Researchers at Lund University in Sweden have discovered that sugarbeets produce hemoglobin. They now hope that this hemoglobin could serve as a blood substitute—a substance that is currently in short supply.
“Previously, it has been presumed that certain plants produce this iron protein only when stressed, such as in drought or frost, because it has been seen that this is the case for certain other plants. However, we have shown that hemoglobin is produced even in a normal state,” said Nélida Leiva, a doctoral student of applied biochemistry at Lund University, who has just presented the findings in a doctoral thesis.
Leiva’s supervisor, Professor Leif Bülow, has spent many years conducting research on the production of human hemoglobin, primarily with the help of bacteria, because hemoglobin from blood donors is far from sufficient to cover the needs of society.
The process of extracting hemoglobin from sugarbeets is not much more complicated than extracting sugar, according to the researchers. The challenge lies in obtaining sufficient volumes. However, Leiva and Bülow believe there is good reason to think that sugarbeets and other crops could become a realistic alternative.
“From one hectare, we could produce 1–2 tons of hemoglobin, which could save thousands of lives,” said Bülow. The human body contains almost 1kg of hemoglobin.
In just over a year, the researchers will start testing the hemoglobin from plants in animal experiments with researchers at University College London, who have world-leading expertise on blood transfusions.
In the work on her thesis, Leiva has also discovered that the hemoglobin in sugarbeet is almost identical to human hemoglobin, especially the form of hemoglobin we have in our brains.
“There is a difference in a small detail on the surface of the protein, but this simply appears to extend the lifespan of the hemoglobin from sugarbeet, which is good news,” said Leiva.
But why is there hemoglobin in plants at all? They surely don’t need to transport oxygen?
Leiva has discovered that the substance has a completely different function, despite its similarity to human hemoglobin.
“We have found that the hemoglobin in the plant binds nitric oxide. It is probably needed to keep certain processes in check, for example so that the nitric oxide doesn’t become toxic, and to ward off bacteria.”
In humans, there are several types of hemoglobin. The majority is of the type found in the blood, but hemoglobin is also present in the testicles and the brain. It is the hemoglobin in the brain that is most like that in sugarbeets. Leiva has not only discovered hemoglobin in the sugarbeet root, but also in the leaves and flowers.
Hemoglobin as a blood substitute
Following an accident, it is important that additional hemoglobin is quickly supplied to the patient so that oxygen can be transported around the body—the main task of hemoglobin. Hemoglobin (Hb) is needed in the initial period up to five hours after an accident. After this, complete blood must be given.
Besides human donations and waste from abattoirs, bacteria-cultivated hemoglobin is the method we have available to create a stock of the vital iron proteins.
In some countries, such as China and India, blood banks are non-existent or very limited, which means that alternatives must be developed quickly. It is especially important to get hold of these substitutes in emergency situations where safe blood transfusions are of vital importance, according to Bülow.
“The Ebola epidemic in Africa is a current example where these blood substitutes could save lives,” he added.