Antioxidative and Anti-Inflammatory Activities of Rosebud Extracts of Newly Crossbred Roses

Abstract

Oxidative stress and inflammation are basic pathogenic factors involved in tissue injury and pain, as well as acute and chronic diseases. Since long-term uses of synthetic steroids and non-steroidal anti-inflammatory drugs (NSAIDs) cause severe adverse effects, novel effective materials with minimal side effects are required. In this study, polyphenol content and antioxidative activity of rosebud extracts from 24 newly crossbred Korean roses were analyzed. Among them, Pretty Velvet rosebud extract (PVRE) was found to contain high polyphenols and to show in vitro antioxidative and anti-inflammatory activities. In RAW 264.7 cells stimulated with lipopolysaccharide (LPS), PVRE down-regulated mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and thereby decreased nitric oxide (NO) and prostaglandin E₂ (PGE₂) production. In a subcutaneous air-pouch inflammation model, treatment with PVRE decreased λ-carrageenan-induced tissue exudation, infiltration of inflammatory cells, and inflammatory cytokines such as tumor necrosis factor-α and interleukin-1β concentrations, as achieved with dexamethasone (a representative steroid). Notably, PVRE also inhibited PGE₂, similar to dexamethasone and indomethacin (a representative NSAID). The anti-inflammatory effects of PVRE were confirmed by microscopic findings, attenuating tissue erythema, edema, and inflammatory cell infiltration. These results indicate that PVRE exhibits dual (steroid- and NSAID-like) anti-inflammatory activities by blocking both the iNOS-NO and COX-2-PG pathways, and that PVRE could be a potential candidate as an anti-inflammatory material for diverse tissue injuries.

Keywords: Pretty Velvet; anti-inflammation; antioxidation; nitric oxide; polyphenol; prostaglandin E2; rosebud extract.

Figure 1

Antioxidant contents in 24 rosebud extracts and their antioxidative and anti-inflammatory activities (100 μg/mL). (A) Polyphenol contents. (B) 2,2-Azino-bis(3-ethylbenzothiazoline 6-sulfonic acid) (ABTS) radical-scavenging activity. (C) 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. (D) Inhibitory activity on nitric oxide (NO) production from RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS, 1 μg/mL).

Figure 2

Correlations between antioxidant ingredients in 24 rosebud extracts and their antioxidative or anti-inflammatory activities (100 μg/mL). (A) Correlation between polyphenols and 2,2-azino-bis(3-ethylbenzothiazoline 6-sulfonic acid) (ABTS) radical-scavenging activity. (B) Correlation between polyphenols and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. (C) Correlation between polyphenols and nitric oxide (NO)-inhibitory activities.

Figure 3

Cytotoxicity and anti-inflammatory activity of Pretty Velvet rosebud extract (PVRE) in RAW 264.7 cells. (A) Cytotoxicity of PVRE. (B–E) Inhibitory activities on inducible nitric oxide synthase (iNOS) expression (B), cyclooxygenase-2 (COX-2) expression (C), nitric oxide (NO) production (D), and prostaglandin E₂ (PGE₂) production (E) from RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS). * Significantly different from control (p < 0.05). ^# Significantly different from LPS alone (p < 0.05).

Figure 4

Anti-inflammatory activities of Pretty Velvet (PV) rosebud extract (PVRE) in a dermatitis animal model. (A) Effects on λ-carrageenan-induced exudation. (B–E) Effects on the infiltration of white blood cells (WBCs, (B)), neutrophils (C), monocytes (D), and lymphocytes (E) in the exudate. Dex2: 2 mg/kg dexamethasone, Ind2: 2 mg/kg indomethacin, PV10: 10 mg/kg PVRE, PV30: 30 mg/kg PVRE, and PV100: 100 mg/kg PVRE. * Significantly different from control (p < 0.05). ^# Significantly different from λ-carrageenan alone (p < 0.05).

Figure 5

Anti-inflammatory activities of Pretty Velvet (PV) rosebud extract (PVRE) in a dermatitis animal model. (A,B) Effects on the λ-carrageenan-induced accumulation of tumor necrosis factor-α (TNF-α, (A)) and interleukin-1β (IL-1β, (B)). (C,D) Effects on the accumulation of nitric oxide (NO, (C)) and prostaglandin E2 (PGE2, (D)). Dex2: 2 mg/kg dexamethasone, Ind2: 2 mg/kg indomethacin, PV10: 10 mg/kg PVRE, PV30: 30 mg/kg PVRE, and PV100: 100 mg/kg PVRE. * Significantly different from control (p < 0.05). ^# Significantly different from λ-carrageenan alone (p < 0.05).

Figure 6

Anti-inflammatory activities of Pretty Velvet (PV) rosebud extract (PVRE) in a dermatitis animal model. (A) Representative findings of λ-carrageenan-induced erythema (vascular swelling) in the skin (upper: gross findings, lower: ImageJ findings). (B) Blood vessel area analyzed with ImageJ. Dex2: 2 mg/kg dexamethasone, Ind2: 2 mg/kg indomethacin, PV10: 10 mg/kg PVRE, PV30: 30 mg/kg PVRE, and PV100: 100 mg/kg PVRE. * Significantly different from control (p < 0.05). ^# Significantly different from λ-carrageenan alone (p < 0.05).

Figure 7

Anti-inflammatory activities of Pretty Velvet (PV) rosebud extract (PVRE) in a dermatitis animal model. (A) Representative microscopic findings of λ-carrageenan-induced edema (tissue thickening) and inflammatory cell infiltration in the skin. (B) The thickness of air-pouch lining tissue. Dex2: 2 mg/kg dexamethasone, Ind2: 2 mg/kg indomethacin, PV10: 10 mg/kg PVRE, PV30: 30 mg/kg PVRE, and PV100: 100 mg/kg PVRE. * Significantly different from control (p < 0.05). ^# Significantly different from λ-carrageenan alone (p < 0.05). Scale bar = 200 μm.