Chemical constituents of Geum rivale L. and their biological activity

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INTRODUCTION

The genus Geum L. (Rosaceae) is represented by 58 species [1], about 20 of which grow on the territory of the Russian Federation [2-5]. G. rivaleis is a perennial plant, the distribution area includes most of Europe up to the Ural Mountains, with the exception of the West of France, Spain and the Mediterranean region, as well as Western Siberia, Central Asia, some regions of North America [6, 7].

G. rivale is widely used in folk medicine for prevention and treatment of gastrointestinal diseases, including lack of appetite and diarrhea, malaria [8], for febrile diseases, muscle pain, hemorrhoids, for inflammatory diseases of the mucous membranes and skin integuments, as an antiseptic and astringent agent [9, 10]. In homeopathy, it is used for inflammatory diseases of the bladder and urinary tract, as well as for arthritis [9, 11, 12].

To date, a number of studies have been carried out to study the qualitative and quantitative composition of biologically active substances in the arial and underground parts of G. rivale, and some aspects of the pharmacological activity of extracts and individual groups of biologically active substances have been experimentally revealed.

The study of widespread plants as sources of pharmaceutical substances for the production of medicines and biologically active additives is an urgent task, since they show high efficiency along with low toxicity and allergenicity.

Based on this, the aim of the study was to review the literature data on the chemical composition of biologically active constituents of G. rivale and their pharmacological activity.

MATERIALS AND METHODS

The Internet resources (Google Scholar, PubMed) and library databases (e-Library, Scopus, Web of Science) as sources of information were used. The main research methods were the review and analysis of the literature data on the research topic for the period from 1958 up to the present.

RESULTS

Chemical components of Geum rivale L.

To date, a lot of data have been obtained on various groups of secondary metabolites contained in the arial and underground parts of the G. rivale. Thus, using the method of gas chromatography combined with a mass spectrometric detector (GC-MS), the component composition of the essential oil has been studied in sufficient detail [13, 14]. In the experiments, the essential oil was isolated from various parts of plant material by hydrodistillation. The components of a complex mixture of the essential oil were separated by gas chromatography with a flame ionization detector (GC-FID). The component identification was based on a comparison of mass spectra of the essential oil components with mass spectra of commercial libraries. The identification of isomers was based on a comparison of the retention index (RI) with the literature data. In the course of the experiment, more than 80 components were found in the samples of the essential oil of the arial and underground parts of G. rivale (compounds 51–143 in Table 1). The dominant components in G. rivale essential oil are 3-octen-1-ol (33.9%) and 3-hexenol (16.2%). In addition, the essential oil contains a large amount of sesquiterpenoids (32 compounds), a certain amount of monoterpenoids has been found [14]. Vollmann, C. et al. (1995) conducted a comparative analysis of the qualitative and quantitative composition of the essential oil of various species of the genus Geum L. As a result of the experiment, all species of the genus were divided into 2 large groups: the first group comprised the species containing a high percentage of eugenol (66–92%) and a low content pinene derivatives – G. urbanum, G. fauriei Levl. and G. macrophyllum Willd.; the second group comprised the species with a high content of pinene derivatives and a low content of eugenol (0.3–4.1%) – G. rivale L., G. rhodopeum Stoj. et Stefanov, G. bulgaricum Pancic, G. borisii Kellerer ex Siindermann, and G. chiloense Balb. [13].

 

Table 1 – Biologically active compounds of G. rivale

№	Compounds	Morphological parts	References
Triterpenoids (Ursanes)
1	α-amyrin	Arial part	14, 15
2	Ursolic acid
3	Euskafic acid
4	Euskafic acid 28-glucoside		15
5	Tormentic acid		14, 15
6	Nigaishigoside F1		14, 15, 22, 67
Other Triterpenoids
7	Oleanolic acid	Arial part	14, 15
8	Betulin
9	Epifriedelonol
10	Cescropic acid		14, 15, 22, 67
Phenylpropanoids
11	Chlorogenic acid	Arial and underground parts	14, 15, 17, 45
12	6-O-caffeyl-1-O-methyl-β-D-glucopyranose		14, 15, 22, 67
13	p-hydroxybenzoic acid		16
14	Caffeic acid	Arial parts	14, 15, 17, 45
15	Lilac acid	Arial and underground parts	16, 17
16	p-coumaric acid	Arial parts	16, 45
17	Ferulic acid	Arial and underground parts	16, 17
18	Sinapic acid		16, 17
19	Skopoletin		14, 15, 16
20	Esculetin
21	Decursin
Other constituents
22	Gallic acid	Arial and underground parts	14, 15, 16, 19, 23, 45, 67
23	Protocatechuic acid		14, 15, 16
24	Ellagic acid		14, 15, 16, 19, 45
25	Salicylic acid		14, 15, 16
26	Vanillin	Arial parts	14, 16, 67
27	1-O-protocatechioyl glucose	Arial parts	22
28	Sucrose	Arial parts
29	3,3’-dimethoxy-4-sulfoxyellagic acid potassium salt	Underground parts	23
30	3,3 ‘, 4’-trimethoxy-4-sulfoxyellagic acid potassium salt
Flavonoids
31	Luteolin	Arial part	14, 15
32	Luteolin 7-O-glucoside
33	Apigenin
34	Apigenin 7-O-glucoside
35	Quercetin
36	Quercetin 3-O-rhamnoside
37	Quercetin 3-O-glucoside
38	Kaempferol
39	Kaempferol 3-O-glucoside
40	Kaempferol 3-O-arabinoside
41	Tiliroside
42	Quercetin 3-O-glucuronide
43	Kaempferol 3-O-glucuronide
Ellagitannins
44	Gemin A	Arial part	20, 21
45	Pedunculagin		21
46	Stachiurin / casuarinin
47	Tellimagrandin 1
48	Gemin B
49	Gemin C
50	Gemin D
Essential oil constituents
51	(E) -2-hexenal	Arial part	13, 14
52	(Z), (E) -3-hexene-1-ol
53	Hexanol
54	Heptanol
55	6-methyl-5-hepten-2-ol
56	(Z) -3-hexenyl acetate
57	α-pellandrene
58	β-pellandrene
59	(E) -β-ocimene
60	(E) -2-octene-1-ol
61	Octanol
62	Terpinolen
63	Nonanal
64	Nonanol
65	Terpinen-4-ol
66	Deanal
67	β-cyclocitral
68	Dodecane
69	(Z) -3-hexenyl-2-methylbutanoate
70	(Z) -3-hexenyl isovalerate
71	Tridecan
72	(Z) -3-hexenyl crucible
73	δ-element
74	α-cubeben
75	β-damascenone
76	α-ylangen
77	β-bourbonene
78	β-cubeben
79	β-caryophyllene
80	β-copen
81	α-humulene
82	Alloaromadendren
83	β-ionone
84	γ-muurelen
85	Germacren D
86	(Z, E) – α-farnesene
87	α-muurelen
88	(E, E) – α-farnesene
89	γ-cadinen
90	α-calacoren
91	Trans-nerolidol
92	(Z) -3-hexenyl benzoate
93	Caryophyllene oxide
94	Viridiflorol
95	Humulene epoxy II
96	Farnesene epoxy
97	Cubenol
98	T-muurolol
99	α-cadinol
100	Pentadecanal
101	Heptadecan
102	Benzyl benzoate
103	Octadecan
104	Fitol
105	Tricosan
106	Tetracosan
107	Hexacosan
108	(Z) -hexenyl butyrate
109	1-zopropylcyclohex-1-ene	Underground part	13, 14
110	Trans-linalool oxide
111	Trans-myrtanal
112	Palmitic acid
113	Oct-1-en-ol
114	α-guayenne
115	Cumin aldehyde
116	Nerol
117	trans-anethole
118	Geraniol
119	2-methoxy-6-vinylphenol
120	Isoeugenol
121	Eugenol
122	Perilla aldehyde
123	Fellandral
124	Perilla alcohol
125	Mirtenal
126	trans-pinocarveol
127	Camphene	Arial and underground part	13, 14
128	1-octene-3-ol
129	3-octanol
130	Limonen
131	Cis-linalool oxide
132	Camphor
133	Citronellol
134	p-cymene
135	δ-cadinen
136	α-copen
137	cis-myrtanol
138	trans-myrtanol
139	α-terpineol
140	Mirtenol
141	Linalool
142	Nopinone
143	cis-myrtanal

 

Table 2 – Pharmacological effects of the main groups of constituents of G. rivale

Pharmacological effect	Extraction type or group of biologically active substances	References
Anti-inflammatory activity due to PAF-induced exocytosis	Total water extract	24, 25, 26
Antioxidant activity (DPPH-, FRAP-tests, linoleic acid peroxidation test)	Polyphenolic compounds	27
Antioxidant activity (DPPH and ABTS tests)	Phenolic acids and proanthocyanidins	33
Antimicrobial activity:		14, 15, 38, 68
a) antimicrobial activity against gram-positive and gram-negative microorganisms	Total polar extracts, triterpene fraction, flavonoid fraction, tannin fraction, ursolic acid, caffeic acid
b) antifungal activity	Total polar extract, triterpene fraction, caffeic acid
c) Candida albicans	Chloroform extract, total polar extracts, triterpene fraction, caffeic acid
d) Staphilococcus aureus, Pseudomonas aeruginosa	Triterpene fraction, quercetin, kaempferol, caffeic acid, gallic acid
Antiviral activity (influenza virus types A and B)	Ethanol extracts from the arial part	40

 

Panizzi et al. (2000) analyzed the composition of triterpenoids in the arial part of G. rivale in the extracts obtained by extracting raw materials in a Soxhlet apparatus with n-hexane, chloroform, and an alcohol-chloroform mixture (1: 9). The isolation of compounds in pure form was carried out by sequential purification on Sephadex, silica gel, thin layer chromatography and reverse phase chromatography. The structure was confirmed using IR and UV spectroscopy, as well as ¹H and ¹³C NMR methods. The compounds identified during the study are shown in Fig. 1 and numbered 1-10 in Table 1 [15, 16].

 

Figure 1 – Triterpenoids of the arial part of G. rivale (Panizzi, L. et al., 2000)

Note: 1 – α-amyrin; 2 – ursolic acid; 3 – euskafic acid; 4 – euskafic acid 28-glucoside; 5 – tormentic acid; 6 – nigaishigoside F1; 7 – oleic acid; 8 – betulin; 9 – epifriedelonol; 10 – cescropic acid

 

The most extensively represented group of secondary metabolites in the arial and underground parts of G. rivaleis are polyphenolic compounds. Obtaining extracts using solvents of different polarity makes it possible to study the qualitative and quantitative composition of various groups of polyphenolic compounds. The analysis of phenolic acids and coumarins is based on obtaining extracts with a methanol-chloroform mixture [15, 16, 18], petroleum ether [17] and n-butanol [22]. By means of IR spectroscopy methods and 1H- and 13C-NMR, HPLC-UV in comparison with standard samples, GC-MS, their component composition in the arial and underground parts of the river gravel was determined. The compounds identified in the work of several scientific groups, are shown in Fig. 2 and Table 1 under numbers 11-26 (Fig. 2). According to the estimates by Owczarek et al. (2013), the content of phenolic acids in the arial part is 5.9 mg/g, and in the underground part it is 18.9 mg/g [17]. In addition, Owczarek et al. (2014) determined the content of free ellagic acid (0.52± 0.01mg/g) in the arial part of the river gravity (gallic acid was not detected in this case); in the underground part there was 0.43±0.002 mg/g of ellagic acid, and gallic acid was not found there either [20].

 

Figure 2 – Phenolic acids and coumarins of G. rivale (Panizzi et al.,2000; Owczarek et al., 2013)

Note: 11 – chlorogenic acid; 12 – 6-O-caffeyl-1-O-methyl-β-D-glucopyranose; 13 – p-hydroxybenzoic acid; 14 – caffeic acid; 15 – lilac acid; 16 – p-coumaric acid; 17 – ferulic acid; 18 – sinapic acid; 19 – scopoletin; 20 – esculetin; 21 – decursin; 22 – gallic acid; 23 – protocatechuic acid; 24 – ellagic acid; 25 – salicylic acid; 26 – vanillin

 

Panizzi et al. (2000) also carried out extensive work on the study of the composition of flavonoids of the aerial part of G. rivale L. The extraction of this group of compounds was carried out from a mixture of the plant material pretreated with n-hexane, chloroform, and chloroform-methanol (9:1) by maceration with methanol at room temperature with subsequent purification on Sephadex and silica gel and separation on a C18 reverse phase column. In the study, 13 compounds were isolated, the structures of which were established by IR and UV spectroscopy, ¹H and ¹³C NMR (Fig.3, Table 1) [16]. Owczarek et al. (2013) evaluated the quantitative content of flavonoids according to the method described in the Polish Pharmacopoeia of the VIII edition: in the underground part – 0.3 mg/g; in the aerial part – 3.0 mg/g [17].

 

Figure 3 – Flavonoids of G. rivale (Panizzi et al., 2000)

Note: 31 – luteolin; 32 – luteolin-7-O-glucoside; 33 – apigenin; 34 – apigenin-7-O-glucoside; 35 – quercetin; 36 – quercetin-3-Oramnoside; 37 – quercetin-3-O-glucoside; 38 – kaempferol; 39 – kaempferol-3-O-glucoside; 40 – kaempferol-3-O-arabinoside; 41 – tilyroside; 42 – quercetin-3-O-glucuronide; 43 – kaempferol-3-O-glucuronide

 

Another group of polyphenolic compounds – tannins – is of great interest. The main methods of analysis of this group and the experimental data on the pharmacological activity were described in our previously published review [21]. In G. rivale, the composition of ellagitannins was also widely studied in the works by Moilanen et al. (2008, 2015). After the extraction of raw materials with 70% acetone with the addition of 0.1% ascorbic acid to prevent the oxidation of the compounds, the composition of ellagitannins (44–50) [22-23] was established by using HPLC-ESI-MS. The total acid content was determined by Owczarek et al. (2014) after hydrolysis of tannins with a 25% hydrochloric acid solution: ellagic acid – 40.31±1.08 mg/g in the arial part, 60.64±0.87 mg/g in the underground part; gallic acid – 7.45±0.08 mg/g in the arial part and 9.57±0.27 mg/g in the underground part (in terms of dry plant material). On the basis of the obtained results the authors made a conclusion about the greater prevalence of ellagitannins in comparison with gallotannins, both in the arial and underground parts of the studied species [20].

Rare sulfonated derivatives of ellagic acid obtained by precipitation from the aqueous extraction with boiling methanol, were studied by Owczarek et al. (2017). The following structures were established by UV spectroscopy, mass spectrometry, and ¹H- and ¹³C-NMR: potassium salt of 3,3’-dimethoxy-4-sulfoxyellagic acid (29) and 3,3‘, 4’-trimethoxy-4-sulfoxyellagic acid potassium salt (30) (Fig. 4) [25].

 

Figure 4 – Ellagitannins of G. rivale (Moilanen et al.,2008, 2015; Owczarek et al., 2017)

Note: 29 – 3,3’-dimethoxy-4-sulfoxyellagic acid potassium salt; 30 – 3,3’,4’-trimethoxy-4-sulfoxyellagic acid potassium salt; 44 – Gemin A; 45 – Pedunculagin; 46 – Stachiurin / casuarinin; 47 – Tellimagrandin 1; 48 – Gemin B; 49 – Gemin C; 50 – Gemin D

 

Determination of the antioxidant activity of the extracts showed that the roots of G. rivale have a high antioxidant potential. According to the results, the authors of the work suggest that polyphenolic compounds bear the main responsibility for the antioxidant activity thanks to the transfer of a hydrogen atom during the reaction (HAT mechanism) [30].

Oszmianski et al. (2007) screened the antioxidant activity of tannins in the roots of G. rivale. During the research, the following experiments were carried out: thiolysis of proanthocyanidins according to the method described by Guyot et al. (2001) [37]; reverse phase HPLC after thiolysis; the content of proanthocyanidins (10.5 g/kg) and phenolic compounds (3.0 g/kg) in the feed were determined, as well as the degree of polymerization of proanthocyanidins – 3. For screening of the antioxidant activity, two methods were used by the authors: the DPPH test according to Yen et al.’s method (1995) [38] and the ABTS test by Re et al.’s the method (1999) [39]. This study demonstrated a significant antioxidant potential of the extract containing phenolic compounds [36].

Pharmacological activity of extracts and components of G. rivale

Simultaneously with the study of the component composition of the secondary metabolites in the arial and underground parts of G. rivale, extensive studies of the pharmacological activity of the total extracts obtained using solvents of different polarities, as well as individual metabolites, were carried out. Thus, Tunon et al. (1995) conducted a study of the anti-inflammatory activity of the total water extract from the arial part of G. rivale, obtained by a two-stage extraction at room temperature, in tests of the effect on prostaglandin synthesis and PAF-induced exocytosis. The extract showed a high inhibitory activity in the PAF test, while an inhibitory effect on the biosynthesis of prostaglandins was not found [27]. In addition, the use of extracts from G. rivale as an anti-inflammatory agent in traditional medical practice is reported in the works by Birnesser et al. and Parimala et al. [28, 29].

Owczarek et al. (2015) investigated the total extracts of different polarity, obtained by the extraction of the methanol extract from the arial and underground parts of the G. rivale, in tests for antioxidant activity: DPPH test by method of Brand Williams, Cuvier and Berset [31] with the previously described modifications [32]; the FRAP test described by Pulido et al. [33] with some modifications [34]; the test for linoleic acid peroxidation according to Azuma et al.’s modified method [35, 32].

Panizzi et al. (2000) investigated the antimicrobial activity of extracts of different polarity from the arial part of G. rivale, and some individual compounds. The dried raw material was extracted in a Soxhlet apparatus with n-hexane, chloroform, a mixture of chloroform-methanol 9:1, and then by maceration with methanol at room temperature. Then, the obtained total extracts were purified by column chromatography to individual compounds, their identification was carried out by IR and UV spectroscopy, ¹H and ¹³C NMR. All the investigated fractions were dissolved in DMSO and screened for the antimicrobial activity by the agar diffusion method described by Clark, et al. (1981), using test microorganisms: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Aspergillus niger [40]. The study showed that the total methanol extract has a high antimicrobial and antifungal activity, while the n-hexane extract showed a weak activity against bacteria and Aspergillus niger; chloroform extract had a pronounced activity against Candida albicans; and chloroform-methanol and water-methanol extracts were found active against all the tested organisms. When analyzing the purified extracts and individual compounds, the following results were obtained: triterpene fraction showed an efficiency comparable to methanol and chloroform-methanol extracts against all studied microorganisms; a mixture of flavonoids was found active against gram-positive and gram-negative bacteria in the absence of antifungal activity; the tannin fraction was active only against bacteria, but its effectiveness was lower than that of the flavonoid fraction; ursolic acid had zones of inhibition very similar to those obtained using a chloroform-methanol extract in the absence of antifungal effect; among the flavonoid aglycones, kaempferol and quercetin affected only Staphylococcus aureus and Pseudomonas aeruginosa, respectively, while apigenin had no antimicrobial and antifungal activity; caffeic acid showed a moderate activity against all test organisms, while gallic acid showed a pronounced effectiveness against Staphylococcus aureus, Escherichia coli and Candida albicans [16].

The identification of natural metabolites and synthetic agents that are effective in the prevention and treatment of diseases caused by influenza viruses of various types, is an urgent problem of the last decade. Researchers suggest that total native complexes of metabolites, as well as individual natural compounds of various natures, such as polyphenols, triterpenoids, alkaloids, organic acids, and some others, can be used as agents for inhibiting infections at various stages [42]. Therefore, in the work by Lobanov et al. (2016) the antiviral activity of 70 plant species belonging to 14 different families, including the aerial part of the G. rivale, was considered. The study was carried out using ethanol extracts obtained by the method described in the work by Kostina et al. (2013) [44]; avian influenza virus A / chicken / Kurgan / 05/2005 (H5N1) and a strain of human influenza virus A / Aichi / 2/68 (H3N2) adapted to laboratory mice, the titer of which was calculated by Spearman-Kerber’s method using statistical processing according to Sachs, L. (1976) [45]. In the course of the study it was revealed that the ethanol extract from the arial part of G. rivale has a pronounced antiviral activity against both studied viral strains and can be recommended for a further research in this area in order to create phytopreparations for the prevention and treatment of influenza caused by these virus strains [43].

Ellagic acid is a metabolite of higher plants, it is in sufficiently large quantities in the arial and underground parts of G. rivale, both in free and bound forms as parts of ellagitannins. Due to its wide distribution, the possibilities of using this compound in medical practice are well studied. Thus, for the first time, a systematic review of the literature was conducted by García-Niño et al. (2015) and the following possible pharmacological effects of ellagic acid were described in detail [47]: antimutagenic [48], antigenotoxic [49–50], antiapoptotic [51], anticarcinogenic [52], antibacterial [53], antiviral [54], antimalarial [55], antiallergic [56], anti-inflammatory [57], antiatherogenic [58], antidiabetic [59], antiepileptic [60], antidepressant [61], antinociceptive [62], neuroprotective [63], nephroprotective [64], cardioprotective [65] and hepatoprotective [66] activities. However, the work notes: the contribution of ellagic acid to the pharmacological effects of the extracts obtained from the arial parts of G. rivale, has not been revealed.

CONCLUSIONS

The analysis of the literature showed that Geum rivale L. has been subjected to phytochemical studies for a long period of time. This is due to both the rich raw material base of the plants and its widespread use in folk medicine.

For the period from 1958 to the present, more than 80 components have been identified in the arial and underground parts of the river gravity. The main groups of secondary metabolites have been characterized, including the essential oil, triterpenoids and phenolic compounds of the arial and underground parts of Geum rivale L. The most extensively represented group of secondary metabolites is polyphenolic compounds. Despite the sufficient knowledge of the chemical composition, the plant is not official in Russia.

The rich composition of polyphenolic compounds determines characteristic pharmacological effects of the plant, including anti-inflammatory, antioxidant, antimicrobial and antiviral activity. The pharmacological activity has been experimentally confirmed, both the extraction obtained by the extraction with solvents of polarity or fractionation, and some compounds. These types of activity may be useful against some socially significant pathologies, for example, antioxidant activity in the prevention and treatment of diseases of the cardiovascular, urinary and nervous systems, the antimicrobial and antiviral activities in the treatment of the diseases caused by resistant strains of microorganisms and viruses.

However, the currently available data on the chemical composition and activity of Geum rivale L. do not give a general picture of the potential for using a plant as a source of new pharmaceutical substances of natural origin for the creation of medicines and biologically active additives.

Modern analytical methods in phytochemistry, dictate the development of the allocation of natural resources and compounds with the establishment of their exact structures using one of the methods of analytical magnetic resonance and infrared spectroscopy with a further study of their pharmacological potential. Therefore, it is advisable to continue the study of the composition of secondary metabolites of the arial and underground parts of this plant using modern methods of analysis to identify both – previously not discovered, as well as new for science natural compounds. The identification of specific compounds responsible for the development of types of biological activity valuable for medicine using in silico methods, the analysis of possible synergistic or additive effects of combinations of secondary metabolites, as well as the prediction of the mechanisms associated with the manifestation of a certain effect, may become a promising direction for further studies of Geum rivale L. The data obtained will make it possible to expand the range of use of Geum rivale L. in medicine.

FUNDING

This study did not have any financial support from other organizations.

AUTHOR’S CONTRIBUTION

All authors equally contributed to the research work.

CONFLICT OF INTERESTS

The authors declare no conflict of interest.

About the authors

Anastasia A. Orlova

Saint Petersburg State Chemical Pharmaceutical University

Author for correspondence.
Email: anastasiya.lebedkova@spcpu.ru
ORCID iD: 0000-0002-7836-5785

postgraduate student of the Department of Pharmacognosy, Junior Researcher of the Research Department

Russian Federation, 14 lit. A, Professor Popov St., St. Petersburg,197022

Maria N. Povydysh

Saint Petersburg State Chemical Pharmaceutical University

Email: maria.povydysh@pharminnotech.com
ORCID iD: 0000-0002-7768-9059

Doctor of Sciences (Biology), Candidate of Sciences (Pharmacy), Associate Professor of the Department of Pharmacognosy, Head of the Research Department

Russian Federation, 14 lit. A, Professor Popov St., St. Petersburg, 197022

References

Supplementary files