Antinociceptive effect of Russelia equisetiformis leave extracts: identification of its active constituents

A Polyphenols-Rich Extract from Moricandia sinaica Boiss. Exhibits Analgesic, Anti-Inflammatory and Antipyretic Activities In Vivo

In this study, the aerial parts of Moricandia sinaica were evaluated for their in vivo analgesic, anti-inflammatory and antipyretic activities. The analgesic activities were examined using acetic acid-induced writhing, the hot plate test and the tail flick method. The anti-inflammatory and the antipyretic activities were evaluated using carrageenan-induced paw edema in rats and brewer’s yeast-induced pyrexia in mice, respectively. The aqueous fraction of the methanol extract (MS-3) showed to be the most bioactive among the other investigated fractions. At the dose of 500 mg/kg, the fraction (MS-3) showed a significant percentage inhibition of the carrageenan-induced edema by 52.4% (p < 0.05). In addition, MS-3 exhibited a significant inhibition of acetic acid-induced writhes by 44.4% and 61.5% (p < 0.001) at 250-mg/kg and 500-mg/kg doses, respectively. At 120 min post-treatment, the rat groups treated with MS-3 displayed statistically significant reduction in rectal temperature (p < 0.001) by 1.7 °C and 2.2 °C at 250- and 500-mg/kg doses, respectively. The phytochemical composition of the fraction (MS-3) was characterized by high-performance liquid chromatography-mass spectrometry (HPLC-PDA-MS/MS). Molecular docking studies demonstrated that the polyphenols identified in MS-3 revealed good binding energy upon docking to some target proteins involved in pain response and inflammation, such as the cannabinoid receptors CB1 and CB2, the fatty acid amide hydrolase (FAAH) and the cyclooxygenase COX-1 and COX-2 enzymes. Based on the findings from the present work, it could be concluded that the aerial parts extract of M. sinaica exerts potential analgesic, anti-inflammatory and antipyretic effects in rats.

Analgesic and Antiallodynic Effects of 4-Fluoro-N-(4-Sulfamoylbenzyl) Benzene Sulfonamide in a Murine Model of Pain

INTRODUCTION

Physical, chemical, thermal injuries along with infectious diseases lead to acute pain with associated inflammation, being the primary cause of hospital visits. Moreover, neuropathic pain associated with diabetes is a serious chronic disease leading to high morbidity and poor quality of life.

OBJECTIVE

Earlier multiple sulphonamides have been reported to have an antinociceptive and antiallodynic profile. 4-Fluoro-N-(4-sulfamoylbenzyl) Benzene Sulfonamide (4-FBS), a synthetic sulfonamide with reported carbonic anhydrase inhibitory activity, was investigated for its potential effects in mice model of acute and diabetic neuropathic pain.

METHODS AND RESULTS

4-FBS was given orally (p.o.) one hour before the test and then mice were screened for antinociceptive activity by using the tail immersion test, which showed significant antinociceptive effect at both 20 and 40 mg/kg doses. To explore the possible mechanisms, thermal analgesia of 4-FBS was reversed by the 5HT3 antagonist ondansetron 1mg/kg intraperitoneally (i.p.) and by the µ receptor antagonist naloxone (1 mg/kg i.p.), implying possible involvement of serotonergic and opioidergic pathways in the analgesic effect of 4-FBS. Diabetes was induced in mice by a single dose of streptozotocin (STZ) 200 mg/kg i.p. After two weeks, animals first became hyperalgesic and progressively allodynic in the fourth week, which was evaluated through behavioral parameters like thermal and mechanical tests. 4-FBS at 20 and 40 mg/kg p.o. significantly reversed diabetes-induced hyperalgesia and allodynia at 30, 60, 90, and 120 minutes.

CONCLUSION

These findings are significant and promising while further studies are warranted to explore the exact molecular mechanism and the potential of 4-FBS in diabetic neuropathic pain.

A review on the structure and pharmacological activity of phenylethanoid glycosides

Phenylethanoid glycosides (PhGs) are compounds made of phenylethyl alcohol, caffeic acid and glycosyl moieties. The first published references about phenylethanoid glycosides concerned the isolation of echinacoside from Echinaceu ungustifolia (Asteraceae) in 1950 and verbascoside from Verbascum sinuatum (Scrophulariaceae) in 1963. Over the past 60 years, many compounds with these structural characteristics have been isolated from natural sources, and most of these compounds possess significant bioactivities, including antibacterial, antitumor, antiviral, anti-inflammatory, neuro-protective, antioxidant, hepatoprotective, and immunomodulatory activities, among others. In this review, we will summarize the phenylethanoid glycosides described in recent papers and list all the compounds that have been isolated over the past few decades. We will also attempt to present and assess recent studies about the separation, extraction, determination, and pharmacological activity of the excellent natural components, phenylethanoid glycosides.

Ethanol Extract of Blighia sapida Stem Bark Show Remarkable Prophylactic Activity in Experimental Plasmodium berghei-Infected Mice

This work explores the antiplasmodial potential of ethanol extract of Blighia sapida (Lin. Sapindaceae) in chloroquine (CQ)-resistant Plasmodium berghei (ANKA strain)-infected mice. Chloroquine-resistant (ANKA) strain of P berghei was inoculated intraperitoneally into Swiss albino mice. Mice were treated orally for 4 consecutive days, before and after inoculation (prophylactic, suppressive, and curative models) with graded doses of the plant extracts with Artemether-Lumefantrine (Coartem) as control. Prophylactically, the extract showed a remarkable activity in the chemosuppression of P berghei parasites (P < .01) ranging from 57% to 36.5% at doses of 200 to 800 mg/kg, respectively, whereas Coartem (10 mg/kg) produced 62.1% chemosuppression. No significant chemosuppression was observed in the curative and suppressive models. The plant extract appeared to be safe at the highest dose tested (5000 mg/kg) for acute toxicity, with no adverse effect on the different organs. The plant extract possesses prophylactic antimalarial activity, which supports its use in the prevention of malaria.

In vivo Antimalarial Activities of Russelia Equisetiformis in Plasmodium Berghei Infected Mice

The rising problem of resistance to most commonly used antimalarials remains a major challenge in the control of malaria suggesting the need for new antimalarial agents. This work explores the antiplasmodial potential of ethanol extract of Russelia equisetiformis in chloroquine Plasmodium berghei infected mice. Swiss albino mice were intraperitoneally infected with chloroquine-resistant P. berghei (ANKA). Experimental mice were treated for four days consecutively with graded doses of plant extracts and standard antimalarial drugs (artesunate and chloroquine) at a dose of 10 mg/kg body weight used as control. The extract showed a dose-dependent activity in the chemosuppression of P. berghei parasites by 31.6, 44.7, 48.4 and 86.5% at doses of 100, 200, 400 and 800 mg/kg, while chloroquine (10 mg/kg) and artesunate produced 59.4 and 68.4%, respectively. The extract showed a significant decrease in parasitaemia (P<0.05). The level of parasitemia and decrease in weight in all the treated groups was significantly lower (P<0.05) compared with the infected but untreated mice. The plant extract was devoid of toxicity at the highest dose tested (5000 mg/kg). The study concluded that the ethanol extract of R. equisetiformis possesses antimalarial effect, which supports the folk medicine claim of its use in the treatment of malaria.

The uniqueness and therapeutic value of natural products from West African medicinal plants, part III: least abundant compound classes

In this review, a continuation of our in-depth coverage of natural products derived from West African medicinal plants with diverse biological activities has been given.

Antiallodynic and analgesic effects of maslinic acid, a pentacyclic triterpenoid from Olea europaea

The effects of maslinic acid (1), a pentacyclic triterpenoid obtained from Olea europaea, were studied in several tests for nociception in mice. Systemic administration of 1 reduced acetic acid-induced writhing, the inflammatory phase of formalin-induced pain, and capsaicin-induced mechanical allodynia. However, it did not induce motor incoordination in the rotarod test. The topical administration of 1 also reduced the inflammatory phase of the formalin test, indicating that at least some of its effects are mediated peripherally. The present results demonstrate for the first time that maslinic acid induces antinociceptive and antiallodynic effects.

Anti-inflammatory iridoids of botanical origin

Inflammation is a manifestation of a wide range of disorders which include; arthritis, atherosclerosis, Alzheimer's disease, inflammatory bowel syndrome, physical injury and infection amongst many others. Common treatment modalities are usually nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, paracetamol, indomethacin and ibuprofen as well as corticosteroids such as prednisone. These however, may be associated with a host of side effects due to non-selectivity for cyclooxygenase (COX) enzymes involved in inflammation and those with selectivity may be highly priced. Thus, there is a continuing search for safe and effective antiinflammatory molecules from natural sources. Research has confirmed that iridoids exhibit promising anti-inflammatory activity which may be beneficial in the treatment of inflammation. Iridoids are secondary metabolites present in various plants, especially in species belonging to the Apocynaceae, Lamiaceae, Loganiaceae, Rubiaceae, Scrophulariaceae and Verbenaceae families. Many of these ethnobotanicals have an illustrious history of traditional use alluding to their use to treat inflammation. Although iridoids exhibit a wide range of pharmacological activities such as cardiovascular, hepatoprotection, hypoglycaemic, antimutagenic, antispasmodic, anti-tumour, antiviral, immunomodulation and purgative effects this review will acutely focus on their anti-inflammatory properties. The paper aims to present a summary for the most prominent iridoid-containing plants for which anti-inflammatory activity has been demonstrated in vitro and / or in vivo.

A new iridoid glycoside and NO production inhibitory activity of compounds isolated from Russelia equisetiformis

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Russelia equisetiformis, one new iridoid glucoside was isolated along with 24 known compounds, comprising iridoids and iridoid glucosides, phenyl propane glucosides, phenyl ethanoids, lignan glucosides, and flavonoid glucosides. The structure of the new compound was elucidated to be 10-O-cinnamoyl sinuatol. Of the 25 compounds isolated, rehmaglutin B exhibited moderate inhibitory activity toward NO production, which was not associated with cytotoxicity.

Free radical scavenging: a possible mechanism of action for the anti-inflammatory activity of Russelia equisetiformis (Schlect & Chan) (Scrophulariacae)

The methanol extract of Russelia equisetiformis (MRE), which exhibited significant antiinflammatory activity, was evaluated for the possible mode of action by studying its antioxidant potential in adjuvant- induced arthritic rats. 1, 1 diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect was determined by spectrophotometric method. The enzymatic activity of the superoxide dismutase, glutathione peroxidase, showed a significant increase, while the lipid peroxide content was found to decrease to a large extent in MRE and indomethacin-treated rats. There was also significant and concentration-dependent increase in the percentage inhibition of DPPH, comparable to that of vitamin E and butylated hydroxyanisole (BHA) which are natural and synthetic antioxidants, respectively. The results obtained in the present study indicate that MRE possesses free radical scavenging and antioxidant properties.