人類自古以來對「長生不老」趨之若鶩,時至今日「抗衰老」仍是不少人窮一生希望掌握的秘密,香港大學醫學院生物化學系教授周中軍的團隊正向着謎底邁進,他 們發現提子皮所含的物質「白藜蘆醇」可刺激動物體內的「長壽基因」,並研發出治療早老症的藥物,已在動物實驗證實可延長近三成壽命,去年起更開始於內地安 排病人參與試驗。憑藉對衰老研究領域的貢獻,周中軍獲得本年度裘槎優秀科研者獎。
早老症屬非常罕見的疾病,病發率約四百萬分 之一,患者一般在六個月大已開始衰老,普遍不能活過十三歲。周中軍指,此病並非遺傳病,而是由基因突變而起。他在過去十多年的研究中發現,提子等水果表皮 所含的物質「白藜蘆醇」可刺激動物體內的「長壽基因」SIRT1,保護幹細胞以達致延長早老症動物的壽命。
去年底開展臨床試驗
有關研究過去一直利用老鼠進行實驗,發現把「白藜蘆醇」用於患有早老症的老鼠,可延長其壽命兩至三成;若用於正常的老鼠,牠們的毛髮也會明顯變得有光澤,而且白毛比較少,不過就未見有延長壽命的效果,亦未能肯定可以延緩衰老。
研究團隊去年底首次於內地開展臨床試驗,現時有八名由兩歲至十六歲的早老症患者正試用新藥,他們會先接受三個月的觀察期,然後按體重服食不同劑量的新藥物,持續六個月,再監察藥效。八名病人已開始服藥一個月,尚待結果。
周中軍強調,「長壽基因」SIRT1絕非愈活躍愈好,過去有研究發現,如果能夠令動物體內的「長壽基因」增加至原本的兩倍,抗衰老效果最
理想;但如果十倍的「長壽基因」被激活,反而有機會破壞其他非幹細胞的正常細胞。因此,究竟要服食或攝取多少分量的「白藜蘆醇」,才可令SIRT1增兩
倍,以及應用在人體的效果,仍待更多研究確定。
現時坊間有部分加入「白藜蘆醇」的營養補充劑已獲美國食品及藥物管理局(FDA)批准出售。周中軍笑言自己偶爾也有服用這些補充劑,但目前仍未能以科學方法證實這些產品的抗衰老成效,他期望日後可獲更多資源作相關的深入研究。
Professor Zhongjun ZHOU (HKU), Professor, Department of Biochemistry, Li Ka Shing Faculty of Medicine. Professor Zhou is an internationally recognised expert on laminopathy-based premature aging and extracellular matrix. His major research field is bone development, blood vessel development and aging. His research focuses on premature aging and aging-associated diseases, as well as extracellular matrix. Professor Zhou and his team identified prelamin A as an in vivo substrate for metalloproteinase Zmpste24 through a genetic approach and explained how Lamin A’s abnoramality influences development and aging. His team demonstrated lamin A activates longevity protein SIRT1 to maintain the stem cell potency. He revealed for the first time that mutation in nuclear structural protein lamin A compromises DNA repair, which contributes to accelerated aging in Hutchinson-Gilford Progeria Syndrome. His work provides important insights into the molecular mechanisms underlying Hutchinson-Gilford Progeria Syndrome (HGPS). This has an important implication in normal aging and aging–related human degenerative disorders.
2015 croucher award
Activation of SIRT1 by Resveratrol requires lamin A
resveratrol rescues SIRT dependent Adult Stem cell decline
another link
Dr John Pezzuto: cancer chemopreventive action of resveratrol
Genes and Development: Structural basis for allosteric, substratedependent stimulation of SIRT1 activity by resveratrol and here in English and in pdf
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