Effect of Pinocembrin Isolated from Mexican Brown Propolis on Diabetic Nephropathy.

Propolis is a resinous beehive product that has been used worldwide in traditional medicine to prevent and treat colds, wounds, rheumatism, heart disease and diabetes. Diabetic nephropathy is the final stage of renal complications caused by diabetes and for its treatment there are few alternatives. The present study aimed to determine the chemical composition of three propolis samples collected in Chihuahua, Durango and Zacatecas and to evaluate the effect of pinocembrin in a model of diabetic nephropathy in vivo. Previous research demonstrated that propolis of Chihuahua possesses hypoglycemic and antioxidant activities. Two different schemes were assessed, preventive (before renal damage) and corrective (once renal damage is established). In the preventive scheme, pinocembrin treatment avoids death of the rats, improves lipid profile, glomerular filtration rate, urinary protein, avoid increases in urinary biomarkers, oxidative stress and glomerular basement membrane thickness. Whereas, in the corrective scheme, pinocembrin only improves lipid profile without showing improvement in any other parameters, even pinocembrin exacerbated the damage. In conclusion, pinocembrin ameliorates diabetic nephropathy when there is no kidney damage but when it is already present, pinocembrin accelerates kidney damage.

Phytochemical Constituents, Antioxidant, Cytotoxic, and Antimicrobial Activities of the Ethanolic Extract of Mexican Brown Propolis.

Propolis is a complex mixture of natural sticky and resinous components produced by honeybees from living plant exudates. Globally, research has been dedicated to studying the biological properties and chemical composition of propolis from various geographical and climatic regions. However, the chemical data and biological properties of Mexican brown propolis are scant. The antioxidant activity of the ethanolic extract of propolis (EEP) sample collected in México and the isolated compounds is described. Cytotoxic activity was evaluated in a central nervous system and cervical cancer cell lines. Cytotoxicity of EEP was evaluated in a C6 cell line and cervical cancer (HeLa, SiHa, and CasKi) measured by the 3-(3,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium (MTT) assay. The antibacterial activity was tested using the minimum inhibitory concentration (MIC) assay. Twelve known compounds were isolated and identified by nuclear magnetic resonance spectroscopy (NMR). Additionally, forty volatile compounds were identified by means of headspace-solid phase microextraction with gas chromatography and mass spectrometry time of flight analysis (HS-SPME/GC-MS-TOF). The main volatile compounds detected include nonanal (18.82%), α-pinene (12.45%), neryl alcohol (10.13%), and α-pinene (8.04%). EEP showed an anti-proliferative effect on glioma cells better than temozolomide, also decreased proliferation and viability in cervical cancer cells, but its effectiveness was lower compared to cisplatin.