text: One of the first substances that was reported to produce an oxygen diffusion-enhancing effect was crocetin, a carotenoid that occurs naturally in plants such as crocus sativus, and is related to another carotenoid, saffron.  Saffron has been used culturally (e.g., as a dye) and medicinally since ancient times.
  Trans sodium crocetinate (TSC), a synthetic drug containing the carotenoid structure of trans crocetin has been extensively investigated in animal disease models and in human clinical trials. Clinical trials of TSC have focused on testing the compound's effectiveness in sensitizing hypoxic cancer cells to radiation therapy in patients with glioblastoma, an aggressive form of brain cancer. 
  TSC, which is being developed by Diffusion Pharmaceuticals, has been shown to enhance the oxygenation of hypoxic tumor tissue  and belongs to a subclass of oxygen diffusion-enhancing compounds known as bipolar trans carotenoid salts. Diffusion Pharmaceuticals is currently investigating the use of trans sodium crocetinate in the treatment of COVID-19, acute stroke, and solid cancerous tumors.