Potential anti-arthritic and analgesic properties of essential oil and viridiflorol obtained from Allophylus edulis leaves in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Viridiflorol was identified and isolated from the essential oil of Allophylus edulis leaves (EOAE). A. edulis was used as "tereré", which is a drink made by the infusion of herbs in cold water, to treat pain (toothache and headache). All anti-nociceptive (analgesic) and anti-arthritic properties of EOAE and viridiflorol have not been completely scientifically clarified. AIM OF THE STUDY: The aim of the present study was to investigate the analgesic (anti-hyperalgesic and anti-nociceptive) and anti-arthritic properties of EOAE and viridiflorol using in vivo models. MATERIALS AND METHODS: The oral administration (p.o.) of EOAE (30, 100 and 300 mg/kg), viridiflorol (30, 100 and 200 mg/kg), morphine (1 mg/kg, subcutaneous route (s.c.)) and the intraplantar (local) administration (i.pl.) of viridiflorol (100 µg/paw) were tested using formalin model in Swiss mice. EOAE (100 mg/kg, p.o.), viridiflorol (200 mg/kg, p.o.), and dexamethasone (1 mg/kg, s.c.) were tested by zymosan-articular inflammation and in open-field models. Viridiflorol (0.3, 20 and 200 µg/paw) was also tested in carrageenan model, and viridiflorol (200 µg/paw) was also tested in tumor necrosis factor-α (TNF-α), and dopamine (DOPA) models. RESULTS: The oral administration of EOAE (100 and 300 mg/kg, p.o.), viridiflorol (200 mg/kg, p.o.), morphine (1 mg/kg, s.c.) (MOR) and local administration of viridiflorol (100 µg/paw) significantly inhibited edema and nociception in formalin model. Oral treatments with EOAE and viridiflorol (200 mg/kg) did not cause motor impairment in the open field test since they did not reduce locomotor activity. EOAE, viridiflorol and dexamethasone significantly reduced mechanical hyperalgesia, edema, total leukocytes, polymorphonuclear cells, nitric oxide and protein exudation in the zymosan-induced articular inflammation model. The local administration of viridiflorol (200 µg/paw, i.pl.) significantly inhibited mechanical hyperalgesia and edema induced by carrageenan, TNF-α and DOPA. CONCLUSIONS: This study confirms the potential anti-arthritic, anti-nocicepttive and anti-hyperalgesic properties of EOAE and viridiflorol. These properties could explain, at least in part, the folk use of A. edulis against including pain (toothache and headache). Viridiflorol could be partially responsible for the EOAE anti-hyperalgesic, anti-nociceptive and anti-arthritic properties and its mechanism of action could involve the inhibition of TNF-α and DOPA pathways.

Palicourea tomentosa (Aubl.) Borhidi: Microscopy, chemical composition and the analgesic, anti-inflammatory and anti-acetylcholinesterase potential.

ETHNOPHARMACOLOGICAL RELEVANCE: Palicourea tomentosa (Aubl.) Borhidi (synonym Psychotria poeppigiana Müll. Arg.) leaves are used in the popular treatments of inflammation and pain; however, there are no scientific studies demonstrating their activity as the methanolic extract of P. tomentosa. AIM OF STUDY: This study was undertaken to investigate the potential antioxidant, anti-acetylcholinesterase, anti-hyperalgesic, anti-nociceptive and anti-inflammatory properties, as well as the chemical composition and concentrations of constituents of the methanolic extract of P. tomentosa leaves (MEPT). The study also analyzes the micromorphology and histochemistry of leaves of P. tomentosa. MATERIALS AND METHODS: The MEPT was analysed by ultra-high-pressure liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS/MS). The concentrations of total phenols, flavonoids, flavonols and condensed tannin were determined. The micromorphology and histochemistry of leaves were performed using standard reagents, light and field emission scanning electron microscopy, beyond energy-dispersive X-ray spectroscopy. The antioxidant activity was evaluated for DPPH, ß-carotene and MDA. The anti-inflammatory activity of MEPT (30, 100, and 300 mg/kg) was assayed in carrageenan-induced models of paw oedema, mechanical hyperalgesia (Von Frey), cold allodynia (acetone) and pleurisy in mice. The anti-nociceptive potential of MEPT (30, 100, and 300 mg/kg) was evaluated by the formalin method in mice. The anti-acetylcholinesterase properties were evaluated in vivo in four rat brain structures. RESULTS: The total ion chromatogram of MEPT demonstrated two alkaloids, one coumarin, one iridoid and two terpene derivatives. The highest phenol, flavonoid, flavonol and condensed tannin concentrations were found in the extract. A comprehensive explanation of the leaf micromorphology and histochemistry was presented. MEPT was significantly inhibited by the DPPH, ß-carotene and MDA models. MEPT (30, 100 and 300 mg/kg) reduced the inflammation and hyperalgesic parameters in a carrageenan model and reduced formalin-induced nociception in both phases, which were cold sensitivity and oedema formation. The oral administration of 30 and 100 mg/kg MEPT significantly inhibited AChE activity in the frontal cortex. CONCLUSION: This is the first chemical and biological study performed with a P. tomentosa methanolic extract and anatomical and histochemical analysis. The present study showed that MEPT inhibited pain and inflammatory parameters contributing, at least in part, to explain the popular use of this plant as analgesic natural agent. Also, anatomical and histochemistry of leaves described in the present study provide microscopical information, which aids species identification.

Chemical analysis and antioxidant, anti-inflammatory and toxicological evaluations of the hydromethanolic extract of Psidium guineense Swartz leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Psidium guineense, popularly known as "araçá-do-campo", is used in popular medicine for the treatment of inflammatory diseases. Our research group studied an essential oil obtained from its leaves and reported anti-inflammatory and analgesic properties. However, to date, the anti-inflammatory actions of the leaf extract have not been evaluated although the traditional folk use of this plant has these indications. AIM OF STUDY: The current study was designed to evaluate the antioxidant and anti-inflammatory effects and toxicity of the hydromethanolic extract of the leaves from P. guineense (HME-PG), as well as to investigate the chemical composition. MATERIALS AND METHODS: HME-PG was chemically investigated by Ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The antioxidant activity was evaluated with 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and malondialdehyde (MDA). Swiss mice were orally (p.o.) pretreated with HME-PG (30, 100 and 300 mg/kg), and after 1 h received carrageenan via paw injection (edema, cold sensitivity and mechanical hyperalgesia were analyzed) or pleural injection (leukocyte migration was analyzed after 4 h) and for nociception using the formalin model. Acute (14 days) and subacute (28 days) toxicity was assessed with female Wistar rats orally treated with 500 and 2000 mg/kg HME-PG. RESULTS: HME-PG showed high levels of phenolic and flavonoid compounds. Six compounds were identified based on UHPLC-MS/MS analysis, including gallic acid, quercetin, 3'-formyl-2',4',6'-trihydroxy-5'-methyldihydrochalcone, vanillic acid, ursolic acid and corilagin. HME-PG exhibited an IC50 of 48.14 µg/mL in the MDA assay and an IC50 of 45.15 µg/mL in the DPPH test. The treatment with HME-PG (100 and 300 mg/kg) significantly inhibited edema at all time points evaluated, mechanical hyperalgesia after 4 h and the response to cold 3 and 4 h after carrageenan injection and anti-nociceptive effects in both phases of formalin nociception. All oral HME-PG treatments significantly inhibited leukocyte migration and plasma extravasation in the pleurisy model. Toxicity tests did not cause signs of toxicity in the treated animals. CONCLUSIONS: The present study showed that HME-PG has antioxidant and anti-inflammatory properties, and no toxicity was detected after acute or subacute treatment with HME-PG, showing the possibility for the safe traditional use of P. guineense.

Analgesic and anti-inflammatory articular effects of essential oil and camphor isolated from Ocimum kilimandscharicum Gürke leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves from Ocimum kilimandscharicum Gürke (Lamiaceae) are popularly used against articular pain. AIM OF STUDY: The aim of this study was to test the anti-inflammatory and anti-hyperalgesic (analgesic) properties of the essential oil and camphor isolated from O. Kilimandscharicum leaves (EOOK) in 4 models including zymosan induced-articular inflammation model in mice. MATERIAL AND METHODS: For in vivo models, EOOK was tested in carrageenan-induced paw edema model with oral doses of 30, 100, and 300 mg/kg (oral administration = p.o.) and in zymosan-induced articular inflammation (including knee edema, leukocyte infiltration, mechanical hyperalgesia and nitric oxide), EOOK (100 mg/kg, p. o.) and camphor (30 mg/kg, p. o.) were tested. EOOK (100 mg/kg, p. o.) was tested in the rolling and also in the adhesion of leukocytes to the mesenteric microcirculation in situ model of carrageenan induced inflammation and EOOK (1, 3, 10, 30, and 60 µg/mL) was tested in vitro against neutrophils chemotaxis induced by N-formyl methionyl leucyl phenylalanine (fMLP). RESULTS: The treatment with EOOK significantly inhibited the carrageenan-induced edema, mechanical and cold hyperalgesia. Both, EOOK and camphor inhibited all articular parameters induced by zymosan. In situ intravitral microscopy analysis, EOOK significantly inhibited carrageenan-induced leukocyte rolling and adhesion. In vitro neutrophils chemotaxis, EOOK inhibited the leukocyte chemotaxis induced by fMLP. CONCLUSIONS: The present study showed that EOOK inhibited pain and inflammatory parameters contributing, at least in part, to explain the popular use of this plant as analgesic natural agent. This study also demonstrates that camphor and some known anti-inflammatory compounds present in EOOK could contribute for analgesic and anti-inflammatory articular properties.

Antioxidant, anti-rheumatic and anti-inflammatory investigation of extract and dicentrinone from Duguetia furfuracea (A. St.-Hil.) Benth. & Hook. f.

ETHNOPHARMACOLOGICAL RELEVANCE: The preparations of teas and syrups using Duguetia furfuracea have been used in folk medicine to treat rheumatism and back pain. Several rheumatic diseases are anti-inflammatory and are treated with several anti-inflammatories. AIM OF THE STUDY: The objective of this work were to evaluate the chemical investigation of methanolic extract obtained from leaves of D. furfuracea (MEDF) and test the MEDF, such as chloroform (CF), ethyl acetate (EAF) and hydromethanol (HMF) fractions and the alkaloid dicentrinone (DF-1) in vitro antioxidant effects and in vivo models of inflammation. MATERIAL AND METHODS: MEDF and CF were analyzed by LC-PDA and the results revealed the presence of alkaloid aporphine and oxoaporphine. The concentrations of total phenols, flavonoids and flavonols were determined. Additionally, MEDF, fractions and dicentrinone were evaluated free radical scavenging activity 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and peroxidation ß-carotene/linoleic acid and malondialdehyde (MDA) assays. The anti-inflammatory effects of MEDF, fractions and dicentrinone were studied in carrageenan-induced paw edema. The anti-rheumatic potential was studied in air pouch model and zymosan-induced arthritis. RESULTS: CF fractionation resulted in the isolation of the oxaporphine alkaloid dicentrinone (DF-1). The highest phenols (624.37mg GAE/g extract), flavonoids (580.51mg QE/g extract) and flavonols (254.44mg QE/g extract), concentration was found in extract. In antioxidant tests, MEDF exhibited the highest scavenging activity and lipoperoxidation. The extract (30-300mg/kg) and all tested fractions inhibited the edema induced by carrageenan. The oral administration of DF-1 inhibited both edema associated with carrageenan-induced inflammation in mice. In air pouch model of inflammation, MEDF (30-300mg/kg) and DF-1 (100mg/kg) inhibited leukocyte migration and plasmatic leakage induced by carrageenan in mice. Finally, MEDF (100mg/kg) did not alter zymozan-induced arthritis in mice. CONCLUSION: The results showed that D. furfuracea exhibits antioxidant, anti-rheumatic potential and anti-inflammatory activity. The presence of the alkaloid dicentrinone in extract and CF fraction could be responsible, at least in part, for the observed effects.

Antiulcerogenic effect of Croton urucurana Baillon bark.

ETHNOPHARMACOLOGICAL RELEVANCE: Croton urucurana (Euphorbiaceae) bark is used to treat gastric ulcers. However, to our knowledge, no study has been conducted to confirm this therapeutic property. AIM OF THE STUDY: To evaluate the antiulcerogenic effect and any possible toxic effects of Croton urucurana bark in an induced gastric ulcer model in rats. MATERIALS AND METHODS: The preventive and healing properties of Croton urucurana bark methanol extract (CUE) were evaluated in experimental models of acute (ethanol and indomethacin) and chronic (acetic acid) gastric ulcers. The gastric juice and mucous were evaluated using the pylorus ligation model, while the gastroprotective action of sulphydryl compounds and nitric oxide were analysed using the ethanol model. The toxicity was evaluated with acute and subacute toxicity tests. RESULTS: No signs of toxicity were observed in the parameters analysed. All of the CUE doses tested (50, 100 and 250mg/kg) significantly reduced the gastric lesions by 70.25, 95.40 and 98.71%, respectively. Treatment with 30mg/kg lansoprazole (positive control) inhibited 82.58% of the gastric lesions. In the indomethacin model, the 50, 100 and 250mg/kg doses of CUE significantly reduced gastric damage by 67.85, 82.50 and 71.01%, respectively, and the positive control, cimetidine (200mg/kg), reduced gastric damage by 91.02%. The CUE (100mg/kg) and cimetidine (200mg/kg) treatments significantly reduced the ulcerative pathology induced by acetic acid, promoting 81.55 and 72.62% healing, respectively. Nitric oxide did not change the cytoprotection generated by CUE. However, the antiulcerogenic activity of CUE appears to involve sulphydryl compounds because CUE activity was inhibited in animals receiving a sulphydryl compound blocker. In addition, CUE exhibited systemic effects, increasing mucous production and decreasing gastric acidity. CONCLUSIONS: The present study shows that Croton urucurana bark exerts gastroprotective activity in rats without causing toxicity. This effect appears to involve sulphydryl compounds, increasing mucus production and reducing gastric acidity.