New Trends on Antineoplastic Therapy Research: Bullfrog (Rana catesbeiana Shaw) Oil Nanostructured Systems

Abstract

Bullfrog oil is a natural product extracted from the Rana catesbeiana Shaw adipose tissue and used in folk medicine for the treatment of several diseases. The aim of this study was to evaluate the extraction process of bullfrog oil, to develop a suitable topical nanoemulsion and to evaluate its efficacy against melanoma cells. The oil samples were obtained by hot and organic solvent extraction processes and were characterized by titration techniques and gas chromatography mass spectrometry (GC-MS). The required hydrophile-lipophile balance and the pseudo-ternary phase diagram (PTPD) were assessed to determine the emulsification ability of the bullfrog oil. The anti-tumoral activity of the samples was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for normal fibroblast (3T3) and melanoma (B16F10) cell lines. Both extraction methods produced yielded around 60% and the oil was mainly composed of unsaturated compounds (around 60%). The bullfrog oil nanoemulsion obtained from PTPD presented a droplet size of about 390 nm and polydispersity = 0.05 and a zeta potential of about´25 mV. Both the bullfrog oil itself and its topical nanoemulsion did not show cytotoxicity in 3T3 linage. However, these systems showed growth inhibition in B16F10 cells. Finally, the bullfrog oil presented itself as a candidate for the development of pharmaceutical products free from cytotoxicity and effective for antineoplastic therapy.

Oil Extraction from Rana catesbeiana by Supercritical Carbon Dioxide and Mechanical Pressing

“…Based on the total amount of 400 ton year −1 of bullfrog meat produced and that the FBB corresponds to 2 wt.% of this quantity, 4.8 ton year −1 of FBB oil can be obtained. Similar yields (60–62 wt.%) are reported by Amaral‐Machado et al (), Méndez et al (), and Rutckeviski et al (), using cooking as extraction method at temperatures of 80, 98, and 70 °C for 40, 30, and 30 min, respectively. Utilizing the same method, with an extraction time of 40 min, Lopes et al () reported yields within the range of 10 to 85 wt.% for temperatures of 35 to 200 °C, respectively.…”

“…The FB contains lipids mainly in the form of triacylglycerols and represents approximately 2% of the bullfrog weight (Méndez et al, ; Wright et al, ). According to Amaral‐Machado et al (), the bullfrog oil has been used in traditional medicine for the treatment of several diseases.…”

“…The studies reported in the literature about oil extraction from the FB of the R. catesbeiana (Amaral‐Machado et al, ; Méndez et al, ; Rutckeviski et al, ) have only evaluated methods such as solvent extraction and cooking extraction. Taking this into account, the study of fat body of bullfrog (FBB) oil obtained from the conventional ME and unconventional SFE methods can become an opportunity to increase the competitiveness of the bullfrog industry.…”

Bullfrog Oil Reduces the Carrageenan-induced Edema in Wistar Rats by <i>in vitro</i> Reduction of Inflammatory Mediators

“…, docosahenaxoic -DHA 0.8 and eicosapentaenoic -EPA 17. 6 fatty acids, in addition to cholesterol 9. 5 and ethyl-iso allocholate 3.5 6,9,10 .…”

“…6 fatty acids, in addition to cholesterol 9. 5 and ethyl-iso allocholate 3.5 6,9,10 . However, despite its broad popular use, especially against inflammatory conditions, there is a lack of scientific evidence supporting such therapeutic property.…”