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NIMHANS study demonstrates promise in intranasal therapy for Parkinson’s disease

February 18, 2026 5 min read Science & Technology GS Paper 3
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What Happened

  • Researchers at the National Institute of Mental Health and Neuro-Sciences (NIMHANS), Bengaluru, have demonstrated a novel intranasal therapy strategy for Parkinson's disease using a pre-clinical rat model.
  • The study used small extracellular vesicles (sEV) derived from dental pulp stem cells (DPSCs) as carriers for phloroglucinol, a naturally occurring compound with neuroprotective properties.
  • The intranasally delivered sEV-encased phloroglucinol (sEV-Phl) showed significant neuroprotective effects: enhanced survival of dopaminergic neurons, promoted neurogenesis, and reduced neuroinflammation in the substantia nigra pars compacta.
  • The approach bypasses the blood-brain barrier (BBB), a major challenge in treating neurological disorders.
  • The study was published in Stem Cell Research & Therapy and represents the first use of DPSC-derived sEV as a delivery vehicle for phloroglucinol in Parkinson's treatment.
  • The therapy is still in the pre-clinical stage (rat model); human clinical trials have not yet commenced.

Static Topic Bridges

Blood-Brain Barrier and Drug Delivery to the Central Nervous System

The blood-brain barrier (BBB) is a highly selective semi-permeable membrane that separates circulating blood from the brain and central nervous system. While it protects the brain from pathogens and toxins, it also blocks the vast majority of therapeutic drugs from reaching brain tissue.

  • The BBB is formed by tight junctions between endothelial cells lining brain capillaries, supported by astrocyte foot processes and pericytes.
  • Approximately 98% of small-molecule drugs and nearly 100% of large-molecule drugs (proteins, antibodies) cannot cross the BBB.
  • Intranasal delivery exploits the unique connections that the olfactory nerve (cranial nerve I) and trigeminal nerve (cranial nerve V) provide between the nasal cavity and the brain, allowing drugs to reach the central nervous system within minutes.
  • Advantages of intranasal delivery: non-invasive, bypasses BBB, enhances bioavailability in the brain, reduces systemic side effects, allows dose reduction, and avoids first-pass metabolism in the liver.
  • Other strategies to cross the BBB include nanoparticle-based delivery, focused ultrasound, and intrathecal injection, all of which are more invasive.

Connection to this news: The NIMHANS study's use of intranasal delivery to transport stem cell-derived extracellular vesicles directly to brain tissue represents an innovative application of this approach. If validated in human trials, it could offer a non-invasive, targeted treatment for Parkinson's and potentially other neurodegenerative diseases.

Stem Cell Research and Extracellular Vesicles in Medicine

Extracellular vesicles (EVs) are nano-sized particles released by cells that carry proteins, lipids, and genetic material. They play a role in cell-to-cell communication and are increasingly being explored as natural drug delivery vehicles.

  • Dental pulp stem cells (DPSCs) are mesenchymal stem cells found in the soft tissue inside teeth. They are multipotent, easily accessible (from extracted teeth), and have neuroprotective and immunomodulatory properties.
  • Small extracellular vesicles (sEV, also known as exosomes) are typically 30-150 nanometres in diameter and can cross biological barriers, including the BBB.
  • sEV can be loaded with therapeutic compounds (such as phloroglucinol) and used as targeted delivery systems, reducing off-target effects compared to systemic drug administration.
  • India's stem cell research is governed by the National Guidelines for Stem Cell Research (2017), issued by ICMR and DBT, which classify research into permissible, restricted, and prohibited categories.
  • India has over 100 institutions conducting stem cell research, with NIMHANS being a premier centre for neuroscience research.

Connection to this news: The use of DPSC-derived vesicles as drug carriers is a novel approach that combines stem cell biology with nanotechnology. The advantage of using dental pulp stem cells is their easy availability and neural crest origin, which may enhance their affinity for nervous tissue.

Parkinson's Disease: Epidemiology and Current Treatment Landscape

Parkinson's disease (PD) is the second most common neurodegenerative disorder globally (after Alzheimer's disease), characterised by progressive loss of dopaminergic neurons in the substantia nigra, leading to tremor, rigidity, bradykinesia, and postural instability.

  • India has an estimated 0.58 million persons living with Parkinson's disease (2016 figures), with prevalence rates of 15-43 per 100,000 population. India is projected to have the highest absolute prevalence of PD in the world due to its large and ageing population.
  • Indian PD patients display a relatively lower mean age-at-onset (54.2 years) compared to Western populations, with a male-to-female ratio of 2.66:1.
  • Current treatments are symptomatic, not curative: Levodopa (L-DOPA) remains the gold standard, supplemented by dopamine agonists, MAO-B inhibitors, and deep brain stimulation for advanced cases.
  • A major limitation of oral Levodopa is that only 1-5% of the drug crosses the BBB; the rest causes systemic side effects including nausea, dyskinesia, and motor fluctuations.
  • Phloroglucinol, the compound used in this study, is a naturally occurring phenolic compound found in brown algae and certain plants. It has demonstrated anti-inflammatory, antioxidant, and neuroprotective properties in laboratory studies.

Connection to this news: The NIMHANS approach addresses a fundamental limitation of existing Parkinson's treatments -- poor drug delivery across the BBB. By encapsulating phloroglucinol in stem cell-derived vesicles and delivering them intranasally, the therapy achieves targeted delivery to the affected brain region (substantia nigra) with potentially fewer systemic side effects than oral medication.

Key Facts & Data

  • NIMHANS (National Institute of Mental Health and Neuro-Sciences): Premier neuroscience research institute, located in Bengaluru, Karnataka; Institute of National Importance (declared by Act of Parliament, 2012)
  • Study model: Pre-clinical (rat model of Parkinson's disease using MPTP-induced neurodegeneration)
  • Delivery system: Small extracellular vesicles from dental pulp stem cells, loaded with phloroglucinol
  • Route: Intranasal (bypasses blood-brain barrier via olfactory and trigeminal nerve pathways)
  • Key results: Enhanced dopaminergic neuron survival, promoted neurogenesis, reduced neuroinflammation
  • Published in: Stem Cell Research & Therapy (peer-reviewed journal)
  • Parkinson's disease in India: estimated 0.58 million patients; prevalence 15-43 per 100,000
  • Blood-brain barrier blocks approximately 98% of small-molecule drugs and nearly 100% of large-molecule drugs
  • Current gold standard treatment: Levodopa (only 1-5% crosses BBB when taken orally)
  • Stage: Pre-clinical; human clinical trials not yet commenced