In vivo Anti-Inflammatory and Antinociceptive Activity Evaluation of Phenolic Compounds from Sideritis stricta

Chemical profile of the Anatolian Sideritis species with bioactivity studies

CONTEXT

The genus Sideritis L. (Lamiaceae) is represented by 46 species in Turkey with an 79% endemism ratio, 42 of 46 belonging to the section Empodoclia.

OBJECTIVE

In this review article, Sideritis species growing in Turkey have been evaluated for phytochemical constituents and biological activities.

METHODS

The data for the isolates, components and extracts of the Anatolian Sideritis species and their bioactivity studies were retrieved from the main databases WoS, Scopus and PubMed from 1975 until 31 December 2022.

RESULTS

In this review article, terpenoids, flavonoids, phenolics and other secondary metabolites isolated from Turkish Sideritis species were reported. Anatolian Sideritis species, which primarily consist of monoterpenes and sesquiterpenes, were studied in detail. Sideritis plants are represented by 46 species in Turkey, and 25 of them were investigated for their diterpenoids through isolation or LC-MS studies. Most of the diterpenoids of Turkish Sideritis species have ent-kaurene skeleton, among them linearol, siderol, 7-epicandicandiol and sideridiol were found to be the main compounds. Exceptionally, labdane, pimarane and beyerene diterpenoids were only found in a few species. For phenolics and flavonoids, only 12 species were investigated until now, and they were found to be rich in phenylethanoid glycosides and flavonoid glycosides. In terms of activity, most of the species were tested for antioxidant activity, followed by antimicrobial and anti-ulcer/anti-inflammatory activities. Their cytotoxic, enzyme inhibitory, antinociceptive and antistress activities were less frequently studied.

CONCLUSIONS

Sideritis species should be considered promising therapeutic agents in the treatment of upper respiratory tract and ulcer/inflammatory diseases.

From Plant to Chemistry: Sources of Active Opioid Antinociceptive Principles for Medicinal Chemistry and Drug Design

Pain continues to be an enormous global health challenge, with millions of new untreated or inadequately treated patients reported annually. With respect to current clinical applications, opioids remain the mainstay for the treatment of pain, although they are often associated with serious side effects. To optimize their tolerability profiles, medicinal chemistry continues to study novel ligands and innovative approaches. Among them, natural products are known to be a rich source of lead compounds for drug discovery, and they hold potential for pain management. Traditional medicine has had a long history in clinical practice due to the fact that nature provides a rich source of active principles. For instance, opium had been used for pain management until the 19th century when its individual components, such as morphine, were purified and identified. In this review article, we conducted a literature survey aimed at identifying natural products interacting either directly with opioid receptors or indirectly through other mechanisms controlling opioid receptor signaling, whose structures could be interesting from a drug design perspective.

The Chemistry and the Anti-Inflammatory Activity of Polymethoxyflavonoids from Citrus Genus

Polymethoxyflavonoids (PMFs) are a large group of compounds belonging to the more general class of flavonoids that possess a flavan carbon framework decorated with a variable number of methoxy groups. Hydroxylated polymethoxyflavonoids (HPMFs), instead, are characterized by the presence of both hydroxyl and methoxy groups in their structural unities. Some of these compounds are the aglycone part in a glycoside structure in which the glycosidic linkage can involve the -OH at various positions. These compounds are particular to Citrus genus plants, especially in fruits, and they are present mainly in the peel. A considerable number of PMFs and HPMFs have shown promising biological activities and they are considered to be important nutraceuticals, responsible for some of the known beneficial effects on health associated with a regular consumption of Citrus fruits. Among their several actions on human health, it is notable that the relevant contribution in controlling the intracellular redox imbalance is associated with the inflammation processes. In this work, we aim to describe the status concerning the chemical identification and the anti-inflammatory activity of both PMFs and HPMFs. In particular, all of the chemical entities unambiguously identified by isolation and complete NMR analysis, and for which a biochemical evaluation on the pure compound was performed, are included in this paper.

Natural acylated flavonoids: their chemistry and biological merits in context to molecular docking studies

Acylated flavonoids are widely distributed natural dietary bioactives with several health attributes. A large diversity of acylated flavonoids with interesting biological potentialities were reported. Of these, 123 compounds with potential antimicrobial, antiparasitic, anti-inflammatory, anti-nociceptive, analgesic and anti-complementary effects were selected from several databases. Based upon these data, the possible mechanistic evidence for their effects were reported. Generally, aromatic acyls i.e., galloyl derivatives appeared to improve efficacy through enhancement of the binding affinities to molecular targets due to plenty of donating and accepting centers. Docking simulations conducted by Molecular Operating Environment (MOE) of acylated flavonoids revealed that compound 12 is at the top of the list into the antibacterial target DNA gyrase subunit B (GyrB), from E. coli, followed by compounds 10, 4 and 23. Compounds 81, 88, 96, 92, 99, 100, 102 and 103 have the strongest binding affinities into Human matrix metallopeptidase (MMP) 2 and 9 catalytic domains. Compound 103 exerted the most balanced predicted dual MMP-2/MMP-9 inhibition action. Compound 95 recorded the strongest binding affinity into metabotropic glutamate receptor (mglur1) with the lowest energy conformer. The data presented in this review suggests that these candidate acylated flavonoids ought to be considered in future drug developments especially as anti-inflammatory and antimicrobial agents.

Anti-Inflammatory Effects Induced by a Polyphenolic Granular Complex from Olive (Olea europaea, Mainly Cultivar coratina): Results from In Vivo and Ex Vivo Studies in a Model of Inflammation and MIA-Induced Osteoarthritis

MOMAST^® GR25 is a polyphenolic granular complex from olive pressing juice with high total content in polyphenols. In this work, we evaluated the possible anti-inflammatory effects of MOMAST^® GR25 in both acute and chronic inflammatory models. MOMAST^® GR25 decreased the levels of prostaglandin (PG) E₂ and 8-iso-PGF_2α in isolated rat colon, liver, and heart specimens stimulated with lipopolysaccharide (LPS). In vivo, compared to controls, rats treated with MOMAST^® GR25 (100 mg/kg to 1 g/kg) showed a significant reduction in both licking/biting time in the formalin test. In a rat model of osteoarthritis by monoiodoacetate (MIA) injection, MOMAST^® GR25 showed pain-relieving properties when acutely administered, reducing mechanical hyperalgesia and spontaneous pain. Moreover, a repeated daily treatment with MOMAST^® GR25 (300 mg/kg) fully counteracted osteoarticular pain without the development of tolerance to the antinociceptive effect. Taken together, our present findings showed that MOMAST^® GR25 could represent a potential strategy for the treatment of inflammation and pain.

Comparative experimental and theoretical study on the molecular structure and spectroscopic properties of sideroxol isolated from Sideritis stricta and its electronic properties

Sideroxol, a kaurene diterpene, was obtained from the acetone extract of Sideritis stricta plant. The ground-state molecular geometry, vibrational frequencies, and NMR chemical shifts were also investigated by using various density functional theories and Pople basis sets. The computed geometries are in good conformity with the experimental data. The comparison between theory and experiments indicates that B3LYP and M06 methods with the 6-31G(d) basis set are able to provide satisfactory results for predicting vibrational and NMR properties. There seems to be no significant effect of addition of diffuse and polarization functions in the basis set used herein.

Investigations on the anti-ulcerogenic activity of Sideritis caesarea H. Duman, Aytaç & Başer

ETHNOPHARMACOLOGICAL RELEVANCE

Aerial parts of Sideritis caesarea H. Duman, Aytaç & Başer are used for complaints such as stomach-aches, and intestinal spasms as traditional medicine in Kayseri, Turkey.

AIM OF STUDY

To investigate the anti-ulcerogenic activity by using bioassay guided fractionation technique (BAGF) and to identify the compound(s) that are responsible for anti-ulcerogenic activity through ethanol-induced anti-ulcerogenic activity model in vivo.

MATERIALS AND METHODS

Liquid-liquid partition and then different chromatographic techniques were utilized for the BAGF of the ethanol (80%) extract of the aerial parts of Sideritis caesarea. Ethanol-induced gastric ulcer method on rats was employed for the determination of the anti-ulcerogenic activity, and the ulcer index was also calculated for anti-ulcerogenic activity detection.

RESULTS

The ethanol (80%) extract of S. caesarea showed statistically potent anti-ulcerogenic activity (95.9% ulcer inhibition, p < 0.001). Among the liquid-liquid fractions, strongest anti-ulcerogenic activity was observed with the ethyl acetate fraction (91.4% inhibition, p < 0.001) and therefore BAGF studies were proceeded with the ethyl acetate fraction. Two anti-ulcerogenic flavonoids {4'-O-methylhypolaetin-7-O-[6‴-O-acetyl-β-D-allopyranosyl-(1→2)]-6″-O-acetyl-β-D-glucopyranoside and isoscutellarein-7-O-[6‴-O-acetyl-β-D-allopyranosyl-(1→2)]-6″-O-acetyl-β-D-glucopyranoside} were isolated from this fraction together with a sesquiterpene glycoside [(2E,6E)-2,6,10-trimethyl-2,6,11-dodecatriene-1,10-diol-1-O-β-D-glucopyranoside] and two additional flavonoids {4'-O-methylhypolaetin-7-O-[6‴-O-acetyl-β-D-allopyranosyl-(1→2)]-β-D-glucopyranoside and isoscutellarein-7-O-[6‴-O-acetyl-β-D-allopyranosyl-(1→2)]-β-D-glucopyranoside}.

CONCLUSIONS

Traditional use of S. caesarea in the treatment of stomach-aches was supported by this study and four flavonoids were isolated by using BAGF method and two of them were determined to have significant anti-ulcerogenic activity. Additionally, (2E,6E)-2,6,10-trimethyl-2,6,11-dodecatriene-1,10-diol-1-O-β-D-glucopyranoside was obtained from a Sideritis genus for the first time.

Phenolic Profile and Bioactivities of Sideritis perfoliata L.: The Plant, Its Most Active Extract, and Its Broad Biological Properties

Sideritis, also named “ironwort,” “mountain tea,” or “shepherd's tea,” is a genus of flowering plants used as herbal medicine in traditional Mediterranean-area medicine systems, and these plants are generally consumed as a herbal tea. Its use as herbal tea and in traditional herbal medicine is quite popular. There are currently few studies on Sideritis perfoliata L., and only one reports the use of a liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MSⁿ) profile and the content of phenolic compounds without considering a possible correlation with its biological activities. This paper aims to investigate the antioxidant activities by means of several different biological/biochemical assays (radical scavenging, reducing power, ferrous ion chelating, and total antioxidant by phosphomolybdenum and β-carotene bleaching methods) as well as analyze the enzyme inhibitory activities (against AChE (acetylcholinesterase), BChE (butyrylcholinesterase), tyrosinase, α-glucosidase, and α-amylase) as well as the total phenolics, flavonoids, and condensed tannins. The reported results on Sideritis perfoliata highlighted that methanol and water extracts generally showed higher radical scavenging and reducing power activities. A similar trend could be observed for phosphomolybdenum and ferrous ion chelating activities. Methanol extracts showed lower activity only for the β-carotene bleaching assay.

Phytochemical contents, antioxidant effects, and inhibitory activities of key enzymes associated with Alzheimer's disease, ulcer, and skin disorders of Sideritis albiflora and Sideritis leptoclada

In this study, urease, tyrosinase, cholinesterase inhibitory, and antioxidant activities of various extracts of Sideritis albiflora and Sideritis leptoclada were determined together with the phytochemical contents. In addition, the fatty acid compositions and phenolic compounds were investigated by gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), and high performance liquid chromatography-diode array detector (HPLC-DAD). Rosmarinic acid and caffeic acid in both Sideritis species were identified as the most abundant phenolic compounds whereas palmitic acid was found as a major fatty acid. The acetone extract of S. leptoclada indicated the highest antioxidant activity in β-carotene-linoleic acid (IC₅₀ : 17.23 ± 0.11 µg/ml), DPPH^• (IC₅₀ : 28.14 ± 0.05 µg/ml) and ABTS^•+ (IC₅₀ : 15.18 ± 0.02 µg/ml) assays. The acetone extract of S. albiflora (A_0.50 : 32.71 ± 0.44 µg/ml) was found as the best reductant in cupric reducing antioxidant capacity (CUPRAC) assay. Against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), only the hexane extracts of Sideritis species showed moderate inhibitory activity. Moreover, all extracts of S. albiflora and the hexane extract of S. leptoclada exhibited significantly higher urease inhibitory activity than that of thiourea. Further, in vivo activity studies on extracts and isolated constituents obtained from these species are needed to understand the activity in biological systems. PRACTICAL APPLICATIONS: Multiple pharmacological studies have proven that Sideritis species is precious with significant bioactive properties. This is the first comprehensive research to determine the enzyme inhibitory and antioxidant activities of various extracts of S. albiflora and S. leptoclada with phytochemical contents. Both Sideritis species were found to be rich in rosmarinic and caffeic acids. The acetone extracts showed the highest activity in terms of antioxidant activity, while the hexane extracts exhibited superior urease inhibitory activity. These results show that Sideritis species could be used as urease inhibitors' agents and source of antioxidants in food, pharmaceutical, and cosmetic industries.

Genus Sideritis, section Empedoclia in southeastern Europe and Turkey - studies in ethnopharmacology and recent progress of biological activities

BACKGROUND

Over the last two decades there has been a substantial increase of the number of studies on the species of genus Sideritis. Species of section Empedoclia, occurring in the Eastern Mediterranean region and in part of Western Asia possess some remarkable characteristics and are known as valuable medicinal plants used by local people in the traditional medicine and for herbal tea. The objective of the review is to make a survey on the recent studies on the ethnopharmacology and biological activity of the species in Southeastern Europe and in Turkey, which is the center of distribution and their main occurrence.

MAIN BODY

The review focuses on the ethnopharmacology and biological activities of the species of interest. The survey revealed that a total of 47 species belonging to section Empedoclia have been studied either in ethnopharmacological aspect, or in relation to their biological activities, or both. Most species have been used traditionally by the local people as herbal tea or for treatment of various health problems, most frequently flu, cold and respiratory diseases. Sideritis species demonstrate numerous biological activities and are promising for use in the therapy of many diseases and health disorders. Antioxidant activity was found in 40 species, antimicrobial and antibacterial activity - in 27 species, anti-inflammatory - in 14 species, antifungal - in 8 species, cytotoxic - in 7 species. There were also some other, more specific biological activities, found in a few species, but considered promising for further studies and application.

SHORT CONCLUSION

The species of genus Sideritis, section Empedoclia have been used by local people as herbal tea and in traditional medicine since long time ago. People are taking advantage of the high species diversity and are aware of their useful properties. Much more information is available on the biological activities of the target species than on their traditional uses. Most species demonstrate various biological activities and are of substantial interest for further studies on their pharmacological properties and their potential for pharmacy and medicine. Graphical abstract Schematic illustration of traditional uses and biological activities of some Sideritis species. Arrows with different colors represent biological activities of different species. The species and their corresponding color can be seen at the right part of the figure. The colors correspond also to the squares placed in the different parts of human body.

Medicinal Plants of the Family Lamiaceae in Pain Therapy: A Review

Recently, numerous side effects of synthetic drugs have lead to using medicinal plants as a reliable source of new therapy. Pain is a global public health problem with a high impact on life quality and a huge economic implication, becoming one of the most important enemies in modern medicine. The medicinal use of plants as analgesic or antinociceptive drugs in traditional therapy is estimated to be about 80% of the world population. The Lamiaceae family, one of the most important herbal families, incorporates a wide variety of plants with biological and medical applications. In this study, the analgesic activity, possible active compounds of Lamiaceae genus, and also the possible mechanism of actions of these plants are presented. The data highlighted in this review paper provide valuable scientific information for the specific implications of Lamiaceae plants in pain modulation that might be used for isolation of potentially active compounds from some of these medicinal plants in future and formulation of commercial therapeutic agents.

Evaluation of Anti-inflammatory and Some Possible Mechanisms of Antinociceptive Effect of Ferula assa foetida Oleo Gum Resin

Asafetida is well known for its medicinal and therapeutic values in Iranian folk medicine. This study was conducted to investigate the antinociceptive and anti-inflammatory effects of asafetida. In hot plate test, asafetida exhibited a significant antinociceptive effect at all administered doses and the most effective dose was 10 mg/kg. The highest maximum potent effect was observed 15 minutes after asafetida administration. The antinociceptive effect of asafetida was not reversed by administration of any antagonist used in this study but asafetida showed a remarkable antioxidant and also inhibitory action against lipoxygenase activity. Paw weight was significantly reduced only in treated animals with 2.5 mg/kg asafetida. Results clearly indicate that the asafetida could be a potential source of anti-inflammatory and analgesic agent. These effects may be due to its effective constituents such as monoterpenes, flavonoids and phenolic components that have antioxidant properties and inhibit lipoxygenase activity.

Flavonoids from Sideritis Species: Human Monoamine Oxidase (hMAO) Inhibitory Activities, Molecular Docking Studies and Crystal Structure of Xanthomicrol

The inhibitory effects of flavonoids on monoamine oxidases (MAOs) have attracted great interest since alterations in monoaminergic transmission are reported to be related to neurodegenerative diseases such as Parkinson's and Alzheimer's diseases and psychiatric disorders such as depression and anxiety, thus MAOs may be considered as targets for the treatment of these multi-factorial diseases. In the present study, four Sideritis flavonoids, xanthomicrol (1), isoscutellarein 7-O-[6'''-O-acetyl-β-D-allopyranosyl-(1→2)]-β-D-glucopyranoside (2), isoscutellarein 7-O-[6'''-O-acetyl-β-D-allopyranosyl-(1→2)]-6''-O-acetyl-β-D-glucopyranoside (3) and salvigenin (4) were docked computationally into the active site of the human monoamine oxidase isoforms (hMAO-A and hMAO-B) and were also investigated for their hMAO inhibitory potencies using recombinant hMAO isoenzymes. The flavonoids inhibited hMAO-A selectively and reversibly in a competitive mode. Salvigenin (4) was found to be the most potent hMAO-A inhibitor, while xanthomicrol (1) appeared as the most selective hMAO-A inhibitor. The computationally obtained results were in good agreement with the corresponding experimental values. In addition, the x-ray structure of xanthomicrol (1) has been shown. The current work warrants further preclinical studies to assess the potential of xanthomicrol (1) and salvigenin (4) as new selective and reversible hMAO-A inhibitors for the treatment of depression and anxiety.

Phytochemical and biological studies of Stachys species in relation to chemotaxonomy: a review

The genus Stachys is comprised of about 300 species spread throughout the world, hence representing one of the largest genera of the Lamiaceae. Several Stachys species have been exploited in traditional medicine as astringent, wound-healing, anti-diarrhoeal, anti-nephritic and anti-inflammatory agents. Moreover, antimicrobial, antioxidant and cytotoxic activities of some Stachys species are documented. Iridoids, flavonoids, phenolic acids and diterpenoids are reported as secondary metabolites of different species of this genus. The aim of the present review is to summarize and to highlight the recent advances in current knowledge on Stachys species and to compile reports of chemical constituents isolated from the genus Stachys over the past decades, together with their structural features, biological activities, and structure-activity relationships. Diversity of chemical constituents is discussed in relationship with current Stachys infrageneric taxonomy, classification and relationships with systematically close genera.

Mutual regioselective inhibition of human UGT1A1-mediated glucuronidation of four flavonoids

UDP-glucuronosyltransferase (UGT) 1A1-catalyzed glucuronidation is an important elimination pathway of flavonoids, and mutually inhibitory interactions may occur when two or more flavonoids are coadministered. Our recent research suggested that glucuronidation of flavonoids displayed distinct positional preferences, but whether this will lead to the mutually regioselective inhibition of UGT1A1-mediated glucuronidation of flavonoids is unknown. Therefore, we chose three monohydroxyflavone isomers, 3-hydroxyflavone (3HF), 7-hydroxyflavone (7HF), and 4'-hydroxyflavone (4'HF), and one trihydroxyflavone, 3,7,4'-trihydroxyflavone (3,7,4'THF), as the model compounds to characterize the possible mutually regioselective inhibition of glucuronidation using expressed human UGT1A1. Apparent kinetic parameters [e.g., reaction velocity (V), Michaelis-Menten constant (Km), maximum rate of metabolism (Vmax), concentration at which inhibitor achieves 50% inhibition (IC50), and the Lineweaver-Burk plots were used to evaluate the apparent kinetic mechanisms of inhibition of glucuronidation. The results showed that UGT1A1-mediated glucuronidation of three monohydroxyflavones (i.e., 3HF, 7HF, and 4'HF) and 3,7,4'THF was mutually inhibitory, and the mechanisms of inhibition appeared to be the mixed-typed inhibition. Specifically, the inhibitory effects displayed certain positional preference. Glucuronidation of 3HF was more easily inhibited by 3,7,4'THF than that of 7HF or 4'HF. Compared to 7-O-glucuronidation of 3,7,4'THF, 3-O-glucuronidation of 3,7,4'THF was more inhibited by 3HF and 4'HF, whereas glucuronidation at both 3-OH and 7-OH positions of 3,7,4'THF was more easily inhibited by 7HF than by 3HF and 4'HF. In conclusion, 3HF, 7HF, 4'HF, and 3,7,4'THF were both substrates and inhibitors of UGT1A1, and they exhibited mutually regioselective inhibition of UGT1A1-mediated glucuronidation via a mixed-type inhibitory mechanism.

Effects of Sideritis euboea (Lamiaceae) Aqueous Extract on IL-6, OPG and RANKL Secretion by Osteoblasts

The water extract obtained from the aerial parts of Sideritis euboea (Lamiaceae), which is known in Greece as ‘mountain tea’, was investigated by determining the in vitro effect of this extract on the IL-6, OPG and RANKL secretion by osteoblasts, three important molecules in osteoblast-osteoclast interplay. The results showed that this extract reduced significantly the secretion of IL-6 by KS-483 osteoblasts, while it also suppressed RANKL secretion, with both effects being dose-dependent and more potent at the higher concentrations tested (50, 100 μg/mL). We further determined the chemical profile of the extract by applying an analytical U-HPLC-DAD-ESIMS/MS method using the high resolution hybrid LTQ-Orbitrap Discovery spectrometer. An ESI source in negative mode was employed. The analysis indicated that the water extract of S. euboea is rich in flavonoid glycosides, and phenylpropanoid glycosides.

Regioselectivity of human UDP-glucuronosyltransferase isozymes in flavonoid biotransformation by metal complexation and tandem mass spectrometry

Based on reactions with five flavonoids, the regioselectivities of twelve human UDP-glucuronosyltransferase (UGT) isozymes were elucidated. The various flavonoid glucuronides were differentiated based on LC-MS/MS fragmentation patterns of [Co(II)(flavonoid-H)(4,7-diphenyl-1,10-phenanthroline)(2)](+) complexes generated upon post-column complexation. Glucuronide distributions were evaluated to allow a systematic assessment of the regioselectivity of each isozyme. The various UGT enzymes, including eight UGT1A and four UGT2B, displayed a remarkable range of selectivities, both in terms of the positions of glucuronidation and relative reactivity with flavanones versus flavonols.

Sideritis spp.: uses, chemical composition and pharmacological activities--a review

The genus Sideritis (Lamiaceae) comprises more than 150 perennial and annual vegetal species widely distributed in the Mediterranean area, together with Canary and Madeira islands. It is a controversial botanic genus, with a complex taxonomical classification due to the high number of hybridizations that occur between species; their study requires a deep research experience. Sideritis species have been traditionally used as teas for feeding, flavoring agents and in folk medicine as antiinflammatory, antiulcerative, antimicrobial, vulnerary, antioxidant, antispasmodic, anticonvulsant, analgesic and carminative agents. The chemical components found in Sideritis genus include terpenes, flavonoids, essential oil, iridoids, coumarins, lignanes and sterols, among others. Diterpenes, flavonoids and essential oil occur in almost every species and are the main compounds responsible for the observed in vivo and in vitro pharmacological activities. The aim of this review is to provide a comprehensive overview on the botanical, phytochemical and pharmacological aspects from the genus Sideritis, with the objective of establishing scientific basis that explains its ethnopharmacological use.

Advanced research on acteoside for chemistry and bioactivities

Acteoside is one kind of phenylethanoid glycoside, which has shown a lot of biological activities. This article reviewed the study progress of acteoside, such as distribution, preparation, identification, and bioactivities.

Antihyperalgesic activity of verbascoside in two models of neuropathic pain

OBJECTIVES

This study reports on the rapid isolation of verbascoside from Lippia citriodora H.B.K. (Verbenaceae), an inexpensive and widespread source, and the evaluation of its antihyperalgesic activity.

METHODS

Isolation of verbascoside was achieved by size exclusion chromatography with Sephadex LH-20 eluting with 50% EtOH, which is proposed as a fast and efficient method of separation.

KEY FINDINGS

The antihyperalgesic activity of verbascoside was tested by in-vivo assay using the paw-pressure test in two animal models of neuropathic pain: a peripheral mononeuropathy produced either by a chronic constriction injury of the sciatic nerve (CCI) or by an intra-articular injection of sodium monoiodoacetate (MIA).

CONCLUSIONS

Verbascoside administered intraperitoneally at a dose of 100 mg/kg reverted the mechanical hyperalgesia in both CCI and MIA treated rats, as evaluated in the paw-pressure test. Verbascoside was also effective against mechanical hyperalgesia after oral administration at doses of 300 and 600 mg/kg.

Antinociceptive activity of Buddleja globosa (matico) in several models of pain

ETHNOPHARMACOLOGICAL RELEVANCE

Leaf extracts of Buddleja globosa (Buddlejaceae) are used in Chilean folk medicine for wound healing. The anti-inflammatory (topic and per os), analgesic (per os) effects and the antioxidant activity of Buddleja globosa were for the first time reported by us.

AIM OF THE STUDY

Assess the antinociceptive activity of the methanol sequential and global extracts using complementary chemical and thermal models of pain, characterize pharmacologically the antinociception induced, evaluate seasonal influence to support Buddleja globosa medicinal use.

MATERIALS AND METHODS

Global methanol, sequential methanol and ethanol (leaves collected in autumn and summer) extracts were evaluated for oral and topic analgesia in tail flick, formalin and writhing models, verbascoside and 7-O-luteolin glucoside were assayed in tail flick and writhing. Ibuprofen was used as reference. For characterization of induced antinociception, naltrexone, naltrindole, tropisetron, nor-binaltorphimine, prazosin, yohimbine, atropine, and N-nitro-l-arginine methyl ester were used as antagonists and inhibitors drugs.

RESULTS

Seasonal influence was observed since autumn extract resulted less active. Extracts showed a dose-dependent antinociceptive activity in all assays, the highest effects were obtained for the formalin and writhing test. Verbascoside was more active than ibuprofen in the writhing test (67.6% and 50.0% at equimolar doses) and showed similar effects in the tail flick (topic and oral) near 25% at equivalent doses - ED25 or EC25 - to ibuprofen. Luteolin 7-O-glucoside was slightly more active in the tail flick test and nearly half active than verbascoside in the writhing assay. Effectiveness was higher for the sequential than for global alcoholic extracts, and can be increased by selective blocking of opioid receptors. Global methanol extract seems modulated only by naltrexone.

CONCLUSIONS

Analgesic effect of Buddleja globosa is here demonstrated validating its use in traditional medicine. Season influence is important to be considered.