We screened a library of botanical compounds purified from plants of Vietnam for modulators of the activity of a two-pore domain K+ channel, TREK-1, and we identified a hydroxycoumarin-related compound, ostruthin, as an activator of this channel. Ostruthin increased whole-cell TREK-1 channel currents in 293T cells at a low concentration (EC50 = 5.3 μM), and also activity of the TREK-2 channel (EC50 = 3.7 mM). In contrast, ostruthin inhibited other K+ channels, e.g. human ether-à-go-go-related gene (HERG1), inward-rectifier (Kir2.1), voltage-gated (Kv1.4), and two-pore domain (TASK-1) at higher concentrations, without affecting voltage-gated potassium channel (KCNQ1 and 3). We tested the effect of this compound on mouse anxiety- and depression-like behaviors and found anxiolytic activity in the open-field, elevated plus maze, and light/dark box tests. Of note, ostruthin also showed antidepressive effects in the forced swim and tail suspension tests, although previous studies reported that inhibition of TREK-1 channels resulted in an antidepressive effect. The anxiolytic and antidepressive effect was diminished by co-administration of a TREK-1 blocker, amlodipine, indicating the involvement of TREK-1 channels. Administration of ostruthin suppressed the stress-induced increase in anti-c-Fos immunoreactivity in the lateral septum, without affecting immunoreactivity in other mood disorder-related nuclei, e.g. the amygdala, paraventricular nuclei, and dorsal raphe nucleus. Ostruthin may exert its anxiolytic and antidepressive effects through a different mechanism from current drugs.

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The process of enzyme assisted extraction of essential oil from the leaves and branches of the Vietnamese aromatic plant Cinnamomum cassia was studied and optimized using a Box-Wilson central composite design consisting of 05 independent variables (pH, temperature T, time τ, concentration of the enzyme Laccase, and concentration of the enzyme Cellic Htec2) and two dependent variables (reducing sugar and yield of essential oil). Second-order polynomial equations were obtained for the responses, which fitted well with the experimental data. Optimal conditions for oil yield were found at pH = 5.2; T = 440C; τ = 5h30'; Laccase = 0.42 ml/g, and Cellic Htec2 = 1.15%. The experimental value (0.982% oil yield) was close to the predicted value (0.978%). The application of enzyme assisted extraction  in combination with optimization using response surface methodology substantially improved the oil yield as compared with traditional method.

Mud crab Scylla sp. is a common sea crab species in Vietnam as well as in Asia Pacific. Today, mud crabs are raised on a large scale to be harvested at the soft molting stage because of the high economic value of the finished shell crabs. At present, the processing of soft shell crabs is limited to whole packaging and exporting. However, 30% of soft-shelled crabs in processing often lose their feet and claws, which reduce production costs. Therefore, it is necessary to study the technology of processing soft-shell crabs to improve the value of soft-shelled crab products. Recently, the application of enzymes in processing has brought many benefits such as being environmentally friendly and creating many bioactive substances. In this journal, we built the procedure to determine amino acid content in the processing of Scylla sp. to ensure the quality of products obtained after processing. This procedure based on HPLC using a fluorescence reader. The results showed that the amino acid content after hydrolysis process by enzyme technology reached 65.58% dry weight and contains many valuable amino acids such as lysine, leucine, valine, methionine, histidine.

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