No abstract

Kolagen memiliki aktivitas antioksidan dan mampu menghambat aktivitas tirosinase pada proses<br />melanogenesis, salah satu biota laut yang dapat dijadikan sumber kolagen alternatif adalah teripang.<br />Penelitian ini bertujuan menentukan karakteristik kolagen dan aktivitas penghambatan enzim tirosinase<br />oleh kolagen teripang emas (Stichopus hermanii). Penghilangan protein non kolagen dilakukan dengan<br />cara perendaman daging teripang menggunakan NaOH 0,1 M selama 48 jam. Isolasi kolagen dilakukan<br />menggunakan asam asetat 0.5 M selama 48 jam. Analisis gugus fungsi kolagen dilakukan menggunakan<br />FTIR dan analisis aktivitas tirosinase dilakukan menggunakan spektrofotometer. Kadar protein non<br />kolagen yang diperoleh yaitu 0,090 mg/mL dan kolagen teripang emas memiliki rendemen 0,66%. Kolagen<br />teripang memiliki nilai pH 6,91, gugus fungsi khas amida A (3379,29 cm-1), amida B (2924,09 cm-1), amida<br />I (1681,93 cm-1), amida II (1568,13 cm-1), dan amida III (1269,16 cm-1). Aktivitas penghambatan tirosinase<br />menunjukkan bahwa kolagen teripang emas memiliki nilai IC50 5610 ppm. Kolagen teripang emas belum<br />mampu menghambat aktivitas tirosinase.

The excessive number of free radicals in human body could increase lipid peroxides and causes a variety of degenerative diseases. Piper crocatum is a plant containing natural chemicals that may have an antioxidant ability to inhibit fatty acid oxidation and reduce free radicals, however, there is no published scientific reports up to now. Therefore, the objective of this research is to study the ability of ethanol extract of P. crocatum as an antioxidant. The leaves of P. crocatum (25 g) were extracted with 100 ml of 70% ethanol. Antioxidant activity was measured by thiobarbituric acid method and compared with 2,2-diphenil-1-picryl hydrazyl method with α α α α αtocopherol as the standard antioxidant. The results showed that the extract of 200 ppm inhibited fatty acids oxidation by 80.40% and IC 50 for free radical scavenging was 85.82 ppm. There was no significant different (α α α α α = 0.05) inhibition of unsaturated fatty acids oxidation between the sample and á-tocopherol at 200 ppm. This study suggested that the leaves extract of P. crocatum has a potential natural antioxidant.

Piper crocatum is one of medicinal herbal plants with a large number of benefits. Usually herbal plants have activity as antibacterial agent. Therefore, the objectives of this research were to obtain information on antibacterial activities of the leaf extracts of Piper crocatum againts four types of bacteria, in that Staphylococcus, Bacillus substilis, Escherichia coli, and Pseudomonas aeruginosa and then to analyze the phytochemistry of the leaf extracts of Piper crocatum. The leaves of Piper crocatum were extracted by maceration and reflux using ethanol 30%. The assays of the antibacterial activities and phytochemistry on the extracts were carried out using the method of Maria Bintang. Results showed that the yield of the extraction using ethanol by maceration method was 20.8%. Meanwhile, using the reflux method, the yield was obtained about 26.25%. The phytochemistry analysis showed that the leaf extracts of Piper crocatum contained alkaloid, steroid and tanin. According to this study, it was found that the leaf extract of Piper crocatum can be used to inhibit the growth of B. subtilis and P. aeuruginosa, but can not inhibit the growth of E.coli and S. aureus.

Abstract. Development of α-glucosidase inhibitor derived from natural products is an opportunity for a more economic management of diabetes prevention. The objective of this study was to test the activity of α-glucosidase with or without potential inhibitor compounds. By in vitro method, α-glucosidase hydrolizes p-nitrophenyl-α-D-glucopiranoside to glucose and the yellow of p-nitrophenol which can be determined with spectrophotometry at 400 nm. The ability of ethanolic leaf extract of Melia azedarach L. as α-glucosidase inhibitor was compared with that of commercial acarbose (Glucobay®). Acarbose showed strong inhibitory activity against α-glucosidase with IC 50 values of 2.154 µg/mL. The crude ethanolic leaf extract of M. azedarach, however, showed less inhibitory activity with IC 50 value of 3,444.114 μg/mL. Total phenolics of M. azedarach leaves EtOH extract showed 17.94 μg GAE/mg extract and flavonoids total compound of 9.55 μg QE/mg extract. Based on the published wide range of IC 50 values of extracts reported as α-glucosidase inhibitor which were between 10,000 ppm-0.66 ppm, our result suggests that extract of M.azedarach leaves is potential candidate for development of anti-hyperglycemic formulation.