Milk thistle seed extract protects rat C6 astroglial cells from acute cocaine toxicity.

Cocaine is a powerful addictive drug, widely abused in most Western countries. It easily reaches various domains within and outside of the central nervous system (CNS), and triggers varying levels of cellular toxicity. No pharmacological treatment is available to alleviate cocaine-induced toxicity in the cells without side-effects. Here, we discerned the role of milk thistle (MT) seed extract against cocaine toxicity. First, we investigated acute cytotoxicity induced by treatment with 2, 3 and 4 mM cocaine for 1 h in astroglial, liver and kidney cells in vitro, and then in living shrimp larvae in vivo. We showed that astroglial cells are more sensitive to cocaine than liver, kidney cells or larvae. Cocaine exposure disrupted the general architecture of astroglial cells, induced vacuolation, decreased cell viability, and depleted the glutathione (GSH) level. These changes may represent the underlying pathology of cocaine in the astrocytes. By contrast, MT pretreatment (200 µg/ml) for 30 min sustained the cell morphological features and increased both cell viability and the GSH level. Besides its protective effects, the MT extract was revealed to be non-toxic to astroglial cells, and displayed high free-radical scavenging activity. The results from this study suggest that enhanced GSH level underlies cell protection, and indicate that compounds that promote GSH synthesis in the cells may be beneficial against cocaine toxicity.

Regulation of rat MOR-1 gene expression after chronic intracerebroventricular administration of morphine.

The µ-opioid receptor is the primary site for the action of morphine. In the present study, we investigated the regulation of the µ-opioid receptor mRNA levels in the locus ceruleus, ventral tegmental area, nucleus accumbens and hypothalamus of the rat brain following intracerebroventricular administration of morphine for 7 days. The isolated mRNA from these regions was subjected to real-time quantitative RT-PCR to determine the regulation of µ-opioid receptor gene expression. It was observed that 7 days of treatment with morphine significantly down-regulated the µ-opioid receptor mRNA levels in the hypothalamus of the brain in comparison to the control group. However, the µ-opioid receptor levels in the locus ceruleus, ventral tegmental area and nucleus accumbens regions remained the same as the control levels. Down-regulation of µ-opioid receptor mRNA levels in the hypothalamus region of the brain indicates the probable role of opioids to influence neuroendocrine function. The results further indicate that cellular adaptation for morphine tolerance is tissue-specific. These findings help us to understand the mechanism of morphine tolerance in various regions of the brain.

Differential cytotoxicity of triphala and its phenolic constituent gallic acid on human prostate cancer LNCap and normal cells.

BACKGROUND: Prostate cancer is one of the most commonly diagnosed solid malignancies among US men. We identified gallic acid (GA) as a major bioactive cytotoxic constituent of a polyherbal Ayurvedic formulation - triphala (TPL). Both TPL and GA were evaluated on (AR)(+) LNCaP prostate cancer and normal epithelial cells. MATERIALS AND METHODS: Total polyphenols in TPL were determined using Folin and Ciocalteu method, followed by GA quantitation by high performance liquid chromatography. Cell toxicity was evaluated by crystal violet after 24, 48, 72 and 96 h. RESULTS: TPL contains 40% unidentified polyphenolic acids, of which 2.4% comprised GA. GA induced severe morphological alterations and was about 3-fold more cytotoxic towards cancer cells than TPL. This activity increased further in the presence of dihydrotestosterone. GA toxicity on normal cells was low at 72 h. Combination of GA with flutamide caused higher toxicity to cancer cells than either of the compounds alone. CONCLUSION: GA appears to have promising anticancer activity.

Anaerobic glycolysis protection against 1-methy-4-phenylpyridinium (MPP+) toxicity in C6 glioma cells.

The neurotoxin 1-methy-4-phenylpyridinium (MPP(+)) is used for its' capacity to induce Parkinsonism through its inhibitory effects on mitochondrial complex I. This inhibition disrupts cellular energy formation and aerobic glycolysis. The objective of this study was to demonstrate that the toxic effect of mitochondrial aerobic pathway inhibition with MPP(+ )can be reduced by stimulating anaerobic glycolysis using glucose supplementation. In this study, C6 Glioma cell viability was examined in the presence of different concentrations of MPP alone and with the addition of glucose. The results obtained indicate that there was a significant increase (P < 0.001) in cell viability in cells treated with glucose and MPP(+ )verses cells treated with MPP(+ )alone. Fluorometric analysis using 100 microM Rhodamine 123 indicated mitochondrial membrane potential was not restored in MPP(+ )treated cells with glucose; however, normal cell viability was confirmed using 2 microg/ml Fluorescein diacetate. This dual fluorescence indicated mitochondrial damage from MPP(+ )while glucose augmented cell survival. Further confirmation of cell survival upon damage to the mitochondria was evident in TUNEL staining. Positive staining was prominent only in MPP(+) treatment groups alone, while control and co-treated groups exhibited little to no TUNEL staining. ATP measurements of all MPP(+) treated groups exhibited a significant (P < 0.001) decrease verses control. Groups co-treated with MPP(+ )and glucose revealed a significant increase (250 microM group: P < 0.001) in ATP. It was concluded from this study that glucose supplementation was able to sustain cellular viability and ATP production through anaerobic glycolysis despite the inhibitory effect of MPP(+ )on aerobic glycolysis.