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Plants with medicinal potential may also produce adverse effects in humans. This seems to be the case for the species Rubus rosifolius, where preliminary studies demonstrated genotoxic effects attributed to extracts obtained from leaves and stems of this plant using on HepG2/C3A human hepatoma cells as a model. Considering the beneficial properties of this plant as an antidiarrheal, analgesic, antimicrobial, and antihypertensive and its effects in the treatment of gastrointestinal diseases, the present study was developed with the aim of determining the cytotoxic and genotoxic potential of extracts of leaves and stems of R. rosifolius in primary without metabolic competence in human peripheral blood mononuclear cells (PBMC). Cell viability analyses at concentrations of between 0.01 and 100 µg/ml of both extracts did not markedly affect cell viability. In contrast, assessment of the genotoxic potential using the comet assay demonstrated significant damage to DNA within PBMC from a concentration of 10 µg/ml in the stem extract, and a clastogenic/aneugenic response without cytokinesis-block proliferation index (CBPI) alterations at concentrations of 10, 20, or 100 µg/ml for both extracts. Under our experimental conditions, the data obtained demonstrated genotoxic and mutagenic effects attributed to extracts from leaves and stems of R. rosifolius in cells in the absence of hepatic metabolism. [ABSTRACT FROM AUTHOR]

Abstract: Ethnopharmacological relevance: Brassica oleracea L. var. acephala D.C. has been extensively used in Brazilian traditional medicine to treat gastric ulcer. Aim of the study: This study was conducted to evaluate the in vivo genotoxic and/or antigenotoxic potential of a Brassica oleraceae hydroalcoholic extract obtained from the leaves, in different cells of mice. Materials and methods: Analyses were performed using the comet assay, on leukocytes (collected 4 and 24h after treatment), liver, brain, bone marrow and testicular cells (collected 24h after treatment), and using the micronucleus test (MN) in bone marrow cells. Eight groups of albino Swiss mice were treated (N=6): control (C), positive control (doxorubicin 80mg/kg (DXR)), and six experimental groups, which received 500, 1000 and 2000mg/kg of Brassica oleraceae extract alone by gavage, while a further three groups received the same doses plus DXR (80mg/kg). We calculated the damage scores, and their averages were compared by ANOVA followed by the Tukey test for multiple comparisons. Results: The results demonstrated that none of the tested doses of Brassica oleraceae extract showed genotoxic effects by the comet assay, or clastogenic effects by the MN test. On the other hand, for all cells evaluated, the three tested doses of the Brassica extract promoted inhibition of DNA damage induced by DXR. Conclusions: Under our experimental conditions, Brassica oleraceae leaf extract showed no genotoxic or clastogenic effects in different cells of mice. However, it did show a significant decrease in DNA damage induced by doxorubicin. It is suggested that the antigenotoxic properties of this extract may be of great pharmacological importance, and may be beneficial for cancer prevention. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Garcinia achachairu Rusby (Clusiaceae) is popularly known as “achachairu”, and is used in Bolivian folk medicine for its healing, digestive, and laxative properties, and in the treatment of gastritis, rheumatism and inflammation. Despite its widespread therapeutic use, there is a lack of data regarding its in vivo genotoxic effects. Therefore, in this study, we used the comet assay and the micronucleus test, respectively, to evaluate the possible genotoxic and clastogenic effects of Garcinia achachairu seed extract (GAE) on different cells of mice. Material and methods: The GAE was administered by oral gavage at doses of 500, 1000 and 2000mg/kg. For the analysis, the comet assay was performed on the leukocytes (collected 4 and 24h after treatment), liver, bone marrow and testicular cells (collected 24h after treatment), and the micronucleus test (MN) on bone marrow cells. Cytotoxicity was assessed by scoring 200 consecutive polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE/NCE ratio). Results and conclusion: The results showed that GAE did not induce significant DNA damage in leukocytes (4h and 24h samples), liver, bone marrow and testicular cells (24h samples). GAE also did not show any significant increase in micronucleated polychromatic erythrocytes (MNPCEs) at the three tested doses. The PCE/NCE ratio indicated no cytotoxicity. Under our experimental conditions, the data obtained suggest that a single oral administration of G. achachairu extract does not cause genotoxicity and clastogenicity in different cells of mice. [Copyright &y& Elsevier]

Abstract: Relevance: Simaba ferruginea A. St-Hil. (Simaroubaceae) is a subshrub typical of the Brazilian Cerrado, whose rhizomes are popularly used as infusion or decoction for the treatment of gastric ulcers, diarrhea and fever. Aim of the study: To evaluate the pharmacological mechanism(s) of action of the antiulcer effects of the methanol extract of Simaba ferruginea and its alkaloid canthin-6-one. Materials and methods: Rhizome of Simaba ferruginea was macerated with methanol to obtain the methanol extract (MESf) from which was obtained, the chloroform fraction. Canthin-6-one alkaloid (Cant) was purified and then isolated from the chloroform fraction (CFSf). The isolated Cant was identified by HPLC. Anti-ulcer assays were determined using ethanol and indomethacin-induced ulcer models in mice and rats respectively. In order to determine the probable mechanisms of actions of MESf and Cant animals were pretreated with l-NAME prior to anti-ulcer agent treatments and ulcer induction and nitric oxide (NO) level determined in order to assess NO involvement in the gastroprotective effects. Assays of malondialdehyde (MDA), myeloperoxidase (MPO), pro-inflammatory cytokines: interleukin 8 (IL-8) and tumor necrosis factor-alpha (TNF-α) and prostaglandin E2 (PGE2) were also carried out according to previously described methods. Results: The results indicate that the antiulcerogenic effects of MESf and Cant in ethanol-induced ulcer is mediated in part through increase in the production of protective endogenous NO as the antiulcerogenic activity of MESf and Cant was reduced in animals pre-treated with l-NAME. In indomethacin-induced ulcer pre-treatment with MESf and Cant showed reduction in the levels of MPO and MDA in the gastric tissue, thus indicating the participation of the antioxidant mechanisms on the gastroprotective effects. The plasma levels of IL-8 in ulcerated rats with indomethacin were also reduced by Cant, but not by MESf, indicating that inhibition of this cytokine contributes to the gastroprotective effect of Cant. However MESf and Cant had no effect on the mucosal membrane levels of PGE2, indicating that the gastroprotective effects of these agents is independent of PGE2 modulation. Conclusion: The results obtained in this study with MESf and Cant added insights into the pharmacological mechanisms involved in their mode of antiulcer action. The results indicate that Cant is one of the compounds responsible for these effects. Such findings are of extreme importance in the strive for future development of potent, safer and effective antiulcer agent. The efficacy of MESf and Cant in gastroprotection shows that Simaba ferruginea might be a promising antiulcer herbal medicine, in addition to confirming the popular use of this plant against gastric ulcer models utilised in this study. [Copyright &y& Elsevier]

Abstract Ethnopharmacological relevance Popular medicine use stems of Philodendron bipinnatifidum (Araceae) in inflammation cases, such as in erysipelas, as well as orchitis and rheumatism treatment. The present study, conducted for the first time in literature, investigate the antinociceptive and anti-inflammatory activities of P. bipinnatifidum stems ethyl acetate extract (EPB). Materials and methods GC/MS and HPLC analysis were performed for EPB extract. We used EPB at 250, 375 and 500 mg/kg (oral route, p.o.) in male Swiss mice. The antinociceptive activity of the plant extract assessed by acetic acid induced writhing and formalin tests. To investigate the possible participation of opioid system in EPB-mediated effects, we previously administered naloxone to the mice. Anti-inflammatory activity was evaluated using carrageenan-induced paw oedema. The open-field test aimed to investigate the possible EPB effects on the locomotor and exploratory activities. To assess the protective role of EPB on carrageenan-induced oxidative stress, the levels of NPSH, TBARS, as well as SOD and CAT activities were evaluated in blood and paw tissue. The acute toxicity of the EPB was investigated using OECD 423 guideline. Results The EPB chemical analysis by GC/MS and HPLC revealed the presence of flavonoids (luteolin and quercetin) and phytosterols (β-sitosterol and stigmasterol). The oral treatment with the EPB inhibited mice abdominal writhings (P < 0.01) at 375 and 500 mg/kg, and reduced the formalin effect at the first-phase (500 mg/kg, P < 0.05) and also at the second-phase (500 mg/kg, P < 0.001) of the test. E P B (375 and 500 mg/kg) did not alter spontaneous locomotion in open field test, however the number of fecal bolus was significantly lower for the EPB group at 500 mg/kg when compared to the vehicle group (P < 0.05). The pretreatment with naloxone caused significant inhibition of antinociceptive activity induced by EPB in the formalin test, revealing the possible involvement of opioid receptors. EPB extract administered at 500 mg/kg (p.o.) prevented carrageenan-induced paw oedema (P < 0.05 and 0.01) until 6 h after carragenan injection. Evaluation of TBARS and NPSH levels, SOD and CAT activities in the blood and paw tissue of animals submitted to the carrageenan assay suggested that the anti-inflammatory effect of EPB may be linked to oxidative stress inhibition. The acute administration of the EPB (2000 mg/kg, p.o.) caused no mortality, demonstrating low toxicity. Conclusions The extract of P. bipinnatifidum displays antinociceptive and anti-inflammatory activities, causing no toxicological effects. The pharmacological activity of this vegetal species may be related to the presence of flavonoids and phytosterols. Our results support the ethnomedical use of this vegetal species as analgesic and anti-inflammatory agent. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Maytenus robusta Reissek (Celastraceae) is traditionally used in Brazilian folk medicine to treat gastric ulcer, as a substitute for M. ilicifolia , which is almost extinct. The gastroprotective properties of M. robusta were demonstrated previously using only preventive approaches, such as acute gastric ulcer models. However, the healing effect of M. robusta in gastric ulcers remains unclear. Aim of the study The current study was carried out to investigate the healing effectiveness of M. robusta hydroalcoholic extract (HEMR) from aerial parts in the acetic acid-induced chronic ulcer model and to determine its effect on cell proliferation, scavenging free radicals, and inflammatory and oxidative damage. Material and methods To evaluate the healing properties of HEMR in vivo, chronic gastric ulcer was induced in rats by 80% acid acetic. Next, different groups of animals ( n =6) were treated orally with vehicle (water plus 1% tween, 1 ml/kg), omeprazole (20 mg/kg), or HEMR (1–10 mg/kg), twice daily for 7 days. At the end of the treatment, the total ulcer area (mm 2 ) was measured and a sample of gastric tissue was taken for histological and histochemical analysis. Evaluation of GSH and LOOH levels, GST, SOD, CAT and MPO activity was also performed at the site of the lesion. In parallel, radical scavenging activity, cytoprotective effect, and cell proliferation activity in fibroblasts (L929 cells) were determined by in vitro trials. The antisecretory properties were evaluated using the pylorus ligature model in rats, and the anti- Helicobacter pylori activity was determined in vitro. Acute toxicity was evaluated by relative organ weight and biochemical parameters in serum. The prokinetic properties were also evaluated in mice. Results Oral administration of HEMR (10 mg/kg) reduced the gastric ulcer area by 53%, compared to the vehicle group (120.0±8.3 mm 2 ), the regeneration of gastric mucosa was evidenced in histological analysis. Moreover, HEMR treatment increased gastric mucin content and reduced oxidative stress and inflammatory parameters at the site of the ulcer. In vitro, HEMR (1–1000 µg/ml) was able to scavenge free radical DPPH and promote cytoprotection against H 2 O 2 in fibroblasts at 0.1–100 µg/ml. Moreover, HEMR healing properties also were confirmed by enhancement of proliferation and coverage of scratched wounds in fibroblast monolayer. However, HEMR (10 mg/kg) by the intraduodenal route did not promote changes in volume, pH, total acidity or pepsin activity in the pylorus ligature model, and HEMR up to 2000 µg/ml also did not present considerable activity against H. pylori . In relation to gastrointestinal motility, HEMR (10 mg/kg, p.o) did not provoke alterations. It is also important to mention that oral administration of HEMR did not produce any sign of acute toxicity in animals. Conclusions The data here obtained show that M. robusta has evident ulcer healing potential, mainly through the strengthening of protective factors of gastric mucosa, such as mucus layer, antioxidant defenses and cell proliferation. Taking into account the advantages of cultivation and harvesting of M. robusta compared to M. ilicifolia , and the evidence presented here, it is plausible to conclude that hydroalcoholic extract obtained from aerial parts of M. robusta is an interesting source for the development of a phytotherapeutic formulation to treat gastric ulcer. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Rubus niveus Thunb. plant belongs to Rosaceae family and have been used traditionally to treat wounds, burns, inflammation, dysentery, diarrhea and for curing excessive bleeding during menstrual cycle. The present study was undertaken to investigate the in vivo genotoxicity of Rubus niveus aerial parts extract and its possible chemoprotection on doxorubicin (DXR)-induced DNA damage. In parallel, the main phytochemicals constituents in the extract were determined. Materials and methods The animals were exposed to the extract for 24 and 48 h, and the doses selected were 500, 1000 and 2000 mg/kg b.w. administered by gavage alone or prior to DXR (30 mg/kg b.w.) administered by intraperitoneal injection. The endpoints analyzed were DNA damage in bone marrow and peripheral blood cells assessed by the alkaline alkaline (pH>13) comet assay and bone marrow micronucleus test. Results and conclusion The results of chemical analysis of the extract showed the presence of tormentic acid, stigmasterol, quercitinglucoronide (miquelianin) and niga-ichigoside F1 as main compounds. Both cytogenetic endpoints analyzed showed that there were no statistically significant differences ( p >0.05) between the negative control and the treated groups with the two higher doses of Rubus niveus extract alone, demonstrating absence of genotoxic and mutagenic effects. Aneugenic/clastogenic effect was observed only at 2000 mg/kg dose. On the other hand, in the both assays and all tested doses were observed a significant reduction of DNA damage and chromosomal aberrations in all groups co-treated with DXR and extract compared to those which received only DXR. These results indicate that Rubus niveus aerial parts extract did not revealed any genotoxic effect, but presented some aneugenic/clastogenic effect at higher dose; and suggest that it could be a potential adjuvant against development of second malignant neoplasms caused by the cancer chemotherapic DXR. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance In Brazil, a phytotherapeutic preparation produced from a standardized tincture of Cinchona calisaya Weddel such that each mL of product contains 400 µg of quinine, known in Portuguese as Água Inglesa ® (English water), is indicated by the manufacturer as a tonic, appetite stimulant, and digestive. However, this preparation has long been used in folk medicine as a female fertility stimulant. Despite its widespread use in folk medicine to stimulate female fertility, no study has been undertaken to assess the potential teratogenic and genotoxic effects of this phytotherapeutic preparation. The aim of the present study was to investigate possible toxic reproductive effects in mice caused by exposure to Água Inglesa ® , either before mating or during the pre- and post-embryo implantation periods. The genotoxic potential was evaluated using the micronucleus assay. Material, Methods, and Results Virgin female mice, with at least one estrous cycle evidenced by vaginal cytology, were divided into five groups of 15 individuals each (Group I – control, Group II – treated with ethanol solution at 16%, Groups III, IV and V treated with phytotherapeutic preparation at 1.5 mL/kg/day, 3.0 mL/kg/day and 4.5 mL/kg/day, respectively). After the first 28 days of treatment, females were caged individually with adult fertile males. Pregnant females continued to receive treatment for seven days (preimplantation period). Body weight was recorded weekly during treatment. Signs of toxicity (weight loss, food intake, piloerection, apathy, prostration, diarrhea, seizures, behavioral changes, and locomotion) were also observed. The females were sacrificed on the 15th day of pregnancy, uterine horns were evaluated for implantation, and the placental index was recorded. In the micronucleus test, 2000 polychromatic erythrocytes (PCE) per animal, obtained from bone marrow, were scored. Results The results showed that exposure of the females during the pre- and post-implantation periods did not significantly alter the reproductive capacity ( p <0.05); however, in higher dose (three times human dose)reduction of fetal weight was observed . There was no difference between the control and phytotherapeutic preparation ( p >0.05) in terms of the average number of micronucleated polychromatic erythrocytes. Conclusions Although folk medicine suggests that the Água Inglesa ® preparation is useful as a female fertility stimulant, no such effect was confirmed in mice. [ABSTRACT FROM AUTHOR]

Abstract: Ethnopharmacological relevance: Rubus imperialis Cham. Schl. (Rosaceae) is frequently used in traditional medicine as hypoglycemic, antinociceptive and antiviral remedy. Materials and methods: Swiss albino mice were distributed in eight groups for acute treatment with Rubus imperialis extract (24h). The extract doses selected were 50, 250 and 500mg/kg b.w. administered by gavage alone or plus to CPA (50mg/kg b.w.) administered by intraperitoneal injection. Control groups were treated in a similar way. Analyses were performed using the comet assay, on leukocytes (collected 4 and 24h after treatment) and liver (collected 24h after treatment), and using the micronucleus test (MN) in bone marrow cells. Cytotoxicity was assessed by scoring 200 consecutive polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE/NCE ratio). Results and conclusion: The main compounds identified in the Rubus imperialis extract were saponins and steroidal compounds, with niga-ichigoside and tormentic acid being the major compounds. Tested doses of Rubus imperialis extract showed no genotoxic effects on leukocytes from peripheral blood or liver cells by the comet assay. However, the MN test showed an increase in the frequency of micronucleated cells at the two higher doses tested, indicating that this extract has clastogenic/aneugenic effects on bone marrow cells at higher doses. On the other hand, for all cells evaluated, the three tested doses of the Rubus imperialis extract promoted inhibition of DNA damage induced by CPA. Despite the chemoprevention observed, the clastogenicity/aneugenicity observed suggested caution about either continuous or high-dose usage of Rubus imperialis aerial parts extract by humans. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Brassica oleracea var. acephala DC has been extensively used in Brazilian traditional medicine to treat gastric ulcer. Aim of the study: This study was conducted to evaluate the antiulcerogenic property of hydroalcoholic extract obtained from the leaves of Brassica oleracea. Materials and methods: Antiulcer assays were performed using the protocol of ulcer induced by ethanol/HCl, and non-steroidal anti-inflammatory drugs (NSAIDs). Parameters of gastric secretion (volume, pH and [H+]) were determined by the pylorus ligation model and mucus in gastric contents. Results: In the ethanol-induced ulcer model, we observed a significant reduction in all the parameters analyzed, obtaining curative ratios of 58.8±11.5, 86.2±12.2 and 42.8±6.6% for the groups treated with 50 and 100mg/kg of extract and omeprazole (30mg/kg), respectively. The dose of 25mg/kg of hydroalcoholic extract of Brassica oleracea showed no significant results. In the indomethacin-induced ulcer, the percentages of ulcer inhibition were 64.3±9.9, 66.4±12.3 and 81.2±7.5% for the groups treated with 50 and 100mg/kg extract and positive control (cimetidine, 100mg/kg), respectively. The results showed a significant increase in pH and mucus production in the groups treated with Brassica oleracea when compared with the control group. No sign of toxicity was observed in the acute toxicity study. Conclusions: The results of the present study show that hydroalcoholic extract of Brassica oleracea displays antiulcer activity, as demonstrated by the significant inhibition of ulcer formation induced using different models. The data suggest that the effectiveness of the extract is based on its ability to stimulate the synthesis of mucus, increase pH and decrease H+ ions in the stomach. This work corroborates the ethnopharmacology use of Brassica oleracea preparations, contributing to its pharmacological validation by suggesting that preparations obtained from Brassica oleracea could be used for the development of new phytopharmaceuticals for the treatment of gastric ulcer. [Copyright &y& Elsevier]

Ethnopharmacological relevance: Achyrocline satureoides is a medium-sized South American indigenous herb, commonly known as “Marcela” or “Macela”. The infusion obtained from inflorescences of this plant is widely used in Brazilian folk medicine as an antispasmodic, anti-inflammatory, hypoglycemic, and hypocholesterolemic, mainly to treat gastrointestinal disorders such as gastric ulcers and dyspepsia. However, the antiulcer properties of this species have not yet been fully studied. Aim of the study: This study was conducted to evaluate and contribute to validating the antiulcer activity of hydroalcoholic extract of inflorescences of Achyrocline satureoides. Materials and methods: The antiulcer assays were performed using the ethanol-induced ulcer, and nonsteroidal anti-inflammatory drug (NSAID)-induced ulcer protocols. Gastric secretion parameters were also evaluated (volume, pH and total acidity) by the pylorus ligated model, and the mucus in the gastric content was determined. Results: In the ethanol-induced ulcer model, it was observed that the treatment with Achyrocline satureoides extract significantly reduced the lesion index by 75.1±8.6, 85.0±9.2, 86.6±7.4 and 75.5±5.3 for the groups treated with 100, 250 and 500mg/kg of extract of inflorescences of Achyrocline satureoides and the positive control (omeprazole 30mg/kg), respectively. Significant inhibition was also observed in the lesion index in the indomethacin-induced ulcer model, with decreases of 62.5±7.1, 62.5±6.1, 63.6±5.5 and 96.2±3.6 for the groups treated with 100, 250 and 500mg/kg of extract and the positive control (cimetidine 100mg/kg), respectively. The parameters of gastric secretion (pH, volume, [H+]) showed no alteration in the different doses of the treatment. On the other hand the treatment with the hydroalcoholic extract of Achyrocline satureoides (100, 250 and 500mg/kg), significantly increased mucus production (p <0.01), when compared with the groups treated with indomethacin (100mg/kg), cimetidine (100mg/kg) and negative control (vehicle). No signs of toxicity was observed in the acute toxicity study. Conclusions: The results of the present study show that hydroalcoholic extract of Achyrocline satureoides displays antiulcer activity, as demonstrated by the significant inhibition of the formation of ulcers induced using different models. However, this activity appears not be related to the antisecretor mechanisms. Moreover, this work suggests that preparations obtained from Achyrocline satureoides could be used for the development of new phytotherapic drugs for the treatment of gastric ulcer. [Copyright &y& Elsevier]

Maytenus robusta Reissek (Celesteraceae), popularly named as cafezinho do mato or coração de bugre , is employed to treat inflammatory digestive diseases in the south of Brazil. However, despite popular usage, the effects of this species on an experimental model of ulcerative colitis are unknown. To evaluate the effects of M. robusta extract (HEMR) on colon and liver from mice with colitis induced by dextran sulfate sodium (DSS). Firstly, the cytotoxicity of HEMR and its effects on ROS and nitrite production in IEC-6 cells were evaluated. The experimental colitis was established by adding 3% DSS on drinking water of mice and the effects of HEMR (1–100 mg/kg, p.o, once a day by 7 days) in colonic and hepatic tissues were analyzed. The HEMR (1–100 μg/mL) did not alter the cell viability but reduced nitrite production of IEC-6 stimulated by LPS. Moreover, HEMR (100 mg/Kg) attenuates macro and microscopic alterations in the colon from mice exposed to DSS, as evidenced by a reduction of the colon shortening, attenuation of the epithelial erosion, submucosal edema and preservation of the Goblet cells integrity, as well as the restoration of mucin depletion. The treatment with HEMR increased GSH amount, reduced LOOH levels and normalizes CAT activity in the colon. The group treated with HEMR showed increased GST activity, reduced MPO activity and decreased inflammatory cytokines secretion (TNF and IL-6) in the colonic tissue. In the liver, HEMR increased GST activity, decreased the GPx activity and reduced IL-6 levels. Furthermore, the HEMR treatment reduced AST and ALT serum levels in mice exposed to DSS. Finally, the HEMR was able to reduce intestinal transit. HEMR treatment minimizes inflammation of the colon and maintaining the antioxidant homeostasis. In addition, HEMR may be a potential tool to prevent hepatic injury secondary to ulcerative colitis. Image 1 [ABSTRACT FROM AUTHOR]

Luehea divaricata , popularly known in Brazil as "açoita-cavalo", has been widely explored by different ethnic groups native to Brazil to treat different pathologic conditions, including inflammatory pain. However, no report could be found on the effect that extract of L. divaricata has on neuropathic pain. This is an important topic because convergent and divergent mechanisms underlie inflammatory vs. neuropathic pain indicate that there may not always be a clear mechanistic delineation between these two conditions. The study aimed to determine antioxidant activity and macronutrient composition of aqueous extract from leaves of L. divaricata , and the effect of oral administration on nociception in rats with chronic constriction injury (CCI) of sciatic nerve-induced neuropathic pain, one of the most commonly employed animal models of neuropathic pain. The antioxidant activity of the extract was evaluated by total phenolic content and DPPH, ABTS●+ and ORAC methods. Vitexin was determined by HPLC to show that the composition of the extract of the present study is similar to that used in previous studies with this genus. Total sugar and sucrose concentrations were assessed by the anthrone method, while glucose and triacilglycerides were determined using commercially available kits. Fructose concentration was calculated from values for total sugars, glucose and sucrose. Total protein was determined by Bradford assay. The effect on DNA strand breaking was investigated by inhibition of strand breaking of supercoiled DNA by hydroxyl radical. The antinociceptive effects of aqueous extract (100, 300, 500, and 1000 mg/kg, i.g.) were evaluated on thermal and mechanical thresholds for neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve in rats. We also compared the antinociceptive effect of the extract (500 mg/kg, i.g.) with that induced by gabapentin (50 mg/kg, i.g.), a first-line clinical treatment for neuropathic pain. The effect of co-administration of extract (500 mg/kg, i.g.) and low-dose gabapentin (30 mg/kg, i.g.) was also assessed. In addition, the effect of the extract on body weight, and blood and hepatic parameters were investigated to reveal possible side effects of treatment. The extract showed high content of total phenol; good reducing capacity for DPPH, ABTS●+ and ORAC assays; presence of vitexin; and a high capacity to inhibit strand breaking of supercoiled DNA. The predominant sugar was sucrose, followed by glucose and fructose. Total protein was greater than triacylglycerides, with the latter being present in a trace amount in the extract. The extract increased the thermal and mechanical thresholds, which was reduced by CCI. The antinociceptive effect was comparable to gabapentin and was also found after co-administration of extract and low-dose gabapentin. No significant change was found in body weight and blood and hepatic indicators after extract treatment. Aqueous extract from L. divaricata leaves was as effective as gabapentin at attenuating CCI-induced neuropathic pain, indicating for first time the therapeutic potential of this species for this type of pain. Image 1 • Aqueous extract from L. divaricata leaves has beneficial effect on neuropathic pain. • Aqueous extract from L. divaricata leaves alleviates pain as gabapentin. • Aqueous extract from leaves of L. divaricata alleviates pain in CCI rats. • Aqueous extract from leaves of L. divaricata attenuate peripheral neuropathic pain. [ABSTRACT FROM AUTHOR]