Alga cokelat merupakan salah satu jenis makroalga laut yang mendominasi kawasan pesisir Barat Aceh. Penelitian ini bertujuan untuk melakukan eksplorasi senyawa bioaktif alga cokelat Sargassum sp. sebagai sumber antioksidan. Penelitian dilakukan secara deskriptif. Pengujian terdiri dari analisis proksimat, senyawa aktif, total fenol, aktivitas antioksidan metode DPPH dan perhitungan rendemen ekstrak. Hasil penelitian menunjukkan komposisi kimia yang paling dominan terdiri dari kadar abu 52,74% dan kadar karbohidrat 23,77%. Rendemen ekstrak Sargasuum sp. dengan pelarut etanol 0,565%, etil asetat 0,420% dan n-heksan 0,265%. Kadar total fenol etanol ektrak 563,22 mg GAE/g, etil asetat ekstrak 13,48 mg GAE/g, n-heksan ekstrak 30,610 mg GAE/g. Aktivitas antioksidan etanol ekstrak dengan IC50 = 239,51mg/L, etil asetat ekstrak 68,89 mg/L dan n-heksan ekstrak 148.16 mg/L. Ekstrak Sargassum sp. terdeteksi mengandung fenol, alkaloid dan triterpenoid.

Seaweed belongs to marine biota and contains nutrients and secondary metabolites beneficial for health. This study aimed to determine the antidiabetic activity of extracts and fractions of green seaweed Halimeda tuna. The H. tuna sample was extracted with the maceration method using methanol and then partitioned using ethyl acetate and water to obtain ethyl acetate and water fractions. The methanol extract, ethyl acetate fraction, and water fraction of H. tuna were tested for their inhibitory activity against α-amilase and α-glucosidase. The methanol extract and the fractions with the highest inhibitory activity were phytochemically tested and analyzed using gas chromatography–mass spectrometry (GC-MS). The results showed that the ethyl acetate fraction (IC₅₀ = 0.88 ± 0.20 mg/mL) inhibited α-amylase relatively similar to acarbose (IC₅₀ = 0.76 ± 0.04 mg/mL). The methanol extract (IC₅₀ = 0.05 ± 0.01 mg/mL) and the ethyl acetate fraction (IC₅₀ = 0.01 ± 0.00 mg/mL) demonstrated stronger inhibitory activity against α-glucosidase than acarbose (IC₅₀ = 0.27 ± 0.13 mg/mL). Phytochemical testing showed that the methanol extract and the ethyl acetate fraction contained secondary metabolites: alkaloids, flavonoids, steroids, and phenol hydroquinone. The compounds in methanol extract predicted to have inhibitory activity against α-amylase and α-glucosidase were Docosanol, Neophytadiene, Stigmasta-7,22-dien-3-ol,acetate,(3.beta.,5.alpha.,22E), Octadecanoic acid,2-oxo-,methyl ester, and phytol, while those in the ethyl acetate fraction were n-Nonadecane, Phytol, Butyl ester, 14-.Beta.-H-pregna, Octadecenoic acid, and Oleic acid.

Lung cancer is a malignant tumor that attacks the lungs generated by carcinogenic free radicals such as cigarette smoke. Seaweed contains bioactive compounds that have the potential to reduce cancer-causing free radicals. This study aimed to determine the phytochemical content and cytotoxic activity of Halimeda tuna seaweed extract against lung cancer cells (A549). The H. tuna sample was macerated using methanol for 24 h. Cytotoxic test of H. tuna crude extract used the MTT test against A549. The crude extract was phytochemically tested and analyzed using gas chromatography–mass spectrometry (GC-MS). The results showed that the H. tuna crude extract had cytotoxic activity against A549 with an IC50 value of 2771 µg/mL. The phytochemical test showed that H. tuna crude extract contained flavonoids and steroids. showed the presence of fatty acid compounds including palmitic acid, oleic acid, myristic acid, palmitoleic acid and stearic acid. Based on the results can be concluded that H. tuna extract had cytotoxic activity against A549 with low cytotoxicity to be used as a chemo-preventive agent.

West Aceh Region has Nypa fruticans mangrove community distributed almost ±100 Ha. N. fruticans leaves have been used as traditional cigarette paper. The objective of this study was to explore bioactive compound of N. fruticans from the coast of West Aceh as antioxidant. The extraction used 3 solvents including methanol (polar), etyl acetate (semi polar), and n-hexane (non polar). The result showed the methanol extract contained bioactive compound content such as phenolic, flavonoid, tannin, saponin, and steroid while the etyl acetate extract comprised phenolic, tannin, and steroid. Moreover, n-hexane extract only had steroid compound. The result of antioxidant activit assay showed etyl acetate extract had IC50 value 8.81 µg/mL, methanol extract had IC50 value 9.31 µg/mL and n-hexane extract was 238.47 µg/mL with ascorbic acid as positive control. It is indicated the presence of phenolic, flavonoid, tannin, and saponin in the ethyl acetate extract play the role as antioxidant.

Background: Strategies to increase body resistance and prevent disease in aquaculture include using vaccines, antibiotics, and probiotics. Today, the use of antibiotics with natural ingredients is becoming a trend. One of the natural ingredients that contain high antioxidants and antibiotics is Sargassum sp. Methods: This research was conducted from March to May 2022 at the Biotechnology Laboratory, Faculty of Fisheries and Marine, Universitas Riau, in two stages: 1) the sensitivity of extracts of Sargassum sp. and 2) the application of Sargassum sp. extract orally in tilapia (O. niloticus). The parameters measured were clear zone, minimum inhibitory concentration, LD50 test of leaf extract of Sargassum sp. in tilapia (O. niloticus), hemoglobin levels, hematocrit, total leukocytes, total erythrocytes, leukocyte differentiation, and survival rate. Data on hematology parameters were tabulated and analyzed using a One-Way ANOVA followed by a Student Newman Keuls (SNK) test when deemed necessary. Results: The results showed that the extract of Sargassum sp. inhibited the growth of Aeromonas hydrophila bacteria with a clear zone of 6.5-15.0 mm, which is classified as resistant. At doses of 2000, 2500, and 3000 ppm, it did not cause death in fish for 96 hours (LD50). Hematological parameters can be a sign of the health status of fish. Tilapia given Sargassum sp. in different doses gave an effect between treatments, both after 30 days of rearing and post-test against A. hydrophila bacteria (p<0.05). The results showed that the hematology of fish fed with Sargassum sp. extract was in the normal or healthy range. Healthy tilapia had erythrocyte counts ranging from 1.34-2.11×106 cells/mm3, hematocrit 26.17-33.19%, hemoglobin 6.26-11.2 g/dL and total leukocytes 1.01-1.50×104 cells/mm3 and total erythrocytes 5.88-9.13×104 cells/ mm3. Conclusions: A dose of 3000 ppm provided the highest health improvement against A. hydrophila bacterial infection.

PENDAMPINGAN TEKNIK KONSERVASI PENYU LEKANG (Lepidochelys olivacea) DI PESISIR PANTAI LAMPUUK ACEH BESAR