Cristina Cernea

Effects of astaxanthin supplementation on chemically induced tumorigenesis in Wistar rats

BackgroundAstaxanthin (ASTA) is a fat-soluble xanthophyll with powerful antioxidant functions. It is extracted from e.g. salmon, an important food source for certain human populations known to have a reduced risk of tumor development. It is possible that ASTA plays a role in cancer chemoprevention in such populations. The purpose of this study was to investigate the effects of dietary ASTA on chemically induced mammary tumorigenesis using N-methyl-N-nitroso-urea (MNU) in immature Wistar rats.MethodsThirty-six 37 days old juvenile female Wistar rats were at random allocated to 4 groups of which Groups 1 and 2 received a single dose of 55 mg MNU/kg body weight. The effects of ASTA was evaluated by giving rats of Groups 2 and 4 a dose of 50 mg ASTA/kg/day for the entire duration of the study. Group 3 rats received feed added alimentary oil.Necropsy and histopathological examinations were carried out on each rat 14 months after the administration of MNU. Haematological values and antioxidative status were determined. Oxidative stress was evaluated by monitoring superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in hepatic tissue. Lipid peroxidation and carbonylation of proteins was determined in protein extracts from the liver.ResultsTumor development occurred only in rats of Groups 1 and 2, i.e. MNU exposed animals. Frequency of tumor development in general and average number of tumors per animal were insignificant between these two groups. Mammary gland tumors developed in equal frequencies in Group 1 and 2 rats, respectively. Although only rather few tumors were found in the mammary glands, a substantial number of other tumors were found in Group 1 and 2 rats, but at equal rates.Biochemical analyses showed significant higher levels of GPx, malondialdehyde and dinitrophenylhydrazine in Group 1 rats that for rats in all other groups thus indicating protective effects of ASTA on MNU induced hepatic oxidative stress.ConclusionsSupplementation with ASTA did not reduce tumorigenesis induced by MNU in Wistar rats. However, supplementation with ASTA seemed to have anti-inflammatory effects.

Vascular abnormalities of the distal deep digital flexor tendon in 8 draught horses identified on histological examination

The purpose of this study was to provide a detailed description of the vascular changes in the distal part of deep digital flexor tendon (DDFT). Eight isolated forelimbs were collected from 8 horses with DDF tendinopathy diagnosed post-mortem by ultrasound and gross anatomopathological examination. The samples were fixed in 10% neutral buffered formalin, softened in 4% phenol and dehydrated with ethylic alcohol. Goldners Trichrome staining method was used. The histopathological examination revealed vascular proliferation associated with structural disorders of blood vessels. Angiogenesis, fibroplasia and consecutive hypertrophy of the vascular wall with or without vascular occlusion were the most common findings. Other histopathological findings were: endothelial cell edema, progressive metaplasia from squamous to cubic cells, vascular wall hyalinization, endothelial cells apoptosis/necrosis and endothelial desquamation. These results demonstrated damage of the distal deep digital flexor tendon vasculature which may progressively alter the structural integrity of the tendon and contribute to degenerative lesions.