Physico-chemical characterization and antibacterial activity of inclusion complexes of Hyptis martiusii Benth essential oil in ß-cyclodextrin.

Cyclodextrins (CDs) have been used as important pharmaceutical excipients for improve the physicochemical properties of the drugs of low solubility as the essential oil of Hyptis martiusii. This oil is important therapeutically, but the low solubility and bioavailability compromises your use. Therein, the aim of this study was to obtain and to characterize physico-chemically the samples obtained by physical mixture (PM), paste complexation (PC) and slurry complexation (SC) of the essential oil Hyptis martiusii (EOHM) in ß-CD, and to compare the antibacterial and modulatory-antibiotic activity of products obtained and oil free. The physicochemical characterization was performed by differential scanning calorimetry (DSC), thermogravimetry/derivative thermogravimetry (TG/DTG), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Karl Fischer titration. Additionally, the antibacterial tests were performed by microdilution technique. Thus, it was observed that the PM method showed low complexing capacity, unlike PC and SC in which it was observed the formation of inclusion complexes. In addition, the second stage of the TG/DTG curves showed that SC was the best method inclusion with mass loss of 6.9% over the PC that was 6.0%. The XRD results corroborate with the results above suggesting the formation of new solid phase and the SEM photomicrographs showed the porous surface of the samples PC and SC. The essential oil alone demonstrated an antibacterial and modulatory effect against the S. aureus and the Gram negative strain, respectively. However, the ß-CD and the inclusion complex did not demonstrate any biological activity in the performed antibacterial assays.

Inhibition of DMBA-induced Oral Squamous Cells Carcinoma Growth by Brazilian Red Propolis in Rodent Model.

We investigated the effect of oral administration of hydroalcoholic extract of Brazilian red propolis (HERP) on DMBA-induced oral squamous cell carcinomas (OSCC) in rodents. The chemical components of the HERP were assessed by high-performance liquid chromatography (HPLC). Carcinogenesis was topically induced in the lower lip of 25 rats using 9,10-dimethyl-1,2-benzanthracene (DMBA); the tumour was treated with saline (TUM1) and Tween 80 (TUM2) as well as HERP at 10, 50 and 100 mg/kg (HERP10, HERP50 and HERP100, respectively) for 20 weeks. Topical application of saline and oral administration of 100 mg/kg HERP was used in five rats as a control group (CTR). After 26 weeks, the histological malignancy grading and immunohistochemical expression of Ki-67 and p16(INK4A) were assessed in the tumours/tissue samples. The compounds identified were propyl gallate, daidzein, catechin, epicatechin, formononetin and biochanin A. Formononetin, daidzein and biochanin A showed concentration of 23.29, 0.38 and 0.67 mg/g of HERP, respectively. HERP at doses of 50 and 100 mg/kg inhibited 40% of OSCC growth and promoted a 3-week delay in development of clinically detectable tumours. Epithelial dysplasia was observed in all samples with no clinical tumour, except in CTR. No significant difference in the immunoexpression of Ki-67 and p16(INK4A) was observed between HERP-treated and saline/Tween 80-treated groups (p > 0.05). Our results suggest that HERP exerts chemopreventive activity on the progression of DMBA-induced epithelial dysplasia to OSCC in an experimental model of labial carcinogenesis; however, this effect is not associated with Ki-67 and p16(INK4A) immunoexpression.