Analgesic, antiinflammatory and CNS depressant activities of sesquiterpenes and a flavonoid glycoside from Polygonum viscosum

Tonantzitlolone B Modulates the Endogenous Opioid System to Promote Antinociception in Mice

Tonantzitlolone B (TZL-B) is a diterpene isolated from the roots of Stillingia loranthacea. Its antinociceptive effects were investigated in male Swiss mice using the following models of pain: formalin test, inflammation induced by Complete Freund's Adjuvant (CFA), tail flick test, and cold plate test. The influence of TZL-B on the opioid system was assessed in vivo, using opioid antagonists; in silico, investigating the chemical similarity among TZL-B and opioid agonists; and ex vivo, measuring preproenkephalin (PENK) gene expression in the spinal cord by RT-qPCR. TZL-B (10-1000 μg/kg) promoted antinociception in the four experimental models without impairing mice's motor function. TZL-B did not alter paw edema during CFA-induced inflammation. The antinociceptive effects of TZL-B in the tail flick and cold plate tests were diminished by the opioid antagonists naloxone (5 mg/kg), NOR-BNI (0.5 mg/kg), naltrindole (3 mg/kg), and CTOP (1 mg/kg), indicating the involvement of κ-, δ-, and μ-opioid receptors. TZL-B showed no significant chemical similarity to opioid agonists, but the treatment with TZL-B (1000 μg/kg) increased PENK gene expression in the spinal cord of mice. These data suggest that TZL-B promotes antinociception by enhancing the transcription of PENK, hence modulating the endogenous opioid system.

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.

Schinopsis brasiliensis Engler-Phytochemical Properties, Biological Activities, and Ethnomedicinal Use: A Scoping Review

Brazil has the most incredible biodiversity globally and has a vast storehouse of molecules to be discovered. However, there are no pharmacological and phytochemical studies on most native plants. Parts of Schinopsis brasiliensis Engler, a tree from the Anacardiaceae family, are used by several traditional communities to treat injuries and health problems. The objective of this scoping review was to summarize the pharmacological information about S. brasiliensis, from ethnobotanical to phytochemical and biological studies. Data collection concerning the geographical distribution of S. brasiliensis specimens was achieved through the Reflora Virtual Herbarium. The study’s protocol was drafted using the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The search strategy used the keyword “Schinopsis brasiliensis” in the databases: PUBMED, EMBASE, SCOPUS, Science Direct, Web of Science, SciFinder, and SciELO. Rayyan was used for the selection of eligible studies. In total, 35 studies were included in the paper. The most recurrent therapeutic indications were for general pain, flu and inflammation. The bark was the most studied part of the plant. The most used preparation method was decoction and infusion, followed by syrup. Phytochemical investigations indicate the presence of tannins, flavonoids, phenols, and polyphenols. Most of the substances were found in the plant’s leaf and bark. Important biological activities were reported, such as antimicrobial, antioxidant, and anti-inflammatory. S. brasiliensis is used mainly by communities in the semi-arid region of northeastern Brazil to treat several diseases. Pharmacological and phytochemical studies together provide scientific support for the popular knowledge of the medicinal use of S. brasiliensis. In vitro and in vivo analyses reported antimicrobial, antioxidant, anti-inflammatory, antinociceptive, cytotoxic, photoprotective, preservative, molluscicidal, larvicidal, and pupicidal effects. It is essential to highlight the need for future studies that elucidate the mechanisms of action of these phytocompounds.

Effects of Ruzu, a Polyherbal Mixture, on Neurobehaviour and Expression of Serotonin and Dopamine Transporters in Rats

There is increased possibility that combined herbal constituents may interact to increase toxicity and lower efficacy. Ruzu herbal bitters (RHB) is a blend of extracts from Curculigo pilosa, Uvaria chamae, and Citrullus colocynthis, each of which has been shown to possess important bio-effects. There is anecdotal evidence for efficacy of RHB in neurological disorders; however, there are no data on possible neurotoxic effects of RHB. Using behavioural, biochemical and molecular indices as surrogates of neurotoxicity, this study therefore evaluated the nervous system effects of RHB. Twenty male Wistar rats were divided into two groups - a control group and RHB group (n=10). RHB (0.5ml/kg) was administered to the RHB group twice daily while control group took water (0.5ml/kg). Treatments lasted 6 weeks after which behavioural tests were carried out. Animals were subsequently sacrificed and the expression of serotonin transporter (SERT) and dopamine transporter (DAT) was determined in the striatum by immunofluorescence while specific activities of catalase, alkaline phosphatase and gamma glutamyltransferase were determined. In the elevated plus maze and light and dark box tests which are models of anxiety, animals treated with RHB showed significant anxiety compared to control. They also showed impaired locomotor activity in the open field and wire hang tests. The activity of catalase was significantly increased in the brain of the RHB treated rats while an increase in the expression of both DAT and SERT was observed in the striatum.

An Update on Phytochemicals and Pharmacological Activities of the Genus Persicaria and Polygonum

The discovery of new pharmaceutical identities, particularly anti-infective agents, represents an urgent need due to the increase in immunocompromised patients and the ineffectiveness/toxicity of the drugs currently used. The scientific community has recognized in the last decades the importance of the plant kingdom as a huge source of novel molecules which could act against different type of infections or illness. However, the great diversity of plant species makes it difficult to select them with probabilities of success, adding to the fact that existing information is difficult to find, it is atomized or disordered. Persicaria and Polygonum constitute two of the main representatives of the Polygonaceae family, which have been extensively used in traditional medicine worldwide. Important and structurally diverse bioactive compounds have been isolated from these genera of wild plants; among them, sesquiterpenes and flavonoids should be remarked. In this article, we firstly mention all the species reported with pharmacological use and their geographical distribution. Moreover, a number of tables which summarize an update detailing the type of natural product (extract or isolated compound), applied doses, displayed bioassays and the results obtained for the main bioactivities of these genera cited in the literature during the past 40 years. Antimicrobial, antioxidant, analgesic and anti-inflammatory, antinociceptive, anticancer, antiviral, antiparasitic, anti-diabetic, antipyretic, hepatoprotective, diuretic, gastroprotective and neuropharmacological activities were explored and reviewed in this work, concluding that both genera could be the source for upcoming molecules to treat different human diseases.

The analgesic potential of glycosides derived from medicinal plants

Pain represents an unpleasant sensation linked to actual or potential tissue damage. In the early phase, the sensation of pain is caused due to direct stimulation of the sensory nerve fibers. On the other hand, the pain in the late phase is attributed to inflammatory mediators. Current medicines used to treat inflammation and pain are effective; however, they cause severe side effects, such as ulcer, anemia, osteoporosis, and endocrine disruption. Increased attention is recently being focused on the examination of the analgesic potential of phytoconstituents, such as glycosides of traditional medicinal plants, because they often have suitable biological activities with fewer side effects as compared to synthetic drugs. The purpose of this article is to review for the first time the current state of knowledge on the use of glycosides from medicinal plants to induce analgesia and anti-inflammatory effect. Various databases and search engines, including PubMed, ScienceDirect, Scopus, Web of Science and Google Scholar, were used to search and collect relevant studies on glycosides with antinociceptive activities. The results led to the identification of several glycosides that exhibited marked inhibition of various pain mediators based on different well-established assays. Additionally, these glycosides were found to induce most of the analgesic effects through cyclooxygenase and lipoxygenase pathways. These findings can be useful to identify new candidates which can be clinically developed as analgesics with better bioavailability and reduced side effects. Graphical abstract Analgesic mechanisms of plant glycosides.

Phytochemical Evaluation of Roots of Polygonum viscosum Buch-ham

Phytochemical evaluation of the chloroform extract of roots of Polygonum viscosum has yielded six compounds, stigmasterol, 7,4-dimethylquercetin, kaempferol, quercetin, myricetin and scutellarein. Among the six compounds isolated and characterized by chemical and spectral (UV, NMR and Mass) analysis in the present phytochemical evaluation, stigmasterol was not reported earlier from P. viscosum. The compounds, 7,4'-dimethylquercetin, quercetin and scutellarein were reported from P. hydropiper. Kaempferol from P. amphibium, P. aviculare, P. convolvulus, P. hydropiper, P. lapathifolium and P. persicari a and myricetin from P. aviculare and P. lapathifolium were also reported earlier. This appers to be the first report of the occurrence of all the six compounds from P. viscosum.

Flavonoid Glycosides of Polygonum capitatum Protect against Inflammation Associated with Helicobacter pylori Infection. PLoS One. 2015;10:e0126584. [PMID: 25993258 DOI: 10.1371/journal.pone.0126584]

The antibacterial and anti-inflammatory activities, and protective effects of extracts (flavonoid glycosides) of Polygonum capitatum were investigated to detect the evidence for the utilization of the herb in the clinical therapy of gastritis caused by H. pylori. A mouse gastritis model was established using H. pylori. According to treating methods, model mice were random assigned into a model group (MG group), a triple antibiotics group (TG group, clarithromycin, omeprazole and amoxicillin), low/middle/high concentrations of flavonoid glycosides groups (LF, MF and HF groups) and low/middle/high concentrations of flavonoid glycosides and amoxicillin groups (LFA, MFA and HFA groups). A group with pathogen-free mice was regarded as a control group (CG group). The eradicate rates of H. pylori were 100%, 93%, 89% in TG, MFA and HF groups. The serum levels of IFN-gamma and gastrin were higher in a MG group than those from all other groups (P < 0.05). The serum levels of IFN-gamma and gastrin were reduced significantly in LF, MF and HF groups (P < 0.05) while little changes were observed in LFA, MFA and HFA groups. In contrast, the serum levels of IL-4 were lower and higher in MG and CG groups compared with other groups (P<0.05). The serum levels of IL-4 were increased significantly in LF, MF and HF groups (P < 0.05) while little changes were found in LFA, MFA and HFA groups. According to pathological scores, flavonoid glycosides therapy showed better protection for gastric injuries than the combination of flavonoid glycoside and amoxicillin (P < 0.05). The results suggested that flavonoid glycoside has repairing functions for gastric injuries. The results suggest that the plant can treat gastritis and protect against gastric injuries. The flavonoid glycosides from Polygonum capitatum should be developed as a potential drug for the therapy of gastritis caused by H. pylori.

Study of CNS depressant and behavioral activity of an ethanol extract of Achyranthes Aspera (Chirchita) in mouse model

Background

Achyranthes Aspera Linn., known as Chirchira (Hindi), Agadha (Marathi) is an indigenous herb found in India. The herb has been reported to have variety of activities like antifertility, antihyperlipidemic, antidiabetic, immunomodulatory, anticarcinogenic, diuretic and cardiotonic, analgesic, anti-inflammatory, hypnotic, antifungal and antibacterial activity. It has been also reported to have central anti-nociceptive activity in thermal induced pain methods in our earlier studies. We wanted to study its neuropharmacological effects, which may throw light on understanding the underlying mechanism for its central activity.

Purpose

The present study was designed to evaluate CNS depressant and behavioral effects of A. Aspera extract and to study the phytochemical responsible for these activities with possible mode of action.

Methods

The effects on behavioral activity was studied using open field test (OFT). The extract was given intraperitoneally at a dose of 400 mg/kg. Diazepam (2mg/kg body weight i.p.) was used as standard. Data was analyzed by ANOVA test followed by Dunnett’s test. All the results were expressed as Mean (±SEM). P <0.05 was considered significant.

Results

Phytochemical screening revealed presence of triterpenoids, saponins, alkaloids (betaine, achyranthine) and steroids as major constituents. The result of the study demonstrated that ethanol extract of A. Aspera (400 mg/kg i.p.) decreased locomotor activity, produced muscle relaxation and showed antianxiety activity.

Conclusions

Ethanols extract of A. Aspera exhibit CNS depressant action and significant anxiolytic activity comparable to diazepam.

Antioedematous and Analgesic Properties of Fertile Fronds of Drynaria quercifolia

Inflammation is a complex biological response of tissue cells to harmful stimuli including trauma, tissue necrosis, and infections which plays a key role in the pathophysiology of many deadly diseases. In ethnomedicine Drynaria quercifolia fronds are used to treat inflammation as poultice on swellings and as antibacterial, hepatoprotective, and antipyretic agent. Herein, we have evaluated the antioedematous, antiproliferative, and analgesic properties of the ethanolic extract of fertile fronds of D. quercifolia (FF) by standard procedures. Oral administration of FF produced significant inhibition of carrageenan and histamine induced paw oedema in Wistar rats. FF significantly reduced both wet weight and dry weight of granuloma tissue which shows the inhibitory effect on exudative and proliferative phases of inflammation. FF significantly attenuated acute and delayed phases of formalin induced pain, acetic acid-induced writhing, capsaicin-induced nociception, and hot plate test in mice. Phytochemical analysis revealed the presence of coumarins, flavonoids, glycosides, phenolics, saponins, steroids, tannins, and terpenoids. Total phenolic content was 186 mg/g equivalent of gallic acid. The HPLC estimation showed flavanone glycoside naringin (1.2%) and its aglycone naringenin (0.02%). The presence of potent anti-inflammatory and analgesic principles in FF and their synergistic action may be the reason for the proposed therapeutic effects.

Effect of hydroalcoholic extract of Sphaeranthus indicus against experimentally induced anxiety, depression and convulsions in rodents

To investigate the effects of a hydroalcoholic extract of the Sphaeranthus indicus (SIE) against experimentally induced anxiety, depression and convulsions in rodents. The SIE (100, 200, 500 mg/kg, p.o.) was used in elevated plus maze, open field, forced swimming, and tail suspension tests in mice. The same doses were also used to evaluate its anticonvulsant effect on pentylenetetrazole (PTZ)-induced convulsions in mice and maximal electroshock (MES)-induced convulsions in rats. SIE was found to increase the number of entries and the time spent in the open arms of the maze at a dose of 100 mg/kg, p.o., indicating its anxiolytic activity. On the other hand, higher doses of SIE (200 and 500 mg/kg, p.o.) decreased open arm entries and time spent in the open arms of the maze in the elevated plus maze test indicating an absence of anxiolytic activity. However, this effect could have been related to a decrease in the locomotor activity of the mice and not to an anxiogenic effect, as indicated by the reduction in the total number of entries in the elevated plus maze. SIE also (at doses of 200 and 500 mg/kg, p.o.) decreased locomotor activity but did not affect emotional activity parameters in the open field test, suggesting a possible central nervous depressant activity. SIE also increased the immobility time in the forced swimming test at an oral dose of 500 mg/kg but did not significantly modify the activity in the tail suspension test. SIE protected rats against MES-induced convulsions and mice against PTZ-induced convulsions. Sphaeranthus indicus demonstrated anxiolytic, central nervous depressant, and anticonvulsant activities in rodents, thus supporting the folk medicinal use of this plant in nervous disorders.

Study of central nervous system depressant and behavioral activity of an ethanol extract of Achyranthes aspera (Agadha) in different animal models

BACKGROUND

Achyranthes aspera Linn., an indigenous herb, has been reported to have antifertility, antihyperlipidemic, antidiabetic, immunomodulatory, anticarcinogenic, diuretic, cardiotonic, analgesic anti-inflammatory, hypnotic, antifungal, antibacterial, and central antinociceptive activities.

AIMS

This study was designed to evaluate depressant effects on central nervous system (CNS) and behavioral effects of ethanol extract of A. aspera (EEAA) and to find the phytochemical responsible for these activities.

MATERIALS AND METHODS

The pharmacological assays used to study CNS depressant effect in albino mice were rota rod and actophotometer performance test. Effects on behavioral activity were studied using open field test. The extract was given intraperitoneally (i.p.) at a dose of 400 mg/kg. Diazepam (2 mg/kg body weight i.p.) was used as standard.

STATISTICAL ANALYSIS USED

Data were analyzed by using analysis of variance followed by Dunnett's test. P < 0.05 was considered significant.

RESULTS

Phytochemical screening revealed presence of triterpenoids, saponins, alkaloids (betaine, achyranthine), and steroids as major constituents. The result of this study reflected that EEAA (400 mg/kg i.p.) decreased locomotor activity, produced muscle relaxation, and showed anxiolytic activity.

CONCLUSIONS

EEAA exhibit CNS depressant and significant anxiolytic activity comparable to diazepam.