Researchers from the Federal University of Jataí (UFJ) and the Ribeirão Preto Faculty of Medicine at USP identified that a natural substance present in vegetables such as broccoli can alleviate kidney damage caused by persistent hyperglycemia, a typical condition of diabetes.
The compound, known as L-sulforaphane, acts to activate Nrf2, a cellular factor responsible for triggering antioxidant mechanisms. In environments with excess glucose, this protective pathway tends to have reduced activity, which favors the advancement of kidney damage. The information is from the newspaper O Globo.
In an interview with Jornal da USP, professor Rita de Cássia Aleixo Tostes Passaglia, from the Department of Pharmacology at FMRP and supervisor of the study, highlighted that diabetes mellitus is among the main causes of chronic kidney disease and terminal renal failure in the world. According to her, hyperglycemia is the main marker of the disease, which is often only diagnosed when it is already in an advanced stage. “Once established, the disease tends to progress and may lead to the need for dialysis or transplantation,” he said.
The researcher further explained that diabetic nephropathy develops silently. Even without symptoms, the kidney undergoes structural changes and gradual loss of function, a process that can evolve into serious conditions. “Just as hypertension compromises the kidneys, a diseased kidney also worsens cardiovascular risk, creating a harmful cycle for the body”, he highlighted.
The study
The investigation was conducted by professor Rafael Menezes da Costa, from the Institute of Health Sciences at UFJ, during his postdoctoral studies at the Department of Pharmacology at FMRP, under the supervision of Passaglia. For the experiment, Wistar rats were used and were subjected to a diet rich in sugar for 12 weeks, a model that reproduces metabolic changes similar to those observed in people with diabetes. L-sulforaphane was administered in the final four weeks, with the aim of seeing whether activating this pathway could reverse kidney damage.
The researchers analyzed indicators of oxidative stress and inflammation, such as the production of free radicals, the activity of antioxidant enzymes, including superoxide dismutase and catalase, the degree of protein oxidation, as well as structural changes in the kidneys and kidney function parameters, such as creatinine and glomerular filtration rate.
The results indicated that prolonged exposure to high glucose caused significant damage. “We observed dilation of the tubules, accumulation of collagen and expansion of the glomerular matrix, initial signs of renal fibrosis,” explained Costa. Worsening of renal function was also recorded, with a drop in the glomerular filtration rate, an increase in creatinine and high levels of oxidative stress, capable of damaging proteins, lipids and cellular DNA.
The scenario, however, changed after the introduction of L-sulforaphane. According to the researcher, the compound reactivated Nrf2, allowing the antioxidant factor to return to acting in the cell nucleus and reestablishing the production of enzymes responsible for neutralizing free radicals.
As a result, there was a reduction in oxidative stress, a decrease in protein oxidation and an attenuation of the main structural changes observed in the kidneys, such as collagen accumulation and tubule dilation. Functional parameters also improved, indicating partial recovery of blood filtration capacity.
“These findings help to understand why some patients develop kidney failure despite maintaining certain glycemic control. If Nrf2 remains inhibited, the antioxidant defense system remains compromised”, explained Costa.
For researchers, the data reinforces the potential of natural compounds such as L-sulforaphane, or synthetic molecules with similar action, as promising strategies in future studies and possible complementary therapies in the prevention of diabetic nephropathy.
The group’s next step is to investigate whether the same effects can be observed in humans and evaluate other activators of the Nrf2 pathway. “We want to know whether this mechanism is also present in diabetic patients and whether natural substances can offer similar clinical benefits,” concluded Passaglia.
