Anti-neuroinflammatory effects of alkaloid-enriched extract from Huperzia serrata on lipopolysaccharide-stimulated BV-2 microglial cells.

CONTEXT: Alkaloid-enriched extract of Huperzia serrata (Thunb.) Trevis (Lycopodiaceae) (HsAE) can potentially be used to manage neuronal disorders. OBJECTIVE: This study determines the anti-neuroinflammatory effects of HsAE on lipopolysaccharide (LPS)-stimulated BV-2 microglial cells and the underlying mechanisms. MATERIALS AND METHODS: BV-2 cells were pre- or post-treated with different concentrations of HsAE (25-150 µg/mL) for 30 min before or after LPS induction. Cell viability was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and no cytotoxicity was found. Nitric oxide (NO) concentration was determined using Griess reagent. The levels of prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 were determined using enzyme-linked immunosorbent assay. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 and the phosphorylation of mitogen-activated protein kinase (MAPK) were analyzed using western blotting. RESULTS: HsAE reduced LPS-induced NO production with half-maximal inhibitory concentration values of 99.79 and 92.40 µg/mL at pre- and post-treatment, respectively. Pre-treatment with HsAE at concentrations of 50, 100, and 150 µg/mL completely inhibited the secretion of PGE2, TNF-α, IL-6, and IL-1ß compared to post-treatment with HsAE. This suggests that prophylactic treatment is better than post-inflammation treatment. HsAE decreased the expression levels of iNOS and COX-2 and attenuated the secretion of pro-inflammatory factors by downregulating the phosphorylation of p38 and extracellular signal-regulated protein kinase in the MAPK signaling pathway. DISCUSSION AND CONCLUSIONS: HsAE exerts anti-neuroinflammatory effects on LPS-stimulated BV-2 cells, suggesting that it may be a potential candidate for the treatment of neuroinflammation in neurodegenerative diseases.

Anti-hypertensive effects of Callisia fragrans extract on Reno-vascular hypertensive rats.

OBJECTIVES: This study aims to investigate the anti-hypertensive effects of aqueous extract of Callisia fragrans and their underlying mechanism using a two-kidney one-clip (2K1C) model of reno-vascular hypertension in rats. METHODS: The reno-vascular hypertensive rats were treated with C. fragrans leaf extract (100 and 500 mg/kg; p.o.) and a reference drug, captopril (20 mg/kg; p.o.), for 4 weeks. The blood pressure and heart rate were recorded using a tail-cuff. The heart weight, left ventricular wall thickness, and serum creatinine and urea levels were measured. A spectrophotometric assay was used to analyze the angiotensin-converting enzyme (ACE) inhibition activity of the extract and the reference drug. The total volume and the concentration of sodium, potassium, and chloride in urine samples were evaluated. RESULTS: C. fragrans extract significantly reduced both systolic and diastolic blood pressures in the reno-vascular hypertensive rats. No significant difference in the heart rate was observed between each animal group. C. fragrans extract reduced the 2K1C-induced increase in the heart and body weight ratio and the left ventricular wall thickness. Moreover, the extract also attenuated the increase in serum urea induced by the 2K1C treatment. C. fragrans extract inhibited ACE activity in vitro with an IC50 of 20.97 ± 3.94 µg/ml. The urine output and urinary electrolyte excretion significantly increased in C. fragrans extract-treated rats. CONCLUSIONS: These findings demonstrated that C. fragrans extract can mitigate hypertension and alleviate ventricular hypertrophy and renal dysfunction in reno-vascular hypertensive rats, at least in part via ACE activity inhibition and diuretic property.

Protective effects of Bacopa monnieri on ischemia-induced cognitive deficits in mice: the possible contribution of bacopaside I and underlying mechanism.

ETHNOPHARMACOLOGICAL RELEVANCE: Bacopa monnieri (L.) Wettst. (BM) is a medicinal plant which has been not only used as a traditional medicine to improve intelligence and memory but also taken as vegetables in Vietnam for a long time. We previously demonstrated that Bacopa monnieri (BM) alcohol extract attenuated olfactory bulbectomy-induced cognitive deficits and the deterioration of septo-hippocampal cholinergic neurons, suggesting the beneficial effects of BM for dementia patients. AIM OF STUDY: The present study was conducted to further clarify the anti-dementia effects of BM, using transient 2 vessels occlusion (T2VO)-induced cognitive deficits in mice, an animal model of vascular dementia, and also to investigate the constituent(s) contributing to the actions of BM, using oxygen- and glucose-deprivation (OGD)-induced hippocampal cell damage as an in vitro model of ischemia. MATERIALS AND METHODS: In the in vivo experiments, T2VO mice were treated daily with a standardized BM extract (50mg/kg, p.o.) 1 week before and continuously 3 days after surgery. In the in vitro experiments, organotypic hippocampal slice cultures (OHSCs) were incubated with triterpenoid saponins from BM (bacosides) or MK-801 1h before and during a 45-min period of OGD. Neuronal cell damage in OHSCs was analyzed by measurement of propidium iodide uptake 24h after OGD. RESULTS: The BM treatment significantly ameliorated T2VO-induced impairments in non-spatial short term memory performance in the object recognition test. Among the bacosides tested in the in vitro experiments using OHSCs, bacopaside I (25 µM) exhibited potent neuroprotective effects against OGD-induced neuronal cell damage. Double staining with TUNEL and PI revealed that OGD caused necrosis and apoptosis and that bacopaside I attenuated the effects of OGD. The neuroprotective effects of bacopaside I were blocked by the PKC inhibitor Ro-31-8220 and PI3K inhibitor LY294002, but not by the ERK inhibitor U0126. OGD reduced the level of phospho-Akt (p-Akt), an anti-apoptotic factor, in OHSCs. This decrease was reversed by bacopaside I. Moreover, the treatment with bacopaside I itself was able to elevate the level of p-Akt in OHSCs. CONCLUSION: These results suggest that BM was beneficial for the prevention of cognitive deficits related to cerebral ischemia and also that bacopaside I, via PKC and PI3K/Akt mechanisms, played a role in the neuroprotective effects of BM observed in the mouse model.