Young Hun Choi

Anti-inflammatory Effect of Citrus unshiu Peels Fermented with Aspergillus niger

Citrus, yield of which is the highest among fruits produced in Korea, is extensively consumed for processed food items. The amount of by-products of citrus produced from the processing within a short period after the harvest is tremendous. These by-products are mostly dumped into land or neglected because of cost involved in processing them. The aim of the present study was to explore the usefulness of the by-products as a new material by examining the anti-inflammatory activity of fermented extracts of citrus peels. The peels of `unshu` (Citrus unshiu) was fermented with Aspergillus niger and their extracts before or after fermentation were analyzed using HPLC. The analysis showed that neohesperidin level considerably increased and the two new compounds were synthesized after fermentation. The anti-inflammatory activity of the fermented extracts was examined on RAW 264.7 murine macrophage cells stimulated with lipopolysaccharide. Fermented unshu extracts significantly enhanced the decrease of nitric oxide (NO) production, iNOS and COX-2 expression, comparing with those of unfermented extracts. Also TNF- and IL-6 production, both of which are pro-inflammatory cytokine, were more inhibited in fermented extracts. These results showed that the fermentation and promotion of the function of the by-products of citrus peels will help find a new application.

Effect of Foliar Application of GA 3 on the Flower Bud Formation and Fruit Quality of Satsuma Mandarine (C. unshiu Marc. cv. Miyagawa)

Effect of Foliar Application of GA3 on the Flower Bud Formation and Fruit Quality of Satsuma Mandarine (C. unshiu Marc. cv. Miyagawa) Seok-Beom Kang, Young-Eel Moon, Seung-Gab Han, Yong-Ho Kim, Chi-Won Chae and Young-Hun Choi (Citrus Research Station, National Institute of Horticultural and Herbal Science, RDA, Seogwipo, 699-946, Korea, Agricultural Research Center for Climate Change, National Institute of Horticultural and Herbal Science, RDA, Jeju, 690-150, Korea)

Anti-inflammatory activities of Olea europaea extracts from Jeju Island on LPS-induced RAW 264.7 cells

Lipopolysaccharide (LPS)-induced activation of murine RAW 264.7 cells results in the production of pro-inflammatory cytokines including PGE2, IL-6, TNF-α, and IL-1β. In this study, we investigated the anti-inflammatory effects of the Olea europaea extract from Jeju island using LPS which induces an inflammatory response. To examine the potential anti-inflammatory properties of the Olea europaea extract, we measured the amount of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IL-1β on RAW 264.7 cells after the Olea europaea extract treatment. The Olea europaea extracts showed higher anti-inflammatory activity by inhibiting the production of PGE2, NO, TNF-α, IL-6, and IL-1β induced by LPS stimulation in RAW 264.7 cells. Also, Olea europaea extracts decreased mRNA expression of iNOS, and COX-2. There was no cytotoxicity in the macrophage proliferation treated with the Olea europaea extract compared to the control in the LDH assay. These results suggest that the Olea europaea extract may exert significant effects on inflammatory factors and be a potential source as a new natural anti-inflammatory agent. Further investigations will focus on cell-based in vitro assays and in chemically identifying the major active components mediating the anti-aging and anti-inflammation responses.

Effect of Foliar Application of Gibberellic Acid and Machine Oil Emulsion Mixture on Flowering and Fruit Quality of Satsuma Mandarin (C. unshiu Marc. cv. Miyagawa) Cultivated on Open Fields

In satsuma mandarin (C. unshiu Marc. cv. Miyagawa), alternate bearing is frequently occurred. It is very difficult to control and maintain the optimum production because satsuma mandarin is a very sensitive citrus cultivar. We carried out the experiment to find out the effects of foliar application of gibberellic acid (GA₃) and machine oil emulsion mixture on flowering and fruit quality of satsuma mandarin grown on open field. The treatments were composed of control (no application), GA₃ (25, 50 and 100 mg?L -1 ), machine oil emulsion 100 times and mixture of GA₃ (25 and 50 mg?L -1 ) with machine oil emulsion 100 times on 16 year-old ‘Miyagawa’ satsuma mandarin on December 30, 2012. Foliar application of GA₃ during winter season led to a reduction of the flowering in the following year. GA₃ decreased flowering in dose dependant manner. However, application of GA₃ and machine oil emulsion (100 times-diluted mixture) inhibited effectively the flowering compared to GA₃ only. Also, flower-leaf ratio was significantly decreased by the application of GA₃3 25 (0.54) and 50 (0.41) mg?L -1 with machine oil emulsion mixture in comparison to GA₃ 25 (0.86) and 50 (0.60) mg?L -1 only. The number of leaves per fruit increased in application of GA₃ and machine oil emulsion mixture as concentration of GA₃ increased. Fruit weight and sugar-acid ratio also increased in comparison to the control whereas fruit size, soluble solid content and acidity remained unchanged. From the results, it was suggested that GA₃ application can reduce the number of flowers on the alternate bearing of satsuma mandarin. Moreover, application of GA₃ (25 and 50 mg?L -1 ) with machine oil emulsion 100 times mixture can reduce the flowering effectively without altering fruit maturity and soluble solid contents. Therefore, it can be concluded that the application of GA₃ 25 and 50 mg?L -1 with machine oil emulsion 100 times might be useful in controlling alternate bearing in satsuma mandarin.

Establishment of Analytical Method for Chlorophyll Using the N,N -Dimethylformamide and Dimethylsulfoxide in Citrus Leaves

Received: 15 July 2014 / Revised: 31 August 2014 / Accepted: 4 November 2014 Copyright c 2014 The Korean Society of Environmental Agriculture This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.