Brain is a vital organ of the human body which performs very important functions such as analysis, processing, coordination, and execution of electrical signals. For this purpose, it depends on a complex network of nerves which are ensheathed in lipids tailored myelin; an abundant source of lipids in the body. The nervous system is enriched with important classes of lipids; sphingolipids and cholesterol which compose the major portion of the brain particularly in the form of myelin. Both cholesterol and sphingolipids are embedded in the microdomains of membrane rafts and are functional units of the neuronal cell membrane. These molecules serve as the signaling molecules; hold important roles in the neuronal differentiation, synaptogenesis, and many others. Thus, their adequate provision and active metabolism are of crucial importance in the maintenance of physiological functions of brain and body of an individual. In the present review, we have highlighted the physiological roles of cholesterol and sphingolipids in the development of the nervous system as well as the association of their altered metabolism to neurological and neurodegenerative diseases.

Peripheral nerve injury is a complex condition with a variety of signs and symptoms such as numbness, tingling, jabbing, throbbing, burning or sharp pain. Peripheral nerves are fragile in nature and can easily get damaged due to acute compression or trauma which may lead to the sensory and motor functions deficits and even lifelong disability. After lesion, the neuronal cell body becomes disconnected from the axon's distal portion to the injury site leading to the axonal degeneration and dismantlement of neuromuscular junctions of targeted muscles. In spite of extensive research on this aspect, complete functional recovery still remains a challenge to be resolved. This review highlights detailed pathophysiological events after an injury to a peripheral nerve and the associated factors that can either hinder or promote the regenerative machinery. In addition, it throws light on the available therapeutic strategies including supporting therapies, surgical and non-surgical interventions to ameliorate the axonal regeneration, neuronal survival, and reinnervation of peripheral targets. Despite the availability of various treatment options, we are still lacking the optimal treatments for a perfect and complete functional regain. The need for the present age is to discover or design such potent compounds that would be able to execute the complete functional retrieval. In this regard, plant-derived compounds are getting more attention and several recent reports validate their remedial effects. A plethora of plants and plant-derived phytochemicals have been suggested with curative effects against a number of diseases in general and neuronal injury in particular. They can be a ray of hope for the suffering individuals.

Neurodegenerative diseases are conventionally demarcated as disorders with selective loss of neurons. Conventional as well as newer molecules have been tested but they offer just symptomatic advantages along with abundant side effects. The discovery of more compelling molecules that can halt the pathology of these diseases will be considered as a miracle of present time. Several synthetic compounds are available but they may cause several other health issues. Therefore, natural molecules from the plants and other sources are being discovered to replace available medicines. In conventional medicational therapies, several plants have been reported to bestow remedial effects. Phytochemicals from medicinal plants can provide a better and safer alternative to synthetic molecules. Many phytochemicals have been identified that cure the human body from a number of diseases. The present article reviews the potential efficacy of plant-derived alkaloids, which possess potential therapeutic effects against several NDDs including Alzheimer's disease (AD), Huntington disease (HD), Parkinson's disease (PD), Epilepsy, Schizophrenia, and stroke. Alkaloids include isoquinoline, indole, pyrroloindole, oxindole, piperidine, pyridine, aporphine, vinca, β-carboline, methylxanthene, lycopodium, and erythrine byproducts. Alkaloids constitute positive roles in ameliorating pathophysiology of these illnesses by functioning as muscarinic and adenosine receptors agonists, anti-oxidant, anti-amyloid and MAO inhibitors, acetylcholinestrase and butyrylcholinesterase inhibitor, inhibitor of α-synuclein aggregation, dopaminergic and nicotine agonist, and NMDA antagonist.

Naturally occurring food-derived active ingredients have received huge attention for their chemopreventive and chemotherapy capabilities in several diseases. Rosmarinic acid (RA) is a caffeic acid ester and a naturally-occurring phenolic compound in a number of plants belonging to the Lamiaceae family, such as Rosmarinus officinalis (rosemary) from which it was formerly isolated. RA intervenes in carcinogenesis through different ways, including in tumor cell proliferation, apoptosis, metastasis, and inflammation. On the other hand, it also exerts powerful antimicrobial, anti-inflammatory, antioxidant and even antidepressant, anti-aging effects. The present review aims to provide an overview on anticancer activities of RA and to deliberate its therapeutic potential against a wide variety of diseases. Given the current evidence, RA may be considered as part of the daily diet in the treatment of several diseases, with pre-determined doses avoiding cytotoxicity.

Natural products, an infinite treasure of bioactive chemical entities, persist as an inexhaustible resource for discovery of drugs. This review article intends to emphasize on one of the naturally occurring flavonoids, astragalin (kaempferol 3-glucoside), which is a bioactive constituent of various traditional medicinal plants such as Cuscuta chinensis. This multifaceted compound is well known for its diversified pharmacological applications such as anti-inflammatory, antioxidant, neuroprotective, cardioprotective, antiobesity, antiosteoporotic, anticancer, antiulcer, and antidiabetic properties. It carries out the aforementioned activities by the regulation and modulation of various molecular targets such as transcription factors (NF-κB, TNF-α, and TGF-β1), enzymes (iNOS, COX-2, PGE2, MMP-1, MMP-3, MIP-1α, COX-2, PGE-2, HK2, AChe, SOD, DRP-1, DDH, PLCγ1, and GPX), kinases (JNK, MAPK, Akt, ERK, SAPK, IκBα, PI3K, and PKCβ2), cell adhesion proteins (E-cadherin, vimentin PAR-2, and NCam), apoptotic and antiapoptotic proteins (Beclin-1, Bcl-2, Bax, Bcl-x_L, cytochrome c, LC3A/B, caspase-3, caspase-9, procaspase-3, procaspase-8, and IgE), and inflammatory cytokines (SOCS-3, SOCS-5, IL-1β, IL-4, IL-6, IL-8, IL-13, MCP-1, CXCL-1, CXCL-2, and IFN-γ). Although researchers have reported multiple pharmacological applications of astragalin in various diseased conditions, further experimental investigations are still mandatory to fully understand its mechanism of action. It is contemplated that astragalin could be subjected to structural optimization to ameliorate its chemical accessibility, to optimize its absorption profiles, and to synthesize its more effective analogues which will ultimately lead towards potent drug candidates.

Myricetin is a critical nutritive component of diet providing immunological protection and beneficial for maintaining good health. It is found in fruits, vegetables, tea, and wine. The families Myricaceae, Polygonaceae, Primulaceae, Pinaceae, and Anacardiaceae are the richest sources of myricetin. Different researchers explored the therapeutic potential of this valuable constituent such as anticancer, antidiabetic, antiobesity, cardiovascular protection, osteoporosis protection, anti‐inflammatory, and hepatoprotective. In addition to these, the compound has been tested for cancer and diabetic mellitus during clinical trials. Health benefits of myricetin are related to its impact on different cell processes, such as apoptosis, glycolysis, cell cycle, energy balance, lipid level, serum protein concentrations, and osteoclastogenesis. This review explored the potential health benefits of myricetin with a specific emphasis on its mechanism of action, considering the most updated and novel findings in the field.