Bingxin Ma

Antifungal mechanism of essential oil from Anethum graveolens seeds against Candida albicans

This work studied the antifungal mechanism of dill seed essential oil (DSEO) against Candida albicans. Flow cytometric analysis and inhibition of ergosterol synthesis were performed to clarify the mechanism of action of DSEO on C. albicans. Upon treatment of cells with DSEO, propidium iodide penetrated C. albicans through a lesion in its plasma membrane. DSEO also significantly reduced the amount of ergosterol. These findings indicate that the plasma membrane of C. albicans was damaged by DSEO. The effect of DSEO on the functions of the mitochondria in C. albicans was also studied. We assayed the mitochondrial membrane potential (mtΔψ) using rhodamine 123 and determined the production of mitochondrial dysfunction-induced reactive oxygen species (ROS) via flow cytometry. The effects of the antioxidant l-cysteine (Cys) on DSEO-induced ROS production and the antifungal effect of DSEO on C. albicans were investigated. Exposure to DSEO increased mtΔψ. Dysfunctions in the mitochondria caused ROS accumulation in C. albicans. This increase in the level of ROS production and DSEO-induced decrease in cell viability were prevented by the addition of Cys, indicating that ROS are an important mediator of the antifungal action of DSEO. These findings indicate that the cytoplasmic membrane and mitochondria are the main anti-Candida targets of DSEO.

Hepatoprotective activity of flavonoids from Cichorium glandulosum seeds in vitro and in vivo carbon tetrachloride-induced hepatotoxicity.

ETHNOPHARMACOLOGICAL RELEVANCE Cichorium glandulosum Boiss. et Huet was used historically in Uyghur folk medicine. Its roots, seeds, and aerial parts are extensively used by Uyghur residents in Xinjiang to eliminate savda typhoid, dredge and cure obstructive jaundice variety liver disorders. AIM OF THE STUDY To evaluate the hepatoprotective activity of total flavonoids (TFs) obtained from C. glandulosum seeds against carbon tetrachloride (CCl4)-induced liver damage in vitro and in vivo. To investigate the mechanisms of hepatoprotective effects for TFs. MATERIALS AND METHODS The dried seeds of C. glandulosum were extracted with 70% aqueous ethanol, and the extract was chromatographed with D101 macroporous resin. In vitro the antioxidant capacity against lipid peroxidation (LPO) was evaluated using ferrothiocyanate, thiobarbituric acid, β-carotene bleaching, and LPO inhibition assay. The cytotoxicity and hepatoprotective activity of TFs were evaluated in human liver hepatoma cells (HepG2). MTT assay, hepatic injury markers aspartate aminotransferase (AST), alanine aminotransaminase (ALT), lactate dehydrogenase (LDH) leakage, malondialdehyde (MDA), and glutathione (GSH) were performed. In vivo the hepatoprotective activity of TFs against CCl4-induced acute liver injury was evaluated in rats. A series of biochemical and antioxidant parameter levels were measured in liver homogenate. The suppressive effect on pancreatic lipase activity was determined. RESULTS Results indicated that TFs showed antioxidant capacity against lipid peroxidation (LPO). Administrating CCl4 (1%, v/v) caused a significant decrease in HepG2 viability. Treatment with TFs at doses (62.5, 125, and 250 μg/ml) could significantly ameliorate the cytotoxicity and decline the levels of AST, ALT, and LDH induced by CCl4. The markers including MDA and GSH, which were close to oxidative damage, were restored. Oral treatment with TFs in vivo at doses of 100, 200, and 400 mg/kg significantly reduced the levels of AST, ALT, alkaline phosphatase (ALP), total bilirubin (TB), and thiobarbituric acid reactive substances (TBARs) in the serum compared with CCl4-induced acute liver injury in rats. TFs showed dose-dependent suppressive effects on pancreatic lipase activity, and the IC50 was 1.318 ± 0.164 mg/ml. CONCLUSION TFs from C. glandulosum seeds demonstrated significant hepatoprotection against CCl4-induced hepatotoxicity. TFs exhibited significant suppression of LPO and pancreatic lipase capacity, which may be the mechanisms of hepatoprotective effects against CCl4. Our results contribute towards validation of the traditional use of C. glandulosum seeds in the treatment of liver disorders.

Dill (Anethum graveolens L.) seed essential oil induces Candida albicans apoptosis in a metacaspase-dependent manner.

Dill (Anethum graveolens L.) has been used in traditional Uighur medicine for its various pharmacological activities. Previous studies have suggested that dill seed essential oil (DSEO) has anti-Candida potential and the mechanism of its action also has been studied. Our study examined whether DSEO induces apoptosis in the human pathogen Candida albicans ATCC 64550. Our results indicate that C. albicans ATCC 64550 cells treated with DSEO show some typical apoptosis characters, such as decrease in adenosine triphosphatase (ATPase) activity, chromatin condensation, nuclear fragmentation, and phosphatidylserine (PS) exposure. The DSEO promoted cytochrome c (cyt c) release and metacaspase activation, which resulted in C. albicans ATCC 64550 apoptosis. L-cysteine prevented the DSEO-induced nuclear fragmentation, PS externalization, and metacaspase activation, thus indicating that the reactive oxygen species (ROS) is an important mediator of DSEO-induced apoptosis. To our knowledge, this study is the first to report the induction of apoptosis of this pathogen with concomitant metacaspase activation by DSEO.

In vitro and in vivo evaluation of inhibition activity of lotus (Nelumbo nucifera Gaertn.) leaves against ultraviolet B-induced phototoxicity

Lotus (Nelumbo nucifera Gaertn.), an aquatic vegetable, is extensively cultivated in eastern Asia, particularly in China. Our previous study showed that lotus leaf extracts (LLEs) have strong antioxidant effects in vitro and in vivo. The main antioxidants in lotus leaf have been identified via liquid chromatography-mass spectrometry. Ultraviolet B (UVB) protective effects have been associated with plant extracts rich in antioxidants. The current study focuses on the mitochondria model to evaluate the potent inhibition activity of LLE against UVB-induced phototoxicity. The level of thiobarbituric acid reactive substances, glutathione, lipid hydroperoxide, conjugated diene, and 4-hydroxynonenal were measured. The in vivo activity of LLE was also investigated in mice model. The results showed that all concentrations of LLE (10, 100, and 1000μg/ml) possessed strong protective effect against UVB-induced phototoxicity in the mitochondria model. The in vivo test showed that LLE have significant protective effects on the level of superoxide dismutase, catalase, and glutathione peroxidase, as well as the contents of hydroxyproline and malondialdehyde in the skin samples. This study would provide a foundation for broadening the applications of lotus leaf in both the medical and food industries.

Interference and Mechanism of Dill Seed Essential Oil and Contribution of Carvone and Limonene in Preventing Sclerotinia Rot of Rapeseed

This study aimed to evaluate the inhibitory effects of dill (Anethum graveolens L.) seed essential oil against Sclerotinia sclerotiorum and its mechanism of action. The antifungal activities of the two main constituents, namely carvone and limonene, were also measured. Mycelial growth and sclerotial germination were thoroughly inhibited by dill seed essential oil at the 1.00 μL/mL under contact condition and 0.125μL/mL air under vapor condition. Carvone also contributed more than limonene in inhibiting the growth of S. sclerotiorum. Carvone and limonene synergistically inhibited the growth of the fungus. In vivo experiments, the essential oil remarkably suppressed S. sclerotiorum, and considerable morphological alterations were observed in the hyphae and sclerotia. Inhibition of ergosterol synthesis, malate dehydrogenase, succinate dehydrogenase activities, and external medium acidification were investigated to elucidate the antifungal mechanism of the essential oil. The seed essential oil of A. graveolens can be extensively used in agriculture for preventing the oilseed crops fungal disease.

Nine phenylethanoid glycosides from Magnolia officinalis var. biloba fruits and their protective effects against free radical-induced oxidative damage

To systematically study the chemical constituents in Magnolia officinalis var. biloba fruits, nine phenylethanoid glycosides were isolated by solvent extraction, silica gel, and preparative high-performance liquid chromatography (HPLC). Their structures were elucidated by 1D and 2D NMR analyses, including COSY, HMQC and HMBC correlations, and HPLC analysis of sugar residue. Nine phenylethanoid glycosides, namely, magnoloside Ia (1), magnoloside Ic (2), crassifolioside (3), magnoloside Ib (4), magnoloside IIIa (5), magnoloside IVa (6), magnoloside IIa (7), magnoloside IIb (8) and magnoloside Va (9), were first isolated from the n-butanol fraction of Magnolia officinalis var. biloba fruits alcohol extract. Free radical scavenging activities of the nine phenylethanoid glycosides were assessed using the DPPH, ABTS, and superoxide anion radical scavenging assays. Simultaneously, protective effects of all compounds against free radical-induced oxidative damage were evaluated by two different kinds of mitochondrial damage model. The protective effects were assessed by mitochondrial swelling, the formations of malondialdehyde (MDA) and lipid hydroperoxide (LOOH), the activities of catalase (CAT), glutathione reductase (GR) and superoxide dismutase (SOD). All phenylethanoid glycosides showed significant protective effects.

Dicaffeoylquinic Acid-Enriched Fraction of Cichorium glandulosum Seeds Attenuates Experimental Type 1 Diabetes via Multipathway Protection.

Chicory has a major geographical presence in Europe and Asia. Cichorium glandulosum Boiss. et Huet, a genus Cichorium, is used for medicinal and food purposes in Asia. In this study, a dicaffeoylquinic acid-enriched fraction of C. glandulosum seeds n-BuOH fraction (CGSB) could ameliorate type 1 diabetes mellitus (T1DM) in streptozotocin (STZ)-induced diabetic mice with continuous administration for 2 weeks. CGSB treatment showed significantly higher plasma insulin levels but lower free fatty acids in adipose tissue and liver. Moreover, CGSB improved pancreatic islet mass. In vitro, different fractions of C. glandulosum seed (CGS) induced the differentiation of 3T3-L1 preadipocytes. The mRNA level for peroxisome proliferator-activated receptor alpha increased in high glucose treatment group in HepG2 cells, while CGSB significantly down-regulated the mRNA expression. The main compound of CGSB, 3,5-dicaffeoylquinic acid, was isolated and identified, which exhibited α-glucosidase inhibitory activity. These findings demonstrated that CGSB attenuated experimental T1DM via multipathway protection.