Entries tagged with “in vivo”


Aug 5 2010

Olive oil extract shows brain protecting benefits

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An olive extract rich in hydroxytyrosol may protect neurons in the brain from the normal deterioration associated with aging, suggests a new study.

Hydroxytyrosol was found to protect brain cells from the detrimental effects of oxidative stress when exposed to ferrous ion, and may offer a neuroprotective ingredient to slow the decline in cognitive performance that occurs naturally with age, according to findings published in Pharmacological Research.

Hydroxytyrosol is thought to be the main antioxidant compound in olives, and believed to play a significant role in the many health benefits attributed to olive oil. Previous research has linked the compound to cardiovascular benefits, with reductions in LDL or ‘bad’ cholesterol. Data has also suggested the compound may boost eye health and reduce the risk of against macular degeneration.

Researchers from the University of Frankfurt used Genosa I+D’s Hytolive ingredient, and the findings were welcomed by the Spanish company. In an email with NutraIngredients-USA, Genosa’s Carlos Peña said: “This is the second study that confirms the neuro-protection activity of Hytolive, by protecting and preventing neurons and brain from deterioration associated to degenerative diseases.

“In a previous study it was demonstrated that Hytolive protected dissociated brain cells (in vitro and ex-vivo) after subchronic oral administration. This second study has confirmed that the active principle is natural hydroxytyrosol. This means that cytoprotective effects in PC12 cells (a commonly used neuronal-like cell culture model) are likely due to hydroxytyrosol present in Hytolive and not a combination of compounds,” added Peña.

Study details

The Frankfurt-based scientists tested the efficacy of the hydroxytyrosol-rich extract in vitro on cells exposed to both oxidative or nitrosative stress. Cells were exposed to the hydroxytyrosol-rich ingredient and then subjected to the stress.

Results showed that the olive oil compound reduced the cell damaging effects of the oxidative and nitrosative stress in a dose-dependent manner, with higher doses providing increased protection.

Furthermore, the effects appeared to be related to the hydroxytyrosol-content of the extract, said the researchers.

“With respect to hydroxytyrosol, its incorporation into LDL which are transported into the brain, might provide a physiological route for hydroxytyrosol to enter brain cells,” added the researchers.

Source: Pharmacological Research
Published online ahead of print, doi: 10.1016/j.phrs.2010.06.004
“Cytoprotective effects of olive mill waste water extract and its main constituent hydroxytyrosol in PC12 cells”
Authors: S. Schaffer, W.E. Muller, G.P. Eckert

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Jul 30 2010

Study confirms rooibos antioxidant potential

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Italian researchers have found that rooibos tea is able to boost plasma antioxidant defences in humans.

The researchers from the Antioxidant Research Laboratory in Rome found ingestion of fermented and unfermented rooibos tea increased TAC levels, measured as total antioxidant capacity (TAC).

But Professor Mauro Serafini and his team called for more intervention trials to investigate the proposition that rooibos tea can be as good an antioxidant source as green tea.

The study sought to measure how rooibos tea affects TAC levels as well as lipid triacylglycerols, cholesterol and glycemia plasma levels in humans.

In the trial, 15 healthy adults consumed either 500ml of water, unfermented or fermented rooibos teas, with fermented tea increasing antioxidant capacity 6.6 percent and unfermented tea increasing 2.9 percent.

No changes in triacylglycerols, cholesterol or uric acid were observed with any either of the teas or water.

The researchers noted that only a few studies had investigated the effects of rooibos tea in the body and they focused on iron status, antihistaminic effects and dermatological diseases. None of them investigate potential in vivo antioxidant properties.

“Hence, in the present study we evaluated the in vivo antioxidant properties of fermented and unfermented rooibos teas in healthy humans and related these to the in vitro antioxidant capacity of the beverages,” they wrote.

The subjects observed a low antioxidant diet for two days prior to the feeding period of the studies and dietary records were kept. Between feeding periods there was a two-week wash out and all subjects received all three treatments.

“The two rooibos teas exhibited a lower antioxidant potential than did green and black tea infusions but higher than commercially available instant tea,” the researchers said.

Flavonoid questions

But despite the positive antioxidant findings, the researchers enjoined with many other antioxidant researchers in being unable to explain or define potential antioxidant effects.

“On the basis of the data obtained in the bioavailability study, we cannot explain the in vivo antioxidant effect observed after ingestion of the rooibos teas. This is not unusual in intervention studies with antioxidant rich foods where most of the investigations showing an increase in plasma antioxidant defences, measured as TAC, have failed to identify the components responsible, raising questions as to the direct involvement of flavonoid metabolites as antioxidant molecules in vivo.”

Source:

Food Chemistry

123 (2010) 679–683

‘Unfermented and fermented rooibos teas (Aspalathus linearis) increase plasma total antioxidant capacity in healthy humans’

Authors: D. Villaño et al

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