The adverse effects of prolonged and rampant usage of chemical insecticides in controlling the population of vector arthropod have caused the development of resistance among vector populations as well as non-target organism. Application of plant extracts could be alternative sources for mosquito control. The present study assessed larvicidal activities of methanol extracts of leaf and stem of Jacaranda mimosifolia Don (Family: Bignoniaceae), Melaleuca cajuputi Powell (Family: Myrtaceae), Tabebuia chrysantha (Jacq.) Nicholson (Family: Bignoniaceae), Tabebuia pallida (Lindl.) Miers (Family: Bignoniaceae) and Tabebuia rosea Toll (Family: Bignoniaceae) against dengue vectors, Aedes (Diptera: Culicidae) sp. Among plants tested, M. cajuputi exhibited the most effective with the highest mortality against Ae. aegypti and Ae. albopictus. Leaf extracts showed significantly higher larvicidal effects in relative to stem extracts. The findings also revealed that Ae. aegypti is the most susceptible compared to Ae. albopictus. LC50 values of M. cajuputi leaf extracts were 183.35mg/L and 191.82mg/L against Ae. aegypti and Ae. albopictus respectively. These studies suggest leaf extracts of M. cajuputi have moderate potential as larvicidal against vector larvae of Aedes mosquitoes.
Dalam kajian ini, keupayaan Apigenin, Berberin dan Rutin untuk mengurangkan metabolisme kolesterol pada sel kanser hepatoma manusia (Hep G2) telah ditentukan. Penilaian sitotoksik Apigenin, Berberin dan Rutin telah dilakukan dengan mendedahkan Hep G2 kepada Apigenin, Berberin dan Rutin pada kepekatan antara 7.8 sehingga 1000 ,uglmL selama 24 jam pada suhu 37°C dan 5% atmosfera CO2. Apigenin, Berberin dan Rutin masing-masing mempunyai kepekatan perencat 20 (IC2) 7 .8, 125 dan 1000 liglmL. Keupayaan mengurangkan metabolisme kolesterol oleh Apigenin, Berberin dan Rutin pada Hep G2 telah diuji dengan penyemaian Hep G2 dalam plat 6-telaga. Kumpulan rawatan Apigenin, Berberin dan Rutin telah dirawat dengan kepekatan 7 .8, 31 25 dan 62.5 ,uglmL masing-masing dan didedah dengan lipoprotein ketumpatan rendah (LW sebanyak 10 ,uL. Dalam kumpulan kawalan normal (NC), Hep G2 telah dieram dengan media kultur sahaja. Sel diinkubasikan dan media telah diambil untuk analisis Apo Al , LCAT, LDLR dan FDFT1 dengan menggunakan kit. Rutin didapati mampu merendahkan aktiviti HMGR secara signifikan (p<0.05) berbanding kawalan normal. Apigenin dan Berberin mampu meningkatkan kepekatan APO Al . Ketiga - tiga sampel mampu meningkatkan kepekatan LCAT pada sel yang dirawat. Selain itu, Apigenin mampu meningkatkan kepekatan LDLR. Keputusan ujian untuk FDFT1 menunjukkan Berberin dan Rutin merendahkan kepekatan FDFT1 dan berbeza secara signifikan (p<0.05) berbanding kawalan normal. Penemuan ini menunjukkan bahawa Apigenin, Berberin dan Rutin mempunyai potensi dalam mengurangkan metabolisme kolesterol dalam sel Hep G2.
Anacardium occidentale belongs to the Anacardiaceae family. It had been scientifically proven to have antihypercholesterolemia effect in high cholesterol diet induced animal laboratory study. However there is no study regarding the mechanisms involves in cholesterol reducing effect by A. occidentale leaves extract. In this study, cytotoxic assessment and anti-cholesterol activity of A. occidentale leaves aqueous extract (AOE) were investigated. Cytotoxic study was performed by exposing hepatoma cell (Hep G2) towards AOE with concentration ranging from 0.002 to 20 mg/mL for 24 h. Anacardium occidentale extract was found to be not toxic to the cell. Then, the highest and not toxic AOE concentrations (20, 10, 5 and 2.5 mg/mL) were selected for anti-cholesterol study. The ability of AOE to reduce cholesterol in cell culture experiment was carried out by pretreating Hep G2 with selected concentrations of AOE in 6-well plate before the cell was exposed to low density lipoprotein (LDL). The concentration of farnesyl-diphosphate farnesyltransferase (FDFT1), apolipoprotein A1 (Apo A1), lecithin-cholesterol acyltransferase (LCAT), low density lipoprotein receptor (LDL R), scavenger receptor B1 (SR-B1), ATP binding cassette transporter A1 (ABCA-1) and hepatic lipase (HL) were determined from the 6-well plate media. The results showed that AOE did not significantly increase the concentration of LDLR. However, AOE significantly increased the concentration of FDFT1, APO A1, LCAT, SRB-1, ABCA-1 and HL. The HMGR activity experiment showed that all selected AOE concentrations cannot significantly reduce the HMGR enzyme activity. These findings suggested that AOE may involve in reverse cholesterol transport process to reduce cholesterol metabolism in Hep G2 cell.