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.

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.

Metabolic Profile Changes in Mangalarga Marchador Horses Subjected to A Hypercaloric Diet Evaluated by Proton NMR Spectroscopy

The incidence of equine metabolic syndrome, a condition that results in endocrinopathic laminitis, is increasing worldwide. Although it is well known that the development of this syndrome depends on imbalances in energy metabolism and genetic traits, its pathophysiology remains unclear. Hydrogen nuclear magnetic resonance (¹H NMR) is a powerful tool used to compare metabolic profiles and to discriminate metabolites in living beings. The aim was to apply this technology to detect blood biomarkers candidates in horses that were previously demonstrated to developed metabolic changes when subjected to induced obesity. Nine Mangalarga Marchador horses received a hypercaloric diet for 5 months and serum metabolomic analysis was performed before, during, and after the diet period. The ¹H NMR results were subjected to multivariate analysis and NMR analysis allowed to identify six compounds (alanine, threonine, choline, α-glucose, β-glucose, and creatinine), and observe the increasing choline level over the assessment period in four animals. A hypercaloric diet altered the metabolic profile of horses, with an individual bias in the time at which these changes occurred. This study is the first to describe metabolomic compounds in Mangalarga Marchador horses subjected to a hypercaloric diet rich in non-structural carbohydrates.

Development of a bone-targeted pH-sensitive liposomal formulation containing doxorubicin: physicochemical characterization, cytotoxicity, and biodistribution evaluation in a mouse model of bone metastasis

Background

Despite recent advances in cancer therapy, the treatment of bone tumors remains a major challenge. A possible underlying hypothesis, limitation, and unmet need may be the inability of therapeutics to penetrate into dense bone mineral, which can lead to poor efficacy and high toxicity, due to drug uptake in healthy organs. The development of nanostructured formulations with high affinity for bone could be an interesting approach to overcome these challenges.

Purpose

To develop a liposomal formulation with high affinity for hydroxyapatite and the ability to release doxorubicin (DOX) in an acidic environment for future application as a tool for treatment of bone metastases.

Materials and methods

Liposomes were prepared by thin-film lipid hydration, followed by extrusion and the sulfate gradient-encapsulation method. Liposomes were characterized by average diameter, ζ-potential, encapsulation percentage, X-ray diffraction, and differential scanning calorimetry. Release studies in buffer (pH 7.4 or 5), plasma, and serum, as well as hydroxyapatite-affinity in vitro analysis were performed. Cytotoxicity was evaluated by MTT assay against the MDA-MB-231 cell line, and biodistribution was assessed in bone metastasis-bearing animals.

Results

Liposomes presented suitable diameter (~170 nm), DOX encapsulation (~2 mg/mL), controlled release, and good plasma and serum stability. The existence of interactions between DOX and the lipid bilayer was proved through differential scanning calorimetry and small-angle X-ray scattering. DOX release was faster when the pH was in the range of a tumor than at physiological pH. The bone-targeted formulation showed a strong affinity for hydroxyapatite. The encapsulation of DOX did not interfere in its intrinsic cytotoxicity against the MDA-MB-231 cell line. Biodistribution studies demonstrated high affinity of this formulation for tumors and reduction of uptake in the heart.

Conclusion

These results suggest that bone-targeted pH-sensitive liposomes containing DOX can be an interesting strategy for selectively delivering this drug into bone-tumor sites, increasing its activity, and reducing DOX-related toxicity.

Bioguided isolation of myricetin-3-O-β-galactopyranoside with antinociceptive activity from the aerial part of Davilla elliptica St.-Hil

ETHNOPHARMACOLOGICAL RELEVANCE

Davilla elliptica St.-Hil. (Dilleniaceae) is a medicinal plant traditionally used in Brazil to treat inflammatory processes, to relieve pain, as diuretic, gastro- and hepatoprotective agents.

AIM OF THE STUDY

To undertake the fractionation of the ethanolic extract from Davilla elliptica leaves guided by an antinociceptive assay.

MATERIALS AND METHODS

The antinociceptive activity was evaluated through the formalin test in mice. Extract fractionation was performed by percolation through silica gel and partition between immiscible solvents, followed by successive column chromatography over Sephadex LH-20 and preparative RP-HPLC. Structure elucidation of the isolated compound was accomplished by spectroscopic data.

RESULTS

The EtOAc and MeOH fractions derived from the crude extract reduced significantly the licking time in the late phase of the formalin test. The bioguided fractionation of the MeOH fraction resulted in the isolation of myricetin-3-O-β-galactopyranoside, which produced significant inhibition on nociception induced by formalin (ID50=0.26 mg/kg; p.o.).

CONCLUSIONS

These results point out that myricetin-3-O-β-galactopyranoside contributes for the antinociceptive effect of Davilla elliptica extract, a constituent considerably more potent than diclofenac, employed as reference drug.

Quantitative analysis of trigonelline in some Annona species by proton NMR spectroscopy

A quantitative ¹H NMR method (qHNMR) was used to measure the trigonelline content in the leaves of six species of the Annona genus. The methodology employed compared the intensities of the signals at δ 9.14 (H-2) and δ 0.00, the internal standard TSP-d₄. This measuring method was able to establish the concentration of trigonelline in the range from 0.67 to 10.04 mg·g⁻¹ depending on the investigated extract.

Biotransformation of 21-O-acetyl-deoxycorticosterone by cell suspension cultures of Digitalis lanata (strain W.1.4)

Cell cultures of Digitalis species are known to accept exogenous substrates for biotransformation reactions. We here report the biotransformation of 21-O-acetyl-deoxycorticosterone (1) by cell suspension cultures of Digitalis lanata strain W.1.4. Nine derivatives of 1 were obtained and their chemical structures determined by spectroscopic methods. 2β-Hydroxylation and C-21-glucosylation of the steroidal nucleus were described for the first time in suspension-cultured plant cells. Steroid 5α- and 5β-reduction products were also observed. Among the compounds isolated and structures elucidated were 2β,3β,21-trihydroxy-4-pregnen-20-one, 2β,3α,21-trihydroxy-4-pregnen-20-one and 3β,21-dihydroxy-5α-pregnan-20-one-3β-O-β-glucoside.

Chemical composition and vasodilatation induced by Cuphea carthagenensis preparations

The aerial parts of Cuphea carthagenensis (Jacq.) J.F. Macbride (Lythraceae) are traditionally employed in Brazil to treat cardiovascular diseases. The aim of this study was to compare preparations of C. carthagenensis aerial parts (aqueous and ethanol extracts, together with derived fractions) with regard to their total phenolic contents and in vitro vasodilating activity. The main flavonoids found in the extracts were isolated and identified as quercetin derivatives. The extracts and fractions showed similar HPLC profiles with the presence of quercetin-5-O-β-glucopyranoside, quercetin-3-O-α-arabinofuranoside and quercetin-3-sulfate in all of them, but marked differences in the contents of flavonoids, proanthocyanidins, tannis and total phenolics. Excepting the aqueous extract, all assayed preparations elicited vasodilatation on pre-contracted rat aortic rings in the range of pIC(50) 4.53±0.03 to 4.98±0.06. Polynomial regression analysis demonstrated the relationship between vasodilating activity and the contents of flavonoids (r(2)=0.5190), proanthocyanidins (r(2)=0.8016), tannins (r(2)=0.8041) and total phenolics (r(2)=0.6226), suggesting the participation of these compounds in the pharmacological effect and their potential use as chemical markers for the species.

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.

Antimicrobial, antiviral and cytotoxic activity of extracts and constituents from Polygonum spectabile Mart

Polygonum spectabile is used in Brazil for treatment of several infection diseases. Extracts and constituents isolated from this species were evaluated for cytotoxicity and effects on 15 bacterias and yeasts as well on 4 viruses strains (HHV-1, VACV-WR, EMCV, DEN-2). Less polar extracts were effective against Staphylococcus aureus, Bacillus subtillis, Micrococcus luteus, M. canis and Tricophyton mentagrophytes and T. rubrum. Two known chalcones and 3-O-β-D-glucosyl-β-sitosterol were isolated. The ethanol extract was the only one to show antiviral activity (CE50 < 30 μg/ml). One chalcone has inhibited the growth of several bacteria and was significantly active against dermathophytes. The 3 compounds isolated have shown moderate cytotoxicity against Vero and LLCMK(2) cells (CC(50) < 50 μg/ml). These results support the use of P. spectabile as antimicrobial agent.

Dihydroisocoumarin from Xyris pterygoblephara active against dermatophyte fungi

The ethanol extract from Xyris pteygoblephara aerial parts was evaluated against five microorganism strains, by the microdilution and agar diffusion methods. Extract fractionation led to the isolation of three compounds, whose structures were assigned by spectrometric data (1D and 2D NMR, IR, MS and UV) as (3R,4R)-(-)-6-methoxy-3,4-dihydro-3-n-pentil-4-acethoxy-1H-2-benzopyran-1-one (1), moronic acid and quercetin. The absolute configuration of 1 was defined by circular dichroism spectroscopy and comparison with data reported for other dihydroisocoumarins. Assay of 1 (100 microg/disc) by the agar diffusion method against clinical isolates of the dermatophytes Epidermophyton floccosum (inhibition zone, mm+/-s.d.: 4.5+/-0.8), Trichophyton mentagrophytes (4.8+/-0.4) and Trichophyton rubrum (10.2+/-0.8) revealed similar inhibition zones to the positive control amphotericin B (32 microg/disc; 5.0+/-0.2; 5.0+/-0.6 and 8.8+/-1.2, respectively). The result corroborates the ethnomedical use of Xyris species to treat dermatitis.

Antifungal constituents ofClytostoma ramentaceum andMansoa hirsuta

Ethanol extracts of Clytostoma ramentaceum Bur. & K. Schum and Mansoa hirsuta DC. (Bignoniaceae) inhibited the growth of standardized cultures of Aspergillus niger and Fusarium oxysporum, at concentrations of 400 microg and 500 microg, in bioautographic assays. The activity-guided fractionation of C. ramentaceum extract afforded ursolic acid and 2-(3',4'-dihydroxyphenyl) ethanol, both active against the test fungi (100 microg). These compounds are reported for the first time in C. ramentaceum and were not detected in M. hirsuta extract, according to HPLC analysis. The bioguided study of M. hirsuta resulted in five active fractions (100 to 200 microg), whose GC-MS analysis allowed us to identify 11 compounds, mostly alkanols and alkanodiols, that may be regarded as the antifungal constituents of M. hirsuta.

NMR characterization of new 10-membered-ring macrolactones and dihydrobenzophenazine-5-one, oxidized derivatives of benzo[a]phenazines

Peroxidation of the phenazine of beta-lapachone using m-ClC6H4CO3H-CH2Cl2 furnished a macrolactone with a rigid 10-membered ring, and the corresponding N-oxide, along with a dihydrobenzophenazine-5-one. All of the new compounds were fully characterized by spectroscopic methods, with the unambiguous assignment of the hydrogens and carbon NMR signals for the N-oxide, with the aid of 2-D NMR, mainly COSY, HMQC, HSQC and HMBC. For the other two compounds some signals could not be assigned owing to their own intrinsic features.

Diterpenes from Alomia myriadenia (Asteraceae) with cytotoxic and trypanocidal activity

Further investigation of the aerial parts of Alomia myriadenia revealed an halimane diterpene identified as ent-8S,12S-epoxy-7R,16-dihydroxyhalima-5(10),13-dien-15,16-olide along with the known ent-16-hydroxylabda-7,13-dien-15,16-olide, ent-12R-hydroxylabda-7,13-dien-15,16-olide, 6,7-methylenedioxycoumarin (ayapin), and kaempferol-7-methylether (rhamnocitrin). Evaluated in a panel of human cancer cell lines, the 16-hydroxylabade diterpene was the most active, showing an ED(50) value of 0.3 mug/ml against Lu1 (human lung cancer) cells. Tested in vitro against Trypanosoma cruzi in infected murine blood, this compound caused lysis of 100% of the parasites at 250 mug/ml.

In vitro evaluation of the activity of aromatic nitrocompounds against Trypanosoma cruzi

Fourteen compounds were evaluated for their activity against Trypanosoma cruzi blood stream forms at the concentration of 500 g/ml. Six compounds were active and re-tested at lower concentrations.