A stroke occurs when a blood clot blocks a blood vessel or artery, or when a blood vessel breaks and interrupts blood flow to an and bleeding occurs into an area of the brain. Every stroke is different.
ETA Chlorophyll works on the Liver and probably works a little. No it really doesn't, you are not a plant. Tea will oxygenate the blood. No it won't Also don't do as someone else said and drink liquid oxygen, that's really not a good idea.
To get more oxygen to the tissue would require blood transfusions to increase the hemoglobin count (and hence the oxygen carrying capacity), or supplemental oxygen that would increase the oxygen dissolved in plasma. Standard Oxyhemoglobin Dissociation Curve showing the P50, and the SaO2 at PaO2 = 80 mmHg.