Toxicological effects of acute and repeated doses (180 days) of fruits from Malpighia emarginata (acerola) in rodents.

Malpighia emarginata has a high amount of vitamin C with pharmacological or food preservation potential. However, despite its wide use and application possibilities its toxicity in repeated doses and for a long time (6 months) has not yet been studied. In this context, this study aimed to evaluate the acute toxicity and repeated doses from fruits of this plant. The extract was produced with the pulp (EMe) of the lyophilized fruit and submitted to chromatographic and spectroscopic analysis (HPLC and ESI-IT-MSn). In the acute test, the EMe was administered orally and parenterally to rodents (mice and rats) for 14 days, at a dose of 2000 mg/kg. Subsequently, the repeated dose toxicity test was administered orally for 180 days at doses of 50, 300 or 1000 mg/kg. The HPLC assay revealed a high concentration of vitamin C (16.3%), and spectroscopic analyses pointed to the presence of five other polyphenolic compounds. In the acute test, the plant extract showed no apparent toxicity or lethality in rodents. The LD50 was estimated to be greater than 2000 mg/kg and falls into category 5 (low toxicity). In the repeated dose assay, there was no evidence of toxicity, and no differences were observed in water intake, food, weight development, or behavior of the animals in relation to the vehicle group (water). However, hematological and biochemical evaluations pointed out some nonconformities in the levels of cholesterol, leukocytes, and neutrophils of the male rats, but overall, these results did not reveal significant toxicity. Therefore, the Level of Unobserved Adverse Effects (NOAEL) was 1000 mg/kg. Together, the results suggest that the extract obtained from the fruits of M. emarginata does not present representative toxicity in rodents.

Microbiological, thermal and mechanical performance of cellulose acetate films with geranyl acetate.

The present work concerns to investigate the microbiological, thermal and mechanical behavior of cellulose acetate films obtained with addition of 0.5 % (v/v) and 1.0 % (v/v) of geranyl acetate by the casting technique. The antimicrobial activities of the polymeric films were assessed against Staphylococcus aureus and Escherichia coli bacteria and against Aspergillus flavus fungal. The achieved results show that the films presented antibacterial and antifungal activities. Moreover, the incorporation of the geranyl acetate in the polymeric films was confirmed by FTIR and TGA technique, while DSC analysis pointed out the compatibility between the geranyl acetate and cellulose acetate. The addition of the geranyl acetate did not modify the mechanical behavior of the cellulose acetate films concerning stiffness and tensile strength. These results suggest that this new material is promising for future applications in biomedical devices and food packaging.

Antifungal Activity and Acute and Repeated-Dose Toxicity Study of Geranyl Cinnamate Ester in Mice.

In the present study, the antifungal activity and toxicity of the geranyl cinnamate ester (GCE) were investigated. The GCE showed antifungal activity at a minimum concentration of 0.16 µL/mL against Candida albicans and at concentrations greater than 2.5 µL/mL against Aspergillus niger. In acute toxicity studies, the administration of GCE (2.000 mg/kg) affected the body weight gain and food intake but did not induce the mortality of the animals studied. After the investigation of repeated-dose toxicity of GCE at 2 and 4 mg/kg, the hematological and biochemical parameters were changed. In addition, the adrenal weight of male mice treated with GCE at 4 mg/kg was affected. In conclusion, according to the Organization for Economic Cooperation and Development (OECD) acute toxicity parameters, the geranyl cinnamate ester can be classified into safety category number 5. The results of this study suggested that the geranyl cinnamate ester may be a source of natural antifungals.

Encapsulation of geranyl cinnamate in polycaprolactone nanoparticles.

Geranyl cinnamate is an ester derived from natural compounds that has excellent antibacterial properties but is susceptible to degradation in the presence of oxygen, light, heat, moisture and other aggressive agents, making it unstable. In this work, the encapsulation of geranyl cinnamate in polycaprolactone (PCL) nanoparticles and its antibacterial properties towards Escherichia coli and Staphylococcus aureus were investigated. PCL nanoparticles loaded with geranyl cinnamate were obtained by a miniemulsification/solvent evaporation technique resulting in spherical nanoparticles with an average diameter of 177.6 nm. TGA showed that geranyl cinnamate evaporation was retarded at 20 °C after encapsulation. Aqueous dispersions of geranyl cinnamate-loaded PCL nanoparticles stored at 4 °C presented good colloidal stability over 60 days. Minimum inhibitory concentration (MIC) tests showed that geranyl cinnamate was not released from the PCL nanoparticles in aqueous solution even after 72 h, requiring the use of a trigger (e.g. oil phase, lipase to degrade the polymer matrix) to release the active compound.

Microencapsulation of garlic oil by ß­cyclodextrin as a thermal protection method for antibacterial action.

The present study investigated the encapsulation process of garlic oil in ß­cyclodextrin (ßCD) and the antibacterial properties of the ßCD-garlic oil complex against Escherichia coli and Staphylococcus aureus. The encapsulation method increased the thermal stability of garlic oil with a formation constant (Kc) value of 253.78 L·mol-1 for of the ßCD-garlic oil complex, which confirmed the success of the encapsulation process. Scanning electron microscopy analysis showed that the dimensions of the structures formed by the inclusion complex of ßCD-garlic oil had values ranging from 5 to 10 µm. After thermal treatment of the ßCD-garlic oil complex at 60 °C for 1 h, the complex retained significant antibacterial action. The minimum inhibitory concentration (MIC) and agar diffusion results showed that the microcapsules containing 81.73 mmol·L-1 garlic oil exhibited excellent antibacterial action.