Peach (Prunus persica L.)

Peach (Prunus persica L.) belongs to the Rosaceae family, originated in China. Different varieties of peaches are highly consumed worldwide. It is commercially grown in many countries at a fair range of different climate conditions and types of soils.

Peach fruits are a drupe composed of skin (epidermis), flesh (mesocarp), and stone (endocarp) enclosing the seed. Ripening peach can be clingstone (flesh adhering to the stone) or freestone (flesh separating from the stone); melting (flesh quickly softening) or non-melting (flesh remaining firm). The flesh can be white, yellow or red according to mesocarp colour.

Peaches present many secondary metabolites, such as phenolic compounds, carotenoids and tocopherols that present important biological actions and are associated with disease prevention. Two main groups of phenolic compounds present in peach have different structural characteristics – NonFlavonoids, which include phenolic acids; and Flavonoids, which include flavonols, flavan-3-ols and anthocyanins.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]

In vivo study was conducted to investigate tumor growth inhibition and anti-metastatic effects of peach phenolics
Subject	Female athymic nude mice implanted with MDA-MB-435 human breast cancer cells. 10 days after tumor implantation, animals were divided into equal groups (5 per group)
Duration	24 days
Group and Dosage	Xenograft group Group 1 – received 100µL 10% saline solution (xenografted control) Group 2 – received Peach phenolics (0.2 to 1.6 mg chlorogenic acid equivalents (CAE)/day dissolved in saline solution) by oral gavageNon-Xenografted group Group 1 – received 0.8 CAE/day Group 2 – received 1.6 mg CAE/day
Parameters analyzed	Effects on body weight, tumor volume and tumor weight in xenograft and non-xenografted model mRNA analyses for gene expression of matrix metalloproteinases (MMPs) in tumor tissues Gene expression of human-specific β-2 globulin (hβ2G) in the lungs of xenografted and non-xenografted
Outcomes	Visible benefits Peach phenolics in a range of 0.2 – 1.6 mg CAE/day did not exert adverse effects on body weight gain and appearance of major organs including liver and kidney in the non-xenografted controls Treatment with peach phenolics at a dose 0.8 to 1.6 mg CAE/day inhibited the tumor growth (p < 0.05) of the xenografted animals after 12 days compared to the xenografted control group The final weights of the tumors were apparently lower (76.6% and 76.4% of xenografted control, respectively) in mice treated with 0.8 and 1.6 mg CAE/day of peach phenolics Treatment with peach phenolics (1.6 mg CAE/day) inhibited gene expression of MMP-2, MMP-13, and MMP-3 down to 0.68-, 0.57-, and 0.54- fold of the xenografted controls hβ2G gene expression in the lungs of peach phenolics-treated mice, 0.8 and 1.6 mg CAE/day, were 7.5- and 5.4- fold greater than the non-xenografted control, respectively; whereas in the xenografted controls, hβ2G gene expression was 25- fold greater than the non-xenografted controls Tumor growth and lung metastasis were inhibited in vivo by peach polyphenolics in a dose range of 0.8 – 1.6 mg/day and these effects were mediated by inhibition of metalloproteinases gene expression.
Functions	Peach phenolics inhibit tumor growth and protect against angiogenesis and metastasis.

Figure 5: Anti-tumorigenic activity of peach phenolics in xenografted nude mice. Effects on body weight (A), tumor volume (B) and tumor weight (C)

Figure 6: mRNA levels of metalloproteinases (MMPs) MMP-1, MMP-2, MMP13, and MMP-3 in peach phenolics-treated mice (0.8 – 1.6 mg CAE/day)

Figure 7: Expression of human-specific hβ2G in the lungs of xenografted and non-xenografted control mice treated with peach phenolics (0.8 – 1.6 CAE/day)

Materials	Lyophilized samples of: Fresh peach pulp (FPP) Peach peel Preserve peach pulp (PPP) Preserve syrup
Subject	Liver, kidney and brain cortex tissue slices from rats were pre-incubated with peach samples, after that incubated with a ferrous sulphate and hydrogen peroxide (FeSO4 /H2O2) system in order to induce cytotoxicity, producing hydroxyl radicals.

Antioxidant

	Parameter Analyzed	Result
In Vitro Study	Total reactive antioxidant potential (TRAP assay) indicates the quantity of antioxidants present in the plant extract	The peel suspension showed the highest antioxidant activity, followed by the FPP suspension. PPP had no significant effect
	Total antioxidant reactivity (TAR) indicates antioxidant effectiveness	Peel and FPP had the highest TAR indexes, compared to PPP and syrup.
Ex Vivo Study	Level of lactate dehydrogenase (LDH) indicates cytotoxicity	In kidneys, FPP, peel and PPP prevented the increase in LDH caused by the hydroxyl generating system, indicating a protective effect. In liver, FPP and peel had a significant protective effect. In brain cortex, only FPP had a significant effect on LDH activity
	Antioxidant enzymes – Superoxide Dismutase (SOD) and Catalase (CAT) monitor oxidative stress	In kidney and brain cortex slices, pre-incubation with FPP and peel significantly inhibited the activation of CAT by incubation with the FeSO4/H2O2 system. In liver, only FPP was able to inhibit the CAT activities. SOD activation induced by FeSO4/H2O2 system was prevented in kidney by FPP, peel and PPP. In brain cortex, inhibition of SOD activities was observed with FPP and peel as in liver. Since SOD and CAT activities are generally enhanced in conditions of increased substrate production, these results altogether suggest that the pretreatments carried out here conferred antioxidant protection to kidney and brain cortex
	Quantification of total reduced sulfhydryl (SH) groups oxidative status of thiol groups	Protein SH oxidation was not prevented statically by any pre-treatment In liver, FPP group had no difference to control group indicating a possible protection
	Formation of carbonyl groups oxidative damage to proteins	FPP protected all tissues against the reaction with carbonyl groups. PPP was able to prevent carbonyl formation in kidney
	Formation of thiobarbituric acid reactive species (TBARS) oxidative damage on lipids	Pre-treatment with peel significantly reduced Increase in TBARS formation in all tissue slice samples. In brain cortex slices, FPP also had a protective effect.
Function Fresh peach pulp and oeel demonstrated high antioxidant effects preventing against cytotoxicity, oxidative stress and oxidative damage towards lipids and proteins.Peach peels presented antioxidant activity mainly in the lipid fraction while Fresh peach pulp had a major antioxidant effect to soluble protein fractions suggest that different secondary compounds present in distinct parts of the fruit (i.e., pulp and peel) are responsible for these effects.

Anti Glycation

In vitro study
Parameter	Isolated albumin subjected to a glycation protocol through incubation with glucose and fructose during 21 days
Result	Albumin glycation was significantly inhibited by peel and FPP by 40% at different doses. PPP only by 10%, while the syrup alone, probably due to its high sucrose content (more than 20%), enhanced glycation by 30%.
Function	Fresh peach pulp and peel reduce effect of protein glycation

Anti-inflammatory

Ex vitro study
Parameter	Quantification of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β)
Result	In kidney tissue, the FPP, peel and PPP prevented the release of TNF-α and IL-1β. In the liver, only the peel caused a similar effect, preventing the increase of TNF-α and IL-1β release caused by the pro-oxidant insult. FPP also inhibited the release of TNF-α in brain cortex
Function	Fresh peach pulp and peel showed anti-inflammatory effect

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Figure 8: Antioxidant and anti-glycation profile
(A) Total reactive antioxidant potential (TRAP assay)
(B) Kinetics of chemiluminescence intensity
(C) TAR index
(D) Percentage of in vitro albumin glycation[/vc_column_text][vc_column_text]

Figure 9: Effects of FPP, peel, PPP and syrup on cytotoxicity and antioxidant enzyme activities in tissue slices subjected to oxidative stress
(A) LDH activity in the incubation medium was analyzed as a parameter for cytotoxicity (cell rupture).
(B) CAT and (C) SOD activities were assessed in homogenized tissue slices of kidney.
(D), (E), (F) represent respectively the same protocols to liver homogenate, and (G), (H), and (I) to brain cortex.

Figure 10: Effects of FPP, peel, PPP and syrup on biomolecule oxidative damage. Tissues were homogenized and analyzed for (A), (B), (C) protein carbonylation, reduced sulphydryl content and TBARS content in kidney. The same assays were conducted to liver (D), (E), (F) and brain cortex (G), (H), (I).

Figure 11: Effects of FPP, peel, PPP and syrup on interleukin release. (A) TNF-α of kidney, (C) liver and (E) brain cortex was quantified. IL1-β levels in (B) kidney, (D) liver and (F) brain cortex was evaluated.

Reference

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   DOI: 10.3390/ijms16035762.
4. Dabbou S, Maatallah S, Castagna A, Guizani M, Sghaeir W, Hajlaui H, Ranieri A. (2017) Carotenoids, phenolic profile, mineral content and antioxidant properties in flesh and peel of Prunus persica fruits during two maturation stages. Plant Foods for Human Nutrition, 72, 103-110
   DOI: 10.1007/s11130-016-0585-y
5. G. Noratto, W. Porter, D. Byrne, and L. Cisneros-Zevallos (2014) Polyphenolics from peach (Prunus persica var. Rich Lady) inhibit tumor growth and metastasis of MDA-MB-435 breast cancer cells in vivo. The Journal of Nutritional Biochemistry, 25 (7): 796–800
   DOI: 10.1016/j.jnutbio.2014.03.001
6. Gasparotto J, Somensi N, Bortolin RC, et al. (2014) Effects of different products of peach (Prunus persica L. Batsch) from a variety developed in southern Brazil on oxidative stress and inflammatory parameters in vitro and ex vivo. Journal of Clinical Biochemistry and Nutrition, 55(2):110-119
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