Mucuna pruriens Reduces Brain Inflammation and Obesity in Rats

The scientific paper Mucuna pruriens Administration Minimizes Neuroinflammation and Shows Anxiolytic, Antidepressant and Slimming Effects in Obese Rats by Tavares et al. explores the potential of Mucuna pruriens, a legume known for its traditional medicinal use, in addressing the physical and mental health effects of obesity. Obesity is increasingly linked to neuroinflammation, anxiety, and depression due to chronic low-grade inflammation, especially in the brain’s hippocampus. This study focused on evaluating how MP extract, rich in bioactive compounds like levodopa and phenolic antioxidants, could impact weight, appetite, mood, and brain health in rats fed a high-fat cafeteria diet. By targeting both metabolic and neurobehavioral symptoms, the research contributes to a growing body of evidence connecting natural plant compounds to gut-brain health and obesity management.

Obesity is more than just a weight problem—it can also affect the brain and emotions. People with obesity often struggle with anxiety and depression. That’s partly because obesity causes chronic, low-level inflammation throughout the body, including in the brain. This type of inflammation, called neuroinflammation, can change how the brain works and how we feel.

The hippocampus, a part of the brain that helps control emotions and memory, is especially sensitive to inflammation. One of the key signals of brain inflammation is a molecule called interleukin-6 (IL-6). When IL-6 levels go up, it usually means inflammation is happening.

Mucuna pruriens (MP), a tropical legume used in Ayurvedic medicine, may help. It naturally contains powerful plant compounds like levodopa (a precursor to dopamine), catechins, and resveratrol, which are known for their anti-inflammatory and brain-boosting effects. In this study, scientists wanted to see if MP could reduce obesity, calm anxiety and depression, and lower brain inflammation in rats fed a high-calorie “cafeteria” diet.

The researchers worked with 32 male Wistar rats. First, they split them into two groups:

• One group ate a healthy control diet
• The other group ate a high-fat, high-sugar cafeteria-style diet to induce obesity over eight weeks

After this period, they further divided the rats into four groups:

1. Healthy rats (HG)
2. Healthy rats + MP extract (HGMP)
3. Obese rats (OG)
4. Obese rats + MP extract (OGMP)

For the next eight weeks, the MP groups received a daily dose of MP extract (750 mg/kg body weight) by mouth. The extract was rich in plant compounds, including 14% levodopa.

The researchers tracked food intake, body weight, and body measurements. They also ran behavior tests to look for signs of anxiety or depression, like how much time the rats spent exploring or moving. After the study, they examined the rats' brains for signs of inflammation and damage, especially in the hippocampus.

Obese rats that received MP ate less and lost weight than those that didn’t. By the end of the study, the MP-treated obese rats had food intake and weight levels similar to the healthy group. The study notes:

“MP administration caused a reduction (11%) in body weight… maintaining this difference until the end of the experiment.”

Body mass index (BMI) and abdominal measurements also dropped. This shows MP didn’t just lower food intake—it helped reduce fat in risky areas like the belly.

In anxiety tests, obese rats who didn’t receive MP showed anxious behavior. They avoided open spaces, spent less time exploring, and had fewer "head dives," a natural rat behavior. However, MP-treated obese rats showed more of these healthy behaviors.

“Treatment with MP normalized... the number of head dives... indicating an anxiolytic effect.”

MP seemed to help them feel calmer and more curious, which are signs of reduced anxiety.

In the splash test (which measures self-care), obese rats cleaned themselves less—a sign of depression. MP helped bring those cleaning times back up to normal. In the forced swim test, obese rats treated with MP were more active and spent less time floating (a sign of giving up).

“MP was able to reverse the depressive behavior, since the results were equal to those of the control group.”

Microscope images of the brain showed fewer inflamed blood vessels in MP-treated rats. IL-6 levels—a sign of inflammation—were much lower in the MP group. This means MP helped protect the hippocampus from inflammation linked to obesity.

“Treatment with MP extract was able to reduce the expression of this pro-inflammatory cytokine in the hippocampus of obese rats.”

The researchers believe MP’s effects come from a combination of natural plant compounds:

• Levodopa: Boosts dopamine, which supports mood, motivation, and appetite control
• 1-Kestose: A prebiotic that may improve gut health and affect the brain through the gut-brain axis
• Phenolic compounds like catechins, resveratrol, and chlorogenic acid: Known for their anti-inflammatory and brain-protecting effects

These compounds may work together to reduce food cravings, lower inflammation, and boost brain function.

This study shows that Mucuna pruriens may be a helpful natural tool for dealing with both the physical and emotional challenges of obesity. It helped obese rats eat less, lose weight, and feel less anxious or depressed—all while calming inflammation in the brain.

Because the MP extract contained ingredients that support both gut and brain health, the scientists believe it works through a gut-brain connection. This adds to growing research showing that what we eat can affect how we feel, not just in our bodies but in our minds, too.

While this study was done in rats, it lays crucial groundwork for future human studies. The researchers also calculated a safe equivalent dose for humans—around 120 mg per kilogram of body weight.

This scientific study suggests that Mucuna pruriens has powerful potential to support both weight loss and mental well-being. By helping reduce inflammation in the brain, balancing appetite, and easing anxiety and depression in obese rats, MP shows promise as a natural remedy for obesity-related health issues. Its rich content of plant-based compounds like levodopa, catechins, and prebiotics makes it a strong candidate for future research in humans.

If you're looking into herbal support for obesity, mental health, or inflammation, Mucuna pruriens may be worth watching in future studies.