Allocation of trisoxazole macrolides in the sponge Penares cf. nux and the impact on epiphytic bacterial cohabitants.

The correlation between the allocation of trisoxazole macrolides in the capitums, appendages, and bases of the sponge Penares cf. nux and the surface-attached bacteria on the corresponding parts was examined. The kabiramide contents were highest in the capitums, followed by the appendages and bases. Conversely, direct counts of cultivable surface-attached bacteria showed that the bacteria aggregate more densely on the surfaces of the bases. This suggested the repelling effects of the kabiramides against the fouling bacteria, particularly on the capitums and appendages. Twenty-two bacterial strains were isolated and identified to 15 species; however, none has shown the potentials as a producer of any secondary metabolites in the sponge P. nux.

Cordycepin protects PC12 cells against 6-hydroxydopamine induced neurotoxicity via its antioxidant properties.

Parkinson's disease (PD) is a progressive neurodegenerative disorder that is characterized by degeneration and loss of dopaminergic neurons of the substantia nigra. Increasing evidence has indicated that oxidative stress plays a pivotal role in the pathogenesis of Parkinson's disease (PD). Therapeutic options that target the antioxidant machinery may have potential in the treatment of PD. Cordycepin, a nucleoside isolated from Cordyceps species displayed potent antioxidant, anti-inflammatory and anticancer properties. However, its neuroprotective effect against 6-OHDA neurotoxicity as well as underlying mechanisms is still unclear. In this present study, we investigated the protective effect of cordycepin against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity and its underlying mechanism. We observed that cordycepin effectively inhibited 6-OHDA-induced cell death, apoptosis and mitochondrial dysfunction. Cordycepin also inhibited cell apoptosis induced by 6-OHDA as observed in the reduction of cytochrome c release from the mitochondrial as well as the inhibition of caspase-3. In addition cordycepin markedly reduced cellular malondialdehyde (MDA) content and intracellular reactive oxygen species (ROS) level. Cordycepin also significantly increased the antioxidant enzymes; superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in 6-OHDA-treated cells. The results obtained unambiguously demonstrated that cordycepin protects PC12 cells against 6-OHDA-induced neurotoxicity through its potent antioxidant activity.

Polysaccharides purified from Cordyceps cicadae protects PC12 cells against glutamate-induced oxidative damage.

Two polysaccharides CPA-1 and CPB-2 were isolated purified from Cordyceps cicadae by hot water extraction, ethanol precipitation and purification using anion exchange and gel filtration chromatography. Preliminary structural characterization of CPA-1 and CPB-2 were performed. The protective effect of CPA-1 and CPB-2 against glutamate-induced oxidative toxicity in PC12 cells was analyzed. The results indicated that pretreatment of PC12 cells with CPA-1 and CPB-2 significantly increased cell survival, Ca(2+) overload and ROS generation. CPA-1 and CPB-2 also markedly up-regulated the antioxidant status of pretreated PC12 cells. Our results suggested that Cordyceps cicadae polysaccharides can protect PC12 cells against glutamate excitotoxicity and might serve as therapeutic agents for neuronal disorders.

Neuroprotective effects of adenosine isolated from Cordyceps cicadae against oxidative and ER stress damages induced by glutamate in PC12 cells.

Glutamate has been proven to induce oxidative stress through the formation of reactive oxygen species (ROS) and increased calcium overload which results in neuronal injury, development of neurodegenerative diseases and death. Adenosine is one of the bioactive nucleosides found in Cordyceps cicadae and it has displayed several pharmacological activities including neuroprotection. In this study, the protective effects of adenosine from C. cicadae against glutamate-induce oxidative stress in PC12 cells were evaluated. The exposure of PC12 cells to glutamate (5mM) induced the formation of ROS, increased Ca(2+) influx, endoplasmic reticulum (ER) stress and up regulated the expression of pro-apoptotic factor Bax. However, pretreatment with adenosine markedly increased cell viability, decreased the elevated levels of ROS and Ca(2+) induced by glutamate. Furthermore adenosine increased the activities of GSH-Px and SOD, as well as retained mitochondria membrane potential (MMP), increased Bcl-2/Bax ratio, and reduced the expression of ERK, p38, and JNK. Overall, our results suggest that adenosine may be a promising potential therapeutic agent for the prevention and treatment of neurodegenerative disorders.