Japanese quince (Chaenomeles japonica) leaf phenol extract as modulator of the inflammatory response in lipopolysaccharide-triggered murine macrophage RAW 264.7 cells

In the present study we investigated the anti-inflammatory activity of Japanese quince leaf polyphenol-rich extract (JQLPE) in lipopolysaccharide (LPS)-activated murine macrophages (RAW 264.7). The Q-PCR analysis revealed that JQLPE decreased Nfkb1, Ptgs2, and Il1b expression at the mRNA level by 80%, 50% and 48%, respectively. Similarly, JQLPE significantly attenuated expression of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), interleukin-1beta (IL-1β), IL-6 and tumor necrosis factor alpha (TNF-α) (by 60%, 50%, 67%, 37% and 36%, respectively) at the protein level and nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7. Western blot also showed that the expression of nuclear factor kappaB (NF-κB) p65 and p-NF-κB p65 was down-regulated after JQLPE treatment. These results provide the first evidence that JQLPE decreases the expression of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α), inflammatory mediators (COX-2, iNOS) and both NF-κB p65 and p-NF-κB p65 in LPS-stimulated RAW264.7 cells, which may suggest its anti-inflammatory activity.

Comparison of phenolic compounds, antioxidant and cytotoxic activity of extracts prepared from Japanese quince (Chaenomeles japonica L.) leaves

Phenolic compounds are very important in the prevention and treatment of many civilization diseases, including colorectal cancer (CRC). In the present study we investigated and compared the phytochemical composition, antioxidant and cytotoxic activity of Japanese quince (Chaenomeles japonica L.) leaves crude phenolic extract (CPE) and purified phenolic-rich extracts (PRE). The UPLC-Q-TOF-MS analysis showed that both extracts contain diversified phenolics compounds (33 - 36 compounds in the PRE and CPE, respectively), among which chlorogenic acid and naringenin hexoside turned out to be the main constituents. Both FRAP and ABTS tests showed that PRE had 2-fold higher antioxidant activity compared to CPE. Furthermore, PRE exhibited a higher cytotoxic activity towards colon cancer cells (SW-480 and HT-29) than CPE. After 24-hours incubation with PRE the IC₅₀ value for SW-480 cell line was obtained at the concentration of 239 μg/mL, while CPE treatment caused the same decrease only after 72h at 277 μg/mL. In addition, PRE had a stronger cytotoxic effect on the colon cancer cell lines (SW-480 and HT-29) than on normal intestinal cells (CCD-18Co and CCD 841 CoN). These results provide the first evidence that extracts from Japanese quince leaves (especially phenolic-rich extract, PRE) strongly decrease the viability of both SW-480 and HT-29 lines, which may suggest their cytotoxic activity towards colon cancer cells.