In Vitro Identification Of Hdl Receptor, Sr-B1 Regulator From Selected Natural Products - Nadarasan, Karthiyayini (2015)
Aterosklerosis adalah keadaan di mana dinding arteri menebal akibat daripada pengumpulan dan pengekalan bahan-bahan lemak kerana ketiadaan fungsi penyingkiran lemak dan kolesterol oleh lipoprotein berketumpatan tinggi. SR-B1 adalah reseptor permukaan sel yang memainkan peranan penting dalam metabolisme kolesterol melalui laluan pengangkutan kolesterol berbalik (PKB). Esei gen pelapor telah dihasilkan dengan menggunakan rantau penggalak gen SR-B1 sebagai sasaran gen untuk menguji tindakbalas daripada produk semula jadi. Sejumlah 16 ekstrak tumbuhan dan 11 ekstrak marin telah disaring menggunakan asai tersebut. Dua ekstrak , iaitu Andrographis paniculata (hempedu bumi) dan Trochus niloticus (siput cengkerang besar) menunjukkan aktiviti positif dalam penyaringan awal. Experimen seterusnya tidak dapat diteruskan untuk Trochus niloticus disebabkan sampel yang terhad dan variasi antara sampel yang dikumpulkan. Oleh sebab itu, kerja seterusnya hanya diteruskan untuk Andrographis paniculata. Empat kompoun telah dihasilkan daripada ekstrak A.paniculata dan disaring menggunakan asai tersebut. Menggunakan kaedah transfeksi sementara ke atas sel, aktiviti kompoun-kompoun dalam meningkatkan aktiviti rantau penggalak SR-B1 telah dinilai. Atherosclerosis is a condition where the artery wall thickens as a result of the accumulation and retention of fatty materials due to an absent of adequate removal of fats and cholesterols by functional high density lipoprotein. SR-B1 is a cell surface receptor which plays a crucial role in cholesterol metabolism via reverse cholesterol transport (RCT) pathway. A reporter gene based assay was developed by implying the promoter region of SR-B1 gene as target gene to test extracts from natural products for the anti-atherosclerotic properties. Total of 16 plant extracts and 11 marine extracts were screened using the developed assay. Two extracts, namely Andrographis paniculata (Hempedu bumi) and Trochus niloticus (Giant top shell snail) showed an distinguished activity in preliminary screening. The subsequent work was unable to proceed for Trochus niloticus due to insufficient samples and also the samples variation between collected batches. Therefore, works were only carried out using Andrographis paniculata due to its samples availability. Four compounds were isolated from A.paniculata and subjected to screening. Utilising transient transfection approach, the potent activity of the compounds in elevating SR-B1 promoter activity was evaluated.