Judul: Aktivitas antihipertensi aktinomiset endofit asal tanaman pegagan dan belimbing wuluh
Abstrak: Endophytic actinomycetes lives in the plant tissue without causing a negative impact. Several medicinal associates with endophytic microbe which may produce similar bioactive compounds to their host plant. Inhibition of Angiotensin Converting Enzyme (ACE) is one of the effective antihypertension mechanism. The potency of endophytic actinomycetes from the medicinal plant used as ACE inhibitor needs to be elucidated. The research aimed to isolate endophytic actinomycetes from rhizome, stem, leaf of pegagan (Centella asiatica) and also from fruit of belimbing wuluh (Averrhoa bilimbi), and assess their capability to produce bioactive compound which can function as ACE inhibitor. The endophytic actinomycetes were isolated from surface sterilized plant parts, grounded and plated in Humic-acid Vitamin-B agar (HV) medium. The purified isolates were grown on International Streptomyces Project No.2 (ISP2) medium, and the crude extract which consisted of extracellular bioactive compound, was used for in vitro assay of ACE inhibitor activity. Twelve isolates of endophytic actinomycetes were successfully isolated from pegagan leaves (three isolates) and belimbing wuluh fruits (nine isolates). The data showed that nine isolates (AEP-1, AEP-2, AEP-3, AEB-1, AEB-3, AEB-5, AEB-6, AEB-7, and AEB-8), had various ACE inhibitor activities, and belonged to Streptomyces spp.. Three other isolates (AEB-2, AEB-4, and AEB-9) belonged to non-Streptomyces, and also showed various ACE inhibitor activities,. Meanwhile, free endophytic microbes of tissue culture seedling of pegagan did not show any ACE inhibitor activity. The AEP-1 isolated from pegagan had the highest percentage (279.2%) followed by AEB-5 isolated from belimbing wuluh (222,92%) of ACE inhibitor activity, exceeding the ACE inhibition activity of captopril (0.01 mg/mL) which was 61.5% and captopril (0.02 mg/mL) was 66.7%. The data indicate that endophytic actinomycetes isolated from leaf of pegagan and fruit of belimbing wuluh capable of producing ACE inhibitory compound.
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Judul: Inhibition of Pegagan (Centellaasiatica) and Tempuyung (Sonchusarvensis) Extracts towards Angiotensin Converting Enzyme (ACE) Activity
Abstrak: Pegagan dan tempuyung merupakan tanaman obat yang berpotensi sebagai antihipertensi. Ekstrak tanaman ini diteliti daya inhibisinya terhadap aktivitas enzim pengubah angiotensin I (ACE) secara in vitro. Penelitian dilakukan pada kondisi optimum menggunakan ekstrak tunggal dengan konsentrasi 50, 100, dan 150 ppm serta ekstrak gabungan dengan komposisi tertentu. Hasilnya dibandingkan dengan kaptopril sebagai kontrol positif. Uji inhibisi ACE dengan ekstrak tunggal pegagan dan tempuyung 50 ppm menghasilkan daya inhibisi paling tinggi yaitu 54% dan 31%. Esktrak gabungan pegagan tempuyung menghasilkan daya inhibisi yang lebih rendah dibandingkan ekstrak tunggal pegagan, yaitu 45% berbanding 54%. Kaptopril memiliki daya inhibisi yang paling tinggi dibandingkan ekstrak tunggal maupun gabungan, yaitu 88%. Kata Kunci: Inhibisi ACE, kaptopril, pegagan, tempuyung, Pegagan and tempuyung are medicinal plants potential as antihypertension. Extracts of these plants were investigated towards angiotensin I converting enzyme (ACE) inhibition activity in vitro. The study was conducted at the optimum condition by using 50,100 and 150 ppm of single extract concentration, and combined extracts with specific compositions. The results were compared with captopril as positive control. Inhibition test of ACE with single extracts showed that 50 ppm pegagan and tempuyung have the highest inhibition of 54% and 31%. The combined extracts of pegagan and tempuyung showed lower inhibition than single pegagan extract, i.e. 45% versus 54%. Captopril still indicated the highest inhibition (88%) as compared to single or combined extracts. Key words: ACE inhibition, captopril, pegagan, tempuyung
Keyword: Inhibisi ACE, kaptopril, pegagan, tempuyung

Judul: Konstruksi Persamaan Friedmann Alam Semesta Friedmann-Lemaitre-Robertson-Walker Termodifikasi Materi Gelap Superfluida
Abstrak: Kosmologi merupakan salah satu objek kajian dari teori relativitas umum. Salah satu model dalam kosmologi adalah model kosmologi Friedmann. Model kosmologi Friedmann dibangun berdasarkan asumsi bahwa materi dan energi terdistribusi secara homogen dan isotropik di alam semesta. Teori relativitas umum dapat dimodifikasi melalui pendekatan teori materi gelap superfluida (MGS). Persamaan medan Einstein untuk teori MGS dapat dirumuskan melalui prinsip aksi dengan memodifikasi Lagrangian pada aksi teori MGS. Selanjutnya dengan memilih metrik Friedmann-Lemaitre-Robertson-Walker (FLRW) datar dengan indeks kurvatur sama dengan nol, dapat dibangun suatu bentuk persamaan Friedmann yang dimodifikasi teori MGS.
Keyword: kosmologi, teori materi gelap superfluida, persamaan medan Einstein, metrik FLRW, persamaan Friedmann.