Coexistence of anticoagulant and anti-vascular calcification activities in Kribbella sp. UTMC 267 metabolites

Thrombotic disorders increase the risk of cardiovascular/cerebrovascular complications and represent a major health problem worldwide. Anticoagulants are extensively used in treatment of these disorders. Vitamin K antagonists, like Warfarin, are frequently used in medication. Vascular calcification (VC) is a significant side-effect of vitamin K antagonists especially Warfarin. There is an urgent need to find natural, efficient, non-toxic and cost effective anticoagulants without dangerous side-effect like VC. In the present study, we evaluated the potential of thirteen fermentation broth extracts of actinobacteria (FBEA) (200 µg ml-1) to prolong whole blood prothrombin time (PT)/international normalized ratio (INR) and activated partial thromboplastin time (APTT). The fractions of the most effective FBEA were further investigated for their inhibitory effect on VC. The results showed PT/INR of the healthy blood samples was sensitive to the presence of five FBEA. Their INR index fell in the 1.2 to 8.6 range and six FBEA prolonged both PT/INR and APTT parameters (1.7-5 INR, and 46-59 s for APTT). The fractions of Kribbella sp. UTMC 267 FBE (200 µg ml-1), as the most efficient FBE, only inhibited intrinsic and common pathways of coagulation (APTT). Under calcification condition, Kribbella sp. UTMC 267 fractions (20 µg ml-1) showed significant inhibitory effect on VC in alizarin red staining (13.3-76 %) and alkaline phosphatase activity of VSMCs (33-62%). They also inhibited osteopontin mRNA expression in treated vascular smooth muscle cells (VSMCs) under that situation. So, we can introduce Kribbella sp. UTMC 267 FBE as a good candidate for more investigation on thrombotic medication.