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γ rays

This review specifically focuses a current understanding on the dietary sources of polyphenols and their protective effects including mechanisms of action against various major human diseases.

ROS when increased or excessively produced can cause oxidative changes/damages to all cellular macromolecules

Several antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) aid in the removal of free radicals

Peroxynitrite can also destroy lipoproteins and causes lipid peroxidation of cell membranes

ROS can also affect protein synthesis and protein functions. Protein oxidation can result in amino acid modifications

Flavonoids are further classified into different subgroups based on their structures such as flavan-3-ols (examples: catechin, epicatechin, epigallocatechin), isoflavones (examples: genistein, genistin, daidzenin, daidzin, biochanin A, formononetin), flavones (examples: luteolin, apigenin, chrysin), flavonones (examples: hesperetin, naringenin), flavonols (examples: quercetin, kaempferol, galangin, fisetin, myricetin), flavononol (example: taxifolin), flavylium salts (examples: cyanidin, cyanin, pelargonidin), and flavanones (examples: hesperetin, naringenin, eriodictyol, isosakuranetin)

urther, OS exerts deleterious effects on DNA leading to the formation of DNA lesions, which can result in genomic instability and consequently lead to cell death.

Polyphenols are found naturally in fruits and vegetables such as cereals, pulses, dried legumes, spinach, tomatoes, beans, nuts, peppermint, cinnamon, pears, cherries, oranges, apples, red wine, tea, cocoa, coffee and so on (Arts and Hollman, 2005; Scalbert et al., 2005). Polyphenols are classified into different groups depending on the number of aromatic (phenolic) rings they contain and the structural elements that connect these rings. They are broadly grouped into phenolic acids, flavonoids, stilbenes and lignans

Dietary supplements containing elevated amounts of flavonoids from strawberries, lettuce, or blueberries aid in the reversal of age-related discrepancies in the brain and behavioral control in aged rats

Tea catechins

OS can be the primary or secondary reason for various CVDs. Preclinical evidence support that OS is linked to a variety of CVDs, including atherosclerosis, ischemia, stroke, cardiomyopathy, cardiac hypertrophy, and hypertension, as well as congestive heart failure

Dietary flavonoids may reduce endothelial disorders linked with various risk factors for atherosclerosis before plaque creation

The polyphenols of Hibiscus sabdariffa weaken diabetic nephropathy in terms of serum lipid profile and kidney oxidative markers

. Studies suggest that a diet that includes regular consumption of fruits and vegetables (rich in polyphenols such as catechins, resveratrol, ellagic acid, naringenin, quercetin etc.) significantly lowers the risk of developing many cancers.

Black tea polyphenols like EGCG, theaflavins and thearubigins have potent anticancer properties

Increased OS may lead to the vulnerability of the infection and also triggers the malfunctioning of cellular metabolism

In this line of research, novel therapies aim to target apoptosis via mitochondria, using molecules that mimic BH3 proteins and disrupt the interactions of pro-apoptotic and anti-apoptotic proteins.

Therefore, the mechanisms by which mushroom extracts or isolated compounds induce mitochondrial-related apoptosis pathways are diverse and may be related with specific bioactive compounds. Modulation of pathways crucial for cell survival and alterations in lipid homeostasis seem to be related with the pro-apoptotic effects observed in HCC cell lines and in in-vivo xenograft models.

To sum up, mitochondria play a central role in the pathophysiology and progression of NAFLD as well as in the development of HCC, which can be a late-stage consequence of NASH. Hepatic mitochondria undergo bioenergetic remodelling to face the metabolic burden imposed by the increased FFAs load secondary to systemic IR. In turn, a decompensation of these processes may result in ROS formation and mitochondrial dysfunction, contributing to the development of NASH. Lastly, hepatic mitochondria also seem to be involved in anti-apoptotic oncogenic processes driving HCC. Targeting mitochondrial dysfunction is thus a promising approach for the treatment of the NAFLD continuum. The following section describes some of the in-vitro and in-vivo studies on the beneficial effects of mushroom-enriched diets or mushroom-derived compounds/extracts (Box 2) in preventing/reverting such liver damage.

the effect of a very low dose of LA (0.1 mg/kg) was potentiated by the same dose of pentoxifylline (PTX), a known TNF-alpha inhibitor. L

rich in triterpenes

Carrageenan-induced mice paw edema

LA (10, 25 and 50 mg/kg, i.p.) reduced both phases of the formalin test, and the results were significant at the two higher doses. However, the effects were mainly on the 2nd phase with 61% inhibition, whereas the 1st phase was inhibited by 41% at the LA dose of 50 mg/kg, i.p. The naloxone pretreatment completely reversed the LA effect, in the 1st and 2nd phases, indicating the participation of the opioid system in LA antinociceptive and anti-inflammatory actions.

On the other hand, while no significant enzyme release was observed with LA at the concentrations of 1, 10 and 25 μg/mL, a small but significant LDH release (around 2 times) was detected with the higher LA concentration (50 μg/mL), probably related to the presence of 0.2% Tween 80.

The results show that LA at the concentrations of 50, 100 and 200 μg/mL presents no radical scavenging capacity. On the contrary, vitamin E used as the reference drug significantly decreased the absorbance value, as related to controls

In the carrageenan-treated groups pretreated with LA (50 mg/kg, i.p.) or indomethacin (10 mg/kg, i.p.), there were significant reductions of iNOS expressing cells.

Lupeol is found in several other species and its antinociceptive and anti-inflammatory activities have been already demonstrated [24–28]. It is accepted that the anti-inflammatory property of lupeol often accompany its immune modulatory and anti-tumor action

lupeol acetate presents an anti-inflammatory activity by regulating TNF-alpha and IL-2 specific mRNA, besides upregulating the synthesis of IL-10 mRNA [31].

In the present work, we showed that lupeol acetate (LA, 93.2% purity) isolated from the H. drasticus latex presented a potent anti-inflammatory action, in several models of inflammation in mice

These authors concluded that lupeol possessed an anti-inflammatory activity which is probably related to its ability to prevent the production of pro-inflammatory mediators, such as TNF-α and IL-1β.

by PCR. F

Based on the results of the VlvSTS gene transcription analysis, seven transgenic tobacco lines were selected for further experiments.

Expression of the VlvSTS gene in tobacco plants led to a significant increase in the pollen grain size, but with a tendency to a decrease in the total number of pollen grains per anther

In all tests with E. carotovora bacteria, transgenic plants expressing the VlvSTS gene demonstrated a significantly higher resistance versus control plants

The leaf involvement was significantly smaller in transgenic plants expressing the VlvSTS gene.

Overexpression of the VlvSTS gene reduced the corolla pigmentation in transgenic plants.

binary vector

showed a significant fertility reduction,

For the first time it was shown that plants expressing the VlvSTS gene had enhanced resistance to the bacterial pathogen E. carotovora subsp. carotovora B15.

We were the first to show that transgenic tobacco plants carrying the VlvSTS gene had a significantly larger pollen grain size and a smaller number of pollen grains per anther. At the same time, the number of fertile pollen grains decreased, especially in the plant line with the highest expression of the VlvSTS gene.

For example, in apple plants with the grape stilbene synthase gene Vst1 under its own promoter, the expression of the gene had no effect on pollen development

The study showed that the expression of a VlvSTS stilbene syntase gene in tobacco transgenic plants increases their resistance to bacterial pathogen E. carotovora. There was a significant reduction of disease symptoms after infection of leaves by grey mould fungus B. cinerea, but not to Fusarium fungi. We were the first to show that transgenic tobacco plants carrying the VlvSTS gene had a significantly larger pollen grain size and a smaller number of pollen grains per anther. The number of fertile pollen grains decreased, especially in the plant line with the highest expression of the VlvSTS gene. These changes resulted in a decreased weight of seed bolls in the transgenic tobacco lines.

The mechanisms leading to skin damage are not fully understood and may derive from the generation of ROS and subsequent lipid peroxidation

To prevent photodamage, organisms have evolved to provide biochemical and physical defenses to UV by synthesizing robust bioactive compounds

Some algae species synthesize substances with chemical structures that can absorb UV radiation as well as inhibit actions on melanin synthesis

two marine microalgae Pavlova lutheri, currently known as Diacronema lutheri, and Odontella aurita

Marine organisms, including eukaryotic microalgae and cyanobacteria, during evolution, have developed physiological and biochemical traits for defense and/or tolerance to UV rays

This research also mentioned the Antarctic microalgae Chaetoceros dichaeta, Phaeocystis antarctica, and Polarella glacialis, these were subjected to acclimation to photosynthetically active radiation (PAR) and showed resistance to UV-B rays.

It was found that the tolerant species contained substantial amounts of acetolysis-resistant residue

They are abundant in various aquatic and terrestrial environments and are known for being eco-sustainable compounds since they are the outcome of the evolution of algae. Unlike their synthetic counterparts used unconventional sunscreens, there are no possibilities for pollution caused by them [22]. Thus, algal metabolites shape the safety and sustainability profiles of commercial sunscreens [22].

The results obtained point out different resistance and defense mechanisms of the four microalgae in response to UV-B irradiance and suggest that the strain of Nostoc sp. tested is the most suitable for surviving under the high UV irradiation [33]

Certain microalgae produce organic metabolites, such as sporopollenin, scytonemin, and MAAs as well as other UV-absorbing substances to counteract the harmful effects of UV radiation and protect themselves while allowing visible radiation involved in photosynthesis to pass through

For these reasons, they potentially can prevent UV-induced skin damage

It was reported that species of microalgae that were highly tolerant to UV radiation had substantial amounts of sporopollenin. This compound functions as an antimicrobial agent, confers rigidness to the cell wall, and may further protect from UV rays by increasing the optical density, whereas species containing little or no sporopollenin were highly UV radiation susceptible

Other reports determine that scytonemin is suspected to be synthesized from metabolites of aromatic amino acid biosynthesis

ydration

However, some microalgae have a great ability to overcome or counteract different stresses such as intense solar UV radiation, this has been happening over the years and with the evolution of microalgae, some examples of defense and/or tolerance mechanisms are: DNA repair, synthesis of antioxidants, and enzymatic/non-enzymatic compounds, such as MAAs and scytonemin to counteract the harmful effects of UV radiation

Scytonemin is a yellow-brown lipid soluble sheath pigment that absorbs maximally in the UV-A and UV-C regions, but with some absorbance in the UV-B region. It has an in vivo absorption maximum of 370 nm.

tigate UV damage induced.

photosensitizers, their antioxidant

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