Anti-viral and anti-bacterial activities of an extract of blackcurrants (Ribes nigrum L.).
Ikuta K, et al. Microbiol Immunol. 2012.
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Abstract
The inhibitory effects of an extract of the blackcurrant (Ribes nigrum L.) against pathogens associated with oral, nasopharyngeal and upper respiratory infectious diseases; namely respiratory syncytial virus (RSV), influenza virus A and B (IFV-A and IFV-B), adenovirus (AdV), herpes simplex virus type 1, Haemophilus influenzae type B, Streptococcus pneumoniae and Streptococcus mutans, were investigated. Less than 1% concentration of extract of blackcurrant inhibited replication of RSV, IFV-A and -B and HSV-1 by over 50% and a 10% extract inhibited adsorption of these viruses onto the cell surface by over 95%. The effects on AdV were much less pronounced; the half minimal inhibitory concentration of AdV replication was 2.54 ± 0.26, and a 10% concentration of the extract inhibited AdV adsorption on the cell surface by 72.9 ± 3.4%. The antibacterial activities of the blackcurrant were evaluated based on its efficacy as a disinfectant. A 10% extract disinfected 99.8% of H. Influenzae type B and 78.9% of S. pneumoniae in 10 min, but had no demonstrable effect against S. mutans. The blackcurrant extract still showed antiviral and antibacterial activities after the pH had been made neutral with sodium hydroxide, suggesting that these activities are not the result of acidic reactions or of components precipitated at a neutral pH. These findings demonstrate the potential of blackcurrant extract as a functional food for oral care.
PMID 22985050 [PubMed - indexed for MEDLINE]
抗體反應是免疫系統的「招數」之一。簡單解釋，免疫系統針對敵人（例如某一種病毒）身上某一特別之處，即所謂「抗原」（antigen），能造出度身訂造的殲敵武器，即所謂「抗體」（antibody）。抗體是一種很特別的蛋白質。它的基本構造，形狀像一個英文字母「Y」，換言之，有兩條「手臂」，加上一隻「腳」。那隻腳是用來幫助自己進駐體內的據點，碰到病毒時，手臂能牢牢夾上病毒身上一個叫血凝素（hemagglutinin）的蛋白質。基本上，身體有三個地帶會受到抗體式的保護，包括血管、黏膜和皮膚，每一處都有不同的「屯兵」。駐守在血管的淋巴細胞能製造 M 型和 G 型抗體；守護黏膜的淋巴細胞能製造 A 型抗體；至於看守皮膚的淋巴細胞，則能製造 E 型抗體。
由於 TIV 疫苗是經肌肉注射（打針）進入血管，TIV 會引發 M 和 G 抗體，從而守護血管。至於 LAIV 疫苗，噴霧先去到鼻黏膜，再進入肺腔，可以守護肺黏膜。從這個角度考慮，LAIV 比 TIV 更能在第一線（肺黏膜）發功，保護身體。但 TIV 疫苗並非不濟。有一間以生產疫苗為主的惠氏藥廠 Wyeth（現已被輝瑞藥廠收購）曾做過測試，在菲律賓和泰國替2,172名六個月到三歲大的兒童注射流感疫苗，之後，發現他們血中產生丙型干擾素（Interferon Gamma），增加抵抗流感的能力（Clin. Vaccine Immunol., Vol. 15, pp. 1042-1053）；換言之，是激發了他們的先天免疫（見上文）。具體的機制，乃是丙型干擾素提升了身體一個天然抗病因子乙型抵抗素（Beta-Defensin，見J. Immunol., Vol. 179, pp. 984-992）。