Anti-Inflammatory Effects of Lychee (Litchi chinensis Sonn.) Seed Peptide Hydrolysate on RAW 264.7 Macrophage Cells

ABSTRACT

Lychee (Litchi chinensis) seeds, a by-product from the canned lychee processing, were hydrolyzed using various concentrations of proteases (Alcalase, Flavourzyme, and Neutrase). The protein hydrolysate produced with Neutrase at a concentration of 50 mg/mL exhibited the highest free radical scavenging activity. After ultrafiltration, the fraction containing peptides of less than 650 Da was purified by using gel filtration chromatography into G1–G3. The G1 fraction exhibited the highest activity and was further purified by reversed phase high performance liquid chromatography (RP-HPLC). Four fractions (H1–H4) were isolated and exhibited efficient nitric oxide (NO) scavenging activity. The G1 fraction inhibited NO production in lipopolysaccharide (LPS) stimulated RAW 264.7 cells with down-regulation of inducible nitric oxide synthase (iNOS) and interleukin-6 (IL-6). The results showed that lychee seed peptide hydrolysates exhibited potent anti-inflammatory activities, suggesting the peptides may be useful as additives to health products such as functional foods and/or pharmaceuticals.

KEYWORDS:

• Anti-inflammatory
• lychee
• Litchi chinensis
• peptide hydrolysate
• macrophage RAW 264.7

Conflict of interest

The authors have no conflicts of interest to declare.

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Additional information

Funding

This work was partially supported by Rachadapisek Sompote Fund for Postdoctoral Fellowship, Chulalongkorn University, the Higher Education Research Promotion and National Research University Project of Thailand, Office of the Higher Education Commission (NRU59-038-FW) and the Institute of Biotechnology and Genetic Engineering is thanked for their support and use of their facilities.