Potentiation of nerve growth factor-induced elongation of neurites by gelsemiol and 9-hydroxysemperoside aglucone in PC12D cells

Abstract

In PC12D cells, nerve growth factor (NGF) increased the proportion of neurite-bearing cells and made neurites longer. A methanol extract of Verbena littoralis H. B. K. collected in Paraguay only slightly potentiated the proportion of PC12D cells with neurites but markedly increased the length of neurites in the presence of NGF (2 ng mL(-1)). The methanol extract was partitioned between ethyl acetate and water followed by further extraction of water fraction with n-butanol. The potentiating activity of NGF-action was observed in the ethyl acetate and n-butanol fractions. The n-butanol fraction was separated by silica gel chromatography, monitoring the NGF-potentiating activity to give gelsemiol and 9-hydroxysemperoside aglucone (9-OHSA). Neither compound (30-300 microM) exhibited neurite-inducing activity alone. Gelsemiol (100-300 microM) markedly enhanced an increase in the proportion of neurite-bearing cells and an extension of the neurite length in the presence of NGF (2 ng mL(-1)). Interestingly, in the presence of NGF (2 ng mL(-1)), 9-OHSA (100-300 microM) enhanced the elongation of neurites without affecting the increase in the proportion of cells with neurites. These results suggested that gelsemiol and 9-OHSA were major active components of V. littoralis in the NGF-potentiating action. It was possible that the mechanism of neurite elongation by NGF was different from that of the increase in the proportion of neurite-bearing cells, and that 9-OHSA selectively affected the neurite elongation mechanism.

A New Iridoid Glycoside with Nerve Growth Factor-Potentiating Activity, Gelsemiol 6'-trans-Caffeoyl-1-glucoside, from Verbena littoralis

“…1) In the course of our continual investigations of bioactive substances from medicinal plants, [2][3][4] we found that the extract of V. littoralis exhibited significant activity in enhancing nerve growth factor (NGF)-mediated neurite outgrowth from PC12D cells. The EtOAc-soluble materials of the MeOH extract of the aerial parts of V. littoralis were repeatedly subjected to silica gel column and Sephadex LH-20 column chromatography, followed by reverse-phase semipreparative HPLC to yield gelsemiol 6Ј-trans-caffeoyl-1-glucoside (1), together with four known phenylethanoid glycosides, acteoside (2), 2Јacetylacteoside (3), 5) jionoside (4), 6) and isoverbascoside (5), 7) by monitoring the potentiation of NGF action in PC12D cells.…”

Prenylated Xanthones from Garcinia xanthochymus

“…6) In control experiments, the percentage of neurite-bearing cells was 9.9 and 63.1% following incubation with NGF 2 and 30 ng/ml after 48 h, respectively. Compounds 1 (1-3 mM) and 2 (1-10 mM) did not induce neurite outgrowth from PC12D cells in the absence of NGF, but as shown in Fig.…”

“…Bioassay Procedure The enhancement of NGF-mediated neurite outgrowth on PC12D cells was examined using a published method. 6) All test compound stock solutions were prepared at 100 mM in DMSO and diluted to the test concentrations (1, 3, 10, 30 mM). Neurite processes with a length equal to or greater than the diameter of the neuron cell body were scored as neurite-bearing cells.…”

“…5) As part of our search for natural products that possess nerve growth factor (NGF)-potentiating activity or neurotrophic activity from medicinal plants, [6][7][8] we found that the methanol extract of G. xanthochymus significantly enhanced NGF-mediated neurite outgrowth in PC12D cells. The extract was partitioned into EtOAc, n-BuOH, and H 2 O fractions.…”

Search for Constituents with Neurotrophic Factor-Potentiating Activity from the Medicinal Plants of Paraguay and Thailand

“…This extract was chromatographed by monitoring the potentiation of NGF's action, to give four new iridoid or iridoid glycoside compounds, lit toralisone (1), 11) gelsemiol 6 _ trans_ caeoyl1gluco side (2), 12) 7ahydroxygelsemiol (3) and 6methox ysemperoside (4), 13) together with ve known com pounds, gelsemiol (5), 7ahydroxysemperoside aglu cone (7aOHSA, 6), 14) gelsemiol 3ObDglucoside (7), 7ahydroxysemperoside (8), 15) and brasoside (9) (Fig. 1).…”