Judul: Peroksidasi Lipid pada Tikus Hiperkolesterolemia selama Pemberian Ekstrak Kulit Batang Mahoni (Swietenia macrophylla)
Abstrak: Mahogany’s bark is known as wood industrial waste that contains potential secondary metabolites. However, its potency as an antioxidant, especially in rats which are subjected to hypercholesterolemic treatment, has not been carried out. The aim of this study was to test the effect of mahogany’s water extract consumption on the concentration of lipid peroxides in hypercholesterolemic rats. Thirty five male rats were divided into 5 groups (n=7) namely normal group fed with standard rat chow, hypercholesterolemic group (HK) fed with cholesterol chow (1,5%) and PTU (0,5 mg/KgBW), lovastatin group (HK+lovastatin 0,2857 mg/KgBW), E1 group (HK+ mahogany’s extract 4,2 mg/KgBW), and E2 group (HK+mahogany’s extract 21 mg/KgBW). Experiments were carried out for 8 consecutive weeks. The concentration of lipid peroxides in blood were measured with thiobarbituric acid assay at week 0, 2, 4, 6, and 8 using spectrophotometer. Cholesterol chow (0.86%) and PTU increased the lipid peroxides concentration of HK group by 20.92% compared to the normal group (3.380±0.436 nmol/mL). However, it is not statistically significant (p=0.239). The lipid peroxides concentration in E1 and E2 weren’t increased and relatively similar to normal group at concentration of 2.353±0.196 nmol/mL, 2.786±0.256 nmol/mL, and 2.673±0.279 nmol/mL, respectively. Although it is not statistically significant, both doses of extracts tend to prevent the lipid peroxidation in the rat’s blood.
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Judul: Analisis Lipid Peroksida Hati Tikus Hiperkolesterolemia Pasca Terapi Ekstrak Kulit Kayu Mahoni
Abstrak: Mahogany (Swietenia macrophylla King.) bark contains bioactive compounds which are efficacious as antioxidant. Several in vitro studies on antioxidant activity have been carried out previously. However, there is no evidence about the effectiveness of antioxidant activity against lipid peroxidation in liver hypercholesterolemic rat. The aim of this research was to determine the effect of water extract of mahogany bark againist lipid peroxidation by analyzing the lipid peroxide of hypercholesterolemic rats liver. Thirty one male rats were divided into two parts, six were pre-treatment rats and the rest were treatment rats. The latter groups were divided into 5 groups. One normal group fed with standard rat diet and four treatment groups fed with cholesterol diet (1.5%) and propil tiouracil (PTU) (0.5 g/kg bw) during 6 weeks. Positive control group of treatment induced lovastatin (0.2875 mg/kg bw), 1st dose extract (E1) group (150 mg/kg bw), and 2nd dose extract (E2) group (300 mg/kg bw), respectively, during a week. Antioxidant activity of lipid peroxide in the liver were measured with thiobarbituric acid (TBA) assay using spectrophotometer. The diet of hypercholesterolemia 1.5% and PTU as long as 6 weeks increased lipid peroxide concentration of liver pre treatment 141.00%, significantly (p=0.032). Therapy of E1 and E2 tend to decrease lipid peroxide concentration of liver 20.95% and 15.54%. Statistically two doses of the extracts were not significantly different (p> 0.05).
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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