Bioassay-guided isolation of anti-inflammatory and antinociceptive principles from a folk remedy, Rhododendron ponticum L. leaves

Screening of potential bio-molecules from Moringa olifera against SARS-CoV-2 main protease using computational approaches

COVID-19 caused by SARS-CoV-2 is responsible for the deaths of millions of people worldwide. It is having devastating effects on the people of all countries. In this regard, the phytochemicals of medicinal plants could be explored to prevent this disease. M. oleifera is a miracle plant with antibacterial, antiviral, and antioxidant properties because of its high content of flavonoids, glucosides and glucosinolates. Therefore, we constructed a library of 294 phytochemicals of M. oleifera and filtered it through the FAF-Drugs4. Further, molecular docking studies of filtered phytochemicals were performed with Mpro enzyme to investigate the binding interactions. Drug likeness properties, ADMET prediction were analyzed to determine the therapeutic aspect of these compounds. Based on the binding energy score of the top 4 compounds, the results indicate that Vicenin-2 has the highest binding affinity (-8.6 kcal mol^-1) as compared to the reference molecule (-8.4 kcal mol^-1). ADMET result reveals that all top four compounds have minimal toxic effects and good absorption. Further, 500 ns molecular dynamics simulation of the top four compounds showed that Kaempferol-3-O-rutinoside and Vitexin have good stability with Mpro. These two compounds were then subjected for MMPBSA (last 50 ns) calculation to analyze the protein-ligand stability and dynamic behavior. Kaempferol-3-O-rutinoside and Vitexin showed very good binding free energy i.e. -40.136 kJ mol^-1 and -26.784 kJ mol^-1, respectively. Promising outcomes from MD simulations evidence the worth of these compounds for future drug development to combat coronavirus disease.Communicated by Ramaswamy H. Sarma.

Bioassay-Guided Interpretation of Antimicrobial Compounds in Kumu, a TCM Preparation From Picrasma quassioides' Stem via UHPLC-Orbitrap-Ion Trap Mass Spectrometry Combined With Fragmentation and Retention Time Calculation

The stem of Picrasma quassioides (PQ) was recorded as a prominent traditional Chinese medicine, Kumu, which was effective for microbial infection, inflammation, fever, and dysentery, etc. At present, Kumu is widely used in China to develop different medicines, even as injection (Kumu zhusheye), for combating infections. However, the chemical basis of its antimicrobial activity has still not been elucidated. To examine the active chemicals, its stem was extracted to perform bioassay-guided purification against Staphylococcus aureus and Escherichia coli. In this study, two types of columns (normal and reverse-phase) were used for speedy bioassay-guided isolation from Kumu, and the active peaks were collected and identified via an UHPLC-Orbitrap-Ion Trap Mass Spectrometer, combined with MS Fragmenter and ChromGenius. For identification, the COCONUT Database (largest database of natural products) and a manually built PQ database were used, in combination with prediction and calculation of mass fragmentation and retention time to better infer their structures, especially for isomers. Moreover, three standards were analyzed under different conditions for developing and validating the MS method. A total of 25 active compounds were identified, including 24 alkaloids and 1 triterpenoid against S. aureus, whereas only β-carboline-1-carboxylic acid and picrasidine S were active against E. coli. Here, the good antimicrobial activity of 18 chemicals was reported for the first time. Furthermore, the spectrum of three abundant β-carbolines was assessed via their IC₅₀ and MBC against various human pathogens. All of them exhibited strong antimicrobial activities with good potential to be developed as antibiotics. This study clearly showed the antimicrobial chemical basis of Kumu, and the results demonstrated that HRMS coupled with MS Fragmenter and ChromGenius was a powerful tool for compound analysis, which can be used for other complex samples. Beta-carbolines reported here are important lead compounds in antibiotic discovery.

Antinociceptive Activity of Compounds from the Aqueous Extract of Melampodium divaricatum

A decoction prepared from the aerial parts of Melampodium divaricatum showed antinociceptive and antihyperalgesic responses when tested in the formalin model in mice. From the CH₂ Cl₂ fraction of the decoction, two non-previously reported secondary metabolites, 3-O-β-D-glucopyranosyl-16α-hydroxy-ent-kaurane (1) and melampodiamide (2) [(2'R*,4'Z)-2'-hydroxy-N-[(2S*,3S*,4R*)-1,3,4-trihydroxyoctadec-2-yl]tetracos-4-enamide] were separated and characterized by spectroscopic, spectrometric, and computational techniques. The flavonoids isoquercitrin and hyperoside, which possessed noted antinociceptive properties, were obtained from the active AcOEt fraction of the decoction. The chemical composition of the essential oil of the plant was also analyzed by gas chromatography-mass spectrometry. The major constituents were (E)-caryophyllene, germacrene D, β-elemene, δ-elemene, γ-patchoulene, and 7-epi-α-selinene. Headspace solid-phase microextraction analysis detected (E)-caryophyllene as the main volatile compound of the plant.

Effect of Argemone mexicana on Local Edema and LPS-Induced Neuroinflammation

Argemone mexicana L. is a widely used plant in Mexican traditional medicine to treat inflammatory and nervous medical conditions. It has been subjected to several pharmacological and chemical studies in which acute anti-inflammatory activity is indicated. This work aimed at finding an extract and fraction with anti-inflammatory activity by means of 2-O-tetradecanoylphorbol-13-acetate (TPA)-induced auricular edema. Afterward, the extract and the fraction were tested on neuroinflammation caused by lipopolysaccharides (LPS). Treatments obtained from A. mexicana included the methanolic extract (AmMeOH), a fraction extracted with ethyl acetate (AmAcOEt), and four sub-fractions (AmF-1 to AmF-4), which were evaluated in auricular edema with the TPA assay. Both treatments with the most significant inhibitory effect were employed to test these in the LPS neuroinflammation model. AmAcOEt and AmF-3 induced a higher inhibition of edema (%), and both diminished ear inflammation when viewed under a microscope. These treatments also raised an increase in spleen, but not in brain of mice with neuroinflammation. They were able to decrease the concentration of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) in both organs. Furthermore, the accumulation of amyloid-β (Aβ) in hippocampus was not visible. AmF-3 contains the flavonoids isoquercetin, luteolin, and rutin, the former being the most concentrated.

Multiple Biological Activities of Rhododendron przewalskii Maxim. Extracts and UPLC-ESI-Q-TOF/MS Characterization of Their Phytochemical Composition

Backgroud:Rhododendron przewalskii Maxim. is an evergreen shrub that is used as a traditional medicine in China. However, the modern pharmacology and the chemical components of this plant has not been studied. In this paper, we aimed to investigate the antifungal, anti-inflammatory and antioxidant activities and underlying mechanism of its aqueous and ethanol extracts, and analyze their chemical composition and active compounds of R. przewalskii.

Methods: The antifungal activity was determined in vitro, and anti-inflammatory and antioxidant activities and underlying mechanism of its aqueous and ethanol extracts were evaluated in vitro and in RAW 264.7 cells. The chemical composition were analyzed using UPLC-ESI-Q-TOF/MS, and the contents of six compounds were determined via HPLC.

Results: Both extracts of R. przewalskii showed promising anti-inflammatory activity in vitro; decreased the production of four inflammatory cytokines, namely, nitric oxide, IL-1β, IL-6 and TNF-ɑ, in RAW 264.7 cells induced by lipopolysaccharide; and exhibited weak cytotoxicity. The extracts significantly scavenged DPPH radicals, superoxide radicals and hydroxyl radicals to exert antioxidant effects in vitro. The two extracts also exhibited cellular antioxidant activity by increasing superoxide dismutase and CAT activities and decreasing malondialdehyde content in RAW 264.7 cells induced by LPS. However, the antifungal activity of the two extracts was weak. Nine flavonoids were identified by UPLC-ESI-Q-TOF/MS. Of these, six compounds were analyzed quantitatively, including avicularin, quercetin, azaleatin, astragalin and kaempferol, and five compounds (myricetin 3-O-galactoside, paeoniflorin, astragalin, azaleatin and kaempferol) were found in this species for the first time. These compounds demonstrated antioxidant activities that were similar to those of the R. przewalskii extracts and were thought to be the active compounds in the extracts.

Conclusion:R. przewalskii extracts presented promising anti-inflammatory and antioxidant activities. The extracts contained amounts of valuable flavonoids (8.98 mg/g fresh material) that were likely the active compounds in the extract contributing to the potential antioxidant activity. These results highlight the potential of R. przewalskii as a source of natural antioxidant and anti-inflammatory agents for the pharmaceutical industry.

Influence of Accelerated Solvent Extraction Conditions on the LC-ESI-MS/MS Polyphenolic Profile, Triterpenoid Content, and Antioxidant and Anti-lipoxygenase Activity of Rhododendron luteum Sweet Leaves

Evaluation of native plant resources and their efficient use is one of the current trends in phytochemistry. The main aim of the present study was to investigate the biological activities of different Rhododendron luteum Sweet leaf extracts obtained with the use of accelerated solvent extraction using different solvents and extraction temperatures. All extracts were subjected to bioactivity assays, which revealed considerable anti-lipoxygenase (23.07-90.13% lipoxygenase inhibition) and antiradical potential. All samples exhibited high 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) (234.18-621.90 mg Trolox equivalents (TE)/g) and 2,2'-azino-bis-3(ethylbenzthiazoline-6-sulphonic acid) (ABTS^•+) (88.79-349.41 mg TE/g) scavenging activity, high antioxidant potential in the Oxygen Radical Absorbance Capacity (ORAC) assay (495.77-1011.59 mg TE/g), and moderate ion chelating (Fe2+) capacity. The chemical profile of each sample was determined using liquid chromatography/electrospray ionization triple quadrupole mass spectrometry (LC-ESI-MS/MS) and spectrophotometric procedures. Twenty-three compounds representing seven polyphenol subclasses were detected and quantified, including some phenolic acids and flavonoids that had not been previously reported for this plant material. It was shown that 5-O-caffeoylquinic acid, protocatechuic acid, catechin, quercetin and its glycosides (hyperoside, isoquercetin, quercitrin), and pentacyclic triterpenes were the dominant secondary metabolites in R. luteum leaves. The antioxidant activity was found to be strongly related to different polyphenol groups and total triterpene content, while the anti-lipoxygenase potential was highly dependent on catechin.

Determination of the dose-dependent toxic effects of mad honey on mouse liver using ATR-FTIR spectroscopy

Mad honey (MH) is obtained from Rhododendron plants, which are extensively grown in some regions of the world such as Europe, North America, Tropical Asia and Turkey. Although it has been known that MH induces adverse effects in the body due to grayanotoxin (GTX) in it, it is widely used for some medical purposes by the public. In this study, the effects of MH (25, 50 and 75 mg/kg) and GTX-III (0.01 mg/kg), which is the pure form of the most toxic type of the GTXs in MH, were investigated on the mouse liver at molecular level via Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. The results showed that 25 and 50 mg/kg of MH didn't cause any significant alterations in the liver tissue except a decrease in the glycogen amount. However, significant differences were observed between 75 mg/kg MH and GTX-III treated groups and control group. For example, the amounts of saturated lipids, nucleic acids and proteins increased in the 75 mg/kg MH and GTX-III treated groups. A decrease in the ratios of unsaturated/saturated lipid, CH₂/lipid and carbonyl/lipid and an increase in the ratio of CH₃/lipid were observed after the administration of 75 mg/kg MH and GTX-III, all of which may be a consequence of lipid peroxidation. Moreover, 75 mg/kg MH and GTX-III caused a decrease in the membrane order, an increase in the membrane fluidity and some important changes on the secondary structure of proteins indicating protein denaturation. In addition, Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) confirmed these findings. These results revealed that MH induces significant dose-dependent toxic effects in the structure and function of the liver tissue. This study also showed that ATR-FTIR spectroscopy provides a rapid and sensitive monitoring of the changes induced by a toxic compound on biological tissues at molecular level.

The cardiotoxic effects of acute and chronic grayanotoxin-III in rats

The purpose of this study is to histologically and immunohistochemically determine the changes created by grayanotoxin-III (GTX-III), which is a sodium channel neurotoxin, on heart tissues in different dosages. Rats were randomly divided into 10 groups to determine the acute and chronic effects of GTX-III. While the rats in groups 1 and 6 were control rats, the rats in groups 2–5 (1, 2, 4, and 8 μg/kg bw GTX-III) received a single dose of intraperitoneal GTX-III, and the rats in groups 7–10 received GTX-III every day for 3 weeks. As a result of the trial, in the heart tissues, histopathological changes were determined by hematoxylin–eosin staining, interleukin-1 (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and brain natriuretic peptide (BNP) were determined by the avidin–biotin peroxidase method, and apoptosis was examined by immunohistochemistry (IHC) analysis and the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining method. In the immunohistochemistry sense, while the BNP level in the AGTX-III groups did not vary significantly, an increase in dosage significantly increased the IL-6, IL-1β, and TNF-α levels in comparison to the control groups. In their comparison to the control groups, the BNP levels increase and the IL-6 and IL-1β levels decreased in the CGTX-III groups. TUNEL analysis revealed that apoptosis increased in both the acute and chronic groups.

Rhododendron Molle (Ericaceae): phytochemistry, pharmacology, and toxicology

Rhododendron molle G. Don, belonging to the Ericaceae family, is a traditional Chinese medicinal plant with a wide spectrum of pharmacological effects. This paper aimed to review the phytochemistry, pharmacology and toxicology of R. molle, and to discuss the tendency of future investigations on this plant. A systematic review of literature about R. molle was carried out using resources including classic books about Chinese herbal medicine, and scientific data bases including CNKI, Pubmed, SciFinder, Scopus, and Web of Science. Over 67 compounds, including diterpenes, triterpenes, flavonoids, and lignans, had been extracted and identified from R. molle. The extracts/monomers isolated from the root, flower and fruits of this plant were used as effective agents for treating pains, inflammatory diseases, hypertension, and pest, etc. In addition, diterpenes, such as rhodojaponin III, were considered as the toxic agents associated with the toxicities of this plant. These findings will be significant for the discovery of new drugs from this plant and full utilization of R. molle.

Depressor effect of the young leaves of Polygonum hydropiper Linn. in high-salt induced hypertensive mice

A novel chymase inhibitor has been reported to have depressor effect in salt-induced hypertension. Therefore, we examined the hypothesis that chymase inhibitory dried young leaves of Polygonum hydropiper (PPH) or young leaves extract of Polygonum hydropiper (PHE) could reduce salt-induced hypertension. In this study, 8-wk old wild-type mice were allocated into three experiments and experiment I included groups, I- normal water drinking, II- high salt (2% NaCl) water (HSW) drinking, and III- HSW plus PPH (500 mg kg^-1, orally) for 12-wk. Blood pressure (BP) and heart rate (HR) were measured at baseline and weekly up to wk-12. In experiment II, mice were given HSW for 12-wk followed by 8-wk treatment with PPH plus HSW (62.5, 125, 250 and 500 mg kg^-1 for groups I, II, III and IV, respectively). BP and HR were measured at baseline and monthly until wk-12, following weekly for 8-wk. Experiment III comprised of four groups of mice for 12-wk HSW and 8-wk treatment with PHE plus HSW (2.5, 5, 10 and 20 mg kg^-1 for groups I-IV, respectively). BP and HR were measured at baseline and monthly up to wk-12, following weekly for 8-wk. Significant reduction in BP and HR were observed in mice treated with PPH (500 mg kg^-1) compared to HSW control. PPH reduced BP and HR dose dependently in hypertensive mice and the higher dose showed maximum reduction. PHE at its maximum dose (20 mg kg^-1) significantly suppressed BP and HR. Over all, we found that the young leaves of Polygonum hydropiper suppressed salt-induced hypertension.

Mad honey: uses, intoxicating/poisoning effects, diagnosis, and treatment

Honey has been used as a folk medicine since 2100 BC; however, mad honey is different from normal natural or commercially available honey as it is contaminated with grayanotoxins, which leads to intoxication/poisoning upon consumption. Grayanotoxin is generally found in Rhododendron genus (family: Ericaceae) and is extracted by bees from nectar and pollens of flowers. Mad honey has been commonly used as an aphrodisiac (sexual stimulant), in alternative therapy for gastrointestinal disorders (peptic ulcer disease, dyspepsia, and gastritis), and for hypertension for a long time. Grayanotoxin acts on sodium ion channels and muscarinic receptors, leading to cardiac disorders (hypotension and different rhythm disorders including bradycardia, bradydysrhythmias, atrial fibrillation, nodal rhythm, atrioventricular block, and complete atrioventricular block) and respiratory depression. Patients may also exhibit any one symptom out of or combination of dizziness, blurred vision, diplopia, nausea, vomiting, vertigo, headache, sweating/excessive perspiration, extremity paresthesia, impaired consciousness, convulsion, hypersalivation, ataxia, inability to stand, and general weakness. Mad honey intoxication is diagnosed with honey intake history before the appearance of the signs and symptoms (clinical presentation), and the treatment is symptomatic. Prompt treatment includes intravenous infusions of atropine sulfate and fluids (saline infusions or simultaneous infusion of saline with atropine sulfate) if the patient presents bradycardia and severe hypotension. In case of a complete atrioventricular block, a temporary pacemaker is employed. Except for a single case from Lanping County (Southwest China), the prognosis for mad honey intoxication is very good, and no fatalities have been reported in modern medical literature excluding a few in the 1800s. Although fatalities are very rare, mad honey ingestion may still lead to arrhythmias, which can be life-threatening and hard to recognize. This article provides a brief introduction to honey, mad honey and its uses, the effects of mad honey intoxication/poisoning, and its diagnosis, prognosis, and treatment.

Honey has been used as a folk medicine since 2100 BC; however, mad honey is different from normal natural or commercially available honey as it is contaminated with grayanotoxins, which leads to intoxication/poisoning upon consumption.

Evaluation of the effect of Elaeagnus angustifolia alone and combined with Boswellia thurifera compared with ibuprofen in patients with knee osteoarthritis: a randomized double-blind controlled clinical trial

Osteoarthritis (OA) is one of the most common articular disorders. Many patients do not respond to acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs), the mainstay of pharmacotherapy for knee OA. The plants Elaeagnus angustifolia and Boswellia thurifera have anti-inflammatory and analgesic properties. This study aimed to evaluate the effect of E. angustifolia alone and in combination with B. thurifera compared with ibuprofen in patients with knee osteoarthritis. In a randomized double-blind controlled clinical trial, 75 patients with knee OA were randomly and equally assigned to one of three groups Elaeagnus (n = 23), Elaeagnus/Boswellia (n = 26), and ibuprofen (n = 26) to receive the capsules of Elaeagnus, Elaeagnus/Boswellia, and ibuprofen, respectively, three times daily with meals for 4 weeks. Pain severity based on VAS (visual analog scale, 0 to 10 scale) and the scores of LPFI (Lequesne Pain and Function Index) and PGA (patient global assessment) were determined pre- and post-intervention for all patients. All interventions had significant lowering effects on VAS, LPFI, and PGA scores (P < 0.001 for all parameters) with no significant difference between groups in terms of effects on all evaluated parameters. Consumption of E. angustifolia fruit extract either alone or in combination with Boswellia oleo-gum resin extract could decrease pain and improve function in patients with knee osteoarthritis comparable to ibuprofen.

Antihyperalgesic activity of Filipendula ulmaria (L.) Maxim. and Filipendula vulgaris Moench in a rat model of inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Meadowsweet (Filipendula ulmaria (L.) Maxim.), and dropwort (Filipendula vulgaris Moench) flowers are traditionally used to treat various ailments, including inflammatory conditions. The aim of the present study was to validate the aforementioned ethnomedicinal claim by assessing antihyperalgesic and antiedematous activities and toxicity of orally administered lyophilized flower infusions (LFIs) of F. ulmaria and F. vulgaris in experimental animals.

MATERIALS AND METHODS

The phytochemical analysis of LFIs was performed by HPLC-DAD. Antihyperalgesic and antiedematous activities were estimated in a rat model of inflammation induced by intraplantar injection of carrageenan using Von Frey anesthesiometer and plethysmometer, respectively. Moreover, acute oral toxicity of LFIs in mice was evaluated by observing changes in animal behavior and mortality for a period of 14 days following the treatment.

RESULTS

HPLC-DAD analysis revealed the presence of phenolic acids and flavonoids in LFIs, among which spiraeoside was identified as the principal component (56.27±1.03 and 55.67±1.82mg/g of LFI in F. ulmaria and F. vulgaris, respectively). The LFIs of F. ulmaria and F. vulgaris (100-300mg/kg; p.o.) produced significant and dose-dependent antihyperalgesic effects: ED₅₀±SEM values were 164.8±15.4mg/kg (110.3-246.3mg/kg) and 172.2±6.2mg/kg (147.4-201.3mg/kg) for F. ulmaria and F. vulgaris, respectively. On the other hand, LFIs of both species (100-300mg/kg; p.o.) did not significantly reduce edema. Good safety profiles were evidenced in the toxicological study. The median lethal dose (LD₅₀) of the tested extracts is likely to be greater than 2000mg/kg.

CONCLUSION

The results of the present study support the use of F. ulmaria and F. vulgaris flowers in folk medicine for relieving pain in diseases with an inflammatory component.

Anti-inflammatory Effects of Compounds from Polygonum odoratum

Polygonum odoratum is an edible plant traditionally used as an antidiabetic, antimicrobial, anti-inflammatory, and antitumor agent in Asia. The aim of the study was to evaluate the anti-inflammatory effect of P. odoratum and the isolation and characterization of its main fractions. Extracts of the aerial parts were tested for anti-inflammatory activity as indicated by a change in the cytokine secretion in lipopolysaccharide-stimulated macrophages. After separation of the extract by reversed-phase high-performance liquid chromatography, the anti-inflammatory activity of the fractions was determined. Furthermore, the two main fractions were identified by nuclear magnetic resonance spectroscopy (1H- and 13C-NMR). The ethanolic extract significantly reduced IL-6 secretion (IC50 25 μg/mL). The two main fractions (5 and 7) significantly decreased IL-6 production with an IC50 of 102 μM (5) and 77 μM (7), respectively, and were identified as scutellarein-7-glucoside (5) and quercitrin (7). Since inflammation plays a major role in various diseases with high prevalence globally, it may be of importance that P. odoratum and its main constituents scutellarein-7-glucoside and quercitrin can be used as either an alternative or complementary treatment. Additionally, both are glycosides and their activity may be enhanced tremendously by deglycosylation by the gut microbiota.

Acute effects of grayanotoxin in rhododendron honey on kidney functions in rats

The aim of the study is to evaluate the acute biochemical and histological changes in rat kidneys after treatment with grayanotoxin (GTX) of rhododendron honey (RH). A total of 60 Sprague-Dawley female rats were divided into five groups of 12 rats each, one being a control group (group 1) and group 2 was treated with 0.015 mg/kg/bw of GTX standard preparation via intraperitoneal injection. Groups 3, 4, and 5 were given RH at doses of 0.1, 0.5, and 2.5 g/kg/bw, respectively, via oral gavage. Compared to the control group, significant increases were observed in glucose, blood urea nitrogen (BUN), and creatinine levels of the GTX-injected groups after 1 h. However, in low dose RH group, such an increase was not observed and had a normal appearance histologically. Therefore, low dose (1 g/kg/bw) of RH produces no acute adverse effects on renal functions of rats.

Antinociceptive and Anti-Inflammatory Activities of Teucrium persicum Boiss. Extract in Mice

Background. Therapeutic properties of Teucrium species as antioxidant, antibacterial, analgesic, anticancer, diuretic, and tonic compounds have been proved earlier. Materials and Methods. In this study, the antinociceptive and anti-inflammatory effects of the aqueous extract of Teucrium persicum on chronic pain, sciatic nerve ligation as a model of neuropathic pain, and inflammatory models were investigated by formalin, hot-plate, and cotton pellet-induced granuloma models in mice, respectively. T. persicum aqueous extracts (100, 200, and 400 mg/kg) were orally gavaged for one week. On 8th day, the time spent and the number of lickings were recorded in formalin test. Morphine and Diclofenac were used intraperitoneally as positive controls. In sciatic nerve ligated animals, as a model of neuropathic pain, doses (100, 200, and 400 mg/kg) of T. persicum extract (TPE) were orally gavaged for 14 consecutive days. The analgesic effect of this extract was examined 14 days after sciatic nerve ligation using the hot-plate test. Controls received saline and Imipramine (40 mg/kg, i.p.) was used a positive control for neuropathic pain model. Results. In the formalin test, a week oral gavage of all TPE doses (100, 200, and 400 mg/kg) caused a significant decrease on the licking response compared to the control negative animals. In the hot-plate test, doses of 200 and 400 mg/kg showed significant analgesic effects in sciatic nerve ligated animals. Oral gavaged of TPE revealed significant analgesic effect on chronic pain in both formalin test and sciatic nerve ligated animals. The TPEs did not have any significant anti-inflammatory effects in cotton pellet-induced granuloma formation in mice. Conclusions. These results suggest that the aqueous extract from T. persicum Boiss. produced antinociceptive effects. Its exact mechanism of action still remains indistinct.

Topical anti-inflammatory effects of isorhamnetin glycosides isolated from Opuntia ficus-indica

Opuntia ficus-indica (OFI) has been widely used in Mexico as a food and for the treatment of different health disorders such as inflammation and skin aging. Its biological properties have been attributed to different phytochemicals such as the isorhamnetin glycosides which are the most abundant flavonoids. Moreover, these compounds are considered a chemotaxonomic characteristic of OFI species. The aim of this study was to evaluate the effect of OFI extract and its isorhamnetin glycosides on different inflammatory markers in vitro and in vivo. OFI extract was obtained by alkaline hydrolysis of OFI cladodes powder and pure compounds were obtained by preparative chromatography. Nitric oxide (NO), cyclooxygenase-2 (COX-2), tumor necrosis factor- (TNF-) α, and interleukin- (IL-) 6 production were measured. NO production was tested in lipopolysaccharide-stimulated RAW 264.7 cells while in vivo studies were carried on croton oil-induced ear edema model. OFI extract and diglycoside isorhamnetin-glucosyl-rhamnoside (IGR) at 125 ng/mL suppressed the NO production in vitro (73.5 ± 4.8% and 68.7 ± 5.0%, resp.) without affecting cell viability. Likewise, IGR inhibited the ear edema (77.4 ± 5.7%) equating the indomethacin effects (69.5 ± 5.3%). Both IGR and OFI extract significantly inhibited the COX-2, TNF-α, and IL-6 production. IGR seems to be a suitable natural compound for development of new anti-inflammatory ingredient.

Analgesic and anti-inflammatory activities of leaf extract of Mallotus repandus (Willd.) Muell. Arg

In folk medicine Mallotus repandus (Willd.) Muell. Arg. is used to treat muscle pain, itching, fever, rheumatic arthritis, snake bite, hepatitis, and liver cirrhosis. This study aimed to evaluate the antinociceptive as well as the anti-inflammatory activities of the methanol extract of leaf. The leaves were extracted with methanol following hot extraction and tested for the presence of phytochemical constituents. Analgesic and anti-inflammatory activities were evaluated using acetic acid induced writhing test, xylene induced ear edema, cotton pellet induced granuloma, and tail immersion methods at doses of 500, 1000, and 2000 mg/kg body weight. The presence of flavonoids, saponins, and tannins was identified in the extract. The extract exhibited considerable antinociceptive and anti-inflammatory activities against four classical models of pain. In acetic acid induced writhing, xylene induced ear edema, and cotton pellet granuloma models, the extract revealed dose dependent activity. Additionally, it increased latency time in tail immersion model. It can be concluded that M. repandus possesses significant antinociceptive potential. These findings suggest that this plant can be used as a potential source of new antinociceptive and anti-inflammatory candidates. The activity of methanol extract is most likely mediated through central and peripheral inhibitory mechanisms. This study justified the traditional use of leaf part of this plant.

Analysis of grayanatoxin in Rhododendron honey and effect on antioxidant parameters in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Rhododendron honey, locally known as "mad honey", contains gryanotoksin (GTX) and thus induces toxic effects when consumed in large amounts. But, it is still popularly used for treating medical conditions such as high blood pressure or gastro-intestinal disorders. The aim of this study was to evaluate the effect of GTX on antioxidant parameters measured from rats fed with Rhododendron honey.

MATERIAL AND METHODS

A total of sixty Sprague-Dawley female rats were divided into five groups of 12 rats each, one being the control group (Group 1) and the others being the experimental groups (Groups 2 to 5). Group 2 was treated with 0.015 mg/kg/bw of Grayanotoxin-III (GTX-III) standard preparation via intraperitoneal injection. Groups 3, 4 and 5 were respectively given Rhododendron honey (RH) at doses of 0.1, 0.5, and 2.5 g/kg/bw via oral gavage. After one hour, blood samples were collected from the rats. Glutathione peroxidase (GSh-Px), superoxide dismutase (SOD), catalase (CAT) activities and malondialdehyde (MDA) contents were examined in blood, heart, lungs, liver, kidney, testicles, epididiymis, spleen and brain specimens.

RESULTS

The data from the rats in Groups 2 (GTX) and 5 (RH at 2.5 g/kg/bw) showed negative effect on the antioxidants parameters in blood and all tissue samples examined at the specified doses and time period. Administration of GTX to rats at dose of 0.015 mg/kg/bw resulted in lipid peroxidation. (This part needs to be enhanced more).

CONCLUSION

It has been observed that both Grayanotoxin and high dose Rhododendron honey treatments showed oxidant effect on blood plasma and organ tissues investigated.

Chemical composition and antinociceptive effect of aqueous extract from Rourea induta Planch. leaves in acute and chronic pain models

ETHNOPHARMACOLOGICAL RELEVANCE

Rourea induta Planch. is a small tree or shrub growing wild in Brazil and belonging to the Connaraceae family. It is used for the treatment of Chagas disease and as antirheumatic in folk medicine. This study was designed to investigate the antinociceptive activity of the aqueous extract (AERi) of Rourea induta leaves in rodents, as well as isolate and identify components that can be responsible for its effect.

MATERIAL AND METHODS

The antinociceptive effect of orally administered AERi was evaluated in behavioral models of acute (formalin) and chronic [complete Freund׳s adjuvant (CFA)] pain in mice. We also investigated the possible involvement of opioid receptors and proinflammatory cytokines (interleukin-1β and tumor necrosis factor-α) in the antinociceptive effect of the AERi. In addition, a nonspecific effect of AERi was evaluated by measuring locomotor activity and corporal temperature. Finally, we performed a phytochemical analysis of AERi.

RESULTS

HPLC titration revealed the presence of hyperin (21.6 mg/g), quercetin-3-O-β-xyloside (4.4 mg/g), quercetin-3-O-α-arabinofuranoside (12.0 mg/g), and quercetin (2.1 mg/g). It was also possible to isolate minor constituents׳ chlorogenic acid, neochlorogenic acid and procyanidin C1. The oral administration of AERi (100 mg/kg) significantly inhibited the neurogenic (37 ± 5%) and inflammatory (34 ± 7%) phases of formalin-induced pain. Acute and repeated treatment of animals with AERi (100 mg/kg, p.o.) once a day markedly reduced the mechanical hypersensitivity response induced by CFA, and this effect was evident until the day 10. Moreover, repeated treatment with AERi (100 mg/kg, p.o.) significantly reduced the levels of IL-1β and TNF-α in the paw (22 ± 7% and 50 ± 19%) and in the spinal cord (100% and 100%) when compared to the CFA group. The AERi (100 mg/kg, p.o.) markedly reduced biting behavior induced by intrathecal injection of TNF-α (81 ± 11%). Finally, the effect of AERi was not associated with changes in locomotor activity or the corporal temperature of animals.

CONCLUSION

These data show that aqueous extract of Rourea induta has significant antinociceptive action, which seems to be associated with an inhibition of pro-inflammatory cytokines activated pathways. These findings support the ethnomedical uses of this plant.

Antihyperglycemic and antinociceptive activity evaluation of 'khoyer' prepared from boiling the wood of Acacia catechu in water

'Khoyer' is prepared by boiling the wood of Acacia catechu in water and then evaporating the resultant brew. The resultant hard material is powdered and chewed with betel leaves and lime with or without tobacco by a large number of the people of Bangladesh as an addictive psycho-stimulating and euphoria-inducing formulation. There are folk medicinal claims that khoyer helps in the relief of pain and is also useful to diabetic patients to maintain normal sugar levels. Thus far no scientific studies have evaluated the antihyperglycemic and antinociceptive effects of khoyer. The present study was carried out to evaluate the possible glucose tolerance efficacy of methanolic extracts of khoyer using glucose-induced hyperglycemic mice, and antinociceptive effects with acetic acid-induced gastric pain models in mice. In antihyperglycemic activity tests, the extract at different doses was administered one hour prior to glucose administration and blood glucose level was measured after two hours of glucose administration (p.o.) using glucose oxidase method. The statistical data indicated the significant oral hypoglycemic activity on glucose-loaded mice at all doses of the extracts tested. Maximum anti-hyperglycemic activity was shown at 400 mg extract per kg body weight, which was less than that of a standard drug, glibenclamide (10 mg/kg body weight). In antinociceptive activity tests, the extract also demonstrated a dose-dependent significant reduction in the number of writhing induced in mice through intraperitoneal administration of acetic acid. Maximum antinociceptive activity was observed at a dose of 400 mg extract per kg body weight, which was greater than that of a standard antinociceptive drug, aspirin, when administered at a dose of 400 mg per kg body weight. The results validate the folk medicinal use of the plant for reduction of blood sugar in diabetic patients, as well as the folk medicinal use for alleviation of pain.

The genus Rhododendron: an ethnopharmacological and toxicological review

ETHNOPHARMACOLOGICAL RELEVANCE

The vast genus Rhododendron includes species that have been used in traditional medicine for the treatment of inflammatory conditions, pain, gastro-intestinal disorders, common cold, asthma, skin disease, etc. Rhododendrons are also well known for their toxicity and some species have been traditionally used as poison.

AIM OF THE REVIEW

The work reviews and analyses the traditional use, biological activities with the corresponding chemical constituents, and toxicological data on Rhododendron species. The review aims at characterizing the ethnopharmacology of the genus in relation to its toxicity in order to identify the therapeutic potential of Rhododendron species and future directions for research.

METHODS

Data regarding Rhododendron spp. was collected using electronic databases (SciFinder, PubMed, Google Scholar) and library search for selected peer-reviewed articles. Plant taxonomy was validated by the databases The Plant List, Tropicos, eFloras, Flora Iberica and Flora Europaea (RBGE). Additional information on traditional use and botany was obtained from published books. The review encompasses literature, mainly regarding biological activity and toxicological data, from 1898 to the end of December 2012.

RESULTS

Rhododendrons have been used in Asian, North American and European traditional medicine mainly against inflammation, pain, skin ailments, common cold and gastro-intestinal disorders. In vivo and in vitro testing of plant extracts and isolated compounds determined diverse biological activities including anti-inflammatory, analgesic, anti-microbial, anti-diabetic, insecticidal and cytotoxic activity. Rhododendron spp. can cause intoxications in humans following intake of rhododendron honey or medicinal preparations. The toxicity is due to grayanotoxins, diterpenes which activate voltage-gated sodium channels and lead to gastro-intestinal, cardiac and central nervous system symptoms.

CONCLUSION

Rhododendron species are useful traditional remedies for the treatment of inflammation, pain, skin ailments, common cold and gastro-intestinal disorders. Pharmacological data has validated most indications of rhododendrons in ethnomedicine and toxicology studies have confirmed the toxicity observed by traditional use. Ethnopharmacological data point to the therapeutic potential of the genus Rhododendron for the treatment of inflammatory conditions and pain and, thus, research should focus on identification of active compounds and related mechanistic studies. Prolonged and high dose intake of traditional formulations containing rhododendrons should be avoided until more in depth toxicity studies become available.

Identification and characterization of proanthocyanidins of 16 members of the Rhododendron genus (Ericaceae) by tandem LC-MS

The proanthocyanidins of the leaves of 16 taxa of the Rhododendron genus (Ericaceae) [Rhododendron 'Catawbiense Grandiflorum', Rhododendron 'Cunningham's White', Rhododendron smirnowii Trautv., Rhododendron calophytum Franch., Rhododendron dichroanthum ssp. scyphocalyx (Balf. f. & Forrest ) Cowan, Rhododendron micranthum Turcz., Rhododendron praevernum Hutch., Rhododendron ungernii Trautv., Rhododendron kaempferi Planch., Rhododendron degronianum ssp. heptamerum var. hondoense (Nakai ) H. Hara, Rhododendron fortunei Lindl., Rhododendron ponticum L., Rhododendron galactinum Balf. f. ex Tagg., Rhododendron oreotrephes W. W. Sm., Rhododendron brachycarpum ssp. brachycarpum D. Don ex G. Don, and Rhododendron insigne Hemsl. & E. H. Wilson ] were investigated qualitatively by liquid chromatography-mass spectrometry in series. Twenty-nine dimeric proanthocyanidins based on (epi)catechin and (epi)gallocatechin were detected and characterized on the basis of their unique fragmentation pattern in the negative ion mode tandem mass spectrometry spectra. All of them were extracted for the first time from these sources, and ten of them were not reported previously in nature. The position of the galloyl residue was assigned on the basis of the retro-Diels-Alder fragmentation and the dehydrated retro-Diels-Alder fragmentation; it resulted from the loss of gallic acid as a neutral loss in the negative ion mode. Furthermore, four caffeoylquinic acids, six p-coumaroylquinic acids, epigallocatechin, gallocatechin, catechin, epicatechin, epigallocatechin gallate, catechin gallate, epicatechin gallate, gallocatechin gallate, two quercetin-O-hexosides, quercetin-O-galloyl-hexoside, quercetin-O-pentoside, quercetin-O-rhamnoside, quercetin-O-pentoside-O-hexoside, quercetin-O-rhamnoside-O-hexoside, quercetin-O-feruloyl-hexoside, quercetin-O-(p-hydroxy)benzoyl-hexoside, taxifolin-O-pentoside, myricetin-O-rhamnoside, two myricetin-O-pentosides, three myricetin-O-hexosides, and two myricetin-O-galloyl-hexosides were detected and shown to possess characteristic tandem mass spectrometry spectra and were tentatively assigned on the basis of their retention time.

Anti-inflammatory and analgesic properties of the ethanolic extract of Cnidoscolus aconitifolius in rats and mice

BACKGROUND

Ethanolic leaf extract of Cnidoscolus aconitifolius was evaluated for analgesic and anti-inflammatory activities.

METHODS

The analgesic activity of the extract was assayed by the formalin-induced paw licking test, acetic acid-induced abdominal writhing and hot plate test, whereas its anti-inflammatory activity was determined by its effects on carrageenan-induced paw edema.

RESULTS

The extract of C. aconitifolius prolonged the reaction time of mice to pain in a dose-dependent manner. The optimal analgesic effect of the extract was obtained when the extract was administered 90 min before pain stimulation in the hot plate test. The extract of C. aconitifolius (100 or 200 mg/kg b.w.) inhibited acetic acid-induced irritation of paws of rats comparably with that of indomethacin (10 mg/kg b.w.) and had significantly lower mean number of lickings of paws than the control rats (p<0.05). Carrageenan-induced edema was markedly inhibited (p<0.05) by the extracts (100 and 200 mg/kg b.w.) when compared with control rats. Inhibition of writhing movement in rats administered with the extract was lower (p<0.05) than rats administered with indomethacin but its effect was dose-dependent.

CONCLUSIONS

Our investigations show that C. aconitifolius possesses significant anti-inflammatory and analgesic activities that should be explored.

Antinociceptive, anti-inflammatory and acute toxicity effects of juglans regia L. Leaves in mice

BACKGROUND

Juglans regia leaves have been used in folk medicine to alleviate inflammatory diseases. This study investigates the antinociceptive, anti-Inflammatory and acute toxicity effects of Juglans regia L. leaves in mice.

METHODS

351 Male and female albino mice were divided into negative (saline), positive (morphine or diclofenac) controls as well as test groups (n=6-8). The acute (intraperitoneally) toxicity was evaluated for 2 days. Antinociceptive activities were done using hot-plate and writhing tests. Anti-inflammatory effects were studied using xylene induced ear edema and cotton pellet tests.

RESULTS

The LD50 values of J. regia aqueous and ethanolic extrats were 5.5 and 3.3 g/kg, respectively. The aqueous (2.87 and 1.64 g/kg) and ethanolic (2.044 and 1.17 g/kg) extracts showed antinociceptive activity in hot-plate test. The pretreatment of naloxone (2 mg/kg, s.c.) did not inhibit the extracts activities. The extracts exhibited antinociceptive activity in writhing test, which were not blocked by naloxone. In xylene test, both extracts showed anti-inflammatory activity in some doses. The extracts showed anti-inflammatory activity against the chronic inflammation.

CONCLUSION

J. regia leaves demonstrated antinociceptive effect through non-opioid receptors and anti-inflammatory effect against acute and chronic inflammation. The extracts of J. regia could be considered as a promising analgesic and anti-inflammatory agents against diseases such as rheumatoid arthritis.

Antiedematogenic activity and phytochemical composition of preparations from Echinodorus grandiflorus leaves

The leaves of Echinodorus grandiflorus (Alismataceae) are traditionally used in Brazil to treat inflammatory conditions. The aim of the present study was to evaluate the antidematogenic activity of crude aqueous, dichloromethane and hydroethanolic extracts from E. grandiflorus leaves using the carrageenan-induced paw edema model in mice, along with of fractions enriched in diterpenes, flavonoids and hydroxycinnamoyltartaric acids (HCTA). Significant inhibitions of paw edema were elicited by the 50% and 70% EtOH extracts (1000 mg/kg, p.o.), as well as by the fractions enriched in diterpenes (70-420 mg/kg, p.o.) and flavonoids (7.2-36 mg/kg, p.o.). Isovitexin, isoorientin, trans-aconitic and chicoric acids were identified in all extracts by HPLC analysis. Trans-aconitic acid itself exhibited significant antiedematogenic effect (270 mg/kg, p.o.). The biological activity correlated positively with the contents of flavonoids and diterpenes, but negatively with HCTA concentrations, demonstrating the participation of the two classes of compounds in the antiedematogenic activity of E. grandiflorus.

Rapid identification and characterization of antioxidants from Ligularia fischeri

The objectives of this study were to investigate the radical-scavenging activity of Ligularia fischeri on oxidative damage by the radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and to rapidly identify the active components using the bioassay-linked fractionation method. The MeOH extract and fractions of CH(2)Cl(2), BuOH, and H(2)O from L. fischeri showed DPPH radical-scavenging effects in a dose-dependent manner (p < 0.01). In particular, the BuOH fraction had the most effective (p < 0.05) antioxidative capacity. The active constituents from the BuOH fraction of L. fischeri were rapidly isolated by bioassay-linked HPLC method and identified as hyperoside and 2''-acetylhyperoside with potent antioxidant effects against the DPPH radical, with IC(50) values of 1.31 and 7.09 microg/mL, respectively. They have not been reported from L. fischeri yet.