Antinociceptive effect of methanol extract of leaves of Persicaria hydropiper in mice

The antioxidant, anti-inflammatory and analgesic activity effect of ethyl acetate extract from the flowers of Syringa pubescens Turcz

ETHNOPHARMACOLOGICAL RELEVANCE

Syringa Pubescens Turcz. (SP), a member of the Oleaceae family, is a species of plant known as Syringa. Flowers, as the medicinal part, are commonly used in the treatment of hepatitis and tonsillitis.

AIM OF THE STUDY

The research was the first to assess the antioxidant and anti-inflammatory potential of different parts of SP flowers (SPF) in vitro. The most promising fraction was ethyl acetate fraction of SP flower (SPFEA). The antioxidant, anti-inflammatory and analgesic activities of SPFEA were further studied, and the chemical components were identified.

METHODS

HPLC was used to identify the major components in various fraction of SPF. DPPH and ABTS + radical scavenging assays as well as FRAP test and β-carotene bleaching test were employed to assess the antioxidant potential of SPF fraction in vitro. The inhibitory effect on NO production in LPS-treated RAW264.7 cells and heat-induced protein denaturation test were used to evaluate the anti-inflammatory potential of SPF fraction. Further analysis of the biological activity of SPFEA was performed. Acute toxicity test was conducted to assess the toxicity of SPFEA. The anti-inflammatory effect was assessed by utilizing xylene induced ear edema model, carrageenan-induced foot edema model and peritonitis model in vivo. The analgesic effect of SPFEA was evaluated using hot plate test, tail immersion test, formaldehyde test as well as acetic acid-induced abdominal writhing pain experiment in vivo. In carrageenan induced foot edema model, ELISA kits were employed to measure levels of inflammation factors (NO, TNF-α, IL-6, COX-2, IL-1β) in foot tissue as well as MDA, CAT, SOD, GSH-PX levels in liver tissue.

RESULTS

HPLC results showed that there were significant differences in bioactive substances among different fractions of SPF, and SPFEA was rich in bioacitve components. Compared with other fractions of SPF, SPFEA exhibited better antioxidant and anti-inflammatory abilities. The 3000 mg/kg SPFEA group in mice had no obvious side effects. The xylene-induced ear edema model, carrageenan-induced foot edema and peritonitis models demonstrated that the SPFEA had significant anti-inflammatory effect. Moreover, inflammation factors including NO, TNF-α, IL-6, COX-2, IL-1β were significantly reduced in SPFEA groups in foot tissue induced by carrageenan. Additionally, SPFEA effectively decreased liver tissue oxidative stress levels (MDA, SOD, GSH-PX and CAT). The bioactivities of SPFEA demonstrated a clear dose-dependent relationship. The results of the hot plate test, tail immersion test, formaldehyde test and acetic acid-induced abdominal writhing pain experiments indicated the SPFEA possessed an excellent analgesic effect, and this effect was in dose-dependent manner.

CONCLUSION

The study provides a scientific foundation for understanding the pharmacological action of SPFEA. It has been indicated that SPFEA has excellent antioxidant, analgesic and anti-inflammatory effects.

Genome assembly and microsatellite marker development using Illumina and PacBio sequencing in Persicaria maackiana (Polygonaceae) from Korea

BACKGROUND

Persicaria maackiana (Regel) is a potential medicinal plant that exerts anti-diabetic effects. However, the lack of genomic information on P. maackiana hinders research at the molecular level.

OBJECTIVE

Herein, we aimed to construct a draft genome assembly and obtain comprehensive genomic information on P. maackiana using high-throughput sequencing tools PacBio Sequel II and Illumina.

METHODS

Persicaria maackiana samples from three natural populations in Gaecheon, Gichi, and Uiryeong reservoirs in South Korea were used to generate genomic DNA libraries, perform genome de novo assembly, gene ontology analysis, phylogenetic tree analysis, genotyping, and identify microsatellite markers.

RESULTS

The assembled P. maackiana genome yielded 32,179 contigs. Assessment of assembly integrity revealed 1503 (93.12%) complete Benchmarking Universal Single-Copy Orthologs. A total of 64,712 protein-coding genes were predicted and annotated successfully in the protein database. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologs, 13,778 genes were annotated into 18 categories. Genes that activated AMPK were identified in the KEGG pathway. A total of 316,992 microsatellite loci were identified, and primers targeting the flanking regions were developed for 292,059 microsatellite loci. Of these, 150 primer sets were randomly selected for amplification, and 30 of these primer sets were identified as polymorphic. These primers amplified 3-9 alleles. The mean observed and expected heterozygosity were 0.189 and 0.593, respectively. Polymorphism information content values of the markers were 0.361-0.754.

CONCLUSION

Collectively, our study provides a valuable resource for future comparative genomics, phylogeny, and population studies of P. maackiana.

Essential oil from leaves of Myrciaria floribunda (H. West ex Willd.) O. Berg has antinociceptive and anti-inflammatory potential

Myrciaria floribunda is a plant that is distributed across different Brazilian biomes such as the Amazon, Caatinga, Cerrado, and Atlantic Forest, and it possesses antioxidant, antimicrobial, and anticancer properties. The antinociceptive and anti-inflammatory properties of the essential oil from M. floribunda leaves (MfEO) were examined in this study using mouse models. Gas chromatography-mass spectrometry was employed to describe the oil, and the results revealed that δ-cadinene, bicyclogermacrene, α-cadinol, and epi-α-muurolol predominated in the chemical profile. The oil stimulated a decrease in nociception in the chemical and thermal models used to evaluate acute antinociceptive activity. Findings from the use of pain pathway blockers to study the presumed underlying mechanism indicated opioid pathway activity. The anti-edematogenic effect, decreased cell migration, and generation of pro-inflammatory cytokines provided evidence of the anti-inflammatory potential of the essential oil from M. floribunda. According to this research, the essential oil from M. floribunda can effectively alleviate acute pain and inflammation.

Eugenia gracillima essential oil has pharmaceutical applications in pain and inflammation without toxic effects in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia gracillima is widely used by the population in the manufacture of pulps and jellies, with popular reports of its use in the treatment of infections in the urinary system, respiratory and dermatological problems. A previous study reports that EO from E. gracillima leaves proved to be a promising antioxidant agent in combating the promastigote forms of protozoa. Despite this, this species has been little studied due to its pharmacological properties.

STUDY OBJECTIVE

In this study, an essential oil extracted (EO) from Eugenia gracillima leaves was evaluated for its acute toxicity and anti-inflammatory, antinociceptive and behavioral effects in mice.

METHODS

The EO was obtained by hydrodistillation, and the composition analysis was performed by gas chromatography coupled to mass spectrometry. Acute toxicity assessment was performed with observation of hematological parameters and histopathological evaluation, as well as tests to investigate antinociceptive, anti-inflammatory activities and behavioral effects.

RESULTS

Chromatographic analysis showed D-germacrene (16.10%), γ-muurolene-g (15.60%) and bicyclogermacrene (8.53%) as the majority of compounds. In the toxicity evaluation, no death or physiological changes were observed in mice treated with a single oral dose of up to 5000 mg/kg, and it did not lyse erythrocytes in vitro. The hematological parameters evaluated were not changed after treatment; however, 5,000 mg/kg promoted an increase in transaminase levels. In the histopathological evaluation, only the animals that received the dose of 5000 mg/kg showed discrete leukocyte infiltration around the centrilobular vein in the liver. Antinociceptive activity was detected through tests of acetic acid-induced writhing, formalin, and tail flick, promoted in part by the opioid receptor pathway. In the evaluation of anti-inflammatory activity, a reduction in inflammation was observed in the paw edema test and a decrease in the migration of leukocytes and neutrophils in the peritonitis test. The open field and elevated plus maze tests showed that EO did not affect the animals' motor functions or exploratory activity.

CONCLUSION

It was concluded that the essential oil of E. gracillima has potential for the development of pharmaceutical formulations with analgesic and anti-inflammatory actions in non-toxic concentrations.

Schinus terebinthifolia leaf lectin has central and peripheral antinociceptive action mediated by its carbohydrate-recognition domain and delta-opioid receptors

ETHNOPHARMACOLOGICAL RELEVANCE

Preparations from the bark and leaves of Schinus terebinthifolia Raddi are commonly used to treat toothaches and sore throats. The use of medications based on leaves of this plant has also been reported for pain of arthritis, toothache, and sore throat. Some evidence indicated that the lectin SteLL is an antinociceptive agent from leaves.

AIM OF THE STUDY

This study evaluated the antinociceptive activity of S. terebinthifolia leaf lectin (SteLL) using mouse models of peripheral and central nociception.

MATERIALS AND METHODS

Animals were treated intraperitoneally with SteLL at 1, 5, and 10 mg/kg. An acetic acid-induced abdominal writhing test was performed to screen for the antinociceptive effect of the lectin. Next, the formalin test was used to assess the effects of SteLL on neurogenic (first phase) and inflammatory (second phase) pain, as well as to investigate the involvement of the carbohydrate-recognition domain (CRD) of SteLL and opioid receptors in the antinociceptive effect. The tail immersion test was performed to assess the central antinociception. Additionally, a rotarod test was performed to evaluate the effects of lectin on motor coordination in mice.

RESULTS

SteLL reduced the number of acetic acid-induced writhes by 83.5-100.0%. In the first phase of the formalin test, SteLL reduced paw licking time by 49.4-50.5%, while in the second phase, SteLL reduced paw licking time by 80.5-82.6%. This antinociceptive effect was reversed by the previous incubation of the lectin with ovalbumin (indicating the possible involvement of the CRD) and by the administration of naloxone, a nonselective opioid receptor antagonist. When testing selective antagonists of opioid receptors (μ, δ, and κ), only naltrindole, a selective δ receptor antagonist, blocked the antinociceptive action of SteLL during the second phase of the formalin test. In the tail immersion test, SteLL (1, 5, and 10 mg/kg) administration reduced sensitivity to thermal stimulus, which was observed even after 2 h. SteLL (10 mg/kg) did not affect animal motor coordination in rotarod test when compared to the control group.

CONCLUSION

SteLL has peripheral and central analgesic action involving opioid receptor modulation without affecting the motor coordination of animals. These results provide new perspectives for developing analgesic agents using lectins.

Anti-inflammatory, antinociceptive effects and involvement of opioid receptors in the antinociceptive activity of Eugenia uniflora leaves obtained with water, ethanol, and propylene glycol mixture

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia uniflora (Myrtaceae) is a species native to Brazil and has a traditional use in the treatment of inflammation.

AIM OF THE STUDY

To evaluate the anti-inflammatory and antinociceptive effects, and the involvement of opioid receptors in the antinociceptive activity of extract and fractions from Eugenia uniflora leaves.

MATERIALS AND METHODS

TLC and HPLC were used to characterize the spray-dried extract (SDE) and fractions. In the in vivo assays, Swiss (Mus musculus) mice were used. Carrageenan-induced hind-paw edema and carrageenan-induced peritonitis models were used to determine the anti-inflammatory effect of the extract (50, 100, or 200 mg/kg). Acetic acid-induced writhing, tail-flick, and formalin tests were used to determine the antinociceptive effect of the extract (50, 100, or 200 mg/kg). The aqueous (AqF) and ethyl acetate (EAF) fractions (6.25, 12.5, and 25 mg/kg) were then combined with naloxone to evaluate the involvement of opioid receptors in the antinociceptive activity.

RESULTS

In this work, the TLC and HPLC analysis evidenced the enrichment of EAF, which higher concentration of gallic acid (5.29 ± 0.0004 %w/w), and ellagic acid (1.28 ± 0.0002 %w/w) and mainly myricitrin (8.64 ± 0.0002 %w/w). The extract decreased the number of total leukocytes and neutrophils in the peritoneal cavity (p < 0.05), at doses of 100 and 200 mg/kg and showed significant inhibition in the increase of paw edema volume (p < 0.05). The treatment per oral route (doses of 50, 100, and 200 mg/kg) significantly reduced the nociceptive response in acetic acid-induced abdominal writhing (p < 0.05). The effect of the extract on the tail-flick test showed a significant increase in latency time of animals treated at doses of 200 and 100 mg/kg (p < 0.05). The extract and ethyl acetate fraction reduced the nociceptive effect in both phases of formalin at all tested doses. The naloxone reversed the antinociceptive effect of EAF, suggesting that opioid receptors are involved in mediating the antinociceptive activity of EAF of E. uniflora in the formalin test.

CONCLUSION

The current study demonstrates the anti-inflammatory and analgesic activities of water: ethanol: propylene glycol spray-dried extract from E. uniflora leaves using in vivo pharmacological models in mice. Our findings suggest that spray-dried extract and ethyl acetate fraction exhibit peripheral and central antinociceptive activity with the involvement of opioid receptors that may be related to the presence of flavonoids, mainly myricitrin.

Pharmacognostic evaluation of Artemisia maritima L. a highly medicinal specie of genus Artemisia

The light and scanning electron microscopic observations were carried out for anatomical features of leaf, pollens and powder.Microscopic studies provide useful information for identification and authentication of adulteration in A. maritima. Nutritional analysis of A. maritima revealed that life fundamental macromolecules such as carbohydrates (49.63 %) crude proteins (13.17 %) and crude fibers (21.06 %) were present in sufficient quantity while crude fats (4.11 %) reported in low quantity. The life essential elements such as Mg (9.472 ± 0.011), Ca (4.152 ± 0.135) and Fe (4.112 ± 0.002) were found in high concentration while heavy metals reported under the safety threshold of WHO. These observations favored A. maritima an alternative of food.Appreciable quantity of phenolics (17.64 ± 0.574) and flavonoids (7.67 ± 0.069) were found while qualitatively active phytochemicals were reported.

The FTIR characterization of A. maritima crude powder revealed chromatogram in 3328.61 to 408.68 frequency range and 24 characteristic peaks on the basis of which different compounds of biological importance were classified. HPLC-UV technique quantifiedand identified six phenolic compounds morin,epigallocatechin gallate, catechin hydrate,ellagic acid, pyrogallol andrutin. Identification of compounds through GC–MS chromatogram revealed the presence of 46 compounds in methanolic fraction however 17 compounds of biological importance were selected.

In-vitro biological evaluation of A. maritima for antioxidant, antimicrobial, antidiabetic (12.61 ± 0.113 %) and cytotoxic activities (LC₅₀ = 20 μg/ml) suggested that methanolic fractions exhibited the highest activity as compared to chloroform and ethyl acetate fractions. The MIC values of 10 or 15 mg/ml were recorded for most of the fungal pathogens. Antibacterial activity revealed 3.75 mg/ml of MIC values against B. subtilis and 1.87 mg/ml against S. aureus, E. coli and P. aeruginosa. In-vivo biological evaluation revealed thatmaximum inhibition was observed for crude extract at 250 mg/kg body weight. The mechanism underlined in-vivo analgesic responses was carried out which revealed that naloxone (morphine and tramadol antagonist) showed no prominent effect while Glibenclamide pretreatment minutely modified the analgesic action. These observations clearly indicted the absence of opiod receptors and involvement of ATP sensitive potassium channels.

Essential oil from the leaves of Eugenia pohliana DC. (Myrtaceae) alleviate nociception and acute inflammation in mice

Eugenia pohliana DC.(Myrtaceae) is used in folk medicine by communities in Brazil. However, there are no reports on its biological activity. This is the first study to identify the components of E. pohliana essential oil (EpEO) and evaluate their antinociceptive and anti-inflammatory activities in an in vivo model at doses of 25, 50, and 100 mg/kg. The essential oil (EO) was obtained by hydrodistillation, and the analysis was performed by gas chromatography coupled with mass spectrometry. Antinociceptive activity was evaluated by writhing tests, tail movement, and formalin (neurogenic and inflammatory pain); naloxone was used to determine the nociception mechanism. Anti-inflammatory activity was assessed by oedema and peritonitis tests. We found that (E)-β-caryophyllene (BCP) (15.56%), δ-cadinene (11.24%) and α-cadinol (10.89%) were the major components. In the writhing test, there was a decrease in writing by 42.95-70.70%, in the tail movement, an increase in latency time by 69.12-86.63%, and in the formalin test, there was a reduction in pain neurogenic by 29.54-61.74%, and inflammatory pain by 37.42-64.87%. The antinociceptive effect of EpEO occurs through the activation of opioid receptors. In addition, a reduction in inflammation by 74.93‒81.41% was observed in the paw edema test and inhibition of the influx of leukocytes by 51.86‒70.38% and neutrophils by 37.74‒54.72% in the peritonitis test. It was concluded that EpEO has antinociceptive effect by the opioid pathway, as shown by the inhibitory effect of naloxone, and anti-inflammatory actions, and that its use does not cause hemolytic damage or behavioral change.

The complete chloroplast genome of Persicaria maackiana (Regel) Nakai ex T. Mori (Polygonaceae) in Korea

Persicaria maackiana (Regel) Nakai ex T. Mori (1922), a species of the Polygonaceae family, is an annual plant widely distributed in Northeast Asia. We aimed to sequence the complete chloroplast genome of P. maackiana using Illumina HiSeq paired-end sequencing. The chloroplast genome was determined to be 160,635 bp. The complete chloroplast genome contained 129 genes, including 84 protein-coding genes, 37 tRNA, and eight rRNA genes. Phylogenetic analysis of the chloroplast genome sequences of 15 Polygonaceae plants revealed that P. maackiana was most closely related to P. perfoliata. Our findings might be useful for future phylogenetic studies of Polygonaceae.

In Vivo Bioactivities of Hoya parasitica (Wall.) and In Silico Study against Cyclooxygenase Enzymes

Hoya parasitica (Wall.) is extensively used in traditional medicine for the treatment of various diseases including rheumatism, kidney problems, jaundice, urinary tract disorders, fever, and pain. The present study was designed to explore new lead compound(s) to alleviate pain, pyresis, and diarrhea from methanol, ethyl acetate, and n-hexane extracts of H. parasitica (Wall.) leaves (MHP, EAHP, and NHP, respectively). Analgesic activity of the extracts was assessed through acetic acid induced writhing, tail immersion, and hot plate tests while brewer's yeast-induced pyrexia test was employed for the assessment of antipyretic activity. Besides, castor oil and magnesium sulfate induced diarrheal tests were utilized for the evaluation of antidiarrheal properties. Moreover, in silico study of the isolated compounds was undertaken to seek out best-fit phytoconstituent(s) against cyclooxygenase enzymes. MHP revealed substantial antioxidant activities in different in vitro assays compared to EAHP and NHP. In the acetic acid-induced writhing test, among the extracts, MHP (400 mg/kg) revealed maximum 74.15 ± 1% inhibition of writhing comparable to that of standard (85.77 ± 1.39%). Again, in tail immersion and hot plate tests, higher doses of all the test samples exhibited a significant increase of latent period in a time-dependent manner. In brewer yeast-induced pyrexia test, at 3rd and 4th hour of treatment, significant (P < 0.05) antipyretic action was found in the test samples. In both castor oil and magnesium induced diarrheal tests, MHP at 400 mg/kg showed the highest percent inhibition of diarrhea (68.62 ± 4.74 and 64.99 ± 2.90, respectively). Moreover, molecular docking analysis corroborated the results of the present study. The findings of the present study supported the traditional uses of this plant for the alleviation of pain and fever. Furthermore, hoyasterone was found to be the most effective lead compound as cyclooxygenase enzyme inhibitor.

Oral administration of essential oil from Psidium glaziovianum Kiaersk leaves alleviates pain and inflammation in mice

Plants of the genus Psidium have been employed in "in natura" consumption and agroindustry, and owing to the diversity of phytochemicals, the development of new pharmaceutical forms has received remarkable research interest. In this study, the essential oil obtained from Psidium glaziovianum (PgEO) leaves were evaluated antinociceptive and anti-inflammatory activities were evaluated in mouse models. Initially, PgEO was characterized by gas chromatography-mass spectrometry and gas chromatography with flame ionization detection, and the profile was dominated by sesquiterpene compounds. In the evaluation of acute antinociceptive activity (abdominal contortions induced by acetic acid, formalin, tail immersion, and hot plate tests), PgEO promoted a reduction in nociception in the chemical and thermal models. Additionally, the potential underlying mechanism was investigated using pain pathway blockers, and the results revealed a combined action of opioidergic and muscarinic pathways. The anti-inflammatory potential was confirmed by anti-edematogenic action, reduced cell migration, pro-inflammatory cytokine production, and granuloma formation in chronic processes. This study provides evidence that PgEO can be effective for the treatment of pain and acute and chronic inflammation.

Flavonoid-rich fraction from Croton blanchetianus (Euphorbiaceae) leaves exerts peripheral and central analgesic effects by acting via the opioid and cholinergic systems

The ethanolic extract from Croton blanchetianus leaves has been shown to have antinociceptive activity in mice. Here, we investigated the antinociceptive activity of an ethyl acetate fraction (EAF) from this extract in mice and the possible pathways involved in the analgesic effect. Adverse effects on behavior and motor coordination were also evaluated. The EAF was characterized by liquid chromatography coupled with mass spectrometry and evaluated (12.5, 25, and 50 mg/kg per os) in the acetic acid-induced abdominal writhing, formalin, hot plate, and tail immersion assays. Naloxone, atropine, glibenclamide, prazosin, or yohimbine was pre-administered to mice to investigate the involved pathways in the formalin test. The open-field, rotarod, and elevated plus-maze tests were used to assess behavior and locomotion. The main components of the EAF were quercetin-3-O-(2-rhamnosyl) rutinoside, hyperoside, quercetin rutinoside pentoside, and quercetin hexoside deoxyhexoside. EAF showed antinociceptive effects in all models and was effective against both neurogenic and inflammatory pain. The reversion of the effects in the formalin test by naloxone and atropine revealed that the EAF acted via the opioid and cholinergic systems. In the open-field test, the behavior of the animals treated with the EAF was like that of control, except at the highest dose, when hypnosis, eyelid ptosis, decreased walking, hygiene, and rearing behaviors were observed. No muscle relaxant effect was observed, but an anxiogenic effect was observed at all doses. This study provides new scientific evidence on the pharmacological properties of C. blanchetianus leaves and their potential for the development of phytomedicines with analgesic properties.

Optimization for ultrasonic-microwave synergetic extraction of total iridoid glycosides and screening of analgesic and anti-inflammatory active fractions from patrinia scabra Bunge (Valerianaceae)

Background

Patrinia scabra Bunge is a well-known herbal medicine for its favorable treatment on inflammatory diseases owing to its effective ingredients, in which iridoid glycoside plays an extremely significant role. This article aimed to improve the content of total iridoid glycosides in crude extract through a series optimization of extraction procedure. Moreover, considering that both pain and inflammation are two correlated responses triggered in response to injury, irritants or pathogen, the article investigated the anti-inflammatory and analgesic activities of P. scabra to screen out the active fraction.

Method

P. scabra was extracted by ultrasonic-microwave synergistic extraction (UMSE) to obtain total iridoid glycosides (PSI), during which a series of conditions were investigated based on single-factor experiments. The extraction process was further optimized by a reliable statistical method of response surface methodology (RSM). The elution fractions of P. scabra extract were prepared by macroporous resin column chromatography. Through the various animal experiment including acetic acid-induced writhing test, formalin induced licking and flinching, carrageenan-induced mice paw oedema test and xylene-induced ear edema in mice, the active fractions with favorable analgesic and anti-inflammatory effect were reasonably screen out.

Results

The content of PSI could reach up to 81.42 ± 0.31 mg/g under the optimum conditions as follows: ethanol concentration of 52%, material-to-liquid ratio of 1:18 g/mL, microwave power at 610 W and extraction time of 45 min. After gradient elution by the macroporous resin, the content of PSI increased significantly. Compared with other concentrations of elution liquid, the content of PSI in 30 and 50% ethanol eluate was increased to reach 497.65 and 506.90 mg/g, respectively. Owing to the pharmacology experiment, it was reasonably revealed that 30 and 50% ethanol elution fractions of P. scabra could relieve pain centrally and peripherally, exhibiting good analgesic and anti-inflammatory activities.

Conclusion

Patrinia scabra possessed rich iridoids and exhibited significant analgesic and anti-inflammatory activities.

Catalytic and Medical Potential of a Phyto-Functionalized Reduced Graphene Oxide-Gold Nanocomposite Using Willow-Leaved Knotgrass

In the current study, a simple, environmentally friendly, and cost-effective reduced graphene oxide-gold nanoparticle (rGO-AuNP) nanocomposite was successfully phytosynthesized using the aqueous leaf extract of a common weed found on the Nile banks, Persicaria salicifolia, for the first time. The phytosynthesis of rGO-AuNPs was first confirmed via the color transformation from brown to black as well as throughvarious techniques such as transmission electron microscopy (TEM) and Raman spectroscopy. Two UV-vis peaks at 275 and 530 nm were observed for the nanocomposite with a typical particle size of mostly spherical AuNPs of 15-20 nm. However, other shapes were occasionally detected including rods, triangles, and rhomboids. Existing phytoconstituents such as flavonoids and glycosides in the plant extract were suggested to be responsible for the phytosynthesis of rGO-AuNPs. The excellent catalytic efficacy of rGO-AuNPs against MB degradation was confirmed, and a high antibacterial efficiency against Escherichia coli and Klebsiella pneumonia was also confirmed. Promising antioxidant performance of rGO-AuNPs was also proved. Furthermore, it was concluded that rGO-AuNPs acquired higher efficiency than AuNPs synthesized from the same plant extract in all of the studied applications.

A Hydroethanolic Leaf Extract of Persicaria lanigera Possesses Antinociceptive Activity through Cytokine and Glutamatergic Pathways In Vivo

Persicaria lanigera is used traditionally to treat pain. The antinociceptive properties of the hydroethanolic leaf extract of Persicaria lanigera (PLE) were evaluated in rats and mice. Mice were pretreated orally with PLE (30, 100, and 300 mg kg⁻¹) and evaluated for antinociceptive effects in the acetic acid-, glutamate-, and formalin-induced nociception models. Additionally, mechanical hyperalgesia models were used to evaluate PLE's influence on TNF-α- and IL-1β-induced hyperalgesia in rats. In the acetic acid-induced nociception model, 100 mg kg⁻¹ PLE exhibited the highest antinociceptive activity of 95.13 ± 9.52% at p < 0.0001, followed by the 300 mg kg⁻¹ (85.44 ± 5.75%; p < 0.0001) and then the 30 mg kg⁻¹ (67.95 ± 18.55%; p < 0.01), compared to morphine 3 mg kg⁻¹ i.p. (86.97 ± 9.52; p < 0.0001). PLE (30, 100, and 300 mg kg⁻¹) also showed significant (p < 0.05) antinociceptive effect in phase two of the formalin-induced nociception with % inhibitions of 66.88 ± 12.17, 75.12 ± 9.01, and 89.12 ± 4.32%, respectively, compared to 3 mg/kg morphine (97.09 ± 2.84%). Similarly, PLE (30, 100, and 300 mg kg⁻¹) significantly reduced pain in the glutamate-induced nociception model with % inhibitions of 79.28 ± 8.17, 90.54 ± 5.64, and 96.49 ± 1.43%, respectively, whereas ketamine (5 mg/kg i.p.) reduced nociception to be 59.94 ± 18.14%. All doses of PLE significantly reduced nociceptive scores in TNF-α- and IL-1β-induced mechanical hyperalgesia (p < 0.01). Similarly, PLE significantly inhibited bradykinin-induced nociception. The hydroethanolic extract of Persicaria lanigera has antinociceptive effects; this is the first scientific report providing evidence to validate its traditional use for the management of pain.

Involvement of opioidergic and GABAergic systems in the anti-nociceptive activity of the methanolic extract of Cuscuta Epithymum Murr. in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Cuscuta epithymum Murr. (CE) is a parasitic plant used as a traditional medicine to treat various diseases such as muscle and joint pains and headache different parts of the world, Europe in the north, Asia in the east.

AIM OF THE STUDY

In this study, we aimed to investigate the anti-nociceptive effect of the methanolic extract of the aerial parts of CE and its probable mechanism(s) in mice.

MATERIALS AND METHODS

The anti-nociceptive activity of different doses of CE methanolic extract (2.5, 5, 10, 25, 50 and 100 mg/kg, i.p.) was assessed using tail flick, formalin and writhing tests. Morphine (5 mg/kg, s.c.) was used as positive control drug. The possible mechanisms were evaluated by using naloxone (4 mg/kg, i.p.), ondansetron (4 mg/kg, i.p.), picrotoxin (0.6 mg/kg, i.p.) and MK-801 (0.03 mg/kg, i.p.).

RESULTS

GC-MS analysis indicated that one of the main components of CE extract was terpenoid compounds. The CE extract (25-100 mg/kg), like morphine, reduced tail flick latency and nociceptive response in both phases of the formalin test. We also observed that the extract significantly decreased the number of abdominal contractions dose-dependently from 5 to 100 mg/kg. The results of tail flick and the first phase of formalin test proved that unlike ondansetron and MK-801, naloxone and picotroxin were able to reverse the anti-nociceptive effect of CE extract.

CONCLUSION

Our observations showed the anti-nociceptive potential of the CE extract, which may be mediated by opioidergic and GABAergic systems.

Anti-inflammatory and analgesic activities of indigo through regulating the IKKβ/IκB/NF-κB pathway in mice

This study investigated the anti-inflammatory and analgesic activities of indigo in mice and explored the possible related mechanisms. Xylene-induced ear edema, carrageenan-induced paw edema, and acetic acid-induced vascular permeability tests were used in investigating the anti-inflammatory activities. The anti-nociceptive effects of indigo were assessed through acetic acid-induced writhing, hot plate test, and formalin test, and spontaneous locomotor activity and motor performance were evaluated. The mechanisms of activities of indigo were explored by evaluating the expression levels of IκB kinase (IKK)β, p-IKKβ, inhibitor κB (IκB)α, p-IκBα, p65 nuclear factor (NF)-kB, p-p65 NF-κB, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) through western blotting and the expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and prostaglandin E₂ (PGE₂) through enzyme-linked immunosorbent assay. The results showed that indigo significantly reduced xylene-induced ear edema, carrageenan-induced paw edema, and acetic acid-induced vascular permeation. In addition, indigo significantly inhibited nociception induced by acetic acid and formalin. However, the level of nociception was not decreased by indigo in the hot plate test, and indigo did not affect spontaneous locomotor activity and motor performance. The expression levels of p-IKKβ, p-IκBα, p65 NF-kB, p-p65 NF-κB, COX-2, iNOS, TNF-α, IL-1β, IL-6, and PGE₂ decreased, whereas the expression level of IκBα increased obviously after indigo treatment. In conclusion, indigo exerts significant anti-inflammatory and analgesic activities in mice by inhibiting IKKβ phosphorylation and reducing the production of important pain mediators, such as PGE₂ and COX-2, via the IKKβ/IκB/NF-κB pathway.

Persicaria hydropiper (L.) Delarbre: A review on traditional uses, bioactive chemical constituents and pharmacological and toxicological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Various plant parts of Persicaria hydropiper (L.) Delarbre (Syn.: Polygonum hydropiper L., Family: Polygonaceae) are used in traditional medicine systems as astringent, sedative, antiseptic and also for the treatment of respiratory disorders, edema and snake bites. It is also used as a spice in many Asian countries.

AIM OF THE REVIEW

The main aim of this review is to critically analyze the reported traditional uses, bioactive chemical constituents and pharmacological activities of P. hydropiper.

MATERIALS AND METHODS

Scientific database including PubMed, Scopus, SciFinder and secondary resources including books and proceedings were searched using relevant terminologies related to P. hydropiper and available scientific information was critically analyzed.

RESULTS

Analysis of the scientific literature regarding the traditional uses revealed that P. hydropiper is used as a medicine and as spice in food preparations in various parts of the world. Various compounds including flavonoids, phenylpropanoid derivatives, and sesquiterpenoids among others were reported as active compounds. The extracts and compounds from P. hydropiper showed diverse biological activities including anti-inflammatory, antioxidant, cytotoxic, antimicrobial activities, etc. CONCLUSION: Although various research reports showed diverse biological activities for extracts and compounds obtained from P. hydropiper, very few studies were performed using animal models. Many of these studies also lacked proper experimental setting such as use of positive and negative controls and selection of dose as in most of these studies very high doses of extracts were administered. Further, as P. hydropiper is widely used in the treatment of snake bites and insect bites, such effects of extracts and/or compounds are not well explored. Future studies on P. hydropiper should be focused to establish the links between the traditional uses, active compounds and reported pharmacological activities.

Antitumor Activity of Vanicoside B Isolated from Persicaria dissitiflora by Targeting CDK8 in Triple-Negative Breast Cancer Cells

A flavonoid glycoside, quercitrin (1), and two phenylpropanoyl sucrose derivatives, vanicoside B (2) and lapathoside C (3), were isolated for the first time from the herb Persicaria dissitiflora. Vanicoside B (2) exhibited antiproliferative activity against a panel of cancer cell lines in triple-negative breast cancer (TNBC) MDA-MB-231 cells. The underlying mechanisms of the antitumor activity of 2 were investigated in TNBC cells. Upregulation of cyclin-dependent kinase 8 (CDK8) was observed in a claudin-low molecular subtype of TNBC cells. A molecular modeling study indicated that 2 showed a high affinity for CDK8. Further investigations revealed that 2 suppressed CDK8-mediated signaling pathways and the expression of epithelial-mesenchymal transition proteins and induced cell cycle arrest and apoptosis in MDA-MB-231 and HCC38 TNBC cells. Moreover, 2 inhibited tumor growth without overt toxicity in a nude mouse xenograft model implanted with MDA-MB-231 cells. Taken together, these findings demonstrate the significance of CDK8 activity in TNBC and suggest a potential use of 2 as a therapeutic candidate for the treatment of aggressive human triple-negative breast cancer.

Analgesic Effect of 5-(3,4-Dihydroxyphenyl)-3-hydroxy-1-(2-hydroxyphenyl)penta-2,4-dien-1-one in Experimental Animal Models of Nociception

Curcuminoids derived from turmeric rhizome have been reported to exhibit antinociceptive, antioxidant and anti-inflammatory activities. We evaluated the peripheral and central antinociceptive activities of 5-(3,4-dihydroxyphenyl)-3-hydroxy-1-(2-hydroxyphenyl)penta-2,4-dien-1-one (DHHPD), a novel synthetic curcuminoid analogue at 0.1, 0.3, 1 and 3 mg/kg (intraperitoneal), through chemical and thermal models of nociception. The effects of DHHPD on the vanilloid and glutamatergic systems were evaluated through the capsaicin- and glutamate-induced paw licking tests. Results showed that DHHPD significantly (p < 0.05) attenuated the writhing response produced by the 0.8% acetic acid injection. In addition, 1 and 3 mg/kg of DHHPD significantly (p < 0.05) reduced the licking time spent by each mouse in both phases of the 2.5% formalin test and increased the response latency of mice on the hot-plate. However, the effect produced in the latter was not reversed by naloxone, a non-selective opioid receptor antagonist. Despite this, DHHPD decreased the licking latency of mice in the capsaicin- and glutamate-induced paw licking tests in a dose response manner. In conclusion, DHHPD showed excellent peripheral and central antinociceptive activities possibly by attenuation of the synthesis and/or release of pro-inflammatory mediators in addition to modulation of the vanilloid and glutamatergic systems without an apparent effect on the opioidergic system.

Antinociceptive Activity of Macaranga denticulata Muell. Arg. (Family: Euphorbiaceae): In Vivo and In Silico Studies

Background: The present study was conducted to investigate the antinociceptive activity of methanol extract of Macaranga denticulata (Met.MD) in an animal model, followed by molecular docking analysis. Methods: Antinociceptive activity was determined by acetic acid-induced writhing and formalin-induced licking test in mice. Then, molecular docking study was performed to identify compounds having maximum activity against the COX-1 enzyme using Schrödinger Maestro (version 10.1) to determine docking fitness. Results: A preliminary phytochemical analysis of Met.MD revealed that it contained alkaloids, carbohydrates, phenols, flavonoids, tannins, and terpenoids. Met.MD exhibited a dose-dependent and statistically significant antinociceptive activity in the acetic acid and formalin test at the doses of 200 and 400 mg/kg. In addition, our docking study showed that macarangin had the best fitness score of −5.81 with COX-1 enzyme among six major compounds of M. denticulata. Conclusions: Results of the present study confirmed the potential antinociceptive activity of M. denticulata leaf extract in both in vivo and in silico models.

Hydro-ethanolic leaf extract of Ziziphus abyssinica Hochst Ex A. Rich (Rhamnaceae) exhibits anti-nociceptive effects in murine models

BACKGROUND

Despite substantial advances in pain research and treatment, millions of people continue to suffer from pain and this has been attributed mainly to the unavailability of effective and safer analgesics. The use of plants as medicines is still widespread and plants constitute a large source of novel phytocompounds that might become leads for the discovery of newer, effective and safer alternatives. Various parts of Ziziphus abyssinica have been used in folk medicine in several African countries as painkillers. However, there is no report on the possible anti-nociceptive effects of this plant especially the leaves, hence the need for this current study.

METHODS

The possible anti-nociceptive activity of hydro-ethanolic leaf extract of Ziziphus abyssinica (EthE) was assessed in rodents using chemical (acetic acid, formalin and glutamate), thermal (tail-immersion test) and mechanical/inflammatory (carrageenan) models of nociception.

RESULTS

EthE (30-300 mg/kg, p.o.) dose-dependently and significantly inhibited chemical-induced nociception with a maximum inhibition of 86.29 ± 2.27%, 76.34 ± 5.67%, 84.97 ± 5.35%, and 82.81 ± 5.97% respectively for acetic acid, formalin (phase 1), formalin (phase 2) and glutamate tests at its highest dose. EthE also dose-dependently and significantly increased reaction times in both tail-immersion and carrageenan-induced hypernociceptive tests. The activities of the extract in the various models were comparable with the effect of morphine hydrochloride and diclofenac sodium used as standard analgesic drugs.

CONCLUSION

Oral administration of hydro-ethanolic leaf extract of Ziziphus abyssinica ameliorates nocifensive behaviours associated with chemical-, thermal- and mechanical/inflammatory - induced nociceptive pain.

Evaluation of antinociceptive and anti-inflammatory effects of aqueous extract of Armadillidium vulgare Latreille

OBJECTIVE

To assess the antinociceptive and anti-inflammatory properties of the aqueous extract of Armadillidium vulgare (AV).

METHODS

The antinociceptive effect of AV (400, 600 and 800 mg/kg) was investigated in mice using the acetic acid-induced writhing, formalin-induced nociceptive, and hot plate tests. Phlogogen-induced paw edema using carrageenan, dextran, or compound 48/80 as phlogogen was used as inflammatory models to evaluate AV's anti-inflammatory effect. Additionally, the bioactive substances glucosamine (GLcN) and taurine in AV were determined using high-performance liquid chromatography.

RESULTS

Oral treatment of the mice with AV (600 and 800 mg/kg) significantly reduced the number of writhes in the acetic acid-induced writhing test (P<0.01) but not the hot plate test (P>0.05). All doses tested significantly inhibited paw-withdrawal during the second phase of the formalin-induced nociceptive model (P<0.01). AV demonstrated a strong anti-inflammatory effect in all those inflammatory models (P<0.05).

CONCLUSIONS

AV has antinociceptive and anti-inflammatory effects, providing scientific evidence of the efficacy of its traditional use in pain treatment. Furthermore, GLcN and taurine contribute, at least in part, to the anti-inflammatory activity of AV.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Sesquiterpene lactone! a promising antioxidant, anticancer and moderate antinociceptive agent from Artemisia macrocephala jacquem

Background

Sesquiterpene lactones (STLs) make a diverse and huge group of bio-active constituents that have been isolated from several plant families. However, the greatest numbers are present in Asteraceae family having more than 3000 different reported structures. Recently several researchers have reported that STLs have significant antioxidant and anticancer potentials.

Methods

To investigate the antioxidant, anticancer and antinociceptive potentials of STLs, gravity column chromatography technique was used for isolation from the biologically rich chloroform fraction of Artemisia macrocephala Jacquem. The antioxidant activity of the isolated STLs was determined by DPPH and ABTS free radical scavenging activity, anticancer activity was determined on 3 T3, HeLa and MCF-7 cells by MTT assay while the antinociceptive activity was determined through acetic acid induced writhings, tail immersion method and formalin induced nociception method.

Results

The results showed that the STLs of Artemisia macrocephala possesses promising antioxidant activity and also it decreased the viability of 3 T3, HeLa and MCF-7 cells and mild to moderate antinociceptive activity.

Conclusion

Sesquiterpenes lactones (STLs) are widely present in numerous genera of the family Asteraceae (compositae). They are described as the active constituents used in traditional medicine for the treatment of various diseases. The present study reveals the significant potentials of STL and may be used as an alternative for the management of cancer. Anyhow, the isolated compound is having no prominent antinociceptive potentials.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1517-y) contains supplementary material, which is available to authorized users.

Antinociceptive effect of methanol extract of Celosia cristata Linn. in mice

BACKGROUND

Celosia cristata Linn. (Amaranthaceae) is used in traditional medicine for the treatment of headache, sores, ulcers, eye inflammations, skin eruption, painful menstruation and carpal tunnel syndrome. This study was performed to evaluate the antinociceptive activity of methanol extract of the whole plant of C. cristata (MECC).

METHODS

The evaluation of the antinociceptive effect of MECC was performed using thermal (hot plate, tail immersion test) and chemical (acetic acid, formalin, and glutamate-induced nociception test) pain models in mice at four different doses (50, 100, 200, 400 mg/kg; p.o.). Involvement of opioid receptors mediated central antinociceptive mechanism of MECC was evaluated using naloxone. Furthermore, the association of ATP-sensitive K+ channel and cGMP pathway were evaluated using glibenclamide and methylene blue respectively.

RESULTS

Oral treatment of MECC produced significant, strong and dose-dependent central and peripheral antinociceptive effect in experimental pain models. MECC significantly increased the latency time of thermal threshold in both hot plate and tail immersion test. The inhibition of writhing syndrome by the extract in the acetic acid-induced writhing test was remarkable. MECC significantly reduced the formalin-induced neurogenic and inflammatory pain. In addition, the inhibition of glutamate-induced paw licking and edema by MECC was significant. The antinociceptive effect was significantly reversed by naloxone and glibenclamide, suggesting the association of opioid and ATP-sensitive K+ channel system respectively. In addition, MECC also demonstrated the involvement of cGMP pathway in the antinociceptive action.

CONCLUSION

The study suggests that C. cristata possess significant antinociceptive effect which is associated with both central and peripheral mechanisms and provides a rationale for its extensive use at different painful conditions in traditional medicine.

Observing Anti-inflammatory and Anti-nociceptive Activities of Glycyrrhizin Through Regulating COX-2 and Pro-inflammatory Cytokines Expressions in Mice

The present study aimed to investigate the potential anti-inflammatory and anti-nociceptive activities of glycyrrhizin (GL) in mice and to explore the possible related mechanisms. Xylene-induced ear edema, carrageenan-induced paw edema and acetic acid-induced vascular permeability test were used to investigate the anti-inflammatory activities of GL in mice. Anti-nociceptive effects of GL were assessed by using acetic acid-induced writhing, hot plate test and formalin test, as well as evaluation of spontaneous locomotor activity and motor performance. The mRNA expression of pro-inflammatory cytokines (such as TNF-α, IL-6 and iNOS) and the protein expression of cyclooxygenase-2 (COX-2) were explored by using real-time fluorogenic PCR and Western blot, respectively. The results showed that GL significantly reduced xylene-induced ear edema, carrageenan-induced paw edema, and acetic acid-induced vascular permeation. Additionally, GL significantly inhibited the nociceptions induced by acetic acid and formalin. However, the nociceptions could not be decreased by GL in the hot plate test, and GL did not affect spontaneous locomotor activity and motor performance. The expression levels of TNF-α, IL-6, iNOS and COX-2 were significantly downregulated by GL. In conclusion, GL exerts significant anti-inflammatory and analgesic activities by attenuating the expression levels of TNF-α, IL-6, iNOS and COX-2.

Methanolic Extract of Clinacanthus nutans Exerts Antinociceptive Activity via the Opioid/Nitric Oxide-Mediated, but cGMP-Independent, Pathways

The objectives of the present study were to determine the mechanisms of antinociceptive effect of methanol extract of Clinacanthus nutans (Acanthaceae) leaves (MECN) using various animal nociceptive models. The antinociceptive activity of orally administered 10% DMSO, 100 mg/kg acetylsalicylic acid (ASA), 5 mg/kg morphine, or MECN (100, 250, and 500 mg/kg) was determined using the acetic acid-induced abdominal constriction (ACT), formalin-induced paw licking (FT), and hot plate tests (HPT). The role of opioid and nitric oxide/cyclic guanosine monophosphate (NO/cGMP) systems was also investigated. The results showed that MECN produced a significant (p < 0.05) antinociceptive response in all nociceptive models with the recorded ED₅₀ value of 279.3 mg/kg for the ACT, while, for the early and late phases of the FT, the value was >500 mg/kg or 227.7 mg/kg, respectively. This antinociceptive activity was fully antagonized by naloxone (a nonselective opioid antagonist) but was partially reversed by l-arginine (l-arg; a nitric oxide [NO] precursor), Nω-nitro-l-arginine methyl ester hydrochloride (l-NAME; an NO synthase inhibitor), or their combinations thereof. In contrast, 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ; a soluble guanylyl cyclase inhibitor) enhanced the extract's antinociception. UHPLC analysis revealed the presence of several flavonoid-based compounds with antinociceptive action. In conclusion, MECN exerted the peripherally and centrally mediated antinociceptive activity via the modulation of the opioid/NO-mediated, but cGMP-independent, systems.

Antinociceptive effects of hydroalcoholic extract from Euterpe oleracea Mart. (Açaí) in a rodent model of acute and neuropathic pain

Background

Plants rich in flavonoids, such as açaí (Euterpe oleraceae Mart.), can induce antinociception in experimental animals. Here, we tested an extract obtained from the stones of açaí fruits (açaí stone extract, ASE), a native plant from the Amazon region of Brazil, in models of acute/inflammatory and chronic pain.

Methods

Antinociceptive effects of ASE were evaluated in the hot plate, formalin, acetic acid writhing, carrageenan, and neuropathic pain models, as well as in thermal hyperalgesia and mechanical allodynia models induced by spinal nerve ligation. Antinociceptive activities were modulated by the administration of cholinergic, adrenergic, opioid, and L-arginine-NO antagonists.

Results

Oral administration of ASE (30, 100, or 300 mg.kg⁻¹) dose-dependently reduced nociceptive responses to acute/inflammatory pain in mice, including thermal hyperalgesia, acetic acid-induced writhing, and carrageenan-induced thermal hyperalgesia. Moreover, ASE reduced the neurogenic and inflammatory phases after intraplantar injection of formalin in mice. The antinociceptive effect of ASE (100 mg · kg⁻¹) in a hot plate protocol, was inhibited by pre-treatment with naloxone (1 mg · kg⁻¹), atropine (2 mg · kg⁻¹), yohimbine (5 mg · kg⁻¹), or L-NAME (30 mg · kg⁻¹). Furthermore, ASE prevented chronic pain in a rat spinal nerve ligation model, including thermal hyperalgesia and mechanical allodynia.

Conclusion

ASE showed significant antinociceptive effect via a multifactorial mechanism of action, indicating that the extract may be useful in the development of new analgesic drugs.