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Keratoconus is an ectasia that leads to reduced stiffness of the cornea, which acquires a conical shape. Many studies are being carried out aiming at new treatments that lead to the recovery of these cross-links. Therefore, the efficiency of the Stryphnodendron adstringens butanolic extract in promoting cross-linking in corneal stroma of porcine eyes was analyzed. The influence of concentration of this plant extract to form cross-links was analyzed, as well as the influence of the contact time. The denaturation temperature results obtained for corneas treated with 1, 2, or 4% of the barbatimão butanolic extract show an increase of 3.84, 11.37, and 33.23%, respectively. These results suggest a rise in the number of cross-links. As for the contact time of the cornea with the 2% solution of the butanolic extract, it appears that the ideal time was 60 min. Enzymatic digestion assays confirm a decrease of 39% and 59% in the relative area and relative mass of corneas in the control group, while for the group treated with the barbatimão extract, these values were close to 0% and 9%, respectively. Therefore, it was possible to verify the efficiency of the barbatimão butanolic extract in modifying the stroma of porcine corneas, which promoted an increase in resistance to thermal and enzymatic degradation. [ABSTRACT FROM AUTHOR]

Stryphnodendron adstringens is a medicinal plant that has a broad spectrum of action, including antibacterial activity. The aim of the present study was to evaluate the effect of S. adstringens alone and in combination with potassium sorbate (PS) against foodborne bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined and, for most of the bacteria tested, the crude extract (CE), aqueous fraction (AQF), and ethyl-acetate fraction (EAF) of S. adstringens had a MIC and MBC ranging from 500 to ≥ 1000 µg/mL. The AQF and EAF showed greater activity against S. aureus strains (MIC = 125 to 250 µg/mL; MBC = 500 to 1000 µg/m). Quantitative cell viability was determined and was observed reductions ranging from 3.0 to 5.8 log10 CFU/ml.The combination of S. adstringens and PS against seven S. aureus isolates was determined by the checkerboard method at neutral and acid pH. In a neutral medium, the AQF + PS combination presented synergistic or additive interactions against six S. aureus strains. The combination of EAF + PS resulted in additive interactions against four bacterial isolates. In an acidic medium, the AQF + PS combination was synergistic or additive against all S. aureus, while EAF + PS presented the same effect against six S. aureus strains S. adstringens showed important antibacterial effects against foodborne S. aureus strains. Moreover, the combination of S. adstringens fractions and PS improved the antibacterial activity compared to the compounds utilized individually. The combined use of these compounds may be an alternative to reduce bacterial food contamination and improve food safety. [ABSTRACT FROM AUTHOR]

The plant Stryphnodendron adstringens is a species of legume in the genus Stryphnodendron that is found in Brazil. It is also known as "barbatimão-verdadeiro" and it is popularly used in folk medicine due to its healing properties. Purpose: The aim of this study was to evaluate the healing activity of hydrogel, together with an S. adstringens hydroalcoholic extract, in diabetic and non-diabetic rats. Methods: The phytochemical analysis of the S. adstringens hydroalcoholic extract was evaluated through HPLC and its antioxidant activity was measured by the DPPH assay. The cytotoxicity, the scratch assay, and the fibroblast cell proliferation were also evaluated. Forty (40) Wistar rats were submitted to an excision for a full-thickness wound of 1.5 cm × 1.5 cm in their dorsum. The animals were treated twice a day over 16 days, with a rich layer of the corresponding treatment: Hydrogel; Hydrogel associated with 5% S. adstringens hydroalcoholic extract (H + SAHE); S. adstringens hydroalcoholic extract (SAHE); Collagenase with Chloramphenicol; or Carbopol. Morphological and histological analyses of the injury were performed. Results: The phytochemical analysis of SAHE indicated the presence of phenolic compounds, tannins, and flavonoids. The hydroalcoholic extract showed strong antioxidant activities (IC50 = 25.56 ± 1.04 μg/mL). H + SAHE induced the fibroblast proliferation (148 ± 6.9%) and it was not cytotoxic. The association with H + SAHE showed a more pronounced healing activity than did the other treatments in the non-diabetic animals and in the diabetic animals, hence, promoting angiogenesis and reepithelialization. Conclusion: Under these scenarios, this study has demonstrated effectiveness in the recovering wounds of diabetic rats. [ABSTRACT FROM AUTHOR]

Keratoconus is a progressive disease that affects patients' quality of life by producing corneal irregular astigmatism and low vision as the cornea becomes thinner and presents a conical protrusion. Inducing cross-linking in keratoconic corneal stroma is the current preventive intervention that effectively blocks the progression of this ectasia. As a result of this process, there is an increase in biomechanical strength and resistance of the cornea. In this context, two plant extracts rich in polyphenols (Euterpe oleracea and Stryphnodendron adstringens) have been tested in this study to compact and stiffen the tissue, and its effect was evaluated by enzymatic digestion of porcine corneas. Thermal analysis by DSC was employed to verify the corneal resistance to degradation induced by the plant extracts. The values of temperature and enthalpy of denaturation at the initial time were: 65.6 ± 0.3 °C/3.8 ± 0.3 J g−1; 79.4 ± 0.5 °C/5.5 ± 0.4 J g−1; and 93.1 ± 1.2 °C/8.0 ± 0.6 J g−1, respectively, for the control, E. oleracea, and S. adstringens groups. After 24 h of collagenase digestion, these values were: 60.1 ± 0.8 °C/1.3 ± 0.1 J g−1; 78.1 ± 1.0 °C/5.6 ± 0.6 J g−1; and 93.2 ± 0.6 °C/8.1 ± 0.06 J g−1, respectively. These results show that there was no decrease in temperature and enthalpy of denaturation (p < 0.01) in corneas of the groups treated with the E. oleracea or S. adstringens extracts. However, in the control group, the temperature and the enthalpy decreased by approximately 8% and 65%, respectively. Therefore, this work demonstrated for the first time that plant extracts rich in polyphenols were efficient in decreasing the digestion and increasing the denaturation temperature of corneas. [ABSTRACT FROM AUTHOR]

Keratoconus is an eye ectasia that affects the cornea causing distortion of vision. Corneal crosslinking promoted by riboflavin photo-stimulated at 365 nm is a treatment used successfully to block the keratoconus progression. In this study, we characterize rabbit corneas subjected to enhanced crosslinking using different vegetable extracts prepared from Stryphnodendron adstringens (Mart.) Coville bark by differential scanning calorimetry. The extracts tested in this study were: aqueous, ketonic, ethanolic, ethyl acetate and hydroalcoholic, which revealed high levels of polyphenols, such as proanthocyanidins. The corneas, obtained from the slaughter rabbits, were divided into groups: control (consisting of untreated corneal samples) and S. adstringens, where the samples were subjected to 4% vegetable extracts for 2 h. The DSC profiles of the corneas were obtained in nitrogen atmosphere. The results showed that temperature and enthalpy of denaturation of the corneal samples treated with S. adstringens were higher than the control group. The control group presents temperature and enthalpy values of 59.8 ± 1.1 °C and 24.6 ± 2.7 J g, respectively. After crosslinking with ketone extract, the values were 90.1 ± 1.1 °C and 39.9 ± 2.7 J g. These results show that S. adstringens is efficient to increment the crosslinking level of the corneas. [ABSTRACT FROM AUTHOR]

Stryphnodendron adstringens (Martius) Coville is a medicinal plant described as having pharmacological properties as anti-inflammatory and antimicrobial activities. Silver chloride nanoparticles (AgCl-NPs) have shown great potential for biomedical applications with efficient antimicrobial properties. Here, we report the photosynthesis of AgCl-NPs using plant extract from S. adstringens (SaAgCl-NPs) and their cytotoxic and antimicrobial activities. We photosynthesized SaAgCl-NPs nearly spherical with low heterogeneity in size and enveloped by an organic material layer responsible for colloidal stability. SaAgCl-NPs was non-cytotoxic against mammalian VERO cells; however, SaAgCl-NPs presented remarkable antifungal activity against the pathogenic yeast Cryptococcus neoformans (MIC80 of 0.32 µg/mL) the causative agent of human cryptococcosis. Notable antibacterial activity was observed against Gram-negative bacteria Pseudomonas aeruginosa (MIC80 of 2.56 µg/mL) e Serratia marcescens (MIC80 of 20.48 µg/mL) both microorganisms associated with a variety of human infections, in particular pneumonia. In contrast, Gram-positive bacteria Staphylococcus aureus and Staphylococcus epidermidis, microorganisms that cause pathologies as skin infections, were less susceptible to the SaAgCl-NPs both with MIC80 of 40.93 µg/mL. Thus, SaAgCl-NPs represents an organic–inorganic hybrid nanomaterial with very low cytotoxicity against mammalian cells and high antimicrobial efficiency against pathogenic microorganisms and may be explored as an alternative to antimicrobial drugs. [ABSTRACT FROM AUTHOR]