The aim of this research was to study the antidiabetic activity of root extract of Ruellia tuberosa L. on rats (Rattus novergicus) induced by multiple low doses of streptozotocin. The parameters investigated were blood glucose levels, protease activities, and the histopathologic profiles of the kidneys. Three groups of rats, i.e. control, diabetic, and treatment, were used. R. tuberosa L. extracts were given orally for treatment at a dose of 250 mg/kg body weight per day for 21 consecutive days. The induced diabetes group treated with root extract of R. tuberosa L. (group III) had 60.3% lower glucose levels (119 mg/dL) compared to the group with induced diabetes only. Moreover, antidiabetic activity of R. tuberosa L extract was evidenced by the 55% lower protease activity in the treatment group compared to the untreated diabetic group. Finally, a positive effect from root extract of R. tuberosa L. was shown from the less damaged renal glomerulus and smaller gap between extracellular matrices and epithelium cells in the histopathologic profiles of the kidneys in the extract treatment group. These results show the potential of root extract of R. tuberosa L. as a natural product anti-diabetic agent.

Potentiometric urea biosensor development is based on urea hydrolysis by urease resulted CO2. The biosensor is used chitosan membrane and the H3O+ electrode as a transducer. The research was studied of effecting pH and membrane thickness to the biosensor performance. The best biosensor performance resulted at pH = 7.3 and 0.2 mm of membrane thickness. The biosensor has a Nerntian factor 28.47 mV/decade; the concentration range is 0.1 up to 6.00 ppm; and the limit of detection is 0.073 ppm. The response time of this biosensor is 280 seconds, efficiency 32 samples and accuracy 94% up to 99%.   Keywords: biosensor, potentiometry, urea, chitosan membrane

A bioplastic derived from nanocellulose isolated from the pine flower (Pinus Merkusii) waste has been made. The red and yellow colors of bioplastic were afforded from the extract of dragon fruit and turmeric. Meanwhile, nanocellulose was hydrolyzed by citric acid using concentrations of 10%, 30%, and 60%, and obtained crystallinity index of 61.00%, 57.24%, and 52.82% respectively. Each nanocellulose applied has a crystallite size of 15.09 nm (calculated using XRD data with Scherrer’s equation). The result indicated that the increase in both dragon fruit and turmeric extracts concentration increase the red and yellow color intensity of the bioplastic. This study paves the way for further application of nanocellulose in bioplastic.

Litopenaeus vanamme shrimp shell waste, which is abundantly available in Indonesia, could be optimally utilized through chitin extraction. The high-temperature chemical process is a fast and simple conventional method for extracting chitin. However, for economical and environmentally friendly process, it need a green extraction method through bacterial fermentation. Therefore in this research, biological process was carried out through Litopenaeus vanamme shrimp shell fermentation using various bacteria, such as Lactobacillus plantarum (A), Bacillus thuringiensis (B), and the combination of both bacteria (C) compared to chemical method (D). The yield of method A, B, C and D were: 80.67±0.43%; 71.25±0.45%; 63.91±1.20%; and 31.46±0.06% respectively. Co-fermentation method (method C) resulting in brighter color, higher deproteination and demineralization degree than single-fermentation methods (method A and B). The deproteination and demineralization degree of method A; B; C; D were: 28.51±0.69%, 17.41±0.89%; 47.71±1.01%, 15.08±0.36%; 50.29±1.14%, 34.33±1.04%; and 85.17±0.10%, 50.13 ± 0.72% respectively. Chitin produced from biological and chemical method had total nitrogen less than 7%. Based on the calculations through FTIR data, chitin from biological method resulted in higher degree of acetylation than chemical method. The higher the degree of acetylation obtained, the less the polymer is degraded which can preserve chitin structure.

This study was aimed to determine anthocyanin antioxidant performance with a dose of 2 cc/day based on the expression of apoptotic cells in ischemic stroke rats cerebellum. The research was conducted using ischemic stroke rats (Rattus norvegicus) that prepared by ligated for 3 h on the Common Carotid Artery (CCA) and External Carotid Artery (ECA) followed by reperfusion that is commonly known as MCAO (Middle Cerebral Artery Occlusion). The anthocyanin extract was characterized by LC-MS and its IC 50 was measured by DPPH method. The rats were divided into five groups 1) negative control; 2) reperfusion 1 h; 3) reperfusion 72 h; 4) reperfusion 24 h, with anthocyanin therapy; 5) reperfusion 72 h, with anthocyanin therapy. The results of LC-MS showed that anthocyanin from purple sweet potato extracts contained Petunidin-3,5-O-diglucoside (Pt-DG) with an IC 50 value of 22.16 μg/mL, categorized as a very strong antioxidant. The results showed that apoptotic cells expression of cerebellum decreased significantly (p<0.01) after 72 h reperfusion with anthocyanins therapy until 2.42%. The current work proved that anthocyanin extract effectively suppresses the apoptotic cell's expression of the cerebellum on stroke ischemic rats.