Formulations of essential oils obtained from plants traditionally used as condiments or traditional medicine active against Staphylococcus aureus isolated from dairy cows with mastitis

The prophylactic and therapeutic overuse of antimicrobials on the farm has contributed to the emergence of hard-to-fight bacterial strains causing bovine mastitis. Aiming at alternative therapies, this study evaluated the antimicrobial activity of 20 essential oils against clinical Staphylococcus aureus strains. Of them, five with strong activities were selected and evaluated for their minimum inhibitory concentrations (MIC) in culture medium and milk, cytotoxicity against bovine mammary cells (MAC-T), antiadhesive properties, and interactions among themselves and with cefoperazone. The oils remained active on milk, were not cytotoxic, and some concentrations stimulated MAC-T cells growth, suggesting healing potential. Subinhibitory concentrations of Coriandrum sativum, Origanum vulgare, Syzygium aromaticum, and Thymus vulgaris reduced biofilm formation by at least 80%. Several oil and cefoperazone combinations displayed additive interaction, with O. vulgare and C. sativum showing the most promising results. We developed formulations for being used as prophylactic postdipping solutions in the field, containing different concentrations (1% or 3%) of the active oils, alone or in combination, with 3% glycerin, 1% Tween 80, and water. The formulations showed strong antimicrobial activity in milk and enhanced antiadhesive properties, specially when two oils were combined in the formula, indicating promising biotechnological and therapeutical applications.

Hydroalcoholic extract of Remijia ferruginea accelerates the closure of skin wounds by modulating tissue morphology and antioxidant profile: An in vitro and in vivo study

ETHNOPHARMACOLOGICAL RELEVANCE

Remijia ferruginea DC. (Rubiaceae) (syn. Cinchona ferruginea A.St.-Hil.) is used in traditional medicine for the treatment of wounds, fever and malaria.

AIM

This study investigated in vitro the proliferative and antioxidant effects of hydroalcoholic extract of leaves of R. ferruginea (HERF) and in vivo the healing effect of ointment based on HERF.

MATERIALS AND METHODS

The plant extract was characterized by liquid chromatography/mass spectrometry. Cell proliferation assays and in vitro antioxidant activity were performed. In in vivo assays, wound contraction ax was evaluated, as well as histological analyzes such as cellularity, proportion of blood vessels and collagen type I and III index. In addition, analyzes of the antioxidant enzymes SOD, CAT and GST were performed.

RESULTS

Our results showed in the chromatographic analysis that catechin, rutin and quercetin were the main phenolic compounds in the plant extract and may be responsible for the antioxidant and proliferative effects (p < 0.05). In addition, these compounds were found in higher concentration in leaves collected in spring. The ointment containing HERF was able to modulate tissue morphology, increasing cell proliferation, blood vessels, being able to stimulate the production of collagen fibers type I and III, (p < 0.05) contributing to scar tissue maturation and resistance.

CONCLUSION

Our findings indicated that the three doses of HERF tested (1%, 3% and 5%) can modulate the skin repair process, but the best effects were observed after exposure to the highest dose.

Dibenzoylmethane derivative inhibits melanoma cancer in vitro and in vivo through induction of intrinsic and extrinsic apoptotic pathways

Malignant melanoma has a low incidence, but is the most lethal type of skin cancer. Studies have shown that dibenzoylmethanes (DBMs) have interesting biological activities, including antineoplastic properties. These findings led us to investigate whether news DBM derivatives exert antitumor effects against skin cancers. In a previous study, we found that 1,3-diphenyl-2-benzyl-1,3-propanedione (DPBP) has high in vitro antineoplastic activity against murine B16F10 melanoma cells, with an IC50 of 6.25 μg/mL. In the current study, we used transdermal and topical formulations of DPBP to evaluate its activity and molecular mechanism of action in a murine model of melanoma. The compound induces tumor cell death with high selectivity (selectivity index of 41.94) by triggering apoptosis through intrinsic and extrinsic pathways. DPBP treatment reduced tumor volume as well as serum VEGF-A and uric acid levels. Hepatomegaly and nephrotoxicity were not observed at the tested doses. Histopathological analysis of sentinel lymph nodes revealed no evidence of metastases. According to the observed data, the DPBP compound was effective for the topical treatment of melanoma cancer, suggesting that it acts as a chemotherapeutic or chemopreventive agent.

Salvinia auriculata: chemical profile and biological activity against Staphylococcus aureus isolated from bovine mastitis

The aquatic plant Salvinia auriculata has been shown to possess promising properties for the treatment of Staphylococcus aureus bovine mastitis. The disease affects cattle health and compromises dairy cattle productivity, resulting in reduced milk production and higher mortality rates. The aim of this study was to evaluate the antimicrobial activity, antibiofilm activity, and toxicity of S. auriculata root extracts using bovine mammary epithelial cells (MAC-T); determine the chemical composition of the most active extract; and develop an S. auriculata antiseptic solution for pre- and post-milking teat disinfection. Plants were collected during the four seasons of the year. The most active hexane extract was subjected to bioguided fractionation, which resulted in the isolation of six known compounds, stigmast-22-ene-3,6-dione, stigmasterol, friedelinol, β-sitosterol, octadecyl alcohol, and octadecanoic acid. The antimicrobial and antibiofilm activities of the most active extract and isolated compounds were determined against nine S. aureus strains isolated from cows with mastitis. The efficacy of the S. auriculata teat dip formulation was tested using an excised teat model (ex vivo), and promising results were obtained. The S. auriculata extract formulation proved to be as effective as commercial antimicrobials in reducing log counts in excised teats.

In vitro anticariogenic and antibiofilm activities of toothpastes formulated with essential oils

OBJECTIVE

This study aimed to assess the antibacterial and antibiofilm effects of essential oils and herbal toothpastes against bacteria associated with oral diseases.

METHODS

The minimum inhibitory concentration (MIC) and antibiofilm activity of 13 essential oils against Staphylococcus aureus, Streptococcus mutans, Lactobacillus lactis, and Enterococcus faecalis. were determined. Toothpastes were formulated with different concentrations of the most active essential oils, alone and in combination, and evaluated for antibacterial and antibiofilm activities.

RESULTS

Clove, oregano, thyme, and cinnamon essential oils were effective in inhibiting all bacterial strains. The antibacterial activity of cinnamon essential oil was similar to that of the control (0.12 % chlorhexidine gluconate mouthwash). Cinnamon essential oil was a strong inhibitor of S. mutans growth. The antibiofilm activity of clove, oregano, thyme, and cinnamon essential oils at 1, 2, and 4 × MIC against S. mutans did not differ from that of the control. In the hole-plate diffusion assay, 17 out of the 18 tested toothpastes produced an inhibition halo at least half as large as that of the control. Toothpastes containing clove, clove and oregano, or clove, oregano, thyme, and cinnamon essential oils were able to completely disrupt S. mutans biofilms, not differing from the control. Thyme essential oil was found to act synergistically with chlorhexidine against S. mutans.

CONCLUSIONS

The results indicate that clove, oregano, thyme, and cinnamon essential oils may be added to fluoride-free toothpastes to enhance inhibitory effects against bacteria associated with cavities and periodontal disease. Thyme essential oil may increase the efficiency of chlorhexidine-containing dentifrices.

Biometric, histomorphometric, and biochemical profile in atorvastatin calcium treatment of female rats with dexamethasone-induced osteoporosis

OBJECTIVE

To assess the effects of atorvastatin calcium in the treatment of dexamethasone-induced osteoporosis.

METHODS

Osteoporosis induction consisted of the administration of an intramuscular dose of 7.5 mg/kg of body weight of dexamethasone, once a week for four weeks, except for the control animals (G1). The animals were divided into the following groups: G1 (control group without osteoporosis), G2 (control group with untreated osteoporosis), G3 (control group with osteoporosis treated with sodium alendronate 0.2 mg/kg) and G4 (group with osteoporosis treated with atorvastatin calcium 1.2 mg/kg). Serum alkaline phosphatase, bone alkaline phosphatase, and biometric and bone histomorphometric assessments were performed after 30 and 60 days of treatment onset.

RESULTS

In relation to the biometric and histomorphometric analyses, at 60 days of treatment, G4 presented bone density (Seedor index), bone trabecular density, and cortical thickness of 0.222 ± 0.004 g/cm, 59.167 ± 2.401%, and 387,501 ± 8573 μm, respectively, with a positive and statistically significant difference (p < 0.05), in relation to G2. At 30 and 60 days of treatment, G4 presented statistically significant serum levels of alkaline phosphatase alkaline phosphatase (p < 0.05) that were higher than all groups (7.451 ± 0.173 μg/L and 7.473 ± 0.529 μg/L, respectively).

CONCLUSION

Treatment with atorvastatin calcium demonstrated the ability of this drug to increase osteoblastic activity and bone tissue repair activity, acting differently from alendronate sodium, which demonstrated predominantly antirebsorptive activity.

Effect of vitamin K in bone metabolism and vascular calcification: A review of mechanisms of action and evidences

Osteoporosis is a public health concern associated with an increased risk of bone fractures and vascular calcification. Vitamin K presents unique benefits on these issues, although understudied. The two main forms of vitamin K are phylloquinone (vitamin K₁) and menaquinone (vitamin K₂). In this study, it was especially investigated the action of vitamin K₂ in bones and vessels. Vitamin K₂ has shown to stimulate bone formation by promoting osteoblast differentiation and carboxylation of osteocalcin, and increasing alkaline phosphatase, insulin-like growth factor-1, growth differentiation factor-15, and stanniocalcin 2 levels. Furthermore, vitamin K₂ reduces the pro-apoptotic proteins Fas and Bax in osteoblasts, and decreases osteoclast differentiation by increasing osteoprotegerin and reducing the receptor activator of nuclear factor kappa-B ligand. In blood vessels, vitamin K₂ reduces the formation of hydroxyapatite, through the carboxylation of matrix Gla protein and Gla rich protein, inhibits the apoptosis of vascular smooth muscle cells, by increasing growth arrest-specific gene 6, and reduces the transdifferentiation of vascular smooth muscle cells to osteoblasts. The commonly used dosage of vitamin K₂ in human studies is 45 mg/day and its application can be an interesting strategy in benefitting bone and vascular health, especially to osteoporotic post-menopausal women.

Pharmacological activity of the hydroalcoholic extract from Hovenia dulcis thunberg fruit and the flavonoid dihydromyricetin during hypercholesterolemia induced in rats

Cerebrovascular accidents and coronary artery disease are the leading causes of cardiovascular mortalities in Brazil and high levels of LDL cholesterol are one of the main risk factors. In this context, several plant extracts and natural substances have shown promise as cholesterol-lowering. The objective of this study was to evaluate the potential of the hydroalcoholic extract of the fruit of H. dulcisand of dihydromyricetin in cholesterol reduction in hypercholesterolemic rats. Forty-two Wistar male rats were distributed into seven groups of six animals that received diets supplemented with 1% cholesterol and 0.3% cholic acid, with the exception of the control group, which received conventional diets. Animals were treated with oral suspensions containing: atorvastatin 1.0 mg/kg; H. dulcisextract at 50.0 and 100.0 mg/kg and dihydromyricetin at 25.0 and 50.0 mg/kg vehicle (control group). The following biochemical markers were evaluated; total cholesterol, HDL-C, LDL-C, triglycerides, AST, ALT, and alkaline phosphatase. The hypercholesterolemic diet was effective in inducing hypercholesterolemia, increasing total cholesterol by 112.7% relative to the control group. The treatments with two doses of the extract proved to be promising hypocholesterolemic agents, as they were able to substantially reduce total cholesterol and LDL-C, without significantly altering triglycerides, hepatic transaminases, and alkaline phosphatase, thereby encouraging the studies with the plant H. dulcis. The groups treated with the flavonoid dihydromyricetin, although they showed a significant reduction in total cholesterol and LDL-C, and found increases in triglycerides and hepatic transaminases, which is unwanted in the context of hypercholesterolaemia.

Evaluation of immunologic profile in patients with nickel sensitivity due to use of fixed orthodontic appliances

The aim of this study was to develop a new approach to testing the impact of nickel antigen on in vitro cell-proliferation assay, to identify adverse reactions to casting alloys among orthodontic patients. Cell-proliferation assay in vitro was used as the basic methodology to assess the influence of such variables as source of nickel antigen, type of serum used to supplement the culture medium, and number of cells in the culture. We selected 35 orthodontic patients who were classified as nickel sensitive and non-nickel sensitive, based on their clinical records. Our results showed that hexahydrated nickel sulfate at 10 microg/mL, 10% of autologous sera, and 2 x 10(5) cells was the best condition for inducing the most marked nickel proliferation response in vitro. This optimized method was able to distinguish nickel-sensitive from non-nickel-sensitive dental patients and also to discriminate those with positive skin tests. Our data suggest that continuous exposure to nickel casting alloys might lead to oral tolerance mechanisms that modulate nickel sensitivity, as evidenced by the lower cell proliferation index in patients undergoing orthodontic treatment over 24 months. Finally, our findings demonstrated a known nickel-induced type 2 immune response and a marked lack of type 1 immunity (interferon gamma) as the hallmarks of nickel-sensitive patients. Further studies are needed to clarify the major cell phenotype associated with this type 2 immune response and the lack of type 1 immunity observed in nickel-sensitive people.