including geographical region, development stages, and harvesting season, making it significant for medical, cosmetic, and industrial applications. Recent research indicates that the EO of T. serpyllum exhibits notable antioxidant and antimicrobial properties. However, further studies are required to determine the potential use of thymol, carvacrol, and other constituents against cytotoxicity, inflammation, malaria, and hypertension. The pharmaceutical industry values this herb for its diverse pharmacological properties, while the food sector may consider it a source of antioxidants and dietary supplements.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.