The brain and nervous system are prone to oxidative stress, and are inadequately equipped with antioxidant defense systems to prevent 'ongoing' oxidative damage, let alone the extra oxidative damage imposed by the neurodegenerative diseases. Indeed, increased oxidative damage, mitochondrial dysfunction, accumulation of oxidized aggregated proteins, inflammation, and defects in protein clearance constitute complex intertwined pathologies that conspire to kill neurons. After a long lag period, therapeutic and other interventions based on a knowledge of redox biology are on the horizon for at least some of the neurodegenerative diseases.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1471-4159.2006.03907.x

Oxidative stress and neurodegeneration: where are we now?

Potential Therapeutic Effects of Curcumin, the Anti-inflammatory Agent, Against Neurodegenerative, Cardiovascular, Pulmonary, Metabolic, Autoimmune and Neoplastic Diseases

Turmeric, derived from the plant Curcuma longa, is a gold-colored spice commonly used in the Indian subcontinent, not only for health care but also for the preservation of food and as a yellow dye for textiles. Curcumin, which gives the yellow color to turmeric, was first isolated almost two centuries ago, and its structure as diferuloylmethane was determined in 1910. Since the time of Ayurveda (1900 Bc) numerous therapeutic activities have been assigned to turmeric for a wide variety of diseases and conditions, including those of the skin, pulmonary, and gastrointestinal systems, aches, pains, wounds, sprains, and liver disorders. Extensive research within the last half century has proven that most of these activities, once associated with turmeric, are due to curcumin. Curcumin has been shown to exhibit antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, and anticancer activities and thus has a potential against various malignant diseases, diabetes, allergies, arthritis, Alzheimer's disease, and other chronic illnesses. These effects are mediated through the regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other enzymes. Curcumin exhibits activities similar to recently discovered tumor necrosis factor blockers (e.g., HUMIRA, REMICADE, and ENBREL), a vascular endothelial cell growth factor blocker (e.g., AVASTIN), human epidermal growth factor receptor blockers (e.g., ERBITUX, ERLOTINIB, and GEFTINIB), and a HER2 blocker (e.g., HERCEPTIN). Considering the recent scientific bandwagon that multitargeted therapy is better than monotargeted therapy for most diseases, curcumin can be considered an ideal "Spice for Life".

Curcumin: The Indian solid gold

Turmeric (Curcuma longa) is a type of herb belonging to ginger family, which is widely grown in southern and south western tropical Asia region. Turmeric, which has an importance place in the cuisines of Iran, Malesia, India, China, Polynesia, and Thailand, is often used as spice and has an effect on the nature, color, and taste of foods. Turmeric is also known to have been used for centuries in India and China for the medical treatments of illnesses such as dermatologic diseases, infection, stress, and depression. Turmeric's effects on health are generally centered upon an orange-yellow colored, lipophilic polyphenol substance called "curcumin," which is acquired from the rhizomes of the herb. Curcumin is known recently to have antioxidant, anti-inflammatory, anticancer effects and, thanks to these effects, to have an important role in prevention and treatment of various illnesses ranging notably from cancer to autoimmune, neurological, cardiovascular diseases, and diabetic. Furthermore, it is aimed to increase the biological activity and physiological effects of the curcumin on the body by synthesizing curcumin analogues. This article reviews the history, chemical and physical features, analogues, metabolites, mechanisms of its physiological activities, and effects on health of curcumin.

Curcumin, an Active Component of Turmeric (Curcuma longa), and Its Effects on Health

1. Curcumin is the active ingredient of the dietary spice turmeric and has been consumed for medicinal purposes for thousands of years. Modern science has shown that curcumin modulates various signalling molecules, including inflammatory molecules, transcription factors, enzymes, protein kinases, protein reductases, carrier proteins, cell survival proteins, drug resistance proteins, adhesion molecules, growth factors, receptors, cell cycle regulatory proteins, chemokines, DNA, RNA and metal ions. 2. Because of this polyphenol's potential to modulate multiple signalling molecules, it has been reported to possess pleiotropic activities. First demonstrated to have antibacterial activity in 1949, curcumin has since been shown to have anti-inflammatory, anti-oxidant, pro-apoptotic, chemopreventive, chemotherapeutic, antiproliferative, wound healing, antinociceptive, antiparasitic and antimalarial properties as well. Animal studies have suggested that curcumin may be active against a wide range of human diseases, including diabetes, obesity, neurological and psychiatric disorders and cancer, as well as chronic illnesses affecting the eyes, lungs, liver, kidneys and gastrointestinal and cardiovascular systems. 3. Although many clinical trials evaluating the safety and efficacy of curcumin against human ailments have already been completed, others are still ongoing. Moreover, curcumin is used as a supplement in several countries, including India, Japan, the US, Thailand, China, Korea, Turkey, South Africa, Nepal and Pakistan. Although inexpensive, apparently well tolerated and potentially active, curcumin has not been approved for the treatment of any human disease. 4. In the present article, we discuss the discovery and key biological activities of curcumin, with a particular emphasis on its activities at the molecular and cellular levels, as well as in animals and humans.

/pdf/discovery-of-curcumin-a-component-of-golden-spice-and-its-5ge0bwb9x7.pdf

Discovery of curcumin, a component of golden spice, and its miraculous biological activities

Although the cause of dopaminergic cell death in Parkinson's disease (PD) remains unknown, oxidative stress has been strongly implicated. Because of their ability to combat oxidative stress, diet derived phenolic compounds continue to be considered as potential agents for long-term use in PD. This study was aimed at investigating whether the natural phenolic compounds curcumin, naringenin, quercetin, fisetin can be neuroprotective in the 6-OHDA model of PD. Unilateral infusion of 6-OHDA into the medial forebrain bundle produced a significant loss of tyrosine hydroxylase (TH)-positive cells in the substantia nigra (SN) as well as a decreased of dopamine (DA) content in the striata in the vehicle-treated animals. Rats pretreated with curcumin or naringenin showed a clear protection of the number of TH-positive cells in the SN and DA levels in the striata. However, neither pretreatment with quercetin nor fisetin had any effects on TH-positive cells or DA levels. The ability of curcumin and naringenin to exhibit neuroprotection in the 6-OHDA model of PD may be related to their antioxidant capabilities and their capability to penetrate into the brain.

Neuroprotective properties of the natural phenolic antioxidants curcumin and naringenin but not quercetin and fisetin in a 6-OHDA model of Parkinson's disease

Objective: Antioxidants from plants were known to reduce the oxidative stress by scavenging free radicals, chelating metal ions and reducing inflammation. As increased oxidative stress was implicated in the nigrostriatal dopaminergic neuronal loss in Parkinson's disease (PD), we have assessed whether the plant extracts protects the nigrostriatal dopaminergic neurons in the animal model of PD.Methods: Male adult Sprague-Dawley rats were treated orally between 10am–11am each day with the extracts from tangerine peel, grape seeds, cocoa and red clover for four days. One hour after the final dosing, the left medial forebrain bundle was lesioned by infusing the dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA; 12μg) under anaesthesia. Seven days post-lesion, the number of dopaminergic cells in the substantia nigra pars compacta and the levels of dopamine and its metabolites 3, 4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striata were quantified and compared with the vehicle-treated ...

Shabnam Parkar

Papers

Neuroprotective properties of the natural phenolic antioxidants curcumin and naringenin but not quercetin and fisetin in a 6-OHDA model of Parkinson's disease

Short-term supplementation with plant extracts rich in flavonoids protect nigrostriatal dopaminergic neurons in a rat model of Parkinson's disease.