Canthin-6-one ameliorates TNBS-induced colitis in rats by modulating inflammation and oxidative stress. An in vivo and in silico approach.

Canthin-6-one (Cant) is an indole alkaloid found in several botanical drugs used as medicines, reported to be gastroprotective, anti-inflammatory, anti-microbial, anti-diarrheal and anti-proliferative. We aimed to explore Cant in the management of colitis using a trinitrobenzenesulfonic acid (TNBS)-induced rat model. Cant (1, 5 and 25 mg/kg) was administered by oral gavage to Wistar rats followed by induction of colitis with TNBS. Macroscopic and histopathological scores, myeloperoxidase (MPO), malondialdehyde (MDA) and reduced glutathione (GSH) were assessed in colon tissues. Pro- (TNF-α, IL-1ß and IL-12p70) and anti-inflammatory (IL-10) cytokines, and vascular endothelial growth factor (VEGF) were also quantified. Mitogen-activated protein kinase 14 (MAPK14) and Toll-like receptor-8 (TLR8), as putative targets, were considered through in silico analysis. Cant (5 and 25 mg/kg) reduced macroscopic and histological colon damage scores in TNBS-treated rats. MPO and MDA were reduced by up to 61.69% and 92.45%, respectively, compared to TNBS-treated rats alone. Glutathione concentration was reduced in rats administered with TNBS alone (50.00% of sham group) but restored to 72.73% (of sham group) with Cant treatment. TNF-α, IL-1ß, IL-12p70 and VEGF were reduced, and anti-inflammatory IL-10 was increased following Cant administration compared to rats administered TNBS alone. Docking ligation results for MAPK14 (p38α) and TLR8 with Cant, confirmed that these proteins are feasible putative targets. Cant has an anti-inflammatory effect in the intestine by down-regulating molecular immune mediators and decreasing oxidative stress. Therefore, Cant could have therapeutic potential for the treatment of inflammatory bowel disease and related syndromes.

Copaifera malmei Harms leaves infusion attenuates TNBS-ulcerative colitis through modulation of cytokines, oxidative stress and mucus in experimental rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Ethnobotanical studies show that the infusion of the leaves from Copaifera malmei Harms (Fabaceae) has been utilized in the Brazilian traditional medicine to treat provocative and gastrointestinal diseases, among others. Recently, our research team has shown that an infusion extract of the leaves of C. malmei has a strong antiulcer activity and its oral use gives no indications of toxicity. AIM OF THE STUDY: The aim of the study is to evaluate the anti-inflammatory intestinal effect of an infusion extract from the leaves of Copaifera malmei (IECm) in an animal model of ulcerative colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS). MATERIALS AND METHODS: Acute intestinal inflammation was induced in male Wistar rats by TNBS in 20% EtOH (0.25 mL). IECm was administered by oral gavage (for 72, 48, 24 and 2 h) preceding the induction of ulcerative colitis. The colon damage and degree of inflammation were evaluated by morphological observation scores and colon weight. The improved colonic mucosal injury, oxidative stress and inflammatory response were assessed by histopathological investigation and by estimating myeloperoxidase (MPO) activity, malondialdehyde (MDA) and glutathione (GSH) levels and tumor necrosis factor (TNF), interleukin 1ß (IL1-ß), IL-17 and IL-10 colon tissue concentrations. The histopathological changes were done on the colon tissues by hematoxylin and eosin and Periodic Acid-Schiff staining were utilized to measure the mucus. RESULTS: Pre-treatment (25, 100 and 400 mg/kg) with IECm altogether diminished the intestinal inflammation prompted by TNBS in rats by diminishing colonic score by 69.12% (p < 0.01), 19.87% (p < 0.05) and 67.60% (p < 0.01), individually. Improvement of colonic mucosal injury by treatment with IECm was shown by a decline in MPO activity at dosages 25 and 400 mg/kg by 67.98% and 59.68% (p < 0.001), MDA levels 64.80% and 80.00% (p < 0.01) and an expansion in GSH content at all portions (62.53%, 53.38% and 81.20% p < 0.05) compared with vehicle control group. IECm additionally prevention of intestinal inflammation as confirm by decreased cytokine levels, for example, TNF (31.26%, p < 0.05, 50.68% and 45.95%, p < 0.01), IL1-ß (56.41%, 58.83% and 56.65%, p < 0.001), IL-17 (51.66%, p < 0.001, 22.23%, p < 0.05 and 49.67%, p < 0.001) and increased the IL-10 levels at 25 and 400 mg/kg (57.13%, p < 0.01 and 35.83%, p < 0.05) respectively. Histopathological examination of the colon tissue displayed recovery of ulcerative colitis of IECm treated animals by reducing leukocyte infiltrate, epithelial, submucosal and muscular layer damages and maintaining mucus production. CONCLUSION: These findings revealed that IECm was effective and possess anti-colitic activities in a rodent model of UC and can be useful in inflammatory bowel diseases (IBD). The pre-treatment with IECm decreased intestinal inflammation by reducing macroscopical and microscopical colon injury. In addition, the present study demonstrated that IECm ameliorates TNBS-colitis by promoting antioxidant effect, modulation of cytokines release and restauration of mucus production. The study reinforces the traditional use of the Copaifera malmei leaves infusion to inflammatory gastrointestinal disorders and makes IECm a potential herbal medicine for the treatment of IBD.

Piper umbellatum L. (Piperaceae): Phytochemical profiles of the hydroethanolic leaf extract and intestinal anti-inflammatory mechanisms on 2,4,6 trinitrobenzene sulfonic acid induced ulcerative colitis in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Piper umbellatum L. leaves, commonly found in the Amazon, Cerrado and Atlantic rain forest regions of Brazil, are widely used as a traditional medicine to treat gastrointestinal disorders and inflammation, among others diseases. Also, previous scientific studies demonstrated that P. umbellatum has gastroprotective and anti-inflammatory activity. AIM: To investigate the phytochemical profiles and the intestinal anti-inflammatory effect of the hydroethanolic extract of P. umbellatum (HEPu) leaf on ulcerative colitis in rats. MATERIALS AND METHODS: In this study, the chemical composition of HEPu was analyzed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography coupled to mass spectrometry (LC/MS). Also, this work studied the effects of HEPu on ulcerative colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS, 30 mg/mL in 20% ethanol) by intrarectal administration in rats. Simultaneously, animals were pre-treated orally with HEPu (30, 100 and 300 mg/kg), mesalazine (500 mg/kg), or vehicle. At the end of the experimental period, clinical signs of ulcerative colitis were evaluated by determination of weight loss, gross appearance, ulcer area and histological changes. Reduced glutathione (GSH), lipoperoxides (MDA) and nitric oxide (NO) levels, and superoxide dismutase (SOD), myeloperoxidase (MPO) and catalase (CAT) activities were determined in colon tissues. Also, pro-inflammatory mediators such as tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL- 1ß) were quantified by immunoassay on the surface of fluorescent-coded magnetic beads (Luminex MagPix System). RESULTS: GC-MS analysis showed the presence of 17 different phytochemical compounds in the HEPu. LC/MS analyses revealed the presence of compounds in HEPu as protocatechuic acid, ferulic acid, kaempferol, rosmarinic acid, apigenin and ursolic acid. Treatment with HEPu significantly ameliorated weight loss, macroscopic damage, ulcerated area and histopathological changes such as sub-mucosal edema, cell infiltration, ulceration and necrosis (p < 0.001). Furthermore, HEPu (30, 100, and 300 mg/kg, p.o) inhibited the levels of oxidative parameters, such as MPO (49%, 53%, and 62%, p < 0.001), NO (20%, 19%, 22%, p < 0.01), and MDA (75%, 83%, 70%, p < 0.001), whereas increased the antioxidant activities such as SOD (208%, 192%, 64%, p < 0.001), GSH (94%, 75%, 49%, p < 0.01), and CAT (92%, 69%, 108%, p < 0.01). The extract also inhibited the pro-inflammatory cytokines TNF-α (81%, 85%, 85%, p < 0.001) and IL-1ß (95%, 79%, 89%, p < 0.001) levels. CONCLUSION: Together, these results revealed that P. umbellatum L. is a promising source of metabolites to be used in the treatment of inflammatory bowel disease.

Sorocea guilleminiana Gaudich.: Wound healing activity, action mechanisms, and chemical characterization of the leaf infusion.

ETHNOPHARMACOLOGICAL RELEVANCE: Sorocea guilleminina Gaudich. is a tree or shrub endemic to Brazil. Its leaves are used in Brazilian folk medicine for the healing of wounds, stomach problems, inflammation and as diuretic. The present study evaluates the activity and action mechanisms of the healing properties of the aqueous extract of S. guilleminiana leaves (AESg), in experimental models in vivo and in vitro, as well as performs a phytochemical analysis of the extract. MATERIALS AND METHODS: The AESg was prepared by infusion: Ten g of dry leaves powder in 1 L hot water, soaked for 15 min, filtered, lyophilized, and stored at -30 °C. Phytochemical analyses were realized by colorimetry and HPLC/ESI/MS. Its' in vitro cytotoxicity was evaluated on fibroblastic N3T3 cells. The potential of the wound healing activity in vivo was evaluated using excision and incision wound rat models, by histopathology of the injured skin along with the determination of nitric oxide, cytokines (IL-1ß, IL-10, and TNF-α), and antioxidant parameters (GSH, MPO and CAT). In vitro wound healing activity was also demonstrated in scratched N3T3 cells, by measuring the proliferation/migration rate. RESULTS: The phytochemical analysis of the AESg revealed a strong presence of polar compounds, especially flavonoids (4 majoritarian), as well as terpenes and/or sterols (2 majoritarian). The AESg showed no toxicity in the N3T3 cell line (IC50 > 800 µg/mL). Topical treatment with the AESg showed an increase (p < 0.05) in wound contraction with 2 mg/g cream on days 5 and 9 (43.56% and 6.70% increase, respectively), and with 50 mg/g on days 7 and 9 (10.88% and 7.91%, respectively), compared to the vehicle (non-ionic neutral cream). Topical application of AESg (2 or 50 mg/g non-ionic cream) in incised wounds caused an increase in the force necessary for the rupture of the wound when compared to the vehicle group. No changes in cytokines (IL-1ß, IL-10, or TNF-α) or NO accumulation was found with up to 50 mg/g AESg treatment. For antioxidant activity on the incision wound, an increase in GSH levels was denoted with the AESg use, at the lowest and highest dose (2 and 50 mg/g) by 75.86% and 61.20% respectively, when compared to the vehicle. Also, the CAT activity was accentuated by AESg at the highest dose (50 mg/g) by 85.87%. Finally, the AESg at all doses attenuated MPO activity significantly in the incision wound by 71.35%, 73.21%, 78.08%, respectively. In the scratch test on N3T3 cells, the treatment with AESg resulted also in an increase in fibroblast proliferation/migration rate, compared to the vehicle. CONCLUSION: AESg is not cytotoxic. The results confirm the popular use of the leaf infusion of S. guilleminiana for the treatment of cutaneous wounds, possibly by stimulating the proliferation of fibroblasts with a consequent deposition of collagen, fastening rearrangement of collagen fibers, and greater transformation into myofibroblasts, essential in the healing process. Preliminary chemical analyzes of AESg revealed the presence mainly of phenolic compounds, being salicylic acid, gallic acid, pinocembrin and isoquercitrin the majoritarian ones.

Cochlospermum regium (Mart. ex Schrank) Pilg.: Evaluation of chemical profile, gastroprotective activity and mechanism of action of hydroethanolic extract of its xylopodium in acute and chronic experimental models.

ETHNOPHARMACOLOGICAL RELEVANCE: Cochlospermum regium (Bixaceae) is a native shrub of Brazil and its xylopodium (infusion/decoction) is being used for the treatment of gastritis, ulcers, arthritis, intestinal infections, gynaecological infections, skin diseases, among others. The aim of the present study was to evaluate the gastroprotective/antiulcer activity and the mechanism of action of hydroethanolic extract of C. regium xylopodium (HECr), using in vitro and in vivo models. Additionally, phytochemical constituents were identified by high-performance liquid chromatography (HPLC). MATERIALS AND METHODS: C. regium xylopodium was macerated with ethanol/water to obtain the HECr. The phytochemical characterisation was carried out by HPLC. The antiulcer efficacy of HECr (25, 100 and 400 mg/kg, p.o.) was evaluated using acute acidified ethanol (HCl/EtOH), piroxicam and water immersion-induced experimental ulcer models. Chronic gastric ulcer healing activity of HECr was evaluated through acetic acid (99.8%) - induced model. Histological analysis and myeloperoxidase (MPO), glutathione (GSH), catalase (CAT) activities were also evaluated in chronic ulcer induced gastric tissues. The plausible mode of action of the HECr was assessed by estimation of gastric wall mucus production and the role of gastric secretion in pylorus ligature. The animals were also pre-treated with various inhibitors which includes indomethacin (10 mg/kg, p.o.) a selective inhibitor of cyclooxygenase, L-NAME (10 mg/kg, i.p.), an inhibitor of nitric oxide synthase, glibenclamide, a ATP-sensitive potassium channels (K+ATP) blocker (5 mg/kg, p.o.) or yohimbine (2 mg/kg, i.p.), an α2-adrenergic receptor antagonist. In vitro, Helicobacter pylori action was done by broth microdilution method. RESULTS: The HPLC analysis data revealed the presence of gallic acid, rutin, myricetin, morin and kaempferol. HECr promoted protective effect against acute ulcers induced by HCl/EtOH with inhibitions of 47.52% (p < 0.01) and 62.69% (p < 0.001) at 100 and 400 mg/kg, and in piroxicam by 34.11% (p < 0.05), 49.14% (p < 0.01) and 61.34% (p < 0.001), at 25, 100 or 400 mg/kg, respectively, and in water restraint stress by 78.26% inhibition, p < 0.001, at the dose of 400 mg/kg when compared to the vehicle control group respectively. In the chronic gastric ulcer model, HECr (25, 100 and 400 mg/kg p.o.) significantly (p < 0.001) decreased the injured area by 58.80%, 77.87% and 71.10% respectively. Histological examination indicated that oral treatment of HECr promoted healing of gastric lesions by regenerating gastric mucosa layer with less inflammatory cells. HECr augmented the GSH, CAT activities and reduced MPO level. The pre-treatment with HECr increased the gastric wall mucus production. It also significantly altered the gastric secretion parameters by causing the reduction in the gastric juice volume, elevated the pH level and reduced the total acidity at all doses tested when compared with the vehicle group. HECr at the most active dose (100 mg/kg) reversed completely the reduction of PGs, NO production, closure of K+ATP- channels and α2-adrenoreceptor blockage - induced damages. In microdilution assay, the HECr showed good anti-Helicobacter pylori effect with MIC = 100 µg/mL. CONCLUSION: The HECr presented preventive and curative effects in the experimental gastric ulcer models, besides good anti-Helicobacter pylori activity, which supports the traditional medicinal use of the xylopodium of this plant for gastrointestinal diseases. The underlying mechanisms of this antiulcerogenic/antiulcer action involve, at least, augmentation of mucus production, inhibition of gastric secretion, stimulation of PGs and NO synthesis. And that it involves activation of K+ATP channels and α-2-adrenergic receptors, in addition to an antioxidant activity, probably due to the presence of gallic acid and flavonoids in HECr.

Assessment of toxicity and differential antimicrobial activity of methanol extract of rhizome of Simaba ferruginea A. St.-Hil. and its isolate canthin-6-one.

ETHNOPHARMACOLOGICAL RELEVANCE: Simaba ferruginea A. St.-Hil., Simaroubaceae, popularly known as "calunga" is a typical subtropical shrub used in Central Brazil mainly for infection, anti-inflammatory, analgesic and gastric duodenal-ulcers. It presents in its composition the alkaloid canthin-6-one, an alkaloid indole ß-carboxylic. AIM: This study aims to investigate the toxicity, antimicrobial activities of methanol extract of Simaba ferruginea (MESf) and canthin-6-one by using different experimental models. METHODS: The present study evaluated the phytochemical analysis by high performance liquid chromatography (HPLC), toxicological potential of MESf and canthin-6-one, using the cytotoxicity, genotoxicity assays with CHO-K1 cells and in vivo acute test in mice. Antimicrobial activity was evaluated by the broth microdilution assays, while the antimicrobial mechanism of action was also assessed using different in vitro bacterial and fungal models. RESULTS: The HPLC analysis of MESf revealed the presence of canthin-6-one, kaempferol and morin. Differential in vitro toxicities were observed between MESf and canthin-6-one. In the cytotoxicity assay, MESf presented toxicity against CHO-K1, while canthin-6-one did not. In the case of in vitro genotoxicity, both showed to be potentially genotoxic. In the in vivo toxicity study, both MESf (up to 1000 mg/kg) and cantin-6-one (up to 100 mg/kg) caused no toxicologically relevant alterations and are thus considered not to be toxic. MESf was shown to be relatively safe with NOAEL (100 mg/kg) when administrate in mice. Both MESf and canthin-6-one also showed differential antimicrobial activities. On one hand, MESf demonstrated good spectrum of antibacterial action against Staphylococcus aureus (MIC 12.5 µg/mL) and Escherichia coli (MIC 25 µg/mL) and moderate activity against Enterococcus faecalis and Shigella flexneri (MIC 200 µg/mL) but no antifungal effect. On the hand, canthin-6-one showed no antibacterial activity, except against Staphylococcus aureus (100 µg/mL), but potent in vitro fungicidal activity against clinically important Aspergillus niger and Candida species at MFC intervals ranging from 3.12 to 25 µg/mL. Both MESf and canthin-6-one were bacteriostatic in action. MESf antimicrobial mechanism of actions are associated with changes in the permeability of bacterial membranes, evidenced by the increased entry of hydrophobic antibiotic in Shigella flexneri, intense K+ efflux (Shigella flexneri, Staphylococcus aureus) and nucleotides leakage (Staphylococcus aureus). In the antifungal mode of action, canthin-6-one inhibited Saccharomyces cerevisiae growth and including alteration in the cell membrane of Neurospora crassa. CONCLUSION: The results of this work demonstrated the differential antimicrobial activities of MESf and its alkaloid isolate, canthin-6-one with antibacterial and antifungal activities, respectively. The present study support the popular use of Simaba ferruginea in combatting afflictions related to bacterial infections, and demonstrate that canthin-6-one as a promising antifungal agent. Both MESf and canthin-6-one are considered non-toxic based on the in vitro toxicological study.

Antibacterial mode of action of the hydroethanolic extract of Leonotis nepetifolia (L.) R. Br. involves bacterial membrane perturbations.

ETHNOPHARMACOLOGICAL RELEVANCE: Leonotis nepetifolia (L) R. Br., Lamiaceae, a pantropical shrub, popularly known in Brazil as "cordão-de-frade", "rubim", is reportedly used in Brazilian ethnomedicine as well as in different countries in the treatments of ailments such as infections, inflammations, wounds, stomach disorders, among others. AIM OF THE STUDY: To evaluate its potential cytotoxicity and antibacterial mode of action of the hydroethanolic extract of L. nepetifolia (HELn) leaves, including phytochemical analysis. MATERIALS AND METHODS: The cytotoxicity of HELn was investigated by Alamar blue assay, using CHO-K1 cells. Antibacterial activity of HELn was tested by broth microdilution methods against a panel of bacteria of clinical interest. The mode of action of L. nepetifolia was studied by targeting bacterial membranes. Phytochemical analysis was performed by determining total secondary metabolites with spectrophotometric assays and HPLC. RESULTS: HELn is not cytotoxic in the in vitro evaluation (IC50>200 µg/mL). It demonstrated a good spectrum of antibacterial activity with major activity against Shigella flexneri, Enterococcus faecalis, Staphylococcus aureus and Bacillus subtilis with MIC=6.25 µg/mL, Helicobacter pylori with MIC of 25 µg/mL and Streptococcus pyogenes with MIC of 50 µg/mL. Its mode of action is associated, at least partly, with changes in the permeability of bacterial membranes, as evidenced by the increased entry of hydrophobic antibiotics in Shigella flexneri and intense efflux of K(+) and nucleotide leakage in E. faecalis and Shigella flexneri. In addition, the presence of phenols, flavonoids and carotenoids, described in the literature to possess antibacterial effects, were detected in the composition of HELn, with high phenol content (11.55%), especially the flavonoids (6.47%). CONCLUSION: The results indicate that HELn has low cytotoxicity and potent antibacterial activity. It is bacteriostatic in nature, possibly acting at the level of bacterial membranes, especially on the cytoplasmic membrane and outer membrane, thus supporting its popular use in infectious processes. In addition, the presence of phenols, flavonoids, carotenoids, fatty acids and steroids, described in the literature as possessing antimicrobial activity, were detected in the composition of HELn.