Corrigendum to “Bioactive properties of honey with propolis” [Food Chem. 196 (2016) 1215–1223]

Preliminary screening of the possible protective effect of Moroccan propolis against chromium-induced nephrotoxicity in animal model

Background and Aim

Hexavalent chromium (Cr (VI)) compounds have been shown to induce nephrotoxicity associated with oxidative stress in humans and animals. The aim of the present study was to investigate the nephroprotective effect of bee propolis, as highly antioxidant natural product, in vivo using an animal model.

Materials and Methods

First of all, total phenol and flavonoid contents of propolis sample were estimated in vitro. Afterward, to study the protective effect of propolis on renal damages caused by an injection of a single dose of potassium dichromate (15 mg/kg b.wt), 24 male Wister rats were divided into test and control groups. Propolis treatment was performed by oral gavage of 100 mg/kg b.wt/day, while the control groups received water instead. The 24 h urine was collected and blood samples were withdrawn before and after each treatment for further analysis.

Results

Propolis revealed to be rich in polyphenols and flavonoids. Chromate provoked a nephrotoxic effect expressed by a drastic decrease in glomerular filtration assessed by creatinine clearance. However, the administration of propolis attenuated the renal damages induced by the chromate. This attenuation can be seen by the increase of creatinine clearance when comparing propolis treated group to the non-treated group.

Conclusion

Propolis showed a protective potential against chromate-induced nephrotoxicity through the amelioration of chromate's toxic effects. It might be concluded that propolis could be effective as chemoprotectant in the management of potassium dichromate-induced nephrotoxicity.

Identification and classification of honey's authenticity by attenuated total reflectance Fourier-transform infrared spectroscopy and chemometric method

Background and Aim:

The authentication of honey is important to protect industry and consumers from such adulterated honey. However, until now, there has been no guarantee of honey’s authenticity, especially in Indonesia. The classification of honey is based on the bee species (spp.) that produces it. The study used honey from sting bee Apis spp. and stingless bee Tetragonula spp. based on the fact that the content off honey produced between them has differences. Authenticating honey with currently available rapid detection methods, such as ¹³C nuclear magnetic resonance analysis, is costly. This study aimed to develop an inexpensive, fast, precise, and accurate classification method for authenticating honey.

Materials and Methods:

In this study, we use attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy with wavelengths ranging between 550 and 4000 cm⁻¹ as an alternative analysis method, which is relatively less expensive. The spectra of authentic and fake honey samples were obtained using ATR-FTIR and plotted using chemometric discriminant analysis. The authentic honey samples were acquired from a local Indonesian breeder of honey bees, while the fake honey samples were made from a mixture of water, sugar, sodium bicarbonate, and authentic honey. Data were collected using Thermo Scientific’s OMNIC FTIR software and processed using Thermo Scientific’s TQ Analyst software.

Results:

Our method effectively classified the honey as authentic or fraudulent based on the FTIR spectra. To authenticate the honey, we formed two classes: Real honey and fake honey. The wavelengths that can best differentiate between these two classes correspond to four regions: 1600-1700 cm⁻¹; 1175-1540 cm⁻¹; 940-1175 cm⁻¹; and 700-940 cm⁻¹. Similarly, for classification purpose, we formed two classes: Apis spp. and Tetragonula spp. The wavelength region that can best classify the samples as belonging to the Apis spp. or Tetragonula spp. class is explicitly within the range of 1600-1700 cm⁻¹.

Conclusion:

This study successfully demonstrated a method to rapidly and accurately classify and authenticate honey. ATR-FTIR is a useful tool to test the authenticity of honey.