Natural product; delta 5 desaturase

Sesamin pretreatment effectively reduced the excess nitric oxide production in rat primary microglia cells activated with lipopolysaccharide[1].

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Attenuation of NO production by Sesamin and sesamolin in LPS-stimulated microglia cells [1]
Microglia cells have been demonstrated to be the major source of inflammatory factors that mediated LPS-induced neurotoxicity in neuron-glia cultures. Therefore, rat primary microglia cells pretreated with Sesamin or sesamolin were subjected to LPS treatment, and the induced NO release was detected to evaluate whether sesamin and sesamolin could confer neuroprotective effects. The results show that excess generation of NO in the LPS-stimulated microglia cells was inhibited by pretreatment of sesamin or sesamolin in a dose-dependent manner (Fig. 1). For a significant attenuation of NO production in LPS-stimulated microglia cells, sesamolin seemed to be more potent than sesamin.

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Incubation with sesame oil increases the mycelial dihomo-gamma-linolenic acid content of an arachidonic acid-producing fungus, Mortierella alpina, but decreases its arachidonic acid content [Shimizu, S., K. Akimoto, H. Kawashima, Y. Shinmen and H. Yamada (1989) J. Am. Oil Chem. Soc. 66, 237-241]. The factor causing these effects was isolated and identified to be (+)-Sesamin. The results obtained in experiments with both a cell-free extract of the fungus and with rat liver microsomes demonstrated that (+)-Sesamin specifically inhibits delta 5 desaturase at low concentrations, but does not inhibit delta 6, delta 9 and delta 12 desaturases. Kinetic analysis showed that (+)-sesamin is a noncompetitive inhibitor (Ki for rat liver delta 5 desaturase, 155 microM). (+)-Sesamin, (+)-sesaminol and (+)-episesamin also inhibited only delta 5 desaturases of the fungus and liver. These results demonstrate that (+)-sesamin and related lignan compounds present in sesame seeds or its oil are specific inhibitors of delta 5 desaturase in polyunsaturated fatty acid biosynthesis in both microorganisms and animals [2].

Sesamin (op; 20 mg/kg/day) considerably lowers the infarct size by roughly 50% in male gerbils (60-85 g)[1]. The neuroprotective effect of Sesamin and sesamolin was also observed in vivo using gerbils subjected to a focal cerebral ischemia induced by occlusion of the right common carotid artery and the right middle cerebral artery. Repeated treatment of sesamin or a crude sesame oil extract containing both sesamin and sesamolin significantly reduced the infarct size, visualized via 2,3,5-triphenyltetrazolium chloride staining, by approximately 50% when compared with the control group. These results suggest that sesamin and sesamolin exert effective neuroprotection against cerbral ischemia.

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Neuroprotective effects of Sesamin and sesamolin on gerbils in cerebral ischemia The observation of the neuroprotective effect of Sesamin and sesamolin in the LPS-stimulated microglia cells provoked an inquiry if these sesame lignans could act as anti-ischemic agents in vivo. To examine this possibility, gerbils were repeatedly administered with sesamin or a crude sesame oil extract containing both sesamin and sesamolin prior to a focal cerebral ischemia. All the treated animals were found to have infarction in the cortex and caudate-putamen. Mean total infarct sizes, visualized by TTC staining (Fig. 2), in the three groups (control, purified sesamin, and crude sesame oil extract) were 91.9 mm3 (19.4 ± 2.0%), 46.5 mm3 (9.8 ± 3.1%), and 40.2 mm3 (8.5 ± 3.9%), respectively (Fig. 3). These results indicate that pretreatment with sesamin or the crude sesame oil extract for four days significantly reduced infarct sizes of gerbil brains in cerebral ischemia by 56% and 49%, respectively (p<0.05).

Detection of NO production [1]
NO production was assayed by measuring the level of nitrite, the stable NO metabolite, in the conditioned medium. Briefly, 100 L of culture supernatant was reacted with an equal volume of Griess reagent (1 part of 0.1% naphthylethylenediamine and 1 part of 1% sulfanilamide in 5% H3PO4) in 96-well tissue culture plates for 10 min at room temperature in the dark. The absorbance at 540 nm was recorded by a microplate reader.

LPS stimulation of microglia cells pretreated with Sesamin or sesamolin [1]
To evaluate if pretreatment of Sesamin and sesamolin possessed potential neuroprotective activity, a preliminary test was performed to detect their inhibitory capabilities on NO level of rat microglia cells stimulated by LPS. In this test, cells were incubated with Sesamin or sesamolin, dissolved in dimethyl sulfoxide (DMSO) with the final concentration of this solvent added to the cell cultures never exceeding 0.1%, for 1 h prior to the supplement of LPS.

Cerebral ischemia of gerbils [1]
Eighteen male gerbils (60-85 g) were randomly divided into three groups fed by regular meal supplemented (op., 20 mg/kg/day), respectively, with saline (control), purified Sesamin, and the crude sesame oil extract containing 90% Sesamin and 10% sesamolin. After feeding for 4 days, each gerbil was anesthetized with chlorohydrate (400 mg/kg) intraperitoneally and its body temperature was maintained at 37°C with a heating pad (CMA/150). A midline neck incision was made and the right carotid artery was exposed and separated from the vago-sympathetic trunk. The right carotid artery was loosely encircled with a 4-0 suture for later occlusion. The gerbil’s head was placed in a stereotaxic frame with the nose bar positioned 4.0 mm below the horizontal line. Following a midline incision, the skull was partially removed to expose the right middle cerebral artery. The middle cerebral artery was loosely encircled with an 8-0 suture for later occlusion. A focal cerebral ischemia was induced by occlusion of the right common carotid artery (CCA) and the right middle cerebral artery (MCA) for 60 min, followed by reperfusion for 3 h. MBF 3D, a laser probe (0.8 mm in diameter) of a Laser Doppler Blood Flow monitor was positioned onto the cortex with its tip close to the middle cerebral artery. Cerebral blood flow dropped to less than 5% of basal after the occlusion of the MCA. Cerebral blood flow reached its minimal level within 5 min after the start of the occlusion and was confirmed to remain at this level throughout the monitoring period to ensure the validity of the stroke model.

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LD50: Mice 3800mg/kg (i.g.); Rats 6150mg/kg (i.g.)

Mice and rats

[1]. Neuroprotective effects of sesamin and sesamolin on gerbil brain in cerebral ischemia. Int J Biomed Sci. 2006 Sep;2(3):284-8.

[2]. Sesamin is a potent and specific inhibitor of delta 5 desaturase in polyunsaturated fatty acidbiosynthesis. Lipids. 1991 Jul;26(7):512-6.

(+)-Sesamin is a lignan composed of tetrahydro-1H,3H-furano[3,4-c]furan, with the 1 and 4 positions substituted by 1,3-benzodioxane groups (1S,3aR,4S,6aR stereoisomers). It was isolated from the camphor tree (Cinnamomum camphora) and exhibits cytotoxic activity. It can be used as an antitumor agent, neuroprotective agent, and plant metabolite. It is a lignan belonging to the benzodioxane and furan-furan classes. Sesamin has been reported in Otanthus maritimus, honeybees (Apis), and other organisms with relevant data. See also: Sesame oil (partial). Sesamin and sesamol are abundant lignans in sesame oil and have been shown to possess various beneficial biological activities for human health. Pretreatment with sesamin or sesamol significantly reduced the overproduction of nitric oxide in primary rat microglia stimulated by lipopolysaccharide. Neuroprotective effects of sesamin and sesamol were also observed in a gerbil model by induced focal cerebral ischemia by blocking the right common carotid artery and the right middle cerebral artery. Compared with the control group, repeated administration of sesamin or crude sesame oil extract containing sesamin and sesamol significantly reduced the infarct area (as shown by 2,3,5-triphenyltetrazolium chloride staining) by approximately 50%. These results indicate that sesamin and sesamol have effective neuroprotective effects against cerebral ischemia. [1]

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This study shows that pretreatment with sesamin or crude sesame oil extract containing sesamin and sesamol for four consecutive days significantly reduced the infarct area by approximately 50%. Although the neuroprotective mechanism is not yet clear, the combined results of in vitro and in vivo experiments suggest that the reduction in neuronal damage may be related to the production of sufficient free radicals in the brain during cerebral ischemia, thereby inhibiting the induced release of nitric oxide (NO), as the production of these free radicals is sufficient to overcome endogenous antioxidant defense mechanisms. In addition, some studies have suggested that sesamin and sesamol may act as free radical scavengers and lipid peroxidation inhibitors (8). The neuroprotective effects of sesamin and sesamol may also reflect their ability to scavenge free radicals that are excessively generated during cerebral ischemia. In summary, oral administration of sesamin or crude sesame oil extract can alleviate ischemic injury in experimentally occluded gerbils with middle cerebral artery + common carotid artery occlusion and has a neuroprotective effect. The results of this study provide experimental data to confirm the neuroprotective effects of sesamin and sesamol on hypoxia or brain injury. Further research is needed to determine the optimal dosage of sesamin, sesamol and crude sesame oil extract. In addition, it is noteworthy that crude sesame oil extract and pure sesamin were equally effective in providing neuroprotection in this study. Purification of pure sesamin requires multiple steps, resulting in a relatively low recovery rate. Since crude sesame oil extract has the same neuroprotective effect as purified sesamin, it appears to have market potential as a health food supplement. [1]

C20H18O6

354.35

354.11

C, 67.79; H, 5.12; O, 27.09

607-80-7

(-)-Sesamin;13079-95-3

72307

White to off-white solid powder

1.4±0.1 g/cm3

504.4±50.0 °C at 760 mmHg

122-124ºC

212.3±30.0 °C

0.0±1.2 mmHg at 25°C

1.623

3.32

0

6

2

26

482

4

C1[C@H]2[C@H](CO[C@@H]2C3=CC4=C(C=C3)OCO4)[C@H](O1)C5=CC6=C(C=C5)OCO6

PEYUIKBAABKQKQ-AFHBHXEDSA-N

InChI=1S/C20H18O6/c1-3-15-17(25-9-23-15)5-11(1)19-13-7-22-20(14(13)8-21-19)12-2-4-16-18(6-12)26-10-24-16/h1-6,13-14,19-20H,7-10H2/t13-,14-,19+,20+/m0/s1

5-[(3S,3aR,6S,6aR)-3-(1,3-benzodioxol-5-yl)-1,3,3a,4,6,6a-hexahydrofuro[3,4-c]furan-6-yl]-1,3-benzodioxole

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.06 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.06 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (7.06 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)