FRAKSI PHLOROTANNIN BERAT MOLEKUL RENDAH ALGA COKLAT MARGA SARGASSUM SEBAGAI AGEN FOTOPROTEKTIF (PENELUSURAN MEKANISME SEBAGAI ANTIOKSIDAN TOPIKAL)
| Main Authors: | , AGNES NORA ISKA HARNITA, S.SI, M.SI, APT, , Prof. Dr. Sudibyo Martono, MS., Apt. |
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| Format: | Thesis NonPeerReviewed |
| Terbitan: |
[Yogyakarta] : Universitas Gadjah Mada
, 2013
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| Subjects: | |
| Online Access: |
https://repository.ugm.ac.id/122902/ http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=63011 |
Daftar Isi:
- An exposure to UV radiation, especially UV-B (λ 290-320 nm), can generate free radicals and ROS. When the formation of ROS exceeds the antioxidant defense system capabilities in target cells, it can trigger an oxidative stress. In case of an oxidative stress, ROS will result in an oxidative damage of biomolecules, such as DNA and membrane lipids, which can also trigger melanogenesis. Alternative topical antioxidants have emerged to protect the skin from the negative biological effects of UV radiation such as skin cancer and photoaging. Polyphenolic compounds from brown alga Sargassum identified as phlorotannins have been demonstrated as antioxidants. In this study, the low molecular weight (MW) of brown alga Sargassum phlorotannin compounds (100-1000 Da) targeted for an isolation are from the following four species: Alga A (S. polycystum C.Agardh), Alga B (S. hystrix v. buxifolium (Chauvin) J. Agardh), Alga C (S.cymosum C.Agardh), and Alga D (S.polyceratum Montagne), which were obtained from Drini Beach, Gunung Kidul, Yogyakarta (8 Âo 08 LS). The isolation was performed using the maceration method. The total phenolic contents were measured using the Folin Ciocalteu method. The low molecular weights of phlorotannin fractions were characterized by the GC-MS profile. The effect of sunscreen (the ability to absorb the UV-B and UV-A radiation) is a selection indicator of the phlorotannin fractions for further investigation. The antioxidant activity through the inhibition of a lipid peroxidation reaction was investigated using the laser-based photoacoustic method. Furthermore, the inhibition of the DNA damage induced by the UV-B radiation (that formed both 8-OHdG and CPD) was conducted using the immunohistochemistry method. Anti melanogenic activity was investigated through the inhibition of tyrosinase activity and DPPH radical scavenging activity. The phlorotannin fraction of S. hystrix v. buxifolium (Chauvin) J. Agardh (PFSH) possessed low MW phlorotannin contents. PFSH can intensively absorb the UV radiation on a broad spectrum (UV-B and UV-A), and exhibited a potent lipid peroxidaton inhibitory activity. PFSH can also potentially inhibit both 8-OHdG and CPD formations on the human skin exposed by UV-B. Furthermore, PFSH shows an inhibitory effect on the oxidation of L-DOPA by mushroom tyrosinase and potent antioxidant scavenging radicals. From the above results, PFSH can be developed as photoprotective agents, especially as topical antioxidants and anticarcinogenic agents.