Simultaneous Characterization of Intravenous and Oral Pharmacokinetics of Lychnopholide in Rats by Transit Compartment Model.

The pharmacokinetic properties of a new molecular entity are important aspects in evaluating the viability of the compound as a pharmacological agent. The sesquiterpene lactone lychnopholide exhibits important biological activities. The objective of this study was to characterize the pharmacokinetics of lychnopholide after intravenous administration of 1.65 mg/kg (n = 5) and oral administration of 3.3 mg/kg (n = 3) lychnopholide in rats (0.2 ± 0.02 kg in weight) through nonlinear mixed effects modeling and non-compartmental pharmacokinetic analysis. A highly sensitive analytical method was used to quantify the plasma lychnopholide concentrations in rats. Plasma protein binding of this compound was over 99 % as determined by a filtration method. A two-compartment body model plus three transit compartments to characterize the absorption process best described the disposition of lychnopholide after both routes of administration. The oral bioavailability was approximately 68 %. The clearance was 0.131 l/min and intercompartmental clearance was 0.171 l/min; steady-state volume of distribution was 4.83 l. The mean transit time for the absorption process was 9.15 minutes. No flip-flop phenomenon was observed after oral administration. The pharmacokinetic properties are favorable for further development of lychnopholide as a potential oral pharmacological agent.

Development and validation of a rapid RP-HPLC method for analysis of (-)-copalic acid in copaíba oleoresin.

The Copaifera species (Leguminoseae) are popularly known as 'copaíba' or 'copaíva' and are grown in the states of Amazonas, Pará and Ceará in northern Brazil. The oleoresins obtained from these species have been extensively used owing to their pharmacological potential and their application in cosmetic and pharmaceutical preparations. In the present study, the development and validation of a novel, rapid and efficient RP-HPLC methodology for the analysis of the diterpene (-)-copalic acid (CA), pointed out as the only chemical marker of the Copaifera genus, are described. The regression equation (Y = 26,707x - 29,498) was obtained with good linearity (r(2) = 0.9993) and the limits of quantification and detection were 9.182 and 3.032 µg/mL, respectively. The precision and the accuracy of the method were adequate (lower than 4%). Finally, the validation parameters evaluated were satisfactorily met, so the developed method represents a suitable tool for application in the quality control of such natural products. Further studies aiming to develop analytical methodologies for each Copaifera species using a more representative number of chemical markers should be performed.

Effect of the Copaifera langsdorffii Desf. Leaf Extract on the Ethylene Glycol-Induced Nephrolithiasis in Rats.

The potential of the Copaifera langsdorffii leaves extract to prevent stone formation was analyzed by means of an ethylene glycol (EG) animal model of nephrolithiasis and an in vitro crystallization assay. Different doses of the C. langsdorffii leaves extract were administered to rats treated with EG. Urine biochemical parameters were quantified. CaOx deposits count and analysis of osteopontin expression were conducted on kidneys fixed in formalin. The in vitro assay was performed by turbidimetry. Phytochemical analyses of the extract were accomplished by HPLC-UV-DAD, and several compounds were isolated. C. langsdorffii leaf extract was able to avoid stone formation. The number of deposits was 50.30 ± 31.29 at the higher extract dose, compared to the value of 179.5 ± 45.96 achieved with the EG control. Significantly lower oxalate levels and OPN expression and increased citrate levels were observed after extract administration. In the in vitro assay, the extract diluted the formed crystals. Phytochemical analyses showed that the extract is rich in phenolic compounds that are capable of preventing stone formation. Thus, on the basis of our results, we suggest that the C. langsdorffii leaf extract has potential application in the prevention of kidney stone formation.

Clove and eugenol in noncytotoxic concentrations exert immunomodulatory/anti-inflammatory action on cytokine production by murine macrophages.

OBJECTIVES: The extract and essential oil of clove (Syzygium aromaticum) are widely used because of their medicinal properties. Eugenol is the most important component of clove, showing several biological properties. Herein we have analysed the immunomodulatory/anti-inflammatory effect of clove and eugenol on cytokine production (interleukin (IL)-1ß, IL-6 and IL-10) in vitro. METHODS: Macrophages were incubated with clove or eugenol (5, 10, 25, 50 or 100µg/well) for 24h. Concentrations that inhibited the production of cytokines were used before or after incubation with lipopolysaccharide (LPS), to verify a preventive or therapeutic effect. Culture supernatants were harvested for measurement of cytokines by enzyme-linked immunosorbent assay. KEY FINDINGS: Clove (100µg/well) inhibited IL-1ß, IL-6 and IL-10 production and exerted an efficient action either before or after LPS challenge for all cytokines. Eugenol did not affect IL-1ß production but inhibited IL-6 and IL-10 production. The action of eugenol (50 or 100µg/well) on IL-6 production prevented efficiently effects of LPS either before or after its addition, whereas on IL-10 production it counteracted significantly LPS action when added after LPS incubation. CONCLUSIONS: Clove exerted immunomodulatory/anti-inflammatory effects by inhibiting LPS action. A possible mechanism of action probably involved the suppression of the nuclear factor-κB pathway by eugenol, since it was the major compound found in clove extract.

A Validated Reverse Phase HPLC Analytical Method for Quantitation of Glycoalkaloids in Solanum lycocarpum and Its Extracts.

Solanum lycocarpum (Solanaceae) is native to the Brazilian Cerrado. Fruits of this species contain the glycoalkaloids solasonine (SN) and solamargine (SM), which display antiparasitic and anticancer properties. A method has been developed for the extraction and HPLC-UV analysis of the SN and SM in different parts of S. lycocarpum, mainly comprising ripe and unripe fruits, leaf, and stem. This analytical method was validated and gave good detection response with linearity over a dynamic range of 0.77-1000.00 µg mL(-1) and recovery in the range of 80.92-91.71%, allowing a reliable quantitation of the target compounds. Unripe fruits displayed higher concentrations of glycoalkaloids (1.04% ± 0.01 of SN and 0.69% ± 0.00 of SM) than the ripe fruits (0.83% ± 0.02 of SN and 0.60% ± 0.01 of SM). Quantitation of glycoalkaloids in the alkaloidic extract gave 45.09% ± 1.14 of SN and 44.37% ± 0.60 of SM, respectively.

Gastroprotective activity of essential oil of the Syzygium aromaticum and its major component eugenol in different animal models.

Syzygium aromaticum, a medicinal plant commonly known as clove, is used to treat toothache, respiratory disorders, inflammation, and gastrointestinal disorders. From the flower buds of S. aromaticum, it is possible to obtain an essential oil comprised of a mixture of aliphatic and cyclic volatile terpenes and phenylpropanoids, being eugenol as the main component. The aims of this study were: (1) to extract the essential oil of the flower buds of S. aromaticum, (2) to identify and quantify the main component of the essential oil, and (3) to evaluate its antiulcer activity using different animal models. Assays were performed using the following protocols in rats: indomethacin-induced and ethanol/HCl-induced ulcer model. Both essential oils from S. aromaticum and eugenol displayed antiulcer activities in the rat models of indomethacin- and ethanol-induced ulcer. Studies focusing on the possible mechanisms of gastroprotection were also undertaken using the following experiments: evaluation of gastric secretion by the pylorus-ligated model, determination of mucus in gastric content, participation of nitric oxide (NO) and endogenous sulfhydryl in gastric protection. The results show that there was no significant effect on the volume of gastric juice and total acidity. However, the quantification of free gastric mucus showed that the clove oil and eugenol were capable of significantly enhancing mucus production. With regard to the NO and endogenous sulfhydryls, the results demonstrated that the gastroprotection induced by clove oil and eugenol are not related to the activities of the nitric oxide and endogenous sulfhydryls. No sign of toxicity was observed in the acute toxicity study. In conclusion, the results of this study show that essential oil of S. aromaticum, as well as its main component (eugenol), possesses antiulcer activity. The data suggest that the effectiveness of the essential oil and eugenol is based on its ability to stimulate the synthesis of mucus, an important gastroprotective factor. However, further pharmacological and toxicological investigations are required to enable its use for the treatment of gastric ulcer.