Robbert Bipat

By Robbert Bipat

Historical reports mention the application of medicinal plants containing coumarins against various ailments. Current research suggests that at least some of the actions described may be attributable to the action of these coumarins. Warfarin and its derivatives are coumarins used today in medical practice. Their mechanism of action lies in the competitive antagonism of vitamin K, through which they inhibit coagulation in the body by preventing the production of prothrombin. Due to this action, these coumarins are a major group of drugs with anticoagulant activity. Anticoagulants reduce the risks of undesirable blood clots leading to myocardial infarction, pulmonary embolism, and ischemic stroke among others. The anticoagulant activity can also lead to undesired bleeding. Extreme caution is warranted when given to menstruating women, patients suffering from disorders prone to bleeding like gastric ulcer and rheumatoid arthritis, and to persons with a high likelihood of blunt and sharp trauma. In addition, there is a significant augmentation of the anticoagulant activity when used in combination with non-steroidal anti-inflammatory agents and agents interfering with the metabolism of the coumarins. Recent findings propose additional uses like anti-tumor and antibiotic actions for coumarins. The clinical application of these actions has yet to be demonstrated.

Part of the book: Phytochemicals in Human Health

By Robbert Bipat, Paul Steels and Jerry Toelsie

End stage kidney disease contributes to a huge burden on global health. Recent advances have shown that ischemic and hypoxic conditions may contribute to the progression of the disorder and that acute kidney injury may cause and aggravate the condition. Ischemia and hypoxia are two distinct conditions with different pathophysiological and structural consequences as proven in the brain and liver of rats. Until now, these differences have not been shown to exist in the kidney. In this study, we assess the possible functional differences in the outcome of ischemic and hypoxic stress on the kidney. For this purpose, we perfused isolated rabbit kidneys with their autologous blood and applied short periods of ischemia or hypoxia in separate series of experiments. The results showed that the kidneys exposed to hypoxic stress suffered more functional damage than those subjected to ischemia. This conclusion was based on a lower creatinine clearance and urine osmolality, and a higher fractional excretion of urea, sodium, and glucose in the hypoxia series of kidneys. Consequently, we recommend monitoring hypoxemic conditions closely and correcting the condition as soon as possible, since even for a short period it may already have deteriorating effects on the renal function.

Part of the book: Reperfusion Injuries