In this study, we have reported the chemical composition of Equisetum arvense essential oil and the anti-cancer activity of the plant against the prostate cancer cell line. The essential oil was obtained using the hydro-distillation assay. The chemical composition was identified using the gas chromatographic methods including gas chromatography/flame ionization detector and gas chromatography/mass spectrometry. The antioxidant activity of the essential oil and extract was evaluated using classical methods. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was run to evaluate the cytotoxic effect of the essential oil and extract on the prostate cancer cell line of lymph node carcinoma of the prostate. The induction apoptosis of the extract was analyzed by a flow cytometer. Thymol acetate (14.7%), trans-carveol (12.5%), thymol (11.8%), and δ-elemene (9.4%) were identified as the main compounds for the essential oil. The extract scavenged the free radical of 2,2-diphenyl-1-picrylhydrazyl with a half maximal inhibitory concentration (IC50) of 15.2 ± 1.4 μg/mL for the plant extract. In the MTT assay, the IC50 of the extract and essential oil were 25.2 ± 0.3 and 218.9 ± 10.7 μg/mL after 72 h. The highest apoptosis was 31.6% for the plant extract. The obtained results of the present study revealed that E. arvense can be introduced as a potent agent to prevent the growth of prostate tumors.
List of abbreviations
ferrous ion chelating ability
gas chromatography/flame ionization detector
gas chromatography/mass spectrometry
half maximal inhibitory concentration
lymph node carcinoma of the prostate
radical scavenging activity
total phenolic content
total flavonoid content
Prostate cancer is the most common cancer in men. If it is early detected, the survival rate is high [1,2]. Surgery, chemotherapy, or secondary hormonal therapy, which depends on tumor aggressiveness, are usual ways to treat prostate cancer [3,4,5]. Herbal medicine is an alternative to cure diseases due to the minimal side effects . In recent years, there is an increasing interest in diets rich in some ingredients such as lycopene, vitamin C, vitamin K, and polyphenols to improve the survival of patients with prostate cancer due to their ability reported in the literature .
Equisetum arvense, known as horsetail, belongs to Equisetaceae family . E. arvense is a perennial plant. It grows naturally in light sandy soils . In folkloral medicine, E. arvense has been used for urinary and prostatic problems, managing enuresis, managing irritable symptoms of the urinary system ; treatment of digestive disorders and kidney/bladder stones, analgesic, hemostatic, astringent ; skin, hair, and nail remedies ; wounds, metabolic or hormonal edema, rheumatism, and chilblains .
The stem extract of E. arvense showed sedative and anticonvulsant properties . The extract showed analgesic and anti-inflammatory effects . The prepared herbal tea of E. aruense is known as a diuretic agent in folk medicine of different cultures . Various uses have been reported for E. arvense. The plant showed antitumoral, antimicrobial, anticonvulsant, and antidiabetic activity . The plant is an effective agent to treat tuberculosis, ulcers, and bleeding .
E. arvense is rich in polyphenolic compounds such as flavonoids, tannins, sterols, and saponins . Epicatechin, quercetin, catechin, leutolin, and apigenin are the abundant flavonoids, and vanillic acid, caffeic acid, ferulic acid, and coumaric acid are the predominant phenolic compounds [19,20,21]. Oh et al. reported the isolation of phenolic compounds onitin and onitin-9-O-glucoside and of flavonoids luteolin, kaempferol-3-O-glucoside, and quercetin-3-O-glucoside from E. arvense . Calcium, potassium, phosphate, iron, manganese, silicic acid, and silicates are abundant minerals in the plant [23,24].
In the present study, the chemical composition of E. arvense essential oil was analyzed using chromatography methods as well as the antioxidant activity of the plant essential oil and extract. Furthermore, as mentioned earlier, E. arvense is known as an herbal remedy for prostate problems in some traditional medicine around the world; this is a study examining on the anti-cancer activity of the plant volatile oil and extract using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on lymph node carcinoma of the prostate (LNCap) cell line as a standard human prostate cancer cell line.
2 Material and methods
The chemicals with analytical grades were used in this research: 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferrozine, and α-tocopherol (Sigma, USA); Na2SO4, ascorbic acid (AsA) (Merck, Germany); saturated hydrocarbon homologous series (C8–C20 and C21–C40) (Fluka, USA); ferrous sulfate heptahydrate (BD, UK).
2.2 Collection of plant material
The aerial parts of E. arvense were purchased from a medicinal plant store. The plant was identified by Mrs. Yudi Miao with voucher number 20-11-328.
2.3 Isolation of E. arvense essential oil
A 100 g plant sample was put in a Clevenger-type apparatus for 4 h. The hydrodistillation was repeated five times. The obtained essential oil was dried over anhydrous sodium sulfate (Merck) and stored in tightly closed vials at −18°C in the dark before biological and analytical assays.
2.3.1 Gas chromatography/flame ionization detector analysis
22.214.171.124 GC/FID analysis
The essential oil was subjected to GC/FID analysis using a Hewlett-Packard 5890 GC instrument equipped with a DB-5 capillary column (30 m × 0.25 mm i.d.; film thickness, 0.1 mm; from J.W. Scientific, USA). Helium was the carrier gas (1.0 mL/min). The injector and detector temperature was 250°C. The initial temperature was maintained at 40°C for 2 min, then raised at 3°C/min to 240°C, and held for 10 min. The split ratio was 1:20. Hydrogen was applied as fuel in the detector. A homologous series of saturated hydrocarbons (C8 to C40) were subjected to the instrument with the same conditions. Quantification was done by an external standard method using calibration curves generated by running GC analysis of representative compounds.
126.96.36.199 Gas chromatography/mass spectrometry analysis
For the GC-MS analysis of the essential oil, an Agilent GC/MS system (7890A equipped with an Agilent 5975C mass detector) was selected. The sample was injected into an HP-5 capillary column (30 m × 0.32 mm i.d.; 0.25 mm film thickness from J.W. Scientific). All parameters were the same as GC/FID conditions. A 70 eV was the ionization voltage, and the scan mass range was 50–600 amu for the mass detector.
188.8.131.52 Component identification
The identity of the chemical constituents of the volatile oil was established using the GC retention indices Kovats indices, the retention time, and mass spectral fragmentation patterns with those of the known compounds from the literature data  and the standard database of NIST (National Institute of Standards and Technology) . Furthermore, structural assignment confirmation was also made by co-injection of available authentic pure samples. Quantification was done by an external standard method using calibration curves generated by running GC analysis of representative compounds.
2.4 Preparation of E. arvense extract
To obtain the hydroalcoholic extract of E. aevense, 50 g of the aerial parts of the plant was ground and macerated in the solvent for 72 h. The solvent consisted of 70% of ethanol and 30% of water. Then, the solvent was evaporated using a Buchi evaporator (50°C). Finally, the crude extract was put in a freeze-dryer for 48 h. The powder was kept in a dark-and-cold place before biological investigations.
2.4.1 Antioxidant activity evaluation assays
The classical assays including total phenolic content (TPC), total flavonoid content (TFC), radical scavenging activity (RSA), and ferrous ion chelating ability (FIC) were carried out to study the antioxidant activity of E. aevense extract and essential oil [27,28].
First, a mixture that included 0.5 mL of a methanolic solution of E. aevense extract (100 µg/mL), Folin-Ciocalteu Reagent (0.5 mL, 10% in distilled water), and H2O (2 mL) was prepared. After 5 min, 2 mL of sodium carbonate (5%) was added and shaken. Then, the optical density of the mixture was recorded at 760 nm using a Shimadzu instrument (UV-2400) after 2 h. The TPC was reported as mg GAE/g extract, which means mg of gallic acid equivalent per gram of extract. All measurements were carried out in triplicates.
A 1.5 mL of E. aevense extract (200 µg/mL) was added to AlCl3 in methanol (1 mL, 2%) and kept for 40 min. Then, the optical density was read at 415 nm. The TFC was reported as milligram RE/gram extract, that is, the milligram of rutin equivalent per gram of dried extract. The analyses were run three times.
A 0.5 mL of E. aevense extract or essential oil at different concentrations was poured into 0.5 mL of DPPH (1 × 10−3 M) and shaken. After 2 h, the absorbance was read at 517 nm. α-Tocopherol (Toc) and butylated hydroxytoluene (BHT) were the selected positive controls for this assay. All measurements were run three times. The RSA% was obtained by the following equation:
where A c and A s are the control absorbance (DPPH solution) and the sample, respectively.
Ferrozine (100 µL, 5 × 10−3 M) was pipetted to a mixture of FeSO4 (50 µL, 2 × 10−3 M) and 1 mL of E. aevense extract or essential oil at different concentrations. After 10 min. the absorbance was read at 562 nm. Ethylenediaminetetraacetic acid (EDTA) and AsA were chosen as the positive control for this assay. All measurements were run three times. The FIC was calculated using the following equation:
where A c and A s are the absorbance of the control (FeSO4 and ferrozine) and the sample, respectively.
2.5.4 MTT assay
In this research, we used LNCaP cell lines to evaluate the anti-human prostate cancer and cytotoxicity effects of E. arvense extract and essential oil. The assay was run according to previous studies with some modifications [29,30]. The cell line was cultured (1 × 104 cells/well) in a 96-well microplate and incubated at 37°C, CO2 5% for 24 h. Next, the plant extract or essential oil at different concentrations was added to the wells and incubated for 24, 48, and 72 h. After that, 20 µL of MTT (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide) with a concentration of 5 mg/mL in PBS was added and incubated at 37°C for 4 h. Finally, the absorbance of the dissolved formazan crystals in DMSO (dimethyl sulfoxide) was read at 570 nm and 630 by a plate reader (Thermo Lab systems, Franklin, MA USA). The half maximal inhibitory concentration (IC50), which showed the concentration of E. arvense extract or essential oil for 50% mortality rate, was measured through Prism software. All treatments run three times. For this assay, DMSO and docetaxel (0.1 µM) were used as the negative and positive controls, respectively.
2.5.5 Flow cytometric analysis
The apoptosis was screened by propidium iodide (PI) staining of small DNA fragments followed by flow cytometry according to a previous study . Briefly, LNCaP cells (1.5 × 105 cells) were cultured in FBS (10%) and then incubated overnight at 37°C under CO2 (5%). Then, it was treated with the calculated IC50 value of the extract for 24, 48, and 72 h. After that, the cells were taken up and put in an incubator for 24 h with 700 μL of 50 mg/mL PI. After that, a Becton Dickinson flow cytometer was used. A total of 10,000 events were attained with FACS. A flow Jo-V10 software was used to analyze the data.
2.6 Qualitative measurement
The obtained findings were analyzed using SPSS (version 20) software using one-way ANOVA, followed by Duncan's posthoc test (P ≤ 0.01).
3 Results and discussion
3.1 The essential oil composition
The obtained volatile oil was colorless with an average of 0.21 ± 0.03% (W/W) yield. Twenty compounds were identified in the essential oil comprising eight oxygenated monoterpenes (33.4%), four sesquiterpene hydrocarbons (29.1%), two phenolic compounds (26.5%), two oxygenated hydrocarbons (6.0%), and one monoterpene hydrocarbon (0.6%). These represented 95.6% of all oil components. Table 1 shows the chemical composition of E. aevense essential oil. The phenolic compounds of thymol acetate (14.7%) and oxygenated monoterpene of trans-carveol (12.5%) were the main components of the essential oil, followed by thymol (11.8%) and δ-elemene (9.4%).
|No||Compoundsa||RT||RI (Lit.)b||RI (Obsd.)c||Area (%)||Id. Meth.d|
|1||1,8 Cineole||7.16||1,026||1,024||1.6||RI, MS|
|3||Heptyl acetate||9.7||1,112||1,110||0.4||RI, MS|
|4||Octyl formate||10.2||1,127||1,122||5.6||RI, MS|
|11||Methyl nerolate||16.7||1,280||1,279||1.6||RI, MS|
|14||δ-Terpinyl acetate||18.5||1,316||1,318||1.7||RI, MS|
|17||Thymol acetate||19.8||1,349||1,348||14.7||RI, MS|
|20||trans-Carvyl propanoate||29.13||1,454||1,459||3.8||RI, MS|
|I||Oxygenated monoterpenes (OM)||33.4|
|II||Sesquiterpene hydrocarbons (SH)||26.7|
|III||Phenolic compounds (Ph)||26.5|
|IV||Oxygenated hydrocarbons (OH)||6.0|
|V||Oxygenated sesquiterpene (OS)||2.4|
|VI||Monoterpene hydrocarbons (MH)||0.6|
aOxygenated monoterpenes, Nos. 2, 5–11, 14, 20; Sesquiterpene hydrocarbons, Nos. 13, 15,16, 18, 19; Phenolic compounds, Nos. 12 and 17; Oxygenated hydrocarbons, Nos. 3 and 4; Oxygenated sesquiterpene, Nos. 19; Monoterpene hydrocarbons, No. 2.
bRI (Lit.): Retention indices from literatures (Adams ).
cRI (Obsd.) Retention indices (I) on DB-5.
In a previous study, the essential oil of E. aevense from Europe was dominated by hexahydrofarnesyl acetone, cis-geranyl acetone, and trans-β-damascenone . Fons et al. have evaluated the volatile organic compounds of different Equisetum species using GC/MS analysis. According to their reports, E. arvense was rich in 3-hydroxy-7,8-epoxy-β-ionol, (E,E)-pseudoionone, and 3-oxo-α-ionol; E. palustre var. americana was dominated by 1-octen-3-ol, (E)-2-hexenoic acid, and (E)-2-hexenal; 3-hydroxy-7,8-epoxy-β-ionol, 3-hydroxy-α-ionone, and 4-vinylguaiacol were the main component of E. telmateia; (E)-2-heptenal, (E)-and (Z)-ferulic acid isomers were the main compounds for E. hyemale; E. ramosissimum was rich in 4-vinylguaiacol, (E)- and (Z)-ferulic acid; on the other hand, 3-hydroxy-β-ionone, 3-hydroxy-7,8-epoxy-β-ionol (15.5%), and homovanillic acid were identified in E. scirpioides . The essential oil of E. diffusum was dominated by phytol, hexacosane, and cis-cadin-4-ene-7-ol . The difference in the chemical composition of Equisetum plants can be due to the method applied to the isolation of the essential oils, the seasonal variation, drying period, altitudes, environmental circumstances, climatic conditions, and geographical location of the plant [34,35].
3.2 Antioxidant activity
The results of the antioxidant activity of E.aevense extract and essential oil are presented in Table 2. A 389.0 ± 6.4 mg GAE/g for TPC and 57.6 ± 3.8 mg RE/g for TFC of E.aevense were recorded. According to our findings, the extract was more potent in the selected antioxidant assays compared to the essential oil. The extract scavenged DPPH with IC50 of 15.2 ± 1.4 μg/mL. The extract showed more activity than BHT and TOC. Furthermore, the IC50 of 112.7 ± 3.4 μg/mL was calculated for E.aevense extract using FIC assay. The extract was more active than AsA and less than EDTA. For the essential oil, 952.7 ± 15.2 and 1282.7 ± 12.7 μg/mL were calculated for the IC50 using RSA and FIC assays, respectively.
|TPC mg GAE/g extract||TFC (mg RE/g extract)||RSA IC50 (μg/mL)||FIC IC50 (μg/mL)|
|Extract||389.0 ± 6.4||57.6 ± 3.8||15.2 ± 1.4||112.7 ± 3.4|
|Essential oil||—||—||952.2 ± 15.2||1,282.7 ± 12.7|
|BHT||—||—||18.3 ± 1.1||—|
|TOC||—||—||32.4 ± 0.9||—|
|EDTA||—||—||—||56.2 ± 1.8|
|AsA||—||—||—||1371.2 ± 8.7|
Values are presented as means ± SD (n = 3).
Previous studies have reported the ability of E. arvense extract to scavenge DPPH [9,19]. E. arvense from different locations in Romania was rich in polyphenols and flavonoids with a high ability to scavenge the free radical of DPPH , whereas 30% of RSA has been reported for E. hyemal . A 0.675 mg/mL gallic acid equivalent has been reported for the hydroalcoholic extract of E. ramosissimum . The extract of E. ramosissimum also scavenged the free radical of DPPH .
3.3 Cytotoxicity effect of E. arvense on LNCaP cell line
Figures 1 and 2 present the results of the MTT assay of E. arvense extract and essential oil against the human prostate cancer cell line (LNCaP cell line). In most studies on the evaluation of anti-prostate cancer activity, the MTT assay is run on the LNCaP cell line because it is known as the standard cell line. The cell line is androgen-responsive and derived from human prostate cancer with metastatic to bone. According to the results, the viability of the prostate cell line is reduced dose-dependently in the presence of the plant extract and essential oil. Furthermore, the cell viability depends on the treatment time. The IC50 of the plant extract was 43.2 ± 1.7, 29.3 ± 1.6, and 25.2 ± 1.3 μg/mL after treatment for 24, 48, and 72 h, respectively. The plant extract had higher activity than the essential oil with IC50 of 382.2 ± 13.6, 285.3 ± 5.7, and 218.9 ± 10.7 μg/mL for 24, 48, and 72 h treatment, respectively. In a comparison with previous studies on the anti-prostate cancer activity of the plant extract, E. arvense extract exhibited more activity against than Boswellia serrata extract , Scaphechinus mirabilis extract , and Corni fructus extract . However, the anticancer activity of E. arvense extract was less than that of Linum usitatissimum extract against LNCaP cell line .
The diets, which are enriched in phenolic compounds, play a considerable role in preventing and treating prostate cancer [43,44]. According to our results, the extract of E. arvense presented a considerable cytotoxic effect on the LNCaP cell line. According to the previous reports, the presence of secondary metabolites such as polyphenols and flavonoids is the major reason for the ability of E. arvense extract to prevent the prostate cancer cell line. Among the phenolic and flavonoids reported for the extract of E. arvense, quercetin, luteolin, vanillic acid, caffeic acid, and ferulic acid reported as having considerable potential against different cancer cell lines [45,46,47]. Furthermore, the synergistic effect of polyphenols with chemotropic drugs is known as an effective strategy to treat cancer diseases [48,49].
A few studies have reported the anti-cancer activity of the plants from the Equisetum genus. In reported research, E. arvense exhibited a cytotoxic effect against the human leukemic cell line . The ethanolic extract of E. arvense showed a cytotoxic effect on the human pancreatic carcinoma cell line . The plant extract is also active against cervical, breast, and colorectal cell lines . E. ramosissimum showed anticancer activity against three human melanoma cancer cell lines .
3.4 Detection of apoptosis by flow cytometry
Apoptosis and necrosis are known as the two main types of cell death. Apoptosis is programmed cell death. Apoptosis happens in two ways including (1) extrinsic pathway that is started by death receptor–ligand stimulation systems and (2) intrinsic pathway that takes place by DNA damage [3,6]. Figures 3 and 4 exhibit the flow cytometric analysis and the percentage for apoptosis by the extract of E. arvense. The prostate cancer cells were treated with E. arvense extract with concentrations of 25.0, 30.0, and 40.0 μg/mL, which were close to the obtained IC50 from the MTT assay. The results showed that the treated cells with E. arvense extract increased the apoptosis percentage considerably compared to the control. The highest result was calculated for the concentration of 40.0 μg/mL after 72 h with 31.6% apoptosis, while the minimum apoptosis (16.4%) was obtained for 25.0 μg/mL after 24 h.
The results of the present study revealed that thymol acetate, trans-carveol, thymol, and δ-element were the major components of E. arvense essential oil. The plant extract showed higher antioxidant activity than the essential oil and even the positive controls. The extract scavenged the free radical of DPPH with an IC50 of 15.2 ± 1.4 μg/mL. In the MTT assay, the plant extract prevented the growth of LNCaP as the selected prostate cancer cell line more than the plant essential oil with an IC50 of 25.2 ± 1.3 μg/mL after 72 h. The plant extract induced a 31.6% apoptosis in the cell line. According to the obtained results from the study, E. arvense extract can be used as herbal medicine for prostate cancer; however, further research especially in vivo evaluation should be carried out to evaluate the therapeutic potential of E. arvense against prostate cancer.
Funding information: There is no external funding.
Author contributions: Writing–original draft preparation, Hongyong Gu; data curation and software, Ting Yi; conceptualization and methodology, Pengxiu Lin; formal analysis, writing–review and editing, Jin Hu.
Conflict of interest: The authors declare no conflict of interest.
Ethical approval: The conducted research is not related to either human or animal use.
Data availability statement: The data sets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.
 Yoo S, Gujrathi I, Haider MA, Khalvati F. Prostate cancer detection using deep convolutional neural networks. Sci Rep. 2019;9:19518.10.1038/s41598-019-55972-4Search in Google Scholar PubMed PubMed Central
 Chen X, Liu J, Cheng L, Li C, Zhang Z, BaiY, et al. Inhibition of noncanonical Wnt pathway overcomes enzalutamide resistance in castration‐resistant prostate cancer. Prostate. 2019;80:256–66.10.1002/pros.23939Search in Google Scholar PubMed
 Abou-Hashem MMM, Abo-Elmatty DM, Mesbah NM, Abd, EL-Mawgoud AM. Induction of sub-G0 arrest and apoptosis by seed extract of Moringa peregrina (Forssk.) Fiori in cervical and prostate cancer cell lines. J Integr Med. 2019;17:410–22.10.1016/j.joim.2019.09.004Search in Google Scholar PubMed
 Dasari S, Samy ALPA, Narvekar P, Dontaraju VS, Dasari R, Kornienko A, et al. Polygodial analog induces apoptosis in LNCaP prostate cancer cells. Eur J Pharmacol. 2018;828:154–62.10.1016/j.ejphar.2018.03.029Search in Google Scholar PubMed PubMed Central
 Mirza MB, Elkady AI, Al-Attar AM, Syed FQ, Mohammed FA, Hakeem KR. Induction of apoptosis and cell cycle arrest by ethyl acetate fraction of Phoenix dactylifera L.(Ajwa dates) in prostate cancer cells. J Ethnopharmacol. 2018;218:35–44.10.1016/j.jep.2018.02.030Search in Google Scholar PubMed
 Dasari S, Samy ALPA, Kajdacsy B, Bosland AMC, Munirathinam G. Vitamin K2, a menaquinone present in dairy products targets castration-resistant prostate cancer cell-line by activating apoptosis signaling. Food Chem Toxicol. 2018;115:218–27.10.1016/j.fct.2018.02.018Search in Google Scholar PubMed PubMed Central
 Asgharikhatooni A, Bani S, Hasanpoor S, Alizade SM, Javadzadeh Y. The effect of Equisetum arvense (horse tail) ointment on wound healing and pain intensity after episiotomy: a randomized placebo-controlled trial. Iranian Red Cres Med J. 2015;17:35–41.10.5812/ircmj.25637Search in Google Scholar PubMed PubMed Central
 Čanadanović‐Brunet JM, Ćetković GS, Djilas SM, Tumbas VT, Savatović SS, Mandić AI, et al. Radical scavenging and antimicrobial activity of horsetail (Equisetum arvense L.) extracts. Inter J Food Sci Technol. 2009;44:269–78.10.1111/j.1365-2621.2007.01680.xSearch in Google Scholar
 Cordova E, Morganti L, Rodriguez C. Possible drug–herb interaction between herbal supplement containing horsetail (Equisetum arvense) and antiretroviral drugs: report of 2 cases. J Inter Assoc Provid AIDS Care. 2017;16:11–3.10.1177/2325957416680295Search in Google Scholar PubMed
 Saslis-Lagoudakis CH, Bruun-Lund S, Iwanycki NE, Seberg O, Petersen G, Jäger AK, et al. Identification of common horsetail (Equisetum arvense L.; Equisetaceae) using thin layer chromatography versus DNA barcoding. Sci Rep. 2015;5:1–12.10.1038/srep11942Search in Google Scholar PubMed PubMed Central
 Cetojević-Simin DD, Canadanović-Brunet JM, Bogdanović GM, Djilas SM, Cetković GS, Tumbas VT, et al. Antioxidative and antiproliferative activities of different horsetail (Equisetum arvense L.) extracts. J Med Food. 2010;13:452–59.10.1089/jmf.2008.0159Search in Google Scholar PubMed
 Dos Santos Jr JG, Blanco MM, Do Monte FH, Russi M, Lanziotti VM, Leal LK, et al. Sedative and anticonvulsant effects of hydroalcoholic extract of Equisetum arvense. Fitoterapia. 2005;76:508–13.10.1016/j.fitote.2005.04.017Search in Google Scholar PubMed
 dos Santos Junior JG, do Monte FHM, Blanco MM, Lanziotti VMdNB, Maia FD, de-Almeida LK. Cognitive enhancement in aged rats after chronic administration of Equisetum arvense L. with demonstrated antioxidant properties in vitro. Pharmacol Biochem Behav. 2005;8(1):593–600.10.1016/j.pbb.2005.04.012Search in Google Scholar
 Graefe E, Veit M. Urinary metabolites of flavonoids and hydroxycinnamic acids in humans after application of a crude extract from Equisetum arvense. Phytomedicine. 1999;6:239–46.10.1016/S0944-7113(99)80015-4Search in Google Scholar PubMed
 Boeing T, Tafarelo Moreno KG, Gasparotto JA, Mota-da-Silva L, de-Souza P. Phytochemistry and pharmacology of the genus Equisetum (Equisetaceae): A narrative review of the species with therapeutic potential forkidney diseases. Evidence-Based Complement Altern Med. 2021;21:6658434–17.10.1155/2021/6658434Search in Google Scholar PubMed PubMed Central
 Kour J, Ali MN, Ganaie HA, Tabassum N. Amelioration of the cyclophosphamide induced genotoxic damage in mice by the ethanolic extract of Equisetum arvense. Toxicolo Rep. 2017;4:226–33.10.1016/j.toxrep.2017.05.001Search in Google Scholar PubMed PubMed Central
 Bordbar M, Mortazavimanesh N. Green synthesis of Pd/walnut shell nanocomposite using Equisetum arvense L. leaf extract and its application for the reduction of 4-nitrophenol and organic dyes in a very short time. Environ Sci Pollut Res. 2017;24:4093–104.10.1007/s11356-016-8183-ySearch in Google Scholar PubMed
 Pallag A, Jurca T, Pasca B, Sirbu V, Honiges A, Costuleanu M. Analysis of phenolic compounds composition by HPLC and assessment of antioxidant capacity in Equisetum arvense L. extracts. Rev Chim. 2016;67:1623–7.Search in Google Scholar
 Carneiro D, Tresvenzol LMF, Jardim PCBV, Cunha LCd. Equisetum arvense: scientific evidences for clinical use. Int J Bio Pharm Alied Sci. 2013;2:1579–96.Search in Google Scholar
 Qureshi MN, Stecher G, Bonn GK. Quantification of polyphenolic compounds and flavonoids in Achillea millefolium and Equisetum arvense. Pakistan J Pharm Sci. 2016;29:56–64.Search in Google Scholar
 Oh H, Kim DH, Cho JH, Kim YC. Hepatoprotective and free radical scavenging activities of phenolic petrosins and flavonoids isolated from Equisetum arvense. J Ethnopharm. 2004;95:421–4.10.1016/j.jep.2004.08.015Search in Google Scholar PubMed
 Turker H, Turkay M. Effects of Equisetum arvense plant extracts on the kidney stones and its diuretic action. Cell Mol Biol. 2016;1:1–8.Search in Google Scholar
 Badole S, Kotwal S. Equisetum arvense: Ethanopharmacological and phytochemical review with reference to osteoporosis. Inter J Pharm Heal Car. 2014;1:131–41.Search in Google Scholar
 Adams RP. Identification of essential oils components by gas chromatography/quaderupole mass spectroscopy. Illinois: Allured; 2007.Search in Google Scholar
 NIST. NIST data base National Institute of Standards and Technology, U.S. Gaithersburg. MD: Department of Commerce; 2005.Search in Google Scholar
 Abadi Zahra HZ, Mahdavi B, Rezaei-Seresht E. Contents of aerial parts of Salvia leriifolia Benth. J Chem Heal Risk. 2016;6:185–94.Search in Google Scholar
 Li M, Behnam M, Yaacob WA, Din LB. Chemical composition, antioxidant, antimicrobial and anti proliferative activities of essential oil and extract of the fruits of Etlinger sayapensis. J Essent Oil Bear Pl. 2020;23:931–3.10.1080/0972060X.2020.1838332Search in Google Scholar
 Ni J, Mahdavi B, Ghezi S. Chemical composition, antimicrobial, hemolytic, and antiproliferative activity of essential oils from Ephedra intermedia Schrenk & Mey. J Essent Oil Bear Pl. 2019;22:1562–70.10.1080/0972060X.2019.1707717Search in Google Scholar
 Zhou X, Huang N, Chen W, Xiaoling T, Mahdavi B, Raoofi A, et al. HPLC phenolic profile and induction of apoptosis by Linum usitatissimum extract in LNCaP cells by caspase3 and Bax pathways. Amb Express. 2020;10:1–11.10.1186/s13568-020-01138-9Search in Google Scholar PubMed PubMed Central
 Radulović N, Stojanović G, Palić R. Composition and antimicrobial activity of Equisetum arvense L. essential oil, phytotherapy research. Inter J Dev Pharm Toxicol Evalu Nat Prod Deriv. 2006;20:85–8.10.1002/ptr.1815Search in Google Scholar
 Fons F, Froissard D, Bessière JM, Fruchier A, Buatois B, Rapior S. Volatile composition of six horsetails: prospects and perspectives. Nat Prod Commun. 2013;8:1934578X1300800426–12.10.1177/1934578X1300800426Search in Google Scholar
 Takuli P, Khulbe K, Kumar P, Pant C. Chemical composition of essential oil of Equistum diffusum: a noble source of phytol. Inter J Pharm Sci Res. 2020;11:5572–8.Search in Google Scholar
 Dhami A, Singh A, Palariya D, Kumar R, Prakash O, Rawat D. α-pinene rich bark essential oils of Zanthoxylum armatum DC. from three different altitudes of Uttarakhand, India and their antioxidant, in vitro anti-inflammatory and antibacterial activity. J Essent Oil Bear Pl. 2019;22(3):660–74.10.1080/0972060X.2019.1630015Search in Google Scholar
 Mahdavi B, Yaacob WA, Din LB, Heng LY, Ibrahim N. Chemical composition, antioxidant, and antibacterial activities of essential oils from Etlingera brevilabrum valeton. Rec Nat Prod. 2016;10:22–31.Search in Google Scholar
 Pallag A, Bungau S, Tit DM, Jurca T, Sirbu V, Honiges A, et al. Comparative study of polyphenols, flavonoids and chlorophylls in Equisetum arvense L. populations. Rev Chim. 2016;67:530–3.Search in Google Scholar
 de Queiroz GM, Politi FA, Rodrigues ER, Souza-Moreira TM, Moreira RR, Cardoso CR, et al. Phytochemical characterization, antimicrobial activity, and antioxidant potential of Equisetum hyemale L.(Equisetaceae) extracts. J Med Food. 2015;18:830–4.10.1089/jmf.2014.0089Search in Google Scholar PubMed
 Savaya NSA, Issa RA, Talib WH. In vitro evaluation of the antioxidant, anti-Propioni bacterium acne and antityrosinase effects of Equisetum ramosissimum (Jordanian horsetail). Trop J Pharm Res. 2020;19:2147–52.10.4314/tjpr.v19i10.19Search in Google Scholar
 Li PH, Chiu YP, Shih CC, Wen ZH, Ibeto LK, Huang SH, et al. Biofunctional activities of Equisetum ramosissimum extract: protective effects against oxidation, melanoma, and melanogenesis. Oxid Med Cell Longev. 2016;2016:2853543.10.1155/2016/2853543Search in Google Scholar
 Pillai P, Pooleri GK, Nair SV. Role of testosterone levels on the combinatorial effect of Boswellia serrata extract and enzalutamide on androgen dependent LNCaP cells and in patient derived cells. Integr Can Therap. 2021;20:1534735421996824.10.1177/1534735421996824Search in Google Scholar PubMed PubMed Central
 Kim KH, Hong GL, Karunasagara S, Jung JY. Scaphechinus mirabilis extract effectively inhibits the proliferation of BPH-1 and LNCaP prostate epithelial cells. Nat Prod J. 2022;12(2):70–6.10.2174/2210315511666210603153637Search in Google Scholar
 Kim MY, Ji SY, Hwangbo H, Lee H, Hong SH, Choi YH. Inhibition of proliferation of LNCaP prostate cells by corni fructus extract is associated with a decrease in the expression of benign prostatic hyperplasia-causing factors. J Korean Med Obes Res. 2021;21(1):10–21.10.15429/jkomor.2021.21.1.10Search in Google Scholar
 Cho HD, Lee JH, Moon KD, Park KH, Lee MK, Seo KI. Auriculasin-induced ROS causes prostate cancer cell death via induction of apoptosis. Food Chem Toxicol. 2018;111:660–9.10.1016/j.fct.2017.12.007Search in Google Scholar PubMed
 Martínez MSD, Gil-Araujo AB, Gallego B, Chiloeches A, Lasa M. Resveratrol promotes apoptosis through the induction of dual specificity phosphatase 1 and sensitizes prostate cancer cells to cisplatin. Food Chem Toxicol. 2019;124:273–9.10.1016/j.fct.2018.12.014Search in Google Scholar PubMed
 Iida K, Naiki T, Naiki-Ito A, Suzuki S, Kato H, Nozaki S, et al. Luteolin suppresses bladder cancer growth via regulation of mechanistic target of rapamycin pathway. Cancer Sci. 2020;111:1165–79.10.1111/cas.14334Search in Google Scholar PubMed PubMed Central
 Eitsuka T, Tatewaki N, Nishida H, Kurata T, Nakagawa K, Miyazawa T. Synergistic inhibition of cancer cell proliferation with a combination of δ-tocotrienol and ferulic acid. Biochem Biophys Res Commun. 2014;453:606–11.10.1016/j.bbrc.2014.09.126Search in Google Scholar PubMed
 Eroglu C, Ebru A, Secme M, Dodurga Y, Vural H, Kurar E. The combination effect of ferulic acid and gemcitabine on expression of genes related apoptosis and metastasis in PC-3 prostate cancer cells. Eur J Biol. 2018;77:32–7.10.26650/EuroJBiol.2018.0003Search in Google Scholar
 Mahdavi B, Yaacob WA, Din LB. Chemical composition, antioxidant, and antibacterial activity of essential oils from Etlingera sayapensis AD Poulsen & Ibrahim. Asian Pac J Trop Med. 2017;10:819–26.10.1016/j.apjtm.2017.08.006Search in Google Scholar PubMed
 Yatkin E, Polari L, Laajala TD, Smeds A, Eckerman C, Holmbom B, et al. Novel lignan and stilbenoid mixture shows anticarcinogenic efficacy in preclinical PC-3M-luc2 prostate cancer model. PLoS One. 2014;9:e93764.10.1371/journal.pone.0093764Search in Google Scholar PubMed PubMed Central
 Bhat AA, Ahamad B, Rehman MU, Ahmad P. Impact of ethanolic extract of Equisetum arvense (EA1) on pancreatic carcinoma AsPC-1 cells. Saudi J Biol Sci. 2020;27:1260–4.10.1016/j.sjbs.2020.01.029Search in Google Scholar PubMed PubMed Central
© 2022 Hongyong Gu et al., published by De Gruyter
This work is licensed under the Creative Commons Attribution 4.0 International License.