The protective effect of ethanol extract of Korean mistletoe (KM; Viscum album coloratum) on hydrogen peroxide (H2O2)-induced neurotoxicity was examined in primary cultured rat cortical neurons. H2O2 reduced viability of cortical neurons in a concentration-dependent manner. The addition of KM, over a concentration range of 10 to 100 μg/ml, concentration-dependently prevented the H2O2(100 μM)-induced neuronal cell death, as assessed by a 3-[4,5-dimethylthiazol-2-yl]-2,5-di-phenyl-tetrazolium bromide (MTT) assay and Hoechst 33342 staining. KM significantly inhibited H2O2-induced elevation of the cytosolic Ca2+ concentration ([Ca2+]c), which was measured by a fluorescent dye, fluo-4 AM. KM inhibited glutamate release into medium and generation of reactive oxygen species (ROS) induced by H2O2. These results suggest that KM may mitigate the H2O2-induced neurotoxiciy by interfering with the increase of [Ca2+]c, and inhibiting glutamate release and generation of ROS in cultured neurons.

Three known triterpenoids were isolated from MeOH extract of C. apiifolia (Ranunculaceae). Their structures were identified as oleanolic acid (1), ursolic acid (2), hederagenic acid (3) by comparison of their physicochemical and spectral data with the literature values. Among them, 2 was isolated for the first time from this plant. The isolated compounds were evaluated for their cytotoxicity against L1210, HL-60, SK-OV-3 tumor cell lines. All compounds 1-3 were shown good activities with IC50 values ranging from 7.7 to 25.6 μg/ml. This result suggests that triterpenoids 1-3 are main cytotoxic principles of this plant.

Phytochemical study on the EtOAc fraction from the MeOH extract of the leaves of Cedrela sinensis led to the isolation of five known phenolic compounds (1-5), whose structures were identified as (+)-catechin (1), kaempferol-3-0-α- L-rhamnopyranoside (2), quercetin (3), quercetin-3-O-α-L-rhamnopyranoside (4), and quercetin-3-O-β-D-glucopyranoside (5), respectively, by comparing their spectral (uv, JR, IH and 13C-NMR, and ESI-MS) and physicochemical data with those reported in the literature. Among the isolated compounds (1-5), compounds 1 and 3-5 exhibited significant DPPH radical scavenging effects with IC50 values ranging from 21.3±1.4 to 38.1±3.2 μM as well as superoxide anion radical scavenging effects with IC50 values ranging from 9.4±0.7 to 21.2±3.6 μM. Furthermore, compounds 1 and 3-5 also exhibited considerable inhibitory effects on LDL peroxidation induced by either CU2+ or AAPH with IC50 values ranging from 1.4±0.4 to 11.9±1.4 μM. These results indicated that flavonoids are the major constituents of C. sinensis and considered to be antioxidant principles of this plant.

As a result of cytotoxic compounds against cancer cell lines from natural sources, senven compounds were isolated from the leaf and twig of Acer okamotoanum Nakai. The compounds (1-7) were identified as ethyl gallate (1), methyl gallate (2), gallic acid (3), trans resveratrol-3-O-β-D-glucopyranoside (4), acertannin (5), nikoenoside (6), and fraxin (7) by physicochemical and spectroscopic data (including mp, UV, IR, MS, 1H-NMR, 13C-NMR, DEPT, and HMBC) in comparison with those of published papers. All the compounds were tested for their cytotoxic activity against L1210, HL-60, K562, and B16F10 cancer cell lines in vitro by MTT assay method. Compounds 1-3 and 5 showed cytotoxic activity against all tested cell lines with IC50 values ranged from 12.5 to 72.2 μM. Of the compounds, methyl gallate (2) exhibited the most potent cytotoxic activity against L1210, HL-60, K562, and B16F10 tumor cells with IC50 values of 12.5, 48.3, 22.8, and 22.8 μM, respectively. Other compounds did not show any cytotoxic activity against four cancer cell lines.

Paeoniae radix has been widely used for its anti-allergic, anti-inflammatory and analgesic effects, and demonstrated to have anticonvulsant, memory enhancing and anxiolytic activities. The present study was performed to examine the protective effect of methanol extract of Paeoniae radix (PR) from Paeoniae Japonica Miyabe et Takeda (Paeoniaceae) on hydrogen peroxide (H2O2)-induced neurotoxicity using cultured rat cerebral cortical neuron. H2O2 produced a concentration-dependent reduction of neuronal viability, PR, over a concentration range of 10 to 100 μg/ml showed concentration-dependent decrease of the H2O2(100 μM)-induced neuronal cell death, as assessed by a 3-[4,5-dimethylthiazol-2-yl]-2,5-di-phenyl-tetrazolium bromide assay and the number of apoptotic nuclei, evidenced by Hoechst 33342 staining. PR (100 μg/ml inhibited 100 μM H2O2-induced elevation of the cytosolic Ca2+ concentration ([Ca2+]c), which was measured by a fluorescent dye, flue-4 AM. PR (50 μg/ml inhibited glutamate release into medium induced by 100 μM H2O2, which was measured by HPLC, and generation of reactive oxygen species (ROS). These results suggest that PR may mitigate the H2O2-induced neurotoxiciy by interfering with the increase of [Ca2+]c, and then inhibiting glutamate release and generation of ROS in cultured neurons.

Sanguisorbae radix (SR) from Sanguisorba officinalis L. (Losaceae) is widely used in Korea and China due to its various pharmacological activity. The present study aims to investigate the effect of the methanol extract of SR on amyloid β Protein(25-35) (Aβ (25-35)), a synthetic 25-35 amyloid peptide, -induced neurotoxicity using cultured rat cortical neurons. SR, over a concentration range of 10-50 μg/ml, inhibited the Aβ (25-35) (10 μM)-induced neuronal cell death, as assessed by a 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and the number of apoptotic nuclei, evidenced by Hoechst 33342 staining. Pretreatment of SR (50 μg/ml) inhibited 10 μM Aβ (25-35)-induced elevation of cytosolic calcium concentration ([Ca2+]c), which was measured by a fluorescent dye, fluo-4 AM. SR (10 and 50 μg/ml) inhibited glutamate release into medium induced by 10 μM Aβ(25-35), which was measured by HPLC, and generation of reactive oxygen species. These results suggest that SR prevents Aβ (25-35)-induced neuronal cell damage in vitro.

Caulis Bambusae in Taenia is widely used in Korea and China due to its various pharmacological activity. The present study aims to investigate the effect of the methanol extract of Caulis Bambusae in Taenia (CB) from Phyllostachys nigra Munro var. henonis Stapf (Gramineae) on amyloid β protein (25-35) (Aβ (25-35)), a synthetic 25-35 amyloid peptide, -induced neurotoxicity using cultured rat cortical neurons. CB, over a concentration range of 10-50μg/μl, inhibited the Aβ (25-35) (10 μM)-induced neuronal cell death, as assessed by a 3-[4,5-dimethyIthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and the number of apoptotic nuclei, evidenced by Hoechst 33342 staining. CB (50 μg/μl) inhibited glutamate release into medium induced by 10 μM Aβ, (25-35) which was measured by HPLC. Pretreatment of CB (50 μg/μl) inhibited 10μM Aβ (25-35)-induced elevation of cytosolic calcium concentration ([Ca2+]c), which was measured by a fluorescent dye, fluo-4 AM, and generation of reactive oxygen species. These results suggest that CB prevents Aβ (25-35)-induced neuronal ell damage in vitro.

Myristica fragrans seed from Myristica fragrans Houtt (Myristicaceae) has various pharmacological activities peripherally and centrally. The present study aims to investigate the effect of the methanol extract of Myristica fragrans seed (MF) on kainic acid (KA)-induced neurotoxicity in primary cultured rat cerebellar granule neuron. MF, over a concentration range of 0.05 to 5 μg/ml inhibited KA (500 μM)-induced neuronal cell death, which was measured by trypan blue exclusion test and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. MF (0.5 mug/ml) inhibited glutamate release into medium induced by KA (500 μM), which was measured by HPLC. Pretreatment of MF (0.5 mug/ml) inhibited KA (500 μM)-induced elevation of cytosolic calcium concentration ([Ca2+]c), which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). These results suggest that MF prevents KA-induced neuronal cell damage in vitro.

Polygalae Radix (PR) from Polygala tenuifolia. (Polygalaceae) is traditionally used in China and Korea, since this herb has a sedative, antiinflammatory, and antibacterial agent. To extend pharmacological actions of PR in the CNS on the basis of its CNS inhibitory effect, the present study examined whether PR has the neuroprotective action against kainic acid (KA) -induced cell death in primarily cultured rat cerebellar granule neurons. PR, over a concentration range of 0.05 to 5μg/ml inhibited KA (500 μM)-induced neuronal cell death, which was measured by a trypan blue exclusion test and a 3-[4,5-dimethylthiazol-2-y1]-2,5-diphenyl-tetrazolium bromide (MTT) assay. PR (0.5μg/ml) inhibited glutamate release into medium induced by KA (500 μM), which was measured by HPLC. Pretreatment of PR (0.5μg/ml) inhibited KA (500 μM)-induced elevation of cytosolic calcium concentration ([Ca2+]c) which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). These results suggest that PR prevents KA-induced neuronal cell damage in vitro.