Avocado Seed Extract Displays Anti-Inflammatory Properties

The use of colored avocado seed extract (CASE), developed from crushed avocado seeds, displayed anti-inflammatory properties that can be used as either functional food ingredients or as lead compounds for pharmaceutical development, according to Penn State researchers who published their findings in Advances In Food Technology And Nutritional Sciences.

Avocados are known to be rich in essential nutrients such as unsaturated fatty acids, fiber, and vitamins B and E. Researchers of this study previously reported that the avocado seed, when crushed, produces a bright orange extract that can potentially be used as a food additive to alleviate inflammation.

In this laboratory study, Lipopolysaccharide (LPS)-simulated RAW2647 murine macrophage cells were treated with CASE for a 24-hour duration, and subsequently the pro-inflammatory cytokines, Interluekin -6 (IL-6), tumor necrosis factor-α (TNF-α) and IL-1β (Interleukin -1β) were measured along with nitric oxide (NO) production. The researchers also examined if CASE would inhibit the activity of secreted Phospholipase A2 (PLA2) while evaluating the extract’s effect on Cyclooxygenase -2 (COX-2) and prostaglandin E2 (PGE2).

Extract Exhibits Great Promise

According to the study results, the treatment of LPS-stimulated RAW264.7 cells with CASE over 24-hours diminished the production of pro-inflammatory cytokines, IL-6, TNF-α, and IL-1β while NO production was mitigated in a dose-dependent manner, and the reduction was associated with a decrease in the protein expression of inducible nitric oxide synthase (iNOS). Moreover, PGE2 production was significantly reduced by CASE while no deviation in the protein expression of Cyclooxygenase -2 (COX-2) was observed. Furthermore, CASE impeded the activity of purified secreted PLA2 (IC50=36 μg/mL), and kinetic analysis suggested that the inhibition was non-competitive with respect to substrate concentration. Nuclear translocation of nuclear factor κB (NF-kB) to the nucleus was also reduced by treatment with CASE, and this inhibition may underscore the effects of CASE on iNOS and cytokine expression.

“The level of activity that we see from the extract is very good,” said Dr. Joshua Lambert, co-director of Penn State’s Center for Plant and Mushroom Foods for Health, in a press release about the study. “We saw inhibitory activity at concentrations in the low microgram-per-milliliter range, which is an acceptable amount of activity to justify further studies.”

Dr. Lambert, and colleagues have filed a patent application for the use of the extract as a food color additive.

“If we can return value to avocado growers or avocado processors, that would be a benefit, and if we can reduce the amount of this material being dumped in landfills, that would be a good thing, given the huge amount of avocados that are consumed,” he said. “This is encouraging because there is a market for other high-value sources of bioactive compounds we have tested in my lab, such as cocoa and green tea – whereas avocado seeds are essentially considered to be garbage.”