Chitosan coated synergistically engineered nanoemulsion of Ropinirole and nigella oil in the management of Parkinson's disease: Formulation perspective and In vitro and In vivo assessment

Chitosan-coated nanostructured lipid carriers for effective brain delivery of Tanshinone IIA in Parkinson's disease: interplay between nuclear factor-kappa β and cathepsin B

Parkinson's disease (PD) is the second most common progressive neurodegenerative disorder associated with increased oxidative stress, the underlying vital process contributing to cell death. Tanshinone IIA (TAN) is a phytomedicine with a documented activity in treating many CNS disorders, particularly PD owing to its unique anti-inflammatory and antioxidant effect. However, its clinical utility is limited by its poor aqueous solubility, short half-life, and hence low concentration reaching targeted cells. This work aimed to develop a biocompatible chitosan-coated nanostructured lipid carriers (CS-NLCs) for effective brain delivery of TAN for PD management. The proposed nanosystem was successfully prepared using a simple melt-emulsification ultra-sonication method, optimized and characterized both in vitro and in vivo in a rotenone-induced PD rat model. The developed TAN-loaded CS-NLCs (CS-TAN-NLCs) showed good colloidal properties (size ≤ 200 nm, PDI ≤ 0.2, and ζ-potential + 20 mV) and high drug entrapment efficiency (> 97%) with sustained release profile for 24 h. Following intranasal administration, CS-TAN-NLCs succeeded to achieve a remarkable antiparkinsonian and antidepressant effect in diseased animals compared to both the uncoated TAN-NLCs and free TAN suspension as evidenced by the conducted behavioral tests and improved histopathological findings. Furthermore, biochemical evaluation of oxidative stress along with inflammatory markers, nuclear factor-kabba β (NF-Kβ) and cathepsin B further confirmed the potential of the CS-TAN-NLCs in enhancing brain delivery and hence the therapeutic effect of TAN of treatment of PD. Accordingly, CS-TAN-NLCs could be addressed as a promising nano-platform for the effective management of PD.

Nigella sativa and its nano-mediated approach toward management of neurodegenerative disorders: A review

Nigella sativa L., also known as black seed or black cumin, is a plant that has been used for centuries. In the past, this flowering plant was used as a food preservative and medicinal herb. A vital component of Nigella sativa, thymoquinone (TQ), plays a significant therapeutic role in the management of most diseases, including cancer, diabetes mellitus, hypertension, inflammation, gastrointestinal disorders, and neurodegenerative disorders. Neurodegenerative disorders are primarily caused by neurotransmitter hypoactivity, particularly insufficient serotonin activity. It has been discovered that many medicinal herbs and their active compounds have therapeutic value. Black cumin seeds have been used to heal ailments and its history traces back to ancient times such as ancient Babylonia. They can be used applied to alleviate edema, hair loss, and bruising, and consumd to treat stomach issues. It is one of the most feasible and effective medicinal plants. The use of nanoformulations based on Nigella sativa and TQ to treat neurodegenerative diseases (NDs) has yielded promising outcomes. Customized administration of nanoparticle (NP) systems and nanomedicine are two of the many options for drug delivery to the central nervous system (CNS) that are attracting increasing interest. Delivering a therapeutic and diagnostic substance to a particular location is the core target of NPs. Because of their distinct cell uptake and trafficking mechanisms, NPs can reduce the amount that accumulates in undesirable organs. The focus of the current review is on recent studies on the various neuroprotective properties of Nigella sativa as well as nanoformulations for NDs and the brain's uptake of NPs. The review summarizes the In vivo, In vitro, and In silico studies on the protective effects of black cumin against neurodegenerative disorders.

Nanotechnological Advances for Nose to Brain Delivery of Therapeutics to Improve the Parkinson Therapy

Blood-Brain Barrier (BBB) acts as a highly impermeable barrier, presenting an impediment to the crossing of most classical drugs targeted for neurodegenerative diseases including Parkinson's disease (PD). About the nature of drugs and other potential molecules, they impose unavoidable doserestricted limitations eventually leading to the failure of therapy. However, many advancements in formulation technology and modification of delivery approaches have been successful in delivering the drug to the brain in the therapeutic window. The nose to the brain (N2B) drug delivery employing the nanoformulation, is one such emerging delivery approach, overcoming both classical drug formulation and delivery-associated limitations. This latter approach offers increased bioavailability, greater patient acceptance, lesser metabolic degradation of drugs, circumvention of BBB, ample drug loading along with the controlled release of the drugs. In N2B delivery, the intranasal (IN) route carries therapeutics firstly into the nasal cavity followed by the brain through olfactory and trigeminal nerve connections linked with nasal mucosa. The N2B delivery approach is being explored for delivering other biologicals like neuropeptides and mitochondria. Meanwhile, this N2B delivery system is associated with critical challenges consisting of mucociliary clearance, degradation by enzymes, and drug translocations by efflux mechanisms. These challenges finally culminated in the development of suitable surfacemodified nano-carriers and Focused- Ultrasound-Assisted IN as FUS-IN technique which has expanded the horizons of N2B drug delivery. Hence, nanotechnology, in collaboration with advances in the IN route of drug administration, has a diversified approach for treating PD. The present review discusses the physiology and limitation of IN delivery along with current advances in nanocarrier and technical development assisting N2B drug delivery.

New Drug Delivery Systems Developed for Brain Targeting

The blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (B_CSF) are two of the most complex and sophisticated concierges that defend the central nervous system (CNS) by numerous mechanisms. While they maintain the neuro-ecological homeostasis through the regulated entry of essential biomolecules, their conservative nature challenges the entry of most of the drugs intended for CNS delivery. Targeted delivery challenges for a diverse spectrum of therapeutic agents/drugs (non-small molecules, small molecules, gene-based therapeutics, protein and peptides, antibodies) are diverse and demand specialized delivery and disease-targeting strategies. This review aims to capture the trends that have shaped the current brain targeting research scenario. This review discusses the physiological, neuropharmacological, and etiological factors that participate in the transportation of various drug delivery cargoes across the BBB/B_CSF and influence their therapeutic intracranial concentrations. Recent research works spanning various invasive, minimally invasive, and non-invasive brain- targeting approaches are discussed. While the pre-clinical outcomes from many of these approaches seem promising, further research is warranted to overcome the translational glitches that prevent their clinical use. Non-invasive approaches like intranasal administration, P-glycoprotein (P-gp) inhibition, pro-drugs, and carrier/targeted nanocarrier-aided delivery systems (alone or often in combination) hold positive clinical prospects for brain targeting if explored further in the right direction.

Pathogenic mechanisms and therapeutic promise of phytochemicals and nanocarriers based drug delivery against radiotherapy-induced neurotoxic manifestations

Radiotherapy is one of the extensively used therapeutic modalities in glioblastoma and other types of cancers. Radiotherapy is either used as a first-line approach or combined with pharmacotherapy or surgery to manage and treat cancer. Although the use of radiotherapy significantly increased the survival time of patients, but its use has been reported with marked neuroinflammation and cognitive dysfunction that eventually reduced the quality of life of patients. Based on the preclinical and clinical investigations, the profound role of increased oxidative stress, nuclear translocation of NF-kB, production of proinflammatory cytokines such as TNF-α, IL-6, IL-β, increased level of MMPs, increased apoptosis, reduced angiogenesis, neurogenesis, and histological aberrations in CA1, CA2, CA3 and DG region of the hippocampus have been reported. Various pharmacotherapeutic drugs are being used as an adjuvant to counteract this neurotoxic manifestation. Still, most of these drugs suffer from systemic adverse effect, causes interference to ongoing chemotherapy, and exhibit pharmacokinetic limitations in crossing the blood-brain barrier. Therefore, various phytoconstituents, their nano carrier-based drug delivery systems and miRNAs have been explored to overcome the aforementioned limitations. The present review is focused on the mechanism and evidence of radiotherapy-induced neuroinflammation and cognitive dysfunction, pathological and molecular changes in the brain homeostasis, available adjuvants, their limitations. Additionally, the potential role and mechanism of neuroprotection of various nanocarrier based natural products and miRNAs have been discussed.

Neuroinflammation: A Potential Risk for Dementia

Dementia is a neurodegenerative condition that is considered a major factor contributing to cognitive decline that reduces independent function. Pathophysiological pathways are not well defined for neurodegenerative diseases such as dementia; however, published evidence has shown the role of numerous inflammatory processes in the brain contributing toward their pathology. Microglia of the central nervous system (CNS) are the principal components of the brain’s immune defence system and can detect harmful or external pathogens. When stimulated, the cells trigger neuroinflammatory responses by releasing proinflammatory chemokines, cytokines, reactive oxygen species, and nitrogen species in order to preserve the cell’s microenvironment. These proinflammatory markers include cytokines such as IL-1, IL-6, and TNFα chemokines such as CCR3 and CCL2 and CCR5. Microglial cells may produce a prolonged inflammatory response that, in some circumstances, is indicated in the promotion of neurodegenerative diseases. The present review is focused on the involvement of microglial cell activation throughout neurodegenerative conditions and the link between neuroinflammatory processes and dementia.

Nanoparticles: A Hope for the Treatment of Inflammation in CNS

Neuroinflammation, an inflammatory response within the central nervous system (CNS), is a main hallmark of common neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS), among others. The over-activated microglia release pro-inflammatory cytokines, which induces neuronal death and accelerates neurodegeneration. Therefore, inhibition of microglia over-activation and microglia-mediated neuroinflammation has been a promising strategy for the treatment of neurodegenerative diseases. Many drugs have shown promising therapeutic effects on microglia and inflammation. However, the blood–brain barrier (BBB)—a natural barrier preventing brain tissue from contact with harmful plasma components—seriously hinders drug delivery to the microglial cells in CNS. As an emerging useful therapeutic tool in CNS-related diseases, nanoparticles (NPs) have been widely applied in biomedical fields for use in diagnosis, biosensing and drug delivery. Recently, many NPs have been reported to be useful vehicles for anti-inflammatory drugs across the BBB to inhibit the over-activation of microglia and neuroinflammation. Therefore, NPs with good biodegradability and biocompatibility have the potential to be developed as an effective and minimally invasive carrier to help other drugs cross the BBB or as a therapeutic agent for the treatment of neuroinflammation-mediated neurodegenerative diseases. In this review, we summarized various nanoparticles applied in CNS, and their mechanisms and effects in the modulation of inflammation responses in neurodegenerative diseases, providing insights and suggestions for the use of NPs in the treatment of neuroinflammation-related neurodegenerative diseases.