Canadian physician Frederick Banting and his medical student assistant, Charles Best, found in a dog's pancreas a miraculous antidote that saved the lives of millions of diabetics worldwide.
In the University of Toronto laboratory, after hours of continuous and painstaking work, Banting and Best succeeded for the first time on July 27, 1921, in extracting the biologically active substance later known as insulin from the pancreas of a healthy dog, and were able to demonstrate its amazing effectiveness in significantly reducing blood glucose levels in a diabetic dog whose pancreas had been removed.
That landmark experiment, conducted on that historic day, represented the culmination of weeks of arduous laboratory work, during which the Canadian doctor and his assistant carried out several precise methodological steps, including isolating crude insulin from the pancreas of a healthy dog, stimulating the appearance of severe diabetic symptoms in experimental dogs by surgically removing their pancreases, and then administering the extracted substance to the affected dogs via direct intravenous injection.
These injections resulted in a confirmed and unprecedented success, as they were able to reduce the dangerously high blood sugar levels in the infected dogs, restoring them to their normal physiological state within a few hours, which constituted conclusive proof of the validity of their hypotheses.
That pivotal moment marked a radical turning point in the history of modern medicine, as it was proven that a pancreatic substance, later named "insulin" derived from the Latin word "insula" meaning "island," in clear reference to the islets of Langerhans that produce this vital regulatory hormone, possesses an exceptional ability to regulate blood sugar levels with unparalleled efficiency.
Following this tremendous scientific breakthrough, specifically on November 14, 1921, Banting and Best presented the results of their meticulous research to the members of the prestigious Physiological Journal Club at the University of Toronto. A month later, they presented a detailed report to the American Physiological Society in New Haven, Connecticut, and the research was very well received by the specialized academic community.
Meanwhile, Professor John MacLeod, director of the Department of Physiology at the University of Toronto, had changed his initial skeptical opinion of the idea, giving the work his full attention and dedicating all the laboratory's resources and involving all its employees to push this promising project forward to broader horizons.
By January 1922, clinical trials on humans had begun, with the team, joined by the brilliant biochemist James Collip, who had crucially helped purify the extract and remove harmful impurities, successfully treating fourteen-year-old Leonard Thompson, who was suffering from a severe and paralyzing form of the disease.
This successful clinical trial had an immediate and profound impact, saving the lives of countless people with diabetes in every corner of the world, and that day is rightly considered an official declaration of the start of the modern era in the treatment of this intractable disease.
Thus, in a record time of just a few months, this groundbreaking scientific discovery transformed diabetes from a grim death sentence into a chronic condition that could be managed effectively and safely. Before the discovery of insulin, a diabetes diagnosis meant certain death, as patients, especially children and young adults, would succumb within a few months of the onset of symptoms, due to diabetic coma or recurrent infections that crippled their already weakened bodies.
The isolation of insulin was the first and essential step in completely changing this miserable reality, and this huge medical achievement has been described in the scientific literature as the "Big Bang" of diabetes research, because it formed the cornerstone of a whole century of life-saving developments and innovations.
In a later stage, Banting and his assistant Best began extracting insulin from the abundantly available pancreases of cows, which allowed them to dramatically increase the quantitative production of the active ingredient. The amount produced was then sufficient to keep the experimental animals alive for up to seventy consecutive days, which provided a sufficient stock to continue the research.
The year 1922 witnessed a rapid qualitative development when George Walden, chief chemist at Eli Lilly, developed the photoelectric deposition method, which ensured higher stability and greater purity of the extract by about ten times compared to previous traditional methods, thus paving the way for large-scale industrial production.
In recognition of this groundbreaking discovery that changed the course of humanity, Frederick Banting and John Macleod were awarded the prestigious 1923 Nobel Prize in Physiology or Medicine. Banting did not forget the kindness of his young assistant, Best, and shared the monetary value of the prize with him in recognition of his pivotal contribution at the beginning of the journey, reflecting the noble spirit of scientific cooperation.
In short, the isolation of insulin on that historic day in July 1921 was the first major step that transformed a long-established scientific theory into a tangible medical miracle, forever changing the course of diabetes treatment and giving millions a new chance at life and hope.
