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Exposure to ionizing radiation (IR) is a common occurrence in clinical practice and incidents involving nuclear detonation or nuclear reactor accidents. IR triggers cellular events that result in oxidative stress and damage to macromolecules, rendering it harmful. While the central nervous system (CNS) was once believed to be resistant to radiation, emerging evidence suggests that even small doses of IR can adversely impact the brain. Exposure to an unsafe dose of radiation can cause increased permeability of the blood-brain barrier (BBB), neuronal apoptosis, reduced neurogenesis, impaired synaptic plasticity, and cognitive dysfunction. In recent years, the potential benefits of dietary agents and phytochemicals for mental health and radiation-induced damage have been widely investigated. Despite this, few studies have explored the protective effects of plants against radiation-induced brain damage. Here, we present a review collating evidence on the beneficial effects of dietary plants on radiation-induced brain damage based on behavioral studies. Notably, Amaranthus paniculatus , Grewia asiatica , Lycium barbarum , and phytochemicals such as vitamin E, corilagin, curcumin, resveratrol, and ursolic acid have demonstrated potential in mitigating radiation-induced damage to the CNS. Furthermore, preliminary studies have indicated that alpha-tocopherol and the micronutrient selenium have neuroprotective effects in cancer survivors previously treated with radiation to the brain. This review focuses exclusively on behavioral outcomes to assess the impact of ionizing radiation on the CNS and the effectiveness of dietary plants and phytochemicals as neuroprotective agents against radiation-induced neuronal damage.

Although helpful in treating cancer, exposure to ionizing radiation can sometimes cause severe side effects, negating its benefit. In addition to its use in clinics, a nontoxic radioprotective agent can also be beneficial in occupational settings where humans are occupationally exposed for prolonged periods to low doses of radiation. Scientific studies using laboratory animals have shown that the fruits Aegle marmelos , Capsicum annuum , Citrus aurantium , Citrullus lanatus , Crataegus microphylla , Eugenia jambolana , Emblica officinalis , Garcinia kola , Grewia asiatica , Hippophae rhamnoides , Malus baccata , Malpighia glabra or Malpighia emarginata , Mangifera indica , Prunus domestica , Prunus avium , Prunus armeniaca , Psoralea corylifolia , Punica granatum , Solanum lycopersicum , Terminalia chebula , Vaccinium macrocarpon , Vitis vinifera and Xylopia aethiopica , and the phytochemicals gallic acid, ellagic acid, quercetin, geraniin, corilagin, ascorbic acid, hesperetin, ursolic acid, lycopene, naringin, hesperidin, rutin, resveratrol, β-sitosterol, apigenin, luteolin, chlorogenic acid, caffeic acid, mangiferin, diosmin, ferulic acid, and kaempferol are effective in preventing radiation-induced ill effects. Clinical studies with Emblica officinalis and Punica granatum have also shown that fruits help mitigate radiation-induced mucositis, dermatitis, and cystitis. For the first time, the current review summarizes the beneficial effects of fruits and phytochemicals in mitigating radiation-induced damage, the underlying mechanisms and the existing lacunae for future studies to be undertaken for the benefit of humans and the nutraceutical and agri-based industries.

Chemobrain or chemofog is one of the important but less investigated side effects, where the cancer survivors treated with chemotherapy develop long-term cognitive impairments, affecting their quality of life. The biological mechanisms triggering the development of chemobrain are largely unknown. However, a literature study suggests the generation of free radicals, oxidative stress, inflammatory cytokines, epigenetic chromatin remodeling, decreased neurogenesis, secretion of brain-derived neurotropic factor (BDNF), dendritic branching, and neurotransmitter release to be the cumulative contributions to the ailment. Unfortunately, there is no means to prevent/mitigate the development and intensity of chemobrain. Given the lack of effective prevention strategies or treatments, preclinical studies have been underway to ascertain the usefulness of natural products in mitigating chemobrain in the recent past. Natural products used in diets have been shown to provide beneficial effects by inhibition of free radicals, oxidative stress, inflammatory processes, and/or concomitant upregulation of various cell survival proteins. For the first time, this review focuses on the published effects of astaxanthin, omega-3 fatty acids, ginsenoside, cotinine, resveratrol, polydatin, catechin, rutin, naringin, curcumin, dehydrozingerone, berberine, C-phycocyanin, the higher fungi Cordyceps militaris , thyme ( Thymus vulgaris ) and polyherbal formulation Mulmina™ in mitigating cognitive impairments in preclinical models of study, and also addresses their potential neuro-therapeutic mechanisms and applications in preventing/ameliorating chemobrain.

Dietary constituents are shown to play an important role in the development of diabetes. Studies have shown that the fruits of Emblica officinalis Gaertn or Phyllanthus emblica Linn, colloquially known as Indian gooseberry or amla and/or some of its important constituents (including gallic acid, gallotanin, ellagic acid and corilagin), possess anti-diabetic effects through their antioxidant and free radical scavenging properties. Amla has also been reported to prevent/reduce hyperglycemia, cardiac complications, diabetic nephropathy, neuropathy, cataractogenesis and protein wasting. However, clinical trial data with human subjects are limited and preliminary. For the first time this review summarizes the anti-diabetic affects of amla and also addresses the mechanisms mediating these properties.

Liver diseases characterized by inflammation or tissue damage affect the optimal functioning and increase the morbidity and mortality of the affected individual. Liver diseases are a largely neglected health issue and recent reports indicate that they affect over 10% of the world population, with the highest burden in low and middle income countries that have minimal medical resources. To complicate matters the currently available pharmacological therapies are not optimal and when used for extended periods of time impart systemic toxicity. Diet can modify pathophysiological processes, including those of hepatotoxins, and studies have shown that some dietary constituents can afford heptoprotection. Emblica officinalis Gaertn or Phyllanthus emblica Linn, commonly known as the Indian gooseberry in English or amla in Hindi, is one of the most important medicinal and dietary plants in the Indian subcontinent. The fruits are of dietary and medicinal use and have wide applications in both traditional and folk systems of medicine. Scientific studies have shown amla to be effective in preventing/ameliorating the toxic effects of hepatotoxic agents like ethanol, paracetamol, carbon tetrachloride, heavy metals, ochratoxins, hexachlorocyclohexane, antitubercular drugs and hepatotoxicity resulting from iron overload. Amla is also reported to impart beneficial effects on liver function and to mitigate hyperlipidemia and metabolic syndrome. Amla possesses protective effects against chemical-induced hepatocarcinogenesis in animal models of study. Additionally, the phytochemicals quercetin, gallic acid, corilagin and ellagic acid are also reported to protect against the cytotoxic effects of paracetamol, microcystins, galactosamine and lipopolysaccharide. The hepatoprotective actions of amla appear to be mediated by its free radical scavenging, antioxidant, anti-inflammatory and modulation of the xenobiotic detoxification process and lipid metabolism.

The rhizomes of Zingiber officinale Roscoe (Zingiberaceae), commonly known as ginger is an important kitchen spice and also possess a myriad health benefits. The rhizomes have been used since antiquity in the various traditional systems of medicine to treat arthritis, rheumatism, sprains, muscular aches, pains, sore throats, cramps, hypertension, dementia, fever, infectious diseases, catarrh, nervous diseases, gingivitis, toothache, asthma, stroke and diabetes. Ginger is also used as home remedy and is of immense value in treating various gastric ailments like constipation, dyspepsia, belching, bloating, gastritis, epigastric discomfort, gastric ulcerations, indigestion, nausea and vomiting and scientific studies have validated the ethnomedicinal uses. Ginger is also shown to be effective in preventing gastric ulcers induced by nonsteroidal anti-inflammatory drugs [NSAIDs like indomethacin, aspirin], reserpine, ethanol, stress (hypothermic and swimming), acetic acid and Helicobacter pylori-induced gastric ulcerations in laboratory animals. Various preclinical and clinical studies have also shown ginger to possess anti-emetic effects against different emetogenic stimuli. However, conflicting reports especially in the prevention of chemotherapy-induced nausea and vomiting and motion sickness prevent us from drawing any firm conclusion on its effectiveness as a broad spectrum anti-emetic. Ginger has been shown to possess free radical scavenging, antioxidant; inhibition of lipid peroxidation and that these properties might have contributed to the observed gastroprotective effects. This review summarizes the various gastroprotective effects of ginger and also emphasizes on aspects that warranty future research to establish its activity and utility as a gastroprotective agent in humans.

Inflammatory bowel disease (IBD) comprising of ulcerative colitis (UC) and Crohn's disease (CD) is a major ailment affecting the small and large bowel. In clinics, IBD is treated using 5-amninosalicylates, antibiotics, the steroids and immunomodulators. Unfortunately, the long term usages of these agents are associated with undue side effects and compromise the therapeutic advantage. Accordingly, there is a need for novel agents that are effective, acceptable and non toxic to humans. Preclinical studies in experimental animals have shown that curcumin, an active principle of the Indian spice turmeric (Curcuma longa Linn) is effective in preventing or ameliorating UC and inflammation. Over the last few decades there has been increasing interest in the possible role of curcumin in IBD and several studies with various experimental models of IBD have shown it to be effective in mediating the inhibitory effects by scavenging free radicals, increasing antioxidants, influencing multiple signaling pathways, especially the kinases (MAPK, ERK), inhibiting myeloperoxidase, COX-1, COX-2, LOX, TNF-α, IFN-γ, iNOS; inhibiting the transcription factor NF-κB. Clinical studies have also shown that co-administration of curcumin with conventional drugs was effective, to be well-tolerated and treated as a safe medication for maintaining remission, to prevent relapse and improve clinical activity index. Large randomized controlled clinical investigations are required to fully understand the potential of oral curcumin for treating IBD.

Radiation is an important modality in treating people with cancer especially when surgical intervention is impracticable or might debilitate the patient. However, effective use of ionizing radiation is compromised by the side effects that result from radiation-induced damage to normal tissue. The use of radioprotective compounds, which can selectively protect normal tissues against radiation injury is of immense use because in addition to association with protecting the normal tissue, it will also permits use of higher doses of radiation to obtain better cancer control and possible cure. However, till date no ideal radioprotectors are available as most synthetic compounds are toxic at their optimal concentrations. Plants commonly used as dietary and or therapeutic agents have recently been the focus of attention since in most cases they are non-toxic and are easily accepted for human use. Ginger, the rhizomes of Zingiber officinale Roscoe (Zingiberaceae), has widely been used as both culinary and medicinal agent. Preclinical studies carried out in the last decade has shown that ginger and its phytochemicals dehydrozingerone, zingerone possess radioprotective effects in laboratory animals and in cultured cells in vitro. The hydroalcoholic extract of ginger rhizome when administered either through intraperitoneal or oral route was effective in protecting against gamma radiation-induced sickness and mortality. The phytochemicals dehydrogingerone and zingerone present in ginger are also shown to protect mice against radiation-induced sickness and mortality. Mechanistic studies have indicated that the free radical scavenging, antioxidant affects, anti-inflammatory and anti-clastogenic effects may contribute towards the observed protection. Additionally, studies with tumor bearing mice have also shown that zingerone selectively protects the normal tissues against the tumoricidal effects of radiation. This review for the first time summarizes the results related to the radioprotective properties and also emphasizes the aspects that warrant future research to establish its activity and utility as a radioprotective agent.

Long term alcohol consumption is one of the important causes for liver failure and death. To complicate the existing problem there are no dependable hepatoprotective drugs and a large number of patients prefer using complementary and alternative medicines for treating and managing hepatic complications. Almost 25 centuries ago, Hippocrates, the father of medicine, proclaimed "Let food be thy medicine and medicine be thy food." Exploring the association between diet and health continues even today. Preclinical studies carried out in the recent past have shown that the commonly used dietary agents like Allium sativum (garlic), Camellia sinensis (tea), Curcuma longa (turmeric), Emblica officinalis (Indian gooseberry), Ferula asafoetida (asafoetida), Garcinia cambogia (Malabar tamarind), Glycine max (soyabean), Murraya koenigii (curry leaves), Piper betle (beetle leaf), Prunus armeniaca (apricot), Ocimum gratissimum (wild basil), Theobroma cacao (cocoa), Trigonella foenum-graecum (fenugreek) and Vitis vinifera (grapes) protect against ethanol-induced hepatotoxicity. Mechanistic studies have shown that the beneficial effects of these phytochemicals in preventing the ethanol-induced hepatotoxicity are mediated by the antioxidant, free radical scavenging, anti-inflammatory and anti-fibrotic effects. The present review for the first time collates the hepatoprotective effects of these agents and also emphasizes on aspects that need future research to establish their utility in humans.