Development and characterization of liposomal formulations containing sesquiterpene lactones for the treatment of chronic gout

Gout and hyperuricemia are characterized by high uric acid levels, and their treatment involves medications that have adverse effects. In this study, we evaluated oral liposomal formulations with eremantholide C and goyazensolide as a novel approach to reduce the toxicity associated with these substances while maintaining their anti-hyperuricemic activity. We characterized the formulations and evaluated them based on encapsulation efficiency and stability over 12 months and under simulated physiological environments. We determined the toxicity of the liposomal formulations in Caco-2 cells and the anti-hyperuricemic activity in rats. The formulations exhibited nanometric size, a narrow size distribution, and a negative zeta potential, indicating their stability and uniformity. The efficient encapsulation of the sesquiterpene lactones within the liposomes emphasizes their potential for sustained release and therapeutic efficacy. Stability evaluation revealed a small decrease in the eremantholide C concentration and a remarkable stability in the goyazensolide concentration. In Caco-2 cells, the liposomes did not exert toxicity, but did exhibit an antiproliferative effect. In vivo assays demonstrated that the liposomes reduced serum uric acid levels. Our study represents an advancement in gout and hyperuricemia treatment. The liposomal formulations effectively reduced the toxicity associated with the sesquiterpene lactones while maintaining their therapeutic effects.

Lychnopholide loaded in surface modified polylactide nanocapsules (LYC-PLA-PEG-NC) cure mice infected by Trypanosoma cruzi strain a prototype of resistance to benznidazole and nifurtimox: First insights of its mechanism of action

Chagas disease (CD) remains neglected and causes high morbidity and mortality. The great difficulty is the lack of effective treatment. The current drugs cause side effects and have limited therapeutic efficacy in the chronic phase. This study aims to fulfil some gaps in studies of the natural substance lychnopholide nanoencapsulated LYC-PLA-PEG-NC (LYC-NC) and free (Free-LYC): the activity in epimastigotes and amastigotes to determine its selectivity index (SI), the therapeutic efficacy in mice infected with Colombian Trypanosoma cruzi strain and insight of the mechanism of LYC-NC action on T. cruzi. The SI was obtained by calculation of the ratio between the IC50 value toward H9c2 cells divided by the IC50 value in the anti-T. cruzi test. Infected Swiss mice were treated with 2 and 12 mg/kg/day via intravenous and oral, respectively, and the therapeutic efficacy was determined. The IC50 of LYC-NC and Free-LYC for epimastigotes of T. cruzi were similar. Both were active against amastigotes in cell culture, particularly Free-LYC. The SI of LYC-NC and Free-LYC were 45.38 and 32.11, respectively. LYC-NC 2 and 12 mg/kg/day cured parasitologically, 62.5% and 80% of the animals, respectively, infected with a strain resistant to treatment. The fluorescent NC was distributed in the cardiomyocyte cytoplasm, infected or not, and interacted with the trypomastigotes. Together, these results represent advances in demonstrating LYC as a potent new therapeutic option for treating CD.

Chemical Analysis of Eruca sativa Ethanolic Extract and Its Effects on Hyperuricaemia

In vivo assays and chemical analyses were performed on the ethanolic extract from leaves of Eruca sativa. UHPLC-ESI-QTOF analysis confirmed the presence of glucosinolates and flavonol glucosides. The major flavonoid of the ethanolic extract, kaempferol-3,4′-di-O-β-glucoside, was isolated, a HPLC-DAD method developed and validated to quantify its content in the extract. In vivo experiments were carried out on Wistar rats with hyperuricaemia induced by potassium oxonate and uric acid. A hypouricaemic effect was observed in hyperuricaemic Wistar rats treated with ethanolic extract at dose of 125 mg/kg and kaempferol-3,4′-di-O-β-glucoside at dose of 10 mg/kg. The main anti-hyperuricaemic mechanism observed in the extract was uricosuric. Kaempferol-3,4′-di-O-β-glucoside was identified as an important component responsible for the total activity of the ethanolic extract and was considered as a good chemical and biological marker of the ethanolic extract of E. sativa. The obtained results indicated the potential of E. sativa in the treatment of hyperuricaemia and its comorbidities.

Coffea arabica extracts and their chemical constituents in a murine model of gouty arthritis: How they modulate pain and inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Coffea arabica is commonly known for its cardiotonic and neurotonic activities, but in some places' folk medicine, like in Arabia and Africa, C. arabica is used to treat headache, migraine, the flu, anemia, oedema, asthenia, asthma, inflammation and wounds.

AIMS OF THE STUDY

The aims were to evaluate if the aqueous extracts of Coffea arabica, prepared from beans with different degrees of roasting, and their main chemical constituents could exert an in vivo anti-gouty effect.

MATERIALS AND METHODS

Coffea extracts were obtained from the beans of not roasted, light, medium and dark roasted coffee and from decaffeinated and traditional coffees and were prepared with water at 25°C and at 98°C. C57BL/6 mice were induced to gout by an injection of monosodium urate crystals and treated with coffee extracts at doses of 25, 75 and 225 mg/kg and their chemical constituents at a dose of 10 mg/kg. The antinociceptive and anti-inflammatory effects were evaluated.

RESULTS

Treatments with Coffea extracts prepared with water at 98°C were more effective to exert antinociceptive and anti-inflammatory activities than the ones prepared with water at 25°C. Caffeic and chlorogenic acids reduced hypernociception in animals when compared with negative control group (7.79 and 5.69 vs 18.53; P < 0.05 and P < 0.001, respectively), inhibited neutrophil migration (1.59 × 104 and 0.38 × 104 vs 9.47 × 104; P < 0.0001 both) and decreased pro-inflammatory cytokines concentration (IL-1β, IL-6 and TNF-α).

CONCLUSIONS

We have demonstrated that our treatments attenuated gout, and this effect could be attributed to a reducement in hypernociception, neutrophil migration and cytokines concentration. These results suggest coffee as a potential candidate for studies in acute gout therapy.

Lychnophora pinaster's effects on inflammation and pain in acute gout

ETHNOPHARMACOLOGICAL RELEVANCE

Ethanolic extract of aerial parts from Lychnophora pinaster Mart. are used in traditional Brazilian medicine for treating pain, rheumatism and inflammation.

AIM OF THE STUDY

Drugs for the treatment of gout present severe adverse effects, justifying the need to search for new therapeutic options. The aim of the present study was to evaluate the effects of the ethanolic extract of L. pinaster and its main constituents in arthritis induced in mice by the injection of monosodium urate (MSU) crystals.

MATERIALS AND METHODS

Antinociceptive effect was investigated using an electronic pressure-meter nociception paw test in C57BL/6 mice. Anti-gouty arthritis was investigated in mice induced with gout by the injection of MSU crystals into their femur-tibial tissue. Ethanolic extract of the aerial parts of Lychnophora pinaster and its main chemical constituents were evaluated as treatment.

RESULTS

The ethanolic extract and their main chemical constituents inhibited neutrophil migration, reduced IL-1β and TNF-α concentrations in the inflamed tissue and showed antinociceptive activity.

CONCLUSIONS

Gouty arthritis effects of the ethanolic extract can be attached to a synergistic effect of terpenes, flavonoids and phenolic acids present in the extract. Results obtained support the use of this extract and its main chemical constituents in the treatment of gout, inflammation, and pain.

Eremantholide C from aerial parts of Lychnophora trichocarpha, as drug candidate: fraction absorbed prediction in humans and BCS permeability class determination

BACKGROUND

Lychnophora trichocarpha (Spreng.) Spreng. ex Sch.Bip has been used in folk medicine to treat pain, inflammation, rheumatism and bruises. Eremantholide C, a sesquiterpene lactone, is one of the substances responsible for the anti-inflammatory and anti-hyperuricemic effects of L. trichocarpha.

OBJECTIVES

Considering the potential to become a drug for the treatment of inflammation and gouty arthritis, this study evaluated the permeability of eremantholide C using in situ intestinal perfusion in rats. From the permeability data, it was possible to predict the fraction absorbed of eremantholide C in humans and elucidate its oral absorption process.

METHODS

In situ intestinal perfusion studies were performed in the complete small intestine of rats using different concentrations of eremantholide C: 960 μg/ml, 96 μg/ml and 9.6 μg/ml (with and without sodium azide), in order to verify the lack of dependence on the measured permeability as a function of the substance concentration in the perfusion solutions.

RESULTS

Eremantholide C showed Peff values, in rats, greater than 5 × 10-5 cm/s and fraction absorbed predicted for humans greater than 85%. These results indicated the high permeability for eremantholide C. Moreover, its permeation process occurs only by passive route, because there were no statistically significant differences between the Peff values for eremantholide C.

CONCLUSION

The high permeability, in addition to the low solubility, indicated that eremantholide C is a biologically active substance BCS class II. The pharmacological activities, low toxicity and biopharmaceutics parameters demonstrate that eremantholide C has the necessary requirements for the development of a drug product, to be administered orally, with action on inflammation, hyperuricemia and gout.

Sesquiterpene lactones from Lychnophora species: Antinociceptive, anti-inflammatory, and antioxidant pathways to treat acute gout

ETHNOPHARMACOLOGICAL RELEVANCE

Lychnophora trichocarpha and Lychnophora passerina are species used in folk medicine to treat inflammation, pain, and rheumatism. Previous studies have demonstrated the anti-inflammatory effect of ethanol extracts of these species and identified that sesquiterpene lactones contribute to this activity.

AIM OF THE STUDY

Gout is an acute inflammatory arthritis caused by the deposition of monosodium urate (MSU) crystals in joints. Inflammation in joints induces oxidative stress in defense cells, releasing pro-inflammatory mediators. This study has three objectives: (1) to demonstrate the effects of sesquiterpene lactones lychnopholide and eremantholide C isolated from L. trichocarpha and goyazensolide isolated from L. passerina on arthritis induced by MSU crystals in C57BL6 mice; (2) to determine whether or not these compounds can inhibit the migration of neutrophils and the release of TNF-α and IL-1β cytokines in the inflammation region; and (3) to evaluate the effects of sesquiterpene lactones on the activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in the cartilage of C57BL/6 mice with gouty arthritis.

MATERIALS AND METHODS

The anti-inflammatory, antinociceptive, and antioxidant activities of sesquiterpene lactones in C57BL/6 mice with MSU crystal-induced arthritis were evaluated. In our experimental model, the mice were injected with MSU crystals in the tibiofemoral joint to induce arthritis and then treated with indomethacin, vitamin C, and sesquiterpene lactones. Nociception was evaluated before and after inflammation induction and treatments, neutrophil migration, IL-1β and TNF-α concentrations, and SOD and CAT activities.

RESULTS

Sesquiterpene lactones exerted an anti-inflammatory effect by inhibiting neutrophil migration and TNF-α production. These compounds also demonstrated antinociceptive and antioxidant activities.

CONCLUSION

Lychnopholide, eremantholide C, and goyazensolide improved the inflammation induced by MSU crystals by inhibiting the migration of neutrophils to the inflamed area and by blocking the release of the pro-inflammatory cytokine TNF-α. In addition, sesquiterpene lactones reduced oxidative stress by activating SOD and CAT. These results suggest that sesquiterpene lactones have anti-gout activity through the inflammation, pain, and oxidative stress pathways.

Lychnophora pinaster ethanolic extract and its chemical constituents ameliorate hyperuricemia and related inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Lychnophora pinaster, known as "Brazilian arnica" is used in folk medicine as alcoholic extract to treat inflammation, pain, rheumatism and bruises.

AIM OF THE STUDY

Evaluate the effects of the Lychnophora pinaster's ethanolic extract and its chemical constituents on inflammation and hyperuricemia.

MATERIALS AND METHODS

Ethanolic and hexanic extracts were obtained from the aerial parts of L. pinaster. Sesquiterpene E-lychnophoric acid was isolated from hexanic extract and identified by RMN, GC/MS and IR. In vivo anti-hyperuricemic and anti-inflammatory effects of the ethanolic extracts from L. pinaster (40, 125, 375 mg/kg), E-lychnophoric acid and other constituents previous isolated from L. pinaster and identified in the ethanolic extract by HPLC/UV/DAD (rutin, quercetin and vitexina flavonoids, caffeic, cinnamic and chlorogenic acids, lupeol and stigmasterol, at dose of 15 mg/kg) were assayed by experimental model of oxonate-induced hyperuricemia in Swiss mice, liver xanthine oxidase (XOD) inhibition and by MSU-induced paw edema in mice.

RESULTS

Ethanolic extract and all its components presented anti-hyperuricemic activity by inhibiting the hepatic xanthine oxidase activity. Ethanolic extract and its chemical constituents, except quercetin and vitexin, were able to reduce paw edema size induced by urate crystals. Hypouricemic and anti-inflammatory results obtained for the ethanolic extract (40, 125, 375 mg/kg) and E-lychnophoric acid (15 mg/kg) were similar those obtained for standard drugs, allopurinol (10 mg/kg) and indomethacin (3 mg/kg).

CONCLUSION

Ethanolic extract and E-lychnophoric, chlorogenic, cinnamic and caffeic acids, rutin, lupeol and stigmasterol presented anti-inflammatory and anti-hyperuricemic actvities. These compounds are responsible for the activities presented by the ethanolic extract of L. pinaster. Ethanolic extract and its chemical constituents can be considered promising agents in the therapeutic of inflammation, hyperuricemia and gout.

Determination of intestinal permeability using in situ perfusion model in rats: Challenges and advantages to BCS classification applied to digoxin

The purpose of this work was to describe the closed loop in situ perfusion method in rats and to compare the difficulties and advantages with other methods proposed by regulatory agencies for BCS classification and finally to illustrate its application to evaluate the permeability of digoxin at relevant clinical concentrations. Digoxin was evaluated at two concentration levels: 1.0 μg/ml (with and without sodium azide 65.0 μg/ml) and 6.0 μg/ml. These concentrations correspond to the ratio of the highest dose strength (0.25 mg) and the highest single dose administered (1.5 mg) and the 250 ml of water. In situ closed loop perfusion studies in rats were performed in the whole small intestine and also in duodenum, jejunum and ileum segments to evaluate the relevance of P-gp secretion in the overall permeability. A kinetic modelling approach involving passive permeation and efflux transport mechanism allowed the estimation of the passive diffusional component and the Michaelis-menten parameters. The estimated K_m value demonstrated that at clinical luminal concentrations the efflux process is not saturated and then it could be inhibited by other drugs, excipients or food components leading to the already reported clinical drug-drug and drug-food interations. The present data confirms from a mechanistic point of view these interactions.

Acute and sub chronic toxicity study of aqueous extract from the leaves and branches of Campomanesia velutina (Cambess) O. Berg

ETHNOPHARMACOLOGICAL RELEVANCE

Campomanesia velutina leaves and branches infusions are used in Brazilian folk medicine to treat diarrhea and to ameliorate intestinal cramps, respectively.

AIM OF THE STUDY

Carry out the acute and sub chronic pre-clinical evaluation and thus assess the safety and toxicological potential of the specie.

MATERIALS AND METHODS

In vivo toxicity was evaluated by acute and sub chronic toxicity assays conducted according to the guidelines of the Brazilian Agency of National Health Surveillance (Agência Nacional de Vigilância Sanitária - ANVISA). For acute toxicity evaluation, a single dose of aqueous extracts from the leaves (AEL) and branches (AEB) of Campomanesia velutina were orally administered to mice at doses of 300, 600 and 1200mg/kg. Then, the animals were observed for 14 days. In the sub chronic study, the extracts were orally administered to mice for 14 days at doses of 300, 600 and 1200mg/kg. To assess the toxicological effects, animals were closely observed on general behavior, clinical signs of toxicity, body weight, food and water intake. At the end of the experiment, it was performed biochemical and hematological evaluations, as well as histopathological analysis from the following organs: brain, heart, lungs, liver, stomach, small intestine (section) and left kidney. Preliminary phytochemical analysis was performed using thin layer chromatography (TLC) and colorimetric pharmacognostic tests.

RESULTS

In oral acute assay, treatment with AEB at the major dose (1200mg/kg) caused diarrhea, abdominal cramps and tremors in females. These effects were reversed at 4th hour. Normochromic normocytic anemia was observed in males treated with AEL 300mg/kg and AEB 600 and 1200mg/kg as well as in females treated with AEB 300 and 1200mg/kg. The kidney of all treated animals showed moderate inflammation and a few hemorrhagic points. In sub chronic assay, treatment with AEL 600mg/kg, AEL 1200mg/kg and AEB 1200mg/kg caused hyper excitability in females that was not reversed. Treatments also had impact on weight gain and the relative weight of males' brain was increased on group treated with AEL 300mg/kg, AEB 300 and AEB 1200mg/kg. Although changes in hematological parameters were not observed, serum creatinine levels were significantly higher in males treated with AEB 300mg/kg. Besides, the heart of all treated animals showed intense hyperemia. Preliminary phytochemical analysis revealed the presence of flavonoids, tannins and phenolic compounds.

CONCLUSIONS

Toxicity signs were mainly observed after treatment with AEL and AEB at the two highest tested doses (600 and 1200mg/kg), suggesting that the extracts are relatively safe at its effective dose (300mg/kg). However, alterations on hematological and biochemical parameters and on the kidney and heart of the animals were not closely related with the dose, implying caution on its use.

The influence of seasonality on the content of goyazensolide and on anti-inflammatory and anti-hyperuricemic effects of the ethanolic extract of Lychnophora passerina (Brazilian arnica)

ETHNOPHARMACOLOGICAL RELEVANCE

Lychnophora passerina (Mart ex DC) Gardn (Asteraceae), popularly known as Brazilian arnica, is used in Brazilian folk medicine to treat pain, rheumatism, bruises, inflammatory diseases and insect bites.

AIM OF THE STUDY

Investigate the influence of the seasons on the anti-inflammatory and anti-hyperuricemic activities of ethanolic extract of L. passerina and the ratio of the goyazensolide content, main chemical constituent of the ethanolic extract, with these activities.

MATERIALS AND METHODS

Ethanolic extracts of aerial parts of L. passerina were obtained from seasons: summer (ES), autumn (EA), winter (EW) and spring (EP). The sesquiterpene lactone goyazensolide, major metabolite, was quantified in ES, EA, EW and EP by a developed and validated HPLC-DAD method. The in vivo anti-hyperuricemic and anti-inflammatory effects of the ethanolic extracts from L. passerina and goyazensolide were assayed on experimental model of oxonate-induced hyperuricemia in mice, liver xanthine oxidase (XOD) inhibition and on carrageenan-induced paw edema in mice.

RESULTS

HPLC method using aqueous solution of acetic acid 0.01% (v/v) and acetonitrile with acetic acid 0.01% (v/v) as a mobile phase in a gradient system, with coumarin as an internal standard and DAD detection at 270nm was developed. The validation parameters showed linearity in a range within 10.0-150.0µg/ml, with intraday and interday precisions a range of 0.61-3.82. The accuracy values of intraday and interday analysis within 87.58-100.95%. EA showed the highest goyazensolide content. From the third to the sixth hour after injection of carrageenan, treatments with all extracts at the dose of 125mg/kg were able to reduce edema. Goyazensolide (10mg/kg) showed significant reduction of paw swelling from the second hour assay. This sesquiterpene lactone was more active than extracts and presented similar effect to indomethacin. Treatments with ES, EA and EP (125mg/kg) and goyazensolide (10mg/kg) reduced serum urate levels compared to hyperuricemic control group and were able to inhibit liver XOD activity. One of the mechanisms by which ES, EA, EP and goyazensolide exercise their anti-hyperuricemic effect is by the inhibition of liver XOD activity. Goyazensolide was identified as the main compound present in ES, EA, EW and EP and it is shown to be one of the chemical constituents responsible for the anti-inflammatory and anti-hyperuricemic effects of the ethanolic extracts.

CONCLUSION

The anti-inflammatory and anti-hyperuricemic activities of the ethanolic extracts from L. passerina were not proportionally influenced by the variation of goyazensolide content throughout the seasons. The involvement of goyazensolide on in vivo anti-inflammatory and anti-hyperuricemic activities of L.passerina extracts was confirmed, as well as the possibility of participation of other constituents on these effects. This study demonstrated that the aerial parts of L. passerina may be collected in any season for use as anti-inflammatory agent. For use in hyperuricemia, the best seasons for the collection are summer, autumn and spring. The ethanolic extract of L. passerina and goyazensolide can be considered promising agents in the therapeutic of inflammation, hyperuricemia and gout.

Tabebuia roseoalba: In Vivo Hypouricemic and Anti-inflammatory Effects of Its Ethanolic Extract and Constituents

Tabebuia species have several uses in folk medicine, including their use to treat inflammation and rheumatism. The aim of this study was to investigate whether the ethanolic extract of leaves from Tabebuia roseoalba and isolated compounds could be useful to decrease serum uric acid levels and restrain the gout inflammatory process. The compounds α-amyrin, β-amyrin, sitosterol, and stigmasterol were isolated from the ethanolic extract. Rutin and caffeic acid were identified in the ethanolic extract by HPLC analysis. The anti-hyperuricemic effect, liver xanthine oxidoreductase inhibition, and anti-inflammatory activity of the ethanolic extract and isolated compounds were evaluated on hyperuricemic mice and on paw edema induced by monosodium urate crystals in mice. The ethanolic extract of leaves from T. roseoalba, β-amyrin, and stigmasterol were able to reduce serum uric acid levels in hyperuricemic mice through inhibition of liver xanthine oxidase activity and significantly decreased the paw edema induced by monosodium urate crystals. The antioxidant activity of the ethanolic extract and its ability to inhibit xanthine oxidase were also evaluated in vitro. The ethanolic extract of leaves from T. roseoalba showed significant antioxidant activity in the three evaluated assays. Results were analyzed using GraphPad Prism 5.01. One-way ANOVA followed by Student's Newman-Keul's test was used to determine the significant differences between groups. The results show that the ethanolic extract of leaves from T. roseoalba, β-amyrin, and stigmasterol can be promising agents for the treatment for gouty arthritis, hyperuricemia, and inflammation. Stigmasterol, β-amyrin, and rutin contribute to the observed effects of the ethanolic extract of leaves from T. roseoalba.

Effects of Pimenta pseudocaryophyllus extracts on gout: Anti-inflammatory activity and anti-hyperuricemic effect through xantine oxidase and uricosuric action

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves infusion of Pimenta pseudocaryophyllus (Gomes) Landrum is used in Brazilian folk medicine to treat the predisposition to arthritical and gouty affections of the joints, fever and other diseases. A refreshing drink prepared with the specie is also used due to its diuretic, sedative and aphrodisiac actions.

AIM OF THE STUDY

The study was undertaken to investigate the mechanisms of anti-hyperuricemic effect and anti-inflammatory activity of P. pseudocaryophyllus extracts.

MATERIALS AND METHODS

Anti-hyperuricemic effect was investigated using xanthine oxidase assay and uricosuric studies with rats in which hyperuricemia was induced by potassium oxonate and uric acid. Anti-inflammatory activity was investigated on MSU crystal-induced paw edema model. Ethyl acetate extracts of the leaves (EAL) and branches (EAB), ethanolic extracts of leaves (EEL) and branches (EEB) and aqueous extracts of leaves (AL) and branches (AB) were evaluated.

RESULTS

The extracts of P. pseudocaryophyllus evaluated showed expressive results regarding the inhibition of xanthine oxidase enzyme in vitro and they were also able to reduce serum uric acid levels in hyperuricemic rats. The investigation of the mechanism of action, it was found that EAL, EAB, EEB, AB (125 and 250 mg/kg) and AL (250 mg/kg) promoted an increase on the urinary excretion of uric acid and EEL, EEB, AB (125 and 250 mg/kg) and EAB (250 mg/kg) were capable to inhibit liver xanthine oxidase. Treatments with EEL (125 and 250 mg/kg) and EEB (250 mg/kg) were able to reduce edema at 48 th h. EAL and EAB (125 and 250 mg/kg) showed significant anti-inflammatory activity on monosodium urate crystal-induced paw edema model at all evaluated times.

CONCLUSIONS

The specie P. pseudocaryophyllus showed remarkable anti-hyperuricemic effects through uricosuric effects and inhibition of xanthine oxidase and therefore can be considered as a promise in the treatment of diseases related to hyperuricemia. Moreover, ethyl acetate extracts had significant anti-inflammatory activity.

Effects of extracts of leaves from Sparattosperma leucanthum on hyperuricemia and gouty arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

The species Sparattosperma leucanthum (Vell.) K. Schum is used in Brazilian folk medicine to treat rheumatism, throat ulcers, stomatitis, syphilis, bladder stones and as blood cleanser. The aim of this study was to evaluate the potential, in vitro and in vivo, of the extracts of leaves from Sparattosperma leucanthum to treat hyperuricemia and inflammation in the gouty arthritis model.

MATERIALS AND METHODS

Ethyl acetate extract (SLE), methanolic extract (SLM) and aqueous extract (SLW) were evaluated in vitro on XO inhibitory activity and in vivo in an experimental model with oxonate-induced hyperuricemia in mice which was used to evaluate anti-hyperuricemic activity and liver xanthine oxidase (XOD) inhibition. Anti-inflammatory activity was also investigated on MSU crystal-induced paw edema model.

RESULTS

Sparattosperma leucanthum crude extracts showed expressive results on urate-lowering activity in blood. SLW at the dose of 125 mg/kg has proved to be active in reducing hyperuricemia and was capable to inhibit the hepatic xanthine oxidase enzyme (XOD). SLM showed anti-hyperuricemic activity on all doses tested; however, this extract showed activity on the XOD only at the dose of 500 mg/kg. SLE, at the three evaluated doses, has proved to be active in reducing hyperuricemia in vivo and was able to inhibit XO activity in vitro at the concentration of 100 µg/mL. This extract was also able to inhibit XOD activity in vivo at the doses of 250 mg/kg and 500 mg/kg. SLE (125 and 250 mg/kg) and SLW (500 mg/kg) showed significant anti-inflammatory activity on monosodium urate crystal-induced paw edema model.

CONCLUSIONS

The ethyl acetate, methanolic and aqueous extracts of Sparattosperma leucanthum showed significant results on evaluated models and therefore may be important agents for the treatment of gouty arthritis and hyperuricemia.

Sesquiterpene lactone in nanostructured parenteral dosage form is efficacious in experimental Chagas disease

The drugs available for Chagas disease treatment are toxic and ineffective. We studied the in vivo activity of a new drug, lychnopholide (LYC). LYC was loaded in nanocapsules (NC), and its effects were compared to free LYC and benznidazole against Trypanosoma cruzi. Infected mice were treated in the acute phase at 2.0 mg/kg/day with free LYC, LYC-poly-ε-caprolactone NC (LYC-PCL), and LYC-poly(lactic acid)-co-polyethylene glycol NC (LYC-PLA-PEG) or at 50 mg/kg/day with benznidazole solution by the intravenous route. Animals infected with the CL strain, treated 24 h after infection for 10 days, evaluated by hemoculture, PCR, and enzyme-linked immunosorbent assay exhibited a 50% parasitological cure when treated with LYC-PCL NC and 100% cure when treated with benznidazole, but 100% of the animals treated during the prepatent period for 20 days with these formulations or LYC-PLA-PEG NC were cured. In animals with the Y strain treated 24 h after infection for 10 days, only mice treated by LYC-PCL NC were cured, but animals treated in the prepatent period for 20 days exhibited 100, 75, and 62.5% cure when treated with LYC-PLA-PEG NC, benznidazole, and LYC-PCL NC, respectively. Free LYC reduced the parasitemia and improved mice survival, but no mice were cured. LYC-loaded NC showed higher cure rates, reduced parasitemia, and increased survival when used in doses 2five times lower than those used for benznidazole. This study confirms that LYC is a potential new treatment for Chagas disease. Furthermore, the long-circulating property of PLA-PEG NC and its ability to improve LYC efficacy showed that this formulation is more effective in reaching the parasite in vivo.

HPLC-DAD and UV-spectrophotometry for the determination of lychnopholide in nanocapsule dosage form: validation and application to release kinetic study

Simple and sensitive methods using high-performance liquid chromatography-diode array detection (HPLC-DAD) and ultraviolet (UV)-spectrophotometry were developed and compared to quantify lychnopholide (LYC) in poly-ε-caprolactone nanocapsules and to study its release kinetics. Both methods were validated concerning their specificity, linearity, limits of detection and quantification, precision, accuracy and stability. HPLC-DAD analyses were conducted using an RP C18 column, isocratic elution with a methanol-water (60:40 v/v) mobile phase at 0.8 mL/min flow rate and detection at 265 nm. The linear response (r(2) > 0.999) was obtained within a concentration range of 2-25 µg/mL using HPLC-DAD and 5-40 µg/mL using spectrophotometry. Intra-day and inter-day precision were obtained with low relative standard deviation values. The accuracy of the methods was within the range 98-101% for HPLC-DAD and from 96-100% for UV-spectrophotometry. Both methods were suitable to be applied for the determination of drug loading percentage (>96%) and encapsulation efficiency (>90%). Furthermore, the sensitivity of HPLC-DAD method allows studies of LYC release/dissolution in sink conditions. LYC presented 100% dissolution after 24 h, whereas only 60% of LYC was released from the nanocapsule dosage form, with no burst effect. The methods fulfilled all validation parameters evaluated for LYC quantification in the polymeric nanocapsules and have proven to be accurate, selective and sensitive in the previously mentioned applications.

Pharmacological basis for use of Lychnophora trichocarpha in gouty arthritis: anti-hyperuricemic and anti-inflammatory effects of its extract, fraction and constituents

ETHNOPHARMACOLOGICAL RELEVANCE

The ethanolic extract of Lychnophora trichocarpha Spreng. is used in Brazilian folk medicine to treat bruise, pain and inflammatory diseases.

AIM OF THE STUDY

The present study aimed at investigating whether ethanolic extract of L. trichocarpha, its ethyl acetate fraction and its main bioactive compounds could be useful to treat gouty arthritis by countering hyperuricemia and inflammation.

MATERIALS AND METHODS

L. trichocarpha ethanolic extract (LTE), ethyl acetate fraction from ethanolic extract (LTA) and isolated compounds were evaluated for urate-lowering activity and liver xanthine oxidase (XOD) inhibition in oxonate-induced hyperuricemic mice. Anti-inflammatory activity in monosodium urate crystal-induced paw oedema, an experimental model of gouty arthritis, was also investigated.

RESULTS

Crude ethanolic extract and its ethyl acetate fraction showed significant urate-lowering effects. LTE was also able to significantly inhibit liver xantine oxidase (XOD) activity in vivo at the dose of 250mg/kg. Luteolin, apigenin, lupeol, lychnopholide and eremantholide C showed the anti-hyperuricemic activities among tested compounds. Apigenin also showed XOD inhibitory activity in vivo. Luteolin, lychnopholide, lupeol and eremantholide C, in turn, did not shown significant inhibitory activity towards this enzyme, indicating that this mechanism is not likely to be involved in urate-lowering effects of those compounds. LTE, LTA, lupeol, β-sitosterol, lychnopholide, eremantholide, luteolin and apigenin were also found to inhibit monosodium urate crystals-induced paw oedema in mice.

CONCLUSIONS

Ethanolic extract of Lychnophora trichocarpha and some of its bioactive compounds may be promising agents for the treatment of gouty arthritis since they possesses both anti-hiperuricemic and anti-inflammatory properties.

In vivo wound healing effects of Symphytum officinale L. leaves extract in different topical formulations

The present work evaluates wound healing activity of leaves extracts of Symphytum officinale L. (comfrey) incorporated in three pharmaceutical formulations. Wound healing activity of comfrey was determined by qualitative and quantitative histological analysis of open wound in rat model, using allantoin as positive control. Three topical formulations, carbomer gel, glycero-alcoholic solution and O/W emulsion (soft lotion) were compared. The histological analysis of the healing process shows significant differences in treatment, particularly on its intensity and rate. The results indicate that emulsion containing both extracts, commercial and prepared, induced the largest and furthest repair of damaged tissue. This could be evidenced from day 3 to 28 by increase in collagen deposition from 40% to 240% and reduction on cellular inflammatory infiltrate from 3% to 46%. However, 8% prepared extract in emulsion presented the best efficacy. This work clearly demonstrates that comfrey leaves have a wound healing activity. The O/W emulsion showed to be the vehicle most effective to induce healing activity, particularly with extracts obtained from comfrey leaves collected in Minas Gerais state in Brazil. It shows the best efficacy to control the inflammatory process and to induce collagen deposition at 8% concentration.

Anti-inflammatory activity of Lychnophora passerina, Asteraceae (Brazilian "Arnica")

ETHNOPHARMACOLOGICAL RELEVANCE

Lychnophora passerina (Asteraceae), popularly known as "arnica," is used to treat inflammation, pain, rheumatism, contusions, bruises and insect bites in Brazilian traditional medicine.

MATERIALS AND METHODS

The anti-inflammatory activity of crude ethanolic extract of aerial parts of L. passerina and its ethyl acetate and methanolic fractions had their abilities to modulate the production of NO, TNF-α and IL-10 inflammatory mediators in LPS/IFN-γ-stimulated J774.A1 macrophages evaluated. Moreover, the crude ethanolic extract and derived fractions were also in vivo assayed by carrageenan-induced paw oedema in mice.

RESULTS

In vitro assays showed remarkable anti-inflammatory activity of L. passerina crude ethanolic extract (EE) and its ethyl acetate (A) and methanolic (M) fractions, through the inhibition of production of NO and TNF-α inflammatory mediators and induction of production of IL-10 anti-inflammatory cytokine. In vivo assays showed anti-inflammatory activity for EE 10% ointment, similar to the standard drug diclofenac gel. The A and M fraction ointments 20% presented anti-inflammatory activity.

CONCLUSION

The results obtained showed that possible anti-inflammatory effects of EE and its A and M fractions may be attributed to inhibition pro-inflammatory cytokines production, TNF-α and NO and to increased IL-10 production. EE, A and M ointments showed topical in vivo anti-inflammatory activity. The in vivo anti-inflammatory activity of EE of L. passerina may be related to synergistic effects of different substances in the crude extract. Therefore, traditional use of aerial parts of L. passerina in the inflammatory conditions could be beneficial to treat topical inflammatory conditions, as evidenced by the present study.

Antinociceptive and anti-inflammatory activities of ethanolic extracts of Lychnophora species

Extracts from Lychnophora species are traditionally used in Brazil as anti-inflammatory, and to treat bruise, pain and rheumatism. The ethanolic extract of aerial parts of five species of Lychnophoras and one specie of Lychnophoriopsis were examined for the antinociceptive (hot-plate and writhing tests) and anti-inflammatory (carrageenan-induced paw oedema test) activity in mice, by oral and topical routes, respectively. In the hot-plate test, the Lychnophora pinaster (0.75 g/kg) and Lychnophora ericoides (1.50 g/kg) extracts significantly increased the time for licking of the paws. The species Lychnophora passerina, Lychnophoriopsis candelabrum and Lychnophora pinaster, using the dose of 0.75 g/kg, and Lychnophora ericoides and Lychnophora trichocarpha in both doses evaluated (0.75 and 1.50 g/kg) significantly reduced the number of writhes induced by acetic acid. The administration of Lychnophora pinaster and Lychnophora trichocarpha ointments, in both concentrations evaluated (5 and 10%, w/w), and Lychnophora passerina and Lychnophoriopsis candelabrum, in the concentration of 10%, significantly reduced the paw oedema measured 3 h after carrageenan administration, suggesting, for the first time, an anti-inflammatory activity upon topical administration of these species. The present work comparatively demonstrated the antinociceptive and anti-inflammatory activities of some Brazilian Lychnophoras.

Xanthine oxidase inhibitory activity of Lychnophora species from Brazil ("Arnica")

Twenty-two extracts from five Lychnophora species and one Lychnophoriopsis species, traditionally used in Brazil as analgesic, anti-inflammatory, and to treat bruise and rheumatism were examined for the inhibition of xanthine oxidase (XO), the enzyme that catalyses the metabolism of hypoxanthine and xanthine into uric acid. Sixteen extracts were tested. All of them were found to have excellent XO inhibitory activity, with inhibitions greater than 38% at 100 microg/mL in the assay mixture. The most active plants examined were Lychnophora trichocarpha, Lychnophora ericoides, Lychnophora staavioides and Lychnophoriopsis candelabrum, with inhibitions of 77%, 78%, 66% and 63% at 100 microg/mL, respectively, and IC(50) values of 6.16, 8.28, 33.97 and 37.70 microg/mL, respectively.