Citric Acid CQDs May Protect Neurons From Paraquat

A new study has found that carbon quantum dots derived from citric acid may protect dopaminergic neurons from being killed by paraquat.

The study suggests that the carbon quantum dots (CQDs) are a potentially viable treatment for Parkinson’s disease (PD), as well as other neurodegenerative diseases.

Dopaminergic neurons are neurons that produce dopamine, which our body needs for motor control. These neurons do not grow back when they die. So, when too many of them die, dopamine levels fall, leading to the symptoms of PD.

Numerous scientific studies have linked the herbicide paraquat with PD, suggesting that once paraquat gets into the brain, it can lead to the creation of reactive oxygen species (ROS), which induce oxidative stress that kills dopaminergic neurons.

The study found that citric acid-sourced carbon quantum dots (Cit-CQDs) reduce ROS levels in solutions, human nerve cells, and roundworms, suggesting that Cit-CQDs may be able to protect dopaminergic neurons from being killed by paraquat-induced oxidative stress.

Cit-CQDs Are a Potential Parkinson’s Disease Treatment

The study notes that Cit-CQDs may be a new way to treat PD and other neurodegenerative diseases. A potential way to treat neurodegenerative diseases is to design molecules with good tolerability and strong antioxidant activity.

CQDs can savage ROS and can be created in an environmentally friendly manner from biodegradable waste. Studies have suggested that CQDs may protect cells that are exposed to the neurotoxin MPTP, a neurotoxin that can cause the symptoms of Parkinson’s disease in humans and rodents.

Citric acid is often used to prepare CQDs due to its high biocompatibility and low toxicity.

Cit-CQD Research on Roundworms

University of Texas at El Paso researchers tested whether Cit-CQDs can protect roundworms (Caenorhabditis elegans) and human nerve cells from paraquat. Paraquat is chemically structured similarly to MPTP.

The roundworms are small, transparent worms that lack a respiratory system or bloodstream but possess dopaminergic neurons that can be directly monitored.

“We were interested in demonstrating the prophylactic effect of Cit-CQDs and their ability to prevent neuronal cell death by scavenging and inhibiting [Parkinson’s disease],” the study states.

Initial Steps

The researchers first placed Cit-CQDs and ROS in a solution together and found that the Cit-CQDs savaged the ROS, showing that the Cit-CQDs have potential as antioxidants.

The researchers then exposed human nerve cells to paraquat alone and Cit-CQDs alone. While the paraquat caused the cells to die, the Cit-CQDs did not affect the survival rate of the cells except at the highest dose given.

The researchers then exposed the nerve cells to paraquat and Cit-CQDs combined, finding that the Cit-CQDs conferred a significant level of protection from death to the cells at every dose tested.

Findings and Follow-Up Steps

The researchers found that paraquat exposure alone led to higher ROS levels in the nerve cells and that Cit-CQD exposure alone had no impact on the levels of ROS. 

However, when the researchers exposed the nerve cells to Cit-CQDs and paraquat combined, the intercellular ROS was significantly reduced. The researchers noted that this result suggests that Cit-CQDs can mitigate intercellular oxidative stress associated with paraquat.

The researchers then exposed roundworms to paraquat alone and Cit-CQDs alone. The paraquat negatively affected the roundworms’ survival rate, whereas the Cit-CQDs did not. 

The researchers then exposed the roundworms to Cit-CQDs before exposing them to a paraquat dose known to kill 50% of roundworms, finding that the Cit-CQDs led to a significant improvement in the survival rate of the roundworms.

Final Steps and Findings

Finally, researchers modified roundworms to have green fluorescent dopaminergic neurons, then exposed those roundworms to paraquat alone, as well as a combination of paraquat and Cit-CQDs. 

While the roundworms exposed to paraquat alone lost 75% of their fluorescence, the loss of dopaminergic neurons was prevented by the Cit-CQDs in the roundworms exposed to Cit-CQDs before being exposed to paraquat.

Carbon Quantum Dots

CQDs are nanoparticles composed of carbon that possess a coating that makes them less readily corroded or affected by their environment. The nanoparticles are under 10 nm in size.

CQDs have fluorescent properties that have led to many studies that have hoped to learn how to exploit those properties. CQDs have many potential applications, including biomedicine, bioimaging, sensing, drug delivery, catalysis, optronics, rocket fuels, and fingerprint recovery.

CQDs can, amazingly, resist very high temperatures: up to 1,472° F. CQDs are created through one of two methods:

• The “top-down” route involves using laser ablation, electrochemical techniques, and arc discharge to break down bigger carbon structures like nanodiamonds, carbon nanotubes, and graphite into CQDs.
• The “bottom-up” route involves using microwave synthetic, supported synthetic, and solvothermal/hydrothermal treatment routes to synthesize CQDs from tiny precursors, such as polymer-silica nanocomposites, citrate, and carbohydrates.

Paraquat and Parkinson’s Disease

Paraquat has been linked to PD and causes of PD by numerous scientific studies and analyses:

• A 1999 study associated exposure to paraquat with the death of dopaminergic neurons
• A 2004 study associated paraquat exposure with neuronal cell death and oxidative stress
• A 2009 study associated paraquat exposure with over twice the risk of PD development
• A different 2009 study also associated exposure to paraquat with more than two times the risk of PD development
• A 2011 study associated paraquat exposure with 2.5 times the risk of PD development
• A 2013 meta-analysis associated paraquat exposure with double the risk of PD development
• A 2017 study associated paraquat exposure with neurodegenerative effects which have been linked to PD
• A 2017 study associated exposure to paraquat with 1.54 times the risk of PD development
• A 2018 study associated paraquat exposure with neurotoxic effects on dopaminergic neurons
• A 2019 meta-analysis associated paraquat exposure with a 25 percent higher occurrence of PD
• A 2019 meta-analysis associated paraquat exposure with 1.64 times the risk of PD development
• A 2020 study associated paraquat inhalation with a known symptom of PD

It appears that paraquat, once it gets into the brain, may cause the creation of ROS, which initiates a never-ending cycle known as redox cycling. This cycle repeats indefinitely in the presence of molecular oxygen, which is plentiful in brain cells because more ROS are produced as a result of the cycle. Once it reaches the brain, a single molecule of paraquat can thus cause the formation of countless ROS.

ROS appears to induce oxidative stress in brain cells, leading to the death of dopaminergic neurons, which leads to the symptoms of PD. The symptoms of PD are primarily motor symptoms, and our body needs dopamine to control the motor system.

The primary symptoms of PD are:

• Resting tremor (shaking)
• Bradykinesia (slow reflexes and voluntary movements)
• Rigidity
• Balance issues

PD cannot be cured by existing treatments, and existing treatments cannot slow or stop its progression. Existing PD treatments only partially and temporarily relieve symptoms, and they can cause unwanted side effects.

Paraquat Lawsuits

Paraquat’s link to PD has led to around 1,300 lawsuits being filed against paraquat manufacturers such as Syngenta and Chevron. The lawsuits allege that the manufacturers knew or should have known that paraquat may cause PD, yet sold products containing paraquat anyways without warning the public about the PD risk.

It is paraquat’s redox properties that make it capable of inducing oxidative stress in human brain cells, and the lawsuits claim that science has known about these redox properties of paraquat since at least the 1930s. The lawsuits also claim that science has known since at least the 1960s that paraquat can cause oxidative stress via redox cycling.

According to the lawsuits, paraquat is actually given to lab animals to give the lab animals Parkinson’s-like symptoms for scientists to study.

The lawsuits seek to recover damages based on multiple legal causes of action, including:

• Negligence: The lawsuits allege paraquat manufacturers did not behave in a reasonably careful manner because they did not adequately test their paraquat-containing products and because they failed to warn about the PD risk associated with paraquat despite knowing about it or having ample opportunity to know about it.
• Strict liability – defective design: The lawsuits allege that paraquat manufacturers are strictly liable for damages caused by paraquat because products containing paraquat are defective by design since they present a PD risk even when used correctly.
• Strict liability – failure to warn: The lawsuits claim that paraquat manufacturers knew or should have known about the PD risk associated with paraquat yet failed to warn the public about this risk.

If you or a loved one developed PD after being exposed to paraquat, you may be eligible for financial compensation in a paraquat lawsuit.

Paraquat Lawsuit Recoveries

Those who have developed PD after being exposed to paraquat may be entitled to recover financial compensation in a paraquat lawsuit for many things, including:

• Medical bills: PD sufferers will likely face a lifetime of treatment and medical bills since PD is progressive and incurable. Those who file a paraquat lawsuit may be able to recover financial compensation for any medical bills already incurred that relate to their PD diagnosis, as well as any medical bills they can be reasonably expected to incur in the future related to their PD diagnosis.
• Lost wages: Those with PD may miss a lot of work, and they may qualify for financial compensation for all wages that went unearned as a result of the PD diagnosis.
• Loss of earning capacity: Those with PD may, unfortunately, be left permanently disabled and thus unable to work. You may qualify for financial compensation for any permanent loss of earning capacity caused by your PD diagnosis.
• Pain and suffering: PD can be awful to live with, as it can affect even the tiniest parts of everyday life, such as going to the bathroom and eating. You may qualify for financial compensation for the physical pain and emotional suffering caused by your PD.

Call us today for a free consultation to find out more about what types of financial compensation you may qualify for and how much money you may qualify for in a paraquat lawsuit.

The Cost of Paraquat Lawyers

Nadrich Accident Injury Lawyers are currently representing paraquat victims on a contingency fee basis, meaning no fee is charged until and unless financial compensation is obtained for the client.

The only fee is a percentage of any recovery obtained. No out-of-pocket fee is ever charged, and no upfront fee is ever charged.

This means that you cannot lose money by hiring our lawyers to represent you in a paraquat lawsuit; you can only gain money. This means that anybody can afford to have the experienced paraquat lawyers at Nadrich Accident Injury Lawyers represent them.

Paraquat Attorneys

PD sufferers typically face a lifetime of huge medical bills since the condition isn’t curable and it only gets worse over time. With so much on the line, you can’t afford to get your choice of paraquat lawyer wrong.

Nadrich Accident Injury Lawyers are experienced experts in toxic exposure litigation, having represented victims of toxic exposure for over 30 years. We have recovered over $750,000,000 on behalf of clients. We have represented victims of exposure to numerous toxic chemicals, such as Roundup, asbestos, AFFF firefighting foam, and the contaminated water at Camp Lejeune.

Our tremendous experience in representing hazardous exposure victims means that we know all the ins and outs of proving that our clients were exposed to toxic substances because of product defects or defendants’ negligence and that the defects or negligence caused our clients’ injuries or illnesses.

Contact Nadrich Accident Injury Lawyers Today

If you can’t afford to get treatment for your PD, we can get you to doctors who will treat you on a lien, meaning you won’t be charged until your case is over. Doctors are willing to do this for our clients because they know we get our clients great results.

Call us, text us from this page, or contact us online today for a free consultation if you or a loved one developed PD after being exposed to paraquat. You may be eligible for financial recovery in a paraquat lawsuit.

Jeffrey Nadrich

Jeffrey Nadrich is a nationally-recognized California plaintiff’s personal injury attorney. He is a graduate of UC Berkeley and UC Hastings College of the Law. He has successfully represented thousands of injury clients over the last 40 years.