Protective Effect of Fresh/Dry Dandelion Extracts on APAP-Overdose-Induced Acute Liver Injury.

OBJECITVIE: To compare the liver protective activity of fresh/dried dandelion extracts against acetaminophen (APAP)-induced hepatotoxicity. METHODS: Totally 90 Kunming mice were randomly divided into 10 groups according to body weight (9 mice for each group). The mice in the normal control and model (vehicle control) groups were administered sodium carboxymethyl cellulose (CMC-Na, 0.5%) only. Administration groups were pretreated with high and low-dose dry dandelion extract (1,000 or 500 g fresh herb dried and then decocted into 120 mL solution, DDE-H and DDE-L); low-, medium- and high-dose dandelion juice (250, 500, 1,000 g/120 mL, DJ-L, DJ-M, and DJ-H); fresh dandelions evaporation juice water (120 mL, DEJW); dry dandelion extract dissolved by pure water (1 kg/120 mL, DDED-PW); dry dandelion extract dissolved by DEJW (120 g/120 mL, DDED-DEJW) by oral gavage for 7 days at the dosage of 0.5 mL solution/10 g body weight; after that, except normal control group, all other groups were intraperitonealy injected with 350 mg/kg APAP to induce liver injury. Twenty hours after APAP administration, serum and liver tissue were collected and serum alanine aminotransferase (AST), aspartate transaminase (ALT), alkaline phosphatase (AKP), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) activities were quantified by biochemical kits; tumor necrosis factor (TNF-α), interleukin (IL)-2, and IL-1 ß contents in liver tissue were determined by enzyme linked immunosorbent assay kits. Histopathological changes in liver tissues were observed by hematoxylin and eosin staining; TUNEL Assay and Hoechst 33258 staining were applied for cell apoptosis evaluation. The expressions of heme oxygenase-1 (HO-1), nuclear factor erythroid-2-related factor 2 (Nrf-2), caspase-9, B-cell leukemia/lymphoma 2 (Bcl-2), Bax and p-JNK were determined by Western blot analysis. RESULTS: Pretreatment with fresh dandelion juice (FDJ, including DJ-L, DJ-M, DJ-H, DEJW and DDED-DEJW) significantly decreased the levels of serum ALT, AST, AKP, TNF-α and IL-1ß compared with vehicle control group (P<0.05 or P<0.01). Additionally, compared with the vehicle control group, FDJ decreased the levels of hepatic MDA and restored GSH levels and SOD activity in livers (P<0.05 or P<0.01). FDJ inhibited the overexpression of pro-inflammatory factors including cyclooxygenase-2 and inducible nitric oxide synthase in the liver tissues (P<0.05 or P<0.01). Furthermore, Western blot analysis revealed that FDJ pretreatment inhibited activation of apoptotic signaling pathways via decreasing of Bax, and caspase-9 and JNK protein expression, and inhibited activation of JNK pathway (P<0.05 or P<0.01). Liver histopathological observation provided further evidence that FDJ pretreatment significantly inhibited APAP-induced hepatocyte necrosis, inflammatory cell infiltration and congestion. CONCLUSIONS: FDJ pretreatment protects against APAP-induced hepatic injury by activating the Nrf-2/HO-1 pathway and inhibition of the intrinsic apoptosis pathway, and the effect of fresh dandelion extracts was superior to dried dandelion extracts in APAP hepatotoxicity model mice.

[Preparation of nanoemulsion spray from Moslae Herba volatile oil and its antibacterial activity].

Moslae Herba is a commonly used aromatic Chinese medicinal with volatile oil as the main effective component and exhibits broad-spectrum antibacterial and antiviral effects. However, the irritation and instability of Moslae Herba volatile oil necessitate the preparation into a specific dosage form. In this study, the steam distillation method was employed to extract the Moslae Herba volatile oil. The content of thymol and carvacrol in Moslae Herba volatile oil was determined by HPLC as(0.111 9±0.001 0) and(0.235 4±0.004 7) mg·mL~(-1), respectively. Pseudo-ternary phase diagrams and surfactants compounding were applied in the selection of the optimal excipients(surfactant and cosurfactant). On this basis, a nanoemulsion was prepared from the Moslae Herba volatile oil and then loaded into pressure vessels to get sprays, whose stability and antibacterial activity were evaluated afterward. With clarity, viscosity, smell and body feeling as comprehensive indexes, the optimal formulation of the Moslae Herba volatile oil nanoemulsion was determined as follows: Moslae Herba volatile oil∶peppermint oil∶cremophor EL∶absolute ethanol∶distilled water 7.78∶1.58∶19.26∶6.15∶65.23. The as-prepared nanoemulsion was a light yellow transparent liquid, with Tyndall effect shown under the irradiation of parallel light. It has the pH of 5.50, conductivity of 125.9 µS·cm~(-1), average particle size of 15.45 nm, polydispersity index(PDI) of 0.156, and Zeta potential of-17.9 mV. Under a transmission electron microscope, the Moslae Herba volatile oil nanoemulsion was presented as regular spheres without adhesion and agglomeration. Stability test revealed that the Moslae Herba volatile oil nanoemulsion was stable at 4-55 ℃, which was free from demulsification and stratification within 30 days. After the centrifugation at 12 000 r·min~(-1) for 30 min, there was no stratification either. The nanoemulsion had good inhibitory effects on Escherichia coli, Staphylococcus aureus and resistant S. aureus strains, with the minimum inhibitory concentrations of 0.39, 3.12 and 1.56 mg·mL~(-1), respectively. The above results demonstrated that the nanoemulsion was prepared feasibly and showed stable physical and chemical properties and good antibacterial effects. This study provides a practicable technical solution for the development of anti-epidemic and anti-infection products from Moslae Herba volatile oil.