Inflammation is the response of living tissues to the injury. Prolonged or inappropriate inflammation has been involved with many diseases such as, cancer, diabetes, heart disease… These days, inflammation has been treated by nonsteroidal and steroidal anti-inflammatory drugs, which have a lot of side effects. It opens the need and interest of new drugs discovery. Particularly, scientific and pharmaceutical communities show great interest in finding new anti-inflammatory compounds in traditional medicinal plants. This study aimed to optimize an in vitro anti-inflammatory model. Cell heterogeneity, cell density, LPS concentration and LPS incubation time were chosen to optimize the production of nitric oxide (NO) in RAW 264.7 macrophage cells. Our results show that 104 cells/well, FBS 1 %, starvation for 6 h, LPS 0.5 µg/mL in 24 h were optimized parameters in the model. Then, extracts from Hedyotis capitellata, a traditional medicinal plant used by K’ho minority, Bidoup Nuiba national park, Lam Dong province, Vietnam, was chosen to evaluate the in vitro antiinflammatory model. The anti-inflammatory activity was tested by measuring the production of NO in lipopolysaccharide-activated RAW 264.7 macrophage cells. The experimental data indicate that the extracts of this plant decreased NO production in LPS-stimulated RAW 264.7, particularly, the petroleum ether fraction at the concentration of 23.8 µg/mL inhibited NO production by 128.20 %; whereas dexamethasone 50 µM inhibited NO accumulation to 112 %.

Conyza canadensis (L.) Cronquist (CCL) has been used by K’Ho minority in Bidoup Nui Ba national park, Lam Dong province, Vietnam as one of wound healing remedies. However, the scientific proof of treatment is still unclear. This study aimed to evaluate this wound healing potential of CCL. CCL power was extracted by ethanol and then partitioned consecutively with petroleum ether, ethyl acetate and water. Wound healing potential was evaluated by antibacterial activity, stimulation of fibroblast and keratinocyte proliferation. Agar-well diffusion was used in the antibacterial tests and the results showed that CCL had antibacterial activity against 02 dermatitis bacteria (Pseudomonas aeruginosa, Staphylococcus aureus) and 02 opportunistic infection bacteria (Escherichia coli, Enterococcus faecalis). Moreover, our results illustrated that CCL stimulated the fibroblast and keratinocyte proliferation compared to the control. Particularly, the fibroblast division increased 1.6 times at 31.25 µg/mL when treated by ethanolic extract, while ethyl acetate fraction showed 1.7 times increase at 10 µg/mL in keratinocyte proliferation compared to the control. Taken together, our study contributed scientific base of CCL in the wound healing.

Leptin, a peptide hormone, is produced by mature adipocytes and functions primarily in the hypothalamus to reduce food intake and body weight. Recombinant h-leptin has been shown to be effective in obesity treatment. To overexpression of recombinant human leptin in Escherichia coli, the human leptin gene (hob gene) was cloned into the vector pET-28a. When analysis expression of human leptin in E. coli BL21(DE3) strain, it was found that recombinant vector pET-hob expressed h-leptinproteins in cytoplasm, and mainly as insoluble inclusion bodies. This result will be the premise for researching to produce recombinant human leptin protein.