Xiaoquan Ban

Chemical composition and antifungal activity of essential oil from Cicuta virosa L. var. latisecta Celak

The essential oil extracted from the fruits of Cicuta virosa L. var. latisecta Celak was tested in vitro and in vivo against four foodborne fungi, Aspergillus flavus, Aspergillus oryzae, Aspergillus niger, and Alternaria alternata. Forty-five different components accounting for 98.4% of the total oil composition were identified by gas chromatography-mass spectrometry. The major components were γ-terpinene (40.92%), p-cymene (27.93%), and cumin aldehyde (21.20%). Antifungal activity was tested by the poisoned food technique against the four fungi. Minimum inhibitory concentration against the fungi was 5 μL/mL and percentage inhibition of mycelial growth was determined at day 9. The essential oil had a strong inhibitory effect on spore production and germination in all tested fungi proportional to concentration. The oil exhibited noticeable inhibition on dry mycelium weight and synthesis of aflatoxin B₁ (AFB₁) by A. flavus, completely inhibiting AFB(1) production at 4 μL/mL. The effect of the essential oil on inhibition of decay development in cherry tomatoes was tested in vivo by exposing inoculated and control fruit to essential oil vapor at a concentration of 200 μL/mL. Results indicated that the essential oil from C. virosa var. latisecta (CVEO) has potential as a preservative to control food spoilage.

The Mechanism of Antifungal Action of Essential Oil from Dill (Anethum graveolens L.) on Aspergillus flavus

The essential oil extracted from the seeds of dill (Anethum graveolens L.) was demonstrated in this study as a potential source of an eco-friendly antifungal agent. To elucidate the mechanism of the antifungal action further, the effect of the essential oil on the plasma membrane and mitochondria of Aspergillus flavus was investigated. The lesion in the plasma membrane was detected through flow cytometry and further verified through the inhibition of ergosterol synthesis. The essential oil caused morphological changes in the cells of A. flavus and a reduction in the ergosterol quantity. Moreover, mitochondrial membrane potential (MMP), acidification of external medium, and mitochondrial ATPase and dehydrogenase activities were detected. The reactive oxygen species (ROS) accumulation was also examined through fluorometric assay. Exposure to dill oil resulted in an elevation of MMP, and in the suppression of the glucose-induced decrease in external pH at 4 µl/ml. Decreased ATPase and dehydrogenase activities in A. flavus cells were also observed in a dose-dependent manner. The above dysfunctions of the mitochondria caused ROS accumulation in A. flavus. A reduction in cell viability was prevented through the addition of L-cysteine, which indicates that ROS is an important mediator of the antifungal action of dill oil. In summary, the antifungal activity of dill oil results from its ability to disrupt the permeability barrier of the plasma membrane and from the mitochondrial dysfunction-induced ROS accumulation in A. flavus.

Antioxidant activity of bovine and porcine meat treated with extracts from edible lotus (Nelumbo nucifera) rhizome knot and leaf

Lotus (Nelumbo nucifera) is an extensively cultivated vegetable in eastern Asia, particularly in China. Both lotus rhizome knot (LRK) and lotus leaf (LL) are waste products of the lotus industry. Extracts from LRK and LL are proposed as antioxidants for meat. Porcine and bovine ground meat samples were subjected to three treatments: CONTROL (with no additives), LRK (lotus rhizomes knot extract 3% w/w), and LL (lotus leaf extract 3% w/w). Raw and cooked samples were stored at 4°C and the antioxidant activity was determined at 1, 3, 6 and 10 days. Antioxidant activity was significantly increased in all meat samples with the addition of both LRK and LL, but LRK was more effective against lipid oxidation. The results show the potential for using LRK and LL extracts in the meat industry to prolong shelf life.

In vitro and in vivo antioxidant activity of the ethanolic extract from Meconopsis quintuplinervia

AIMS OF THE STUDY Meconopsis quintuplinervia, a medicinal herb endemic to the Tibetan region, is used to treat hepatitis. The aim of this study is to evaluate the antioxidant potential of the ethanolic extract of this herb using different assays. MATERIALS AND METHODS The antioxidant capacity of Meconopsis quintuplinervia was investigated using various established in vitro systems. An in vivo study of carbon tetrachloride (CCl(4))-induced antioxidant activity in mice was also conducted by examining the levels of malondialdehyde (MDA) and the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). RESULTS The extract showed strong in vitro antioxidant ability. In the in vivo study, CCl(4)-induced oxidative stress caused significant decreases in the SOD, CAT, and GSH levels and a significant increase in the MDA level, most of which were significantly reversed (except for SOD in the liver.) by treatment with the extract and standard Vitamin E. CONCLUSION This study clearly indicates that the ethanolic extract of Meconopsis quintuplinervia is a valuable source of natural antioxidants. These findings provide scientific support for the traditional use of this herb as a Tibetan medicine for liver diseases.

Extracts of Halenia elliptica exhibit antioxidant properties in vitro and in vivo.

The antioxidant properties of different extracts of Halenia elliptica was investigated by employing various established in vitro systems. The results showed that various extracts possessed strong antioxidant activity in vitro, and the 70% methanol extract (ME) had the strongest antioxidant activity. Based on our in vitro results, ME was used for investigating the antioxidant properties of H. ellipticain vivo. The liver and kidney of CCl(4)-intoxicated animals exhibited a significant decrease in superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels. Additionally, these organs exhibited a significant increase in the level of malondialdehyde (MDA). These changes were significantly reversed, in a dose-dependent manner, after treatment with ME and the standard treatment Vitamin E. Thus, it may be concluded that the ME possesses potent antioxidant properties, and might be valuable natural source of antioxidants that could be applicable to both the medical and food industries.

Hepatoprotective and antioxidant effects of the methanolic extract from Halenia elliptica.

AIMS OF STUDY Halenia elliptica, a medicinal herb of Tibetan origin, was commonly used in folk medicine to treat hepatitis. The aim of the present study is to evaluate the hepatoprotective and antioxidant activity of Halenia elliptica against experimentally induced liver injury. MATERIALS AND METHODS The antioxidant property of methanolic extract (ME) of Halenia elliptica was investigated by employing various established in vitro systems. The ME of Halenia elliptica was studied here for its hepatoprotective effects against CCl(4)-induced liver toxicity in rats. Activity was measured by monitoring the levels of alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and total bilirubin. RESULTS The ME possessed strong antioxidant activity in vitro. The results of CCl(4)-induced liver toxicity experiment showed that rats treated with the ME of Halenia elliptica (100 mg/kg and 200 mg/kg), and also the standard treatment, silymarin (50 mg/kg), showed a significant decrease in ALT, AST, ALP, and total bilirubin levels, which were all elevated in the CCl(4) group (p<0.01). The results observed after administration of 100 mg/kg ME were comparable to those of silymarin at 50 mg/kg (p>0.05). The ME did not show any mortality at doses up to 2000 g/kg body weight. CONCLUSION These results seem to support the traditional use of Halenia elliptica in pathologies involving hepatotoxicity, and the possible mechanism of this activity may be due to strong free radical-scavenging and antioxidant activities of ME.

Comparative Analysis of Essential Oil Components and Antioxidant Activity of Extracts of Nelumbo nucifera from Various Areas of China

This study was designed to examine the composition of extracts and essential oil components from Nelumbo nucifera leaves from the principal habitats in China. The amounts of phenolics, flavonoids, and proanthocyanidins in the lotus leaf extracts varied widely, ranging from 354 to 487 mg/g gallic acid equivalents, from 172 to 236 mg/g rutin equivalents, and from 124 to 179 mg/g catechin equivalents, respectively. All of the extracts had strong antioxidant activity in comparison to the standard compounds butylated hydroxytoluene and vitamin C. Wild lotus samples from Baiyangdian Lake and Weishan Lake exhibited a stronger free radical scavenging effect and greater reducing power than the cultural samples, but no such differences were observed in the inhibition of lipid oxidation. Chemical variation in the essential oils from the various samples was analyzed by GC-MS. The main constituents were l-(+)-ascorbic acid 2,6-dihexadecanoate (0-33.5%), trans-phytol (5.1-24.1%), hexahydrofarnesyl acetone (5.6-15.3%), pentadecyl acrylate (2.2-12.4%), geranyl acetone (1.9-8.0%), and beta-ionone (0-8.0%). The rhizome lotus and seed lotus samples were clustered into separate groups by hierarchical cluster analysis according to the composition of the corresponding essential oils. No significant relationship was found between essential oil composition and geographical distribution of the 11 populations. However, the results indicated that region of origin and growing conditions could significantly affect both the bioactivities of the lotus leaf and the content of bioactive compounds in the leaves. Thus, the existence of chemical polymorphism in the N. nucifera leaf in China was demonstrated.

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.

In Vitro and In Vivo Activities of Essential Oil from the Seed of Anethum graveolens L. against Candida spp.

The essential oil produced from the seed of Anethum graveolens L. (Umbelliferae) was tested in vitro and in vivo anti-Candida activity. The microbroth dilution method was used in the minimal inhibitory concentration (MIC), according to M27-A3 of the guidelines of the Clinical and Laboratory Standard Institute (CLSI). And then, efficacy evaluation of essential oil in the prophylaxis and treatment of experimental vaginal candidiasis was performed in immunosuppressed mice. The anti-Candida activity was analyzed by microbiological and histological techniques and was compared with that of fluconazole (FCZ). The results showed essential oil was active in vitro against all tested strains, with MICs ranging from 0.312 μL/mL (for C. tropicalis, C. parapsilosis, and C. krusei) to 0.625 μL/mL (for 6 isolated C. albicans strains). Essential oil (2% v/v) was highly efficacious in accelerating C. albicans 09-1555 clearance from experimentally infected mice vagina by prophylaxis and therapeutic treatments. In both therapeutic efficacy and prophylaxis studies, the histological findings confirmed the microbiological results. The experimental results revealed that the tested essential oil is effective against vulvovaginal candidiasis in immunosuppressed mice.

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.