Patricia Santos Lopes

In Vitro Antiophidian Properties of Dipteryx alata Vogel Bark Extracts

Extracts from Dipteryx alata bark obtained with different solvents (hexane, dichloromethane, ethyl acetate and methanol) were mixed in vitro with Bothrops jararacussu (Bjssu, 40 μg/mL) and Crotalus durissus terrificus (Cdt, 15 μg/mL) snake venoms, and applied to a mouse phrenic nerve-diaphragm preparation to evaluate the possible neutralization of venom effects. Cdt venom neurotoxic effect was not inhibited by any of the extracts, while the neurotoxic and myotoxic actions of Bjssu venom were decreased by the methanolic extract. This inhibition appears to be augmented by tannins. Dichloromethane bark extract inhibited ~40% of Bjssu venom effects and delayed blockade induced by Cdt. The methodology used to determine which extract was active allows inferring that: (i) phenolic acids and flavonoids contained in the methanolic extract plus tannins were responsible mostly for neutralization of Bjssu effects; (ii) terpenoids from the dichloromethane extract may participate in the anti-Cdt and anti-Bjssu venom effects; (iii) a given extract could not inhibit venoms from different species even if those belong to the same family, so it is improper to generalize a certain plant as antiophidian; (iv) different polarity extracts do not present the same inhibitory capability, thus demonstrating the need for characterizing both venom pharmacology and the phytochemistry of medicinal plant compounds.

Evaluation of in vitro percutaneous enhancement effect of papain and pequi oil on diclofenac sodium permeation through human skin

The purpose of this research was to determine the potential of papain and pequi oil as penetration enhancers for diclofenac sodium (DS) across human skin in vitro. The permeation studies were conducted with vertical diffusion cells. The enhancers were associated or not in gels in different concentrations. In vitro studies reveled that papain 0.2% (w/v) presented an elevated enhancer property for diclofenac sodium (J = 0.3369 mg/cm2x h). Pequi oil 10% (w/v) generated a reduced flux value (J = 0.1848 mg/cm2x h) and a combination of both enhancers presented a medium value of J = 0.2187 mg/cm2x h. Papain was found to be better enhancer than pequi oil.

Rubus rosaefolius Extract as a Natural Preservative Candidate in Topical Formulations

ABSTRACTEven though the synthetic preservatives may offer a high antimicrobial efficacy, they are commonly related to adverse reactions and regarded as having potentially harmful effects caused by chronic consumption. The development of natural preservatives provides a way of reducing the amount of synthetic preservatives normally used in pharmaceutical and cosmetic preparations. In addition, these agents have less toxic effects and represent a possible natural and safer alternative of the preservatives. The purpose of this research was to evaluate the Rubus rosaefolius Smith extract efficiency as a natural preservative in base formulations. Of the extract, 0.2% (w/w) was assayed for its effectiveness of antimicrobial protection in two different base formulations (emulsion and gel). The microbial challenge test was performed following the standard procedures proposed by The United States Pharmacopoeia 33nd, European Pharmacopoeia 6th, Japanese Pharmacopoeia 15th, and the Cosmetics, Toiletries, and Fragrance Association using standardized microorganisms. The results demonstrated that R. rosaefolius extract at the studied concentration reduced the bacterial inocula, satisfying the criterion in all formulations, even though it was not able to present an effective preservative behavior against fungi. Thus, the investigation of new natural substances with preservative properties that could be applied in pharmaceutical and cosmetic products is relevant due to the possibility of substituting or decreasing the concentration of synthetic preservatives, providing a way for the development of safer formulas for the use of consumers.

Estudo botânico, fitoquímico e avaliação da atividade antimicrobiana de Rubus rosaefolius Sm. - Rosaceae

Rubus rosaefolius Sm., Rosaceae, is a shrub with compound leaves, recurvate prickles, white flowers and aggregate fruit, popularly known as sylvan strawberry. The present research concerns its botany (macroscopic and microscopic studies), phytochemistry and antimicrobial properties. The presence of antraquinones, saponins, flavonoids, alkaloids and tannins on stem, root and leaves, were confirmed by specific phytochemical tests. Antimicrobial activity of aqueous and hydroalchoolic fractions were tested against E. coli, S. aureus, P. aeruginosa and C. albicans. The hydroalchoolic fraction revealed antimicrobial activity against all species tested and the aqueous fraction inhibited the growth of S. aureus and C. albicans.

Development of papain containing pellets produced by extrusion–spheronization: an operational stage approach

Abstract The performance of the standardized extrusion–spheronization technique, operational conditions, formulation parameters and storage of the final product over the bioactivity of papain containing pellets has been evaluated to obtain an insight into the potential of the technique for the manufacture of solid protein formulations. The pellets produced were assayed in terms of biological activity – monitored at each operational stage using N-benzoyl-dl-arginine ρ-nitroanilide as a substrate, and according to the physical properties – evaluated by means of size distribution, apparent density and friability. The produced pellets presented adequate physical and mechanical properties. Monitoring biological activity at each production stage revealed that the most critical steps corresponded to drying and storage, with bioactivity decay ranging from 5 to 30% and 5 to 20% for each process. Dry mixing and extrusion did not hold any influence over papain activity, while wet massing decreased the bioactivity by approximately 0–5% and the spheronization 0–2%. The results varied as a function of the experimental conditions and formulation components. In conclusion, the extrusion--spheronization technique was suitable to produce solid multiparticulate dosage forms for papain, considering the possibility to originate pellets with relatively low bioactivity decay. However, weak points of the technique corresponded to the wet massing and drying stages as well as storage.

In vitro safety assessment of papain on human skin: A qualitative Light and Transmission Electron Microscopy (TEM) study

Papain is a thiol proteolytic enzyme widely used in dermatology that found applications in wound treatment. Recently, papain was also used as absorption enhancer which can modify the peptide/protein material in the bilayer domain. We investigated papain safety using human skin that was exposed to papain in vitro at different times: 4, 24 and 48 hours. The samples were examined using Light and Transmission Electron Microscopy (TEM) to study of the mechanisms involved in enhancer-skin interaction. After 24 hours, changes occurred in corneosomes. However, samples of 48 hours did not show major changes in agreement with the control. These findings indicated that papain could be used safely onto the skin.

Mutagenicity induced by the hydroalcoholic extract of the medicinal plant Plathymenia reticulata Benth

Plathymenia reticulata Benth has an anti-inflammatory effect and is capable of neutralizing the neuromuscular blockade induced by Bothrops jararacussu or Crotalus durissus terrificus venoms, probably by precipitating venom proteins (an effect caused by plant tannins). The present study aimed to evaluate the mutagenic activity of P. reticulata by using the Salmonella mutagenicity assay (Ames test) and the micronucleus test in CHO-K1 cells. P. reticulata extract concentrations of 2.84, 5.68, 11.37, and 19.90 mg/plate were assayed by the Ames test using TA97a, TA98, TA100 and TA102 bacterial strains, with (+S9) and without (-S9) metabolic activation. Concentrations of 5, 1.6 and 0.5 μg/mL of P. reticulata extract were used for the micronucleus test. P. reticulata extract was mutagenic to TA98 (-S9) and showed signs of mutagenic activity in TA97a and TA102 (both -S9) strains. Micronucleus test CBPI values showed that the endogenous metabolic system increased the number of viable cells when compared to the non-activated samples and the micronucleus frequency increased when the cells were treated in the absence of S9. We concluded that P. reticulata extract may present direct mutagenic properties.

Assessment of Cytotoxicity, Fetotoxicity, and Teratogenicity of Plathymenia reticulata Benth Barks Aqueous Extract

Scientific assessment of harmful interactions of chemicals over the entire reproductive cycle are divided into three segments based on the period: from premating and mating to implantation (I), from implantation to major organogenesis (II), and late pregnancy and postnatal development (III). We combined the segments I and II to assess Plathymenia reticulata aqueous extract safety. In order to investigate reproductive toxicity (segment I), pregnant rats received orally 0.5 or 1.0 g/kg of extract, daily, during 18 days. These concentrations were determined by a preliminary in vitro LD50 test in CHO-k1 cells. A control group received deionized water. The offspring was removed at the 19th day, by caesarean, and a teratology study (segment II) was carried out. The corpora lutea, implants, resorptions, live, and dead fetuses were then counted. Placenta and fetuses were weighted. External and visceral morphology were provided by the fixation of fetuses in Bouin, whereas skeletal analysis was carried out on the diaphanizated ones. The increase in the weights of placenta and fetuses was the only abnormality observed. Since there was no sign of alteration on reproduction parameters at our experimental conditions, we conclude that P. reticulata aqueous extract is safe at 0.5 to 1.0 g/kg and is not considered teratogenic.

Thermal Characterization and Cytotoxicity of Complexes Formed by Papain and Cyclodextrin

Papain is a proteolytic enzyme with restricted applications due to its limited stability. Cyclodextrins are widely used in pharmaceutical formulations once they are able to form complexes with other molecules, improving their stability and bioavailability. The purpose of the present paper was to analyze complexes formed by papain/hydroxypropyl-β-cyclodextrin and papain/β-cyclodextrin by thermal analysis and cytotoxicity tests to verify their possible interactions and toxicological behavior. Complex solutions were prepared at different molar ratios and collected as a function of time to be lyophilized and analyzed. Results showed changes in endothermic events and cytotoxicity profiles. A complex formation for both complexes is observed; nevertheless, β-cyclodextrin was able to change the enzyme characteristics more efficiently.

The effect of andiroba oil and chitosan concentration on the physical properties of chitosan emulsion film

Chitosan film is used as a dressing to heal burns. The physical and biological properties of the film can be modified by the addition of phytotherapic compounds. This work used the casting -solvent evaporation technique to prepare chitosan film containing andiroba oil (Carapa guianensis) which has anti-inflammatory, antibiotic, and healing properties. The objective of this study was to determine the effect of the concentrations of chitosan and andiroba oil on the physical properties of chitosan films. The emulsion films were evaluated concerning the mechanical properties and fluid handling capacity. Additionally, scanning electron microscopy and thermal analysis were performed. The results showed that the barrier and mechanical properties were affected by the addition of andiroba oil, and these may be modulated as a function of the concentration of oil added to the film. The thermal analysis showed no evidence of chemical interactions between the oil and chitosan.