Quality control mechanism of mitochondria by 3,4-dihydroxybenzaldehyde through OGT-PINK1 pathway / 中国中药杂志

Based on the O-GlcNAc transferase(OGT)-PTEN-induced putative kinase 1(PINK1) pathway, the mechanism of 3,4-dihydroxybenzaldehyde(DBD) on mitochondrial quality control was investigated. Middle cerebral artery occlusion/reperfusion(MCAO/R) rats were established. SD rats were randomized into sham operation group(sham), model group(MCAO/R), DBD-L group(5 mg·kg~(-1)), and DBD-H group(10 mg·kg~(-1)). After 7 days of administration(ig), MCAO/R was induced in rats except the sham group with the suture method. Twenty-four h after reperfusion, the neurological function and the percentage of cerebral infarct area were measured. Based on hematoxylin and eosin(HE) staining and Nissl staining, the pathological damage of cerebral neurons was examined. Then the ultrastructure of mitochondria was observed under the electron microscope, and the co-localization of light chain-3(LC3), sequestosome-1(SQSTM1/P62), and Beclin1 was further detected by immunofluorescence staining. It has been reported that the quality of mitochondria can be ensured by inducing mitochondrial autophagy through the OGT-PINK1 pathway. Therefore, Western blot was employed to detect the expression of OGT, mitophagy-related proteins PINK1 and E3 ubiquitin ligase(Parkin), and mitochondrial kinetic proteins dynamin-like protein 1(Drp1) and optic atrophy 1(Opa1). The results showed that MCAO/R group had neurological dysfunction, large cerebral infarct area(P<0.01), damaged morphological structure of neurons, decreased number of Nissl bodies, mitochondrial swelling, disappearance of mitochondrial cristae, decrease of cells with LC3 and Beclin1, rise of cells with P62(P<0.01), inhibited expression of OGT, PINK1, and Parkin, up-regulated expression of Drp1, and down-regulated expression of Opa1 compared with the sham group(P<0.01). However, DBD improved the behavioral deficits and mitochondrial health of MCAO/R rats, as manifested by the improved morphology and structure of neurons and mitochondria and the increased Nissl bodies. Moreover, DBD increased cells with LC3 and Beclin1 and decreased cells with P62(P<0.01). In addition, DBD promoted the expression of OGT, PINK1, Parkin, and Opa1 and inhibited the expression of Drp1, enhancing mitophagy(P<0.05, P<0.01). In conclusion, DBD can trigger PINK1/Parkin-mediated brain mitophagy through the OGT-PINK1 pathway, which plays a positive role in maintaining the health of the mitochondrial network. This may be a mitochondrial therapeutic mechanism to promote nerve cell survival and improve cerebral ischemia/reperfusion injury.

Mechanism of Gastrodia elata active ingredient reducing oxygen-glucose deprivation/reoxygenation injury in rat neuron / 中国药房

OBJECTIVE To study the improvement effect and mechanism of Gastrodia elata active ingredient 3，4- dihydroxybenzaldehyde （3，4-DD） on oxygen-glucose deprivation/reoxygenation（OGD/R） injury in rat primary brain microvascular endothelial cells （BMECs）-rat adrenal chromaffin cells PC12 co-culture system. METHODS The co-culture model of BMECs and PC12 cells was replicated in the Transwell chamber， and divided into control group， model group， butylphthalide group （positive control group， 0.1 mmol/L） and 3，4-DD group （0.1 μmol/L）. OGD/R injury model of the co-culture system was induced in those groups except for the control group. After preventively intervention in BMECs with relevant medicine or culture medium for 24 h， cell transendothelial electronic resistance （TEER） value， lactate dehydrogenase （LDH） activity， brain-derived neurotrophic factor （BDNF） level and mRNA expressions of TrkB， Plc-γ， Map-2， GAP-43 in PC12 cells was detected. RESULTS Compared with the control group， TEER of the co-culture model， LDH activity and BDNF level of PC12 cells were decreased significantly in the model group （P＜0.01）， while mRNA expressions of TrkB， Plc-γ， Map-2 and GAP-43 in PC12 cells were increased significantly （P＜0.01）. Compared with the model group， TEER of the co-culture model， LDH activity， BDNF level， and the mRNA expressions of TrkB， Plc-γ， Map-2 and GAP-43 in PC12 cells were increased significantly in the 3，4-DD group and butylphthalide group （P＜0.05 or P＜0.01）. CONCLUSIONS 3，4-DD can relieve the damage of neuronal OGD/R by acting on BMECs， the mechanism of which may be associated with activating the BDNF/TrkB signaling pathway.

Chemical constituents from Coreopsis lanceolata and their bioactivities / 中草药

Objective: To study the chemical constituents in the whole herb of Coreopsis lanceolata and to investigate the antibacterial activity. Methods: The compounds in the whole herb of C. lanceolata were isolated and purified by column chromatography and identified based on spectral analyses (MS, NMR). The antibacterial activities of compounds 1-8 were screened. Results: Fifteen compounds including eight sesquiterpenes were isolated from the chloroform fraction in the whole herb of C. lanceolata and were identified as 1β, 5α-diangeloyloxy-eudesm-(15)-ene (1), 1β, 6α-dihydroxyeudesm-4(15)-ene (2), 10α-hydroxyoplopan-4-one (3), (7R*)-opposit-4(15)-ene-1β, 7-diol (4), (7R*)-opposit-4(15)-ene-1β, 8-diol (5), (7R*)-opposit-4(15)-ene-1β, 11-diol (6), (7R*)-opposit-4(15)-ene-1β, 7α-diol (7), 4(15)-eudesmene-1β, 7α-diol (8), p-hydroxy cinamic acid (9), 3-methoxy4-hydroxy-benzoic acid (10), methyl-p-hydroxybenzoate (11), 3, 4-dihydroxy-benzaldehyde (12), β-sitosterol (13), friedeline (14), and friedelinol (15). Conclusion: Compounds 1-15 are obtained from the whole herb of C. lanceolata for the first time. The bioassays show that the compounds 3 and 4 have the stronger inhibition against Staphylococcus aureus.

Steroidal saponins and phenylic constituents from Lilium lancifolium and their anti-oxidant activities / 中草药

Objective: To study the steroidal saponins and phenylic constituents in the bulbs of Lilium lancifolium and their anti-oxidant activities in vitro. Methods: The constituents were isolated and purified by chromatographic technique and recrystallization, and their structures were identified by spectral methods together with physiochemical analyses. The anti-oxidant effects of these constituents on DPPH and ABTS were screened in vitro. Results: Eleven constituents were isolated including seven first-found ones (1-5, 9, and 10) and four known compounds in this plant. They were cis-1-O-p-coumaroylglycerol (1), trans-1-O-p-coumaroylglycerol (2), caffeoyl glyceride (3), 3,4- dihydroxybenzaldehyde (4), salicylic acid (5), (25R,26R)-26-methoxyspirostan-5- ene-3β-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl- (1→6)]-β-D-glucopyranoside (6), (25R,26R)-3β, 17α-dihydroxy-26-methoxyspirostan-5-ene-3β-0-a-Z.-rhamnopyranosyl-(l- >2)-[β-D-glucopyranosyl-(l-"6)]-β-D-glucopyranoside (7), diosgenin 3-O-{O-α-L-rhamnopyranosyl-(1→2)-O-[β-D-xylopyranosyl- (1→3)]-β-D-glucopyranoside} (8), (25R)-3β,17α-dihydroxy- 5α-spirostan-6-one-3-O-α-L-rhamnopyranosyl-(1→2) -β-D-glucopyranoside (9), (25R)-3β-hydroxy-5α-spirostan-6-one-3- O-α-L-rhamnopyranosyl-0 (1→2)-β-D-glucopyranoside (10), and (25R)-spirost-5-ene-3β-O-α-L-rhamnopyranosyl-(1→2) -[β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside (11). Compounds 1-5 showed the favorable scavenging effects on DPPH and ABTS. Conclusion: The study suggests that the phenylic constituents from the bulbs of L. lancifolium have the anti-oxidant effects.