Anti-neuroinflammatory and neuroprotective effects of the Lindera neesiana fruit in vitro.
BACKGROUND
Lindera neesiana Kurz (Lauraceae), popularly known as Siltimur in Nepal, is an aromatic and spicy plant with edible fruits. It is a traditional herbal medicine widely used for the treatment of diarrhea, tooth pain, headache, and gastric disorders and is also used as a stimulant.


OBJECTIVE
The aim of the present study was to examine in vitro cytoprotective, anti-neuroinflammatory and neuroprotective potential of an aqueous extract of L. neesiana (LNE) fruit using different central nervous system (CNS) cell lines.


METHODS
In order to study the neuroprotective potential of LNE, we used three different types of CNS cell lines: murine microglia (BV2), rat glioma (C6), and mouse neuroblastoma (N2a). Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reagent, and prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and nerve growth factor (NGF) release in the culture media was determined using enzyme linked immunosorbent assay (ELISA) kits. Western blot analysis was performed to determine the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2), mitogen activated protein kinase (MAPK) family proteins, Bax, B cell lymphoma (BCL)-2, and cleaved caspase 3. Neurite outgrowth was determined using the IncuCyte imaging system.


RESULTS
LNE treatment not only reduced nitric oxide (NO) production in a dose-dependent manner, but also significantly reduced proinflammatory cytokines, iNOS and COX-2 production by lipopolysaccharide (LPS) stimulated BV-2 cells. LNE increased the expression of phosphorylated (p)-extracellular signal-regulated kinase (ERK), whereas p-p38 and p- janus kinase (JNK) expression was significantly decreased in activated microglia. Furthermore, LNE increased cell viability of N2a cells, which was accompanied by decreased caspase-3 expression and the ratio of Bax/Bcl2 protein expression as well as increased NGF and neurite outgrowth, suggesting its neuroprotective potential against LPS-induced effects. Additionally, LNE substantially increased nuclear factor erythroid 2-related factor 2 (Nrf2) secretion in N2a cells and inhibited lipid dehydrogenase (LDH) release in H2O2-stimulated BV2 cells demonstrating the strong anti-inflammatory and antioxidant effects of LNE in CNS cell lines.


CONCLUSIONS
Here we found that water the soluble extract of LNE has promising anti-neuroinflammation and anti-apoptotic properties and identify LNE as a potential natural candidate for neuroprotection.
Laboratoy of Pharmacognosy, College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon, 406-799, Republic of Korea.
Lalita
L
Subedi
Laboratory of Neuropharmacology, College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon, 406-799, Republic of Korea.
Bhakta Prasad
BP
Gaire
Laboratoy of Pharmacognosy, College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon, 406-799, Republic of Korea.
Moon Ho
MH
Do
College of Pharmacy, Yonsei University, #162-1 Songdo-dong, Yeonsu-gu, Incheon 406-840, Republic of Korea.
Taek Hwan
TH
Lee
Laboratoy of Pharmacognosy, College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon, 406-799, Republic of Korea. Electronic address: sunnykim@gachon.ac.kr.
Sun Yeou
SY
Kim
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D016207:Cytokines / Q000037:antagonists & inhibitors; D004305:Dose-Response Relationship, Drug; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D027443:Lindera / Q000737:chemistry*; D051379:Mice; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology
D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D052246:Cyclooxygenase 2 Inhibitors; D016207:Cytokines; D018696:Neuroprotective Agents; D010936:Plant Extracts; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II
Anti-apoptosis; Anti-oxidant; Lindera neesiana; Neuroinflammation; Neuroprotection