Analgesic and Anti-Inflammatory Properties of Ethanolic Extract of Piper vicosanum Leaves.

Nonclinical trials are important to validate the efficacy and safety of medicinal plants. Scientific toxicological studies with Piper vicosanum Yuncker have showed its safety; however, no studies have indicated the analgesic or antiarthritic potential of the ethanolic extract of P. vicosanum leaves (EEPV). The objective of the present work was to evaluate the antiarthritic and antinociceptive effects of EEPV in experimental mouse models. The oral administration of EEPV (100, 300, and 700 mg/kg) and dexamethasone (1 mg/kg) were performed in carrageenan-induced pleurisy, in formalin and acetic-acid-induced nociception, and in zymosan-induced articular inflammation models in Swiss mice. The EEPV (300 mg/kg) was tested in zymosan-articular inflammation, the complete Freund's adjuvant (CFA) inflammatory model, and in in situ intravitreal microscopy analysis of rolling and adhesion events of leukocytes in the mesenteric microcirculation in mice. EEPV significantly inhibited: (i) nociceptive response at phase 1 and 2, and also in the cold response in the formalin model; (ii) abdominal contortion induced by acetic acid; (iii) mechanical hyperalgesia after 4 and 6 h, knee edema after 6 h, and leukocyte migration in articular inflammation induced by zymosan. All doses of EEPV reduced the leukocyte migration to the inflamed pleural cavity and knee edema 4 h after the zymosan knee injection. The treatment with the EEPV significantly inhibited the CFA-induced edema, mechanical and cold hyperalgesia, and NAG and MPO. The EEPV also significantly inhibited carrageenan-induced leukocyte rolling and adhesion. The present study revealed, for the first time, the antiarthritic and antinociceptive effects of the EEPV.

Evaluation of the safety of ethanolic extract from Piper amalago L. (Piperaceae) leaves in vivo: Subacute toxicity and genotoxicity studies.

Piper amalago L. (Piperaceae) is traditionally used due to its anti-inflammatory, analgesic, diuretic, and antiparasitic properties. However, few studies have focused on its adverse effects, compromising its safe use. This study evaluated the toxicological safety of ethanolic extract from Piper amalago leaves (EEPA), through subacute toxicity and genotoxicity assays in rodents. In subacute toxicity, 100, 200 or 300 mg/kg of EEPA were tested in female Wistar rats, by gavage, for 28 days. For genotoxicity test, female Swiss mice were orally treated with 17.5, 175 or 1750 mg/kg of EEPA and the comet, micronucleus, and splenic phagocytic assays were evaluated. In subacute toxicity, the extract induced an increase in the food and water intakes, as well as in the liver absolute weight, and in the heart and kidney relative weights. EEPA also provoked alterations in histopathological analysis of liver and in hemato-biochemical parameters, evidenced by a decrease in hematocrit levels and albumin levels, and an increase in the number of platelets and in alkaline phosphatase and cholesterol levels. However, EEPA did not presented genotoxic nor mutagenic properties. EEPA showed hemato-biochemical toxicity profile in rats and should be used with caution, especially when for prolonged period.

Evaluation of the toxicokinetics and apoptotic potential of ethanol extract from Echinodorus macrophyllus leaves in vivo.

This study evaluates the toxicological, genotoxic, mutagenic and apoptotic potential of an in vivo assay from Echinodorus macrophyllus extract (EEM). The acute toxicity test used 02 groups (n = 5) of female Wistar rats: negative control group (saline) and experimental group (2000 mg/kg b.w. EEM), both orally administered (gavage) at single doses and monitored for 14 days. To assess the genotoxic, mutagenic and apoptotic potential, 50 male Swiss mice were divided into 5 groups (n = 10): Group I: negative control (saline solution 0.1 ml/10 g b.w.); Group II: positive control (cyclophosphamide 100 mg/kg b.w.) intraperitoneally administered; groups III-V received EEM at 500, 1000 and 2000 mg/kg b.w., respectively. Groups I, III-V received oral administrations (gavage). The results showed that there was no acute lethality or any signs of acute toxicity, indicating that LD50 is greater than 2000 mg/kg b.w. The groups treated with EEM showed no genotoxic or mutagenic activity and did not induce apoptosis in the liver and kidney. Therefore, EEM showed no acute toxicity and at doses of 500, 1000 and 2000 mg/kg b.w. absence of genotoxicity, mutagenicity and no apoptotic events were observed.

Anti-nociceptive, anti-hyperalgesic and anti-arthritic activity of amides and extract obtained from Piper amalago in rodents.

ETHNOPHARMACOLOGICAL RELEVANCE: Piper amalago (Piperaceae) has been used in folk medicine as an analgesic. This study aimed to evaluate the pharmacological effects of extract and pure amides obtained from P. amalago on pain to provide a pharmacological basis for their use in traditional medicine. AIM OF THE STUDY: This study evaluated the anti-nociceptive, anti-hyperalgesic, anti-arthritic and anti-depressive activities of the ethanolic extract of P. amalago (EEPA) and the amides N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl] pyrrolidine (1) and N-[7-(3',4'-methylenedioxyphenyl)-2(E),4(E)-heptadienoyl] pyrrolidine (2) obtained from P. amalago in animal models. MATERIALS AND METHODS: Mice treated daily with EEPA (100mg/kg, p.o.) were assayed for 20 days for knee edema (micrometer measurement), mechanical hyperalgesia (analgesiometer analysis), heat sensitivity and immobility (forced swim test) in the Complete Freund's Adjuvant (CFA) model. Cold (acetone test) and mechanical hyperalgesia (electronic von Frey analysis) responses were evaluated for 15 days in rats treated with oral EEPA (100mg/kg) in the spared nerve injury (SNI) model. Meanwhile, mice were evaluated for carrageenan-induced edema and mechanical hyperalgesia and for nociception using the formalin model after a single administration of EEPA (100mg/kg) or amides 1 and 2 (1mg/kg). RESULTS: Amides (1) and (2) were detected and isolated from the EEPA. The EEPA inhibited mechanical hyperalgesia, knee edema, and heat hyperalgesia, but not depressive-like behavior, induced by the intraplantar injection of CFA. When evaluated in the SNI model, the EEPA inhibited mechanical and cold hyperalgesia. The EEPA, 1 and 2 prevented the mechanical hyperalgesia induced by carrageenan and the anti-nociceptive effects in both phases of formalin nociception. The EEPA did not induce alterations in the open field test. CONCLUSION: The EEPA was effective for inhibition of pain and arthritic parameters but was not effective against depressive-like behavior; additionally, it did not alter locomotor activity. The amides obtained seemed to be the active component(s) present in the EEPA because they proved to be anti-nociceptive and anti-hyperalgesic in models of acute pain. Considering that few drugs are currently available for the treatment of chronic pain, especially neuropathic pain, the present results may have clinical relevance and open new possibilities for the development of new anti-hyperalgesic and anti-arthritic agents from P. amalago.

Toxicological analysis and anti-inflammatory effects of essential oil from Piper vicosanum leaves.

This study assessed the anti-inflammatory effects of the essential oil from Piper vicosanum leaves (OPV) and evaluated the toxicological potential of this oil through acute toxicity, genotoxicity and mutagenicity tests. The acute toxicity of OPV was evaluated following oral administration to female rats at a single dose of 2 g/kg b.w. To evaluate the genotoxic and mutagenic potential, male mice were divided into five groups: I: negative control; II: positive control; III: 500 mg/kg of OPV; IV: 1000 mg/kg of OPV; V: 2000 mg/kg of OPV. The anti-inflammatory activity of OPV was evaluated in carrageenan-induced pleurisy and paw edema models in rats. No signs of acute toxicity were observed, indicating that the LD50 of this oil is greater than 2000 mg/kg. In the comet assay, OPV did not increase the frequency or rate of DNA damage in groups treated with any of the doses assessed compared to that in the negative control group. In the micronucleus test, the animals treated did not exhibit any cytotoxic or genotoxic changes in peripheral blood erythrocytes. OPV (100 and 300 mg/kg) significantly reduced edema formation and inhibited leukocyte migration analyzed in the carrageenan-induced edema and pleurisy models. These results show that OPV has anti-inflammatory potential without causing acute toxicity or genotoxicity.

Diuretic and antilithiasic activities of ethanolic extract from Piper amalago (Piperaceae).

OBJECTIVE: Piper amalago is used in Brazilian folk medicine as diuretic and for the treatment of urinary calculus disease, although no scientific data have been described to support these effects. Thus, this study aims to evaluate the diuretic effects and antilithiatic activity of the ethanolic extract of P. amalago (EEPam). MATERIALS AND METHODS: Ethanolic extracts of P. amalago (125, 250 and 500mg/kg) were orally administered in male Wistar rats (n=5) and urinary excretion was measured at intervals of up to 24h after administration. The antilithiasic effect of EEPam on calcium oxalate urolithiasis crystallization was examined in a turbidimetric model. RESULTS: The oral administration of all doses of EEPam significantly increased urine output after 24h when compared to control group. Moreover, the application of EEPam, induced an inhibitory effect on calcium oxalate crystallization. CONCLUSIONS: According to results, P. amalago extracts showed diuretic and natriuretic activity and antilithiasic effects.

In vitro trypanocidal activity of phenolic derivatives from Peperomia obtusifolia.

The trypanocidal activity of crude extracts and fractions from the leaves and stems of Peperomia obtusifolia (Piperaceae) was evaluated in vitro against the epimastigote forms of Trypanosoma cruzi. Bioactivity-guided fractionation of the most active extracts afforded seven known compounds, including three chromanes, two furofuran lignans and two flavone C-diglycosides. The most active compounds were the chromanes peperobtusin A and 3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(2''-methyl-2''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2 H-1-benzopyran-6-carboxylic acid, with IC (50) values of 3.1 microM (almost three times more active than the positive control benznidazole, IC (50) 10.4 microM) and 27.0 microM, respectively. Cytotoxicity assays using peritoneal murine macrophages indicated that the chromanes were not toxic at the level of the IC (50) for trypanocidal activity. This is the first report on the trypanocidal activity besides unspecific cytotoxicity of chromanes from Peperomia species. Additionally it represents the first time isolation of 3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(2''-methyl-2''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2 H-1-benzopyran-6-carboxylic acid from P. obtusifolia.