GABAA receptors

Cirsimaritin has previously been reported to bind weakly to the benzodiazepine site on GABAA receptors and researchers also have previously reported the functional activity of a ursolic acid, rosmanol, cirsimaritin, salvigenin and carnosol on GABAA receptors expressed in Xenopus oocytes Salvigenin,rosmanol, cirsimaritin, ursolic acid, carnosol, hesperidin and nepitrin were isolated from Rosmarinus officinalis [1].

In mice, Cirsimaritin markedly lowered anxiety levels. Cirsimaritin (10 mg/kg) did not diminish when flumazenil (2.5 mg/kg) was given in addition to salviagen, rosmanol, and Cirsimaritin(10 mg/kg), suggesting a high-affinity benzodiazepine binding site. [1].

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Rosmanol, Cirsimaritin and salvigenin, all previously shown to have biphasic modulation of GABAA receptors, demonstrated CNS activity in mouse models of antinociception, antidepressant and anxiolysis. The anxiolytic activity of all three compounds was not ameliorated by flumazenil, but was inhibited by pentylenetetrazol, suggesting a mode of action via GABAA receptors at a site other than the high affinity benzodiazepine binding site [1].

Acute toxicity [1]
The acute toxicity study was conducted according to the modified method described by Adebiyi & Abatan. Swiss albino mice (25–30g) were randomly divided into ten groups (n=6). Animals were fasted overnight, but had access to water ad libitum, and then treated intraperitonealy with salvigenin, rosmanol or Cirsimaritin (50, 150 and 200 mg/kg). Mice in the control group received 10 ml/kg i.p. of vehicle (0.9% w/v). Animals were carefully observed for any signs of toxic effects during the first 6 hours after the treatment and then carefully monitored for the subsequent 66 hours, (3-days observation) for any changes in behaviors including grooming, hyperactivity, sedation, respiratory arrest, convulsion, increased or decreased motor activity and mortality, if any.

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Tail Immersion Method [1]
Mice were divided into eleven groups (n=6). The lower 5 cm portion of the tail was immersed in a beaker of water maintained at 55±0.5°C. The time in seconds for tail withdrawal from the water was taken as the reaction time, with a cut-off time of immersion at 10 sec. The reaction time was measured 1 hour before and after administration of salvigenin, rosmanol and Cirsimaritin (1, 30, and 100 mg/kg, i.p) or vehicle (10 mL/kg, i.p.). Tramadol as the positive control (20 mg/kg) was administered subcutaneously, 30 min before the test.

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Hot-plate test [1]
The hot-plate test was used to measure the response latencies in mice according to the previously described method. The mice were screened by placing them on a hot metal plate maintained at 50±0.05 °C. Thermal nociception was measured through discomfort demonstrated by jumping, withdrawal of paws or licking of paws. In the prescreening test, only those mice which offered response within 15 s were selected for the experiment. The prescreened mice were divided in 11 groups (n=6). Mice were injected with the vehicle (10 mL/kg, i.p.) or drug as reported in table 2. The response latencies were recorded at 0, 30, 60, 90 and 120 minutes. Percent inhibition was calculated as follows. % inhibition = (((Mean reaction time (Vehicle))-(Mean reaction time (drug))) / Mean reaction time (drug)) Χ 100

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Elevated plus maze (EPM) [1]
The apparatus consisted of two open arms (30 cm x 5 cm) and two closed arms (30 cm x 5 cm x 15 cm) made of black plexiglass connected by an open central platform (5 cm x 5 cm) and elevated 40 cm from ground level. A raised ledge (3 mm high and 1 mm thick) surrounded the perimeter of the open arms. Mice were injected with vehicle or drugs, and 20 minutes later placed in the center of the apparatus facing an open arm and allowed to explore the maze for 5 min. An arm entry was defined by having all four paws inside the arm. All sessions were videotaped by a camera positioned above the maze, and at the end of the test, the number of arm entries and time spent in arms were recorded. To assess the involvement of the GABAergic system, animals were either pretreated i.p. with vehicle or pentylenetetrazol (PTZ, 20 mg/kg), prior to treatment with salvigenin, rosmanol or Cirsimaritin. The % of open arm entries and the % of time spent in the open arms were recorded as a measure of anxiety state.

Acute toxicity tests [1]
Dose ranges of 50-200 mg/kg for Salvigenin, rosmanol, and Cirsimaritin did not have any significant effect on grooming behavior, sedation, respiratory arrest, convulsions, or muscle activity in the animals. Furthermore, no deaths were observed. During the tests, the animals' food and water intake remained normal.

[1]. Antidepressant, Anxiolytic and Antinociceptive Activities of Constituents from Rosmarinus Officinalis. J Pharm Pharm Sci. 2015;18(4):448-59.

Eryspinol is a dimethoxyflavonoid with a flavonoid structure, where methoxy groups are substituted at positions 6 and 7, and hydroxy groups are substituted at positions 5 and 4'. It is both a dimethoxyflavonoid and a dihydroxyflavonoid. Its function is related to that of flavonoid compounds. Eryspinol has been reported to be found in yarrow (Achillea setacea), artemisia xerophytica, and other organisms with relevant data. See also: Orange peel (partial). Uses: Rosemary (Rosmarinus officinalis), traditionally known as rosemary, is widely used in traditional medicine and has long been hailed as the "herb of memory." However, few studies have explored the effects of the non-volatile components of rosemary on central nervous system function. Methods: Rosemary (R. officinalis) was fractionated to obtain carmine, rosmarinic acid, and erythritol, which were then investigated in mouse models of acute toxicity, analgesia (tail dip test and hot plate test), depression (tail suspension test and forced swimming test), and anxiety (elevated maze and light-dark box test). Results: Rosmarinic acid, erythritol, and carmine did not exhibit any acute toxicity (50-200 mg/kg), but all showed analgesic, antidepressant, and anxiolytic activities. Conclusion: Rosmarinic acid, erythritol, and carmine have previously been shown to have biphasic regulatory effects on GABAA receptors and have demonstrated central nervous system activity in mouse models of analgesia, antidepressant, and anxiolytic activity. Flumazenil did not enhance the anxiolytic activity of these three compounds, but pentylenetetrazol inhibited their anxiolytic activity, suggesting that their mechanism of action may not be through high-affinity benzodiazepine binding sites, but rather through GABAA receptors. This article is open for post-publication peer review. Registered readers (see “Reader’s Guide”) can comment by clicking on the “Abstract” on the table of contents page of this issue. [1]

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Previous studies have shown that sagein, rosmarinic acid and esculin have biphasic regulatory effects on α1β2γ2L GABA receptors and have demonstrated analgesic, antidepressant and anxiolytic activities in the central nervous system in mouse models. We have demonstrated that their anxiolytic activity is likely mediated by GABAA receptors. However, further research is needed to explore the possible mechanisms of action of these compounds in analgesia and antidepressant, as well as the effects of these compounds on other GABAA receptor subtypes besides α1β2γ2L GABAA receptors. [1]

C17H14O6

314.28946

314.079

6601-62-3

188323

Light yellow to light brown solid powder

1.4±0.1 g/cm3

563.6±50.0 °C at 760 mmHg

211.5±23.6 °C

0.0±1.6 mmHg at 25°C

1.646

1.97

2

6

3

23

468

0

COC1=C(C(=C2C(=C1)OC(=CC2=O)C3=CC=C(C=C3)O)O)OC

ZIIAJIWLQUVGHB-UHFFFAOYSA-N

InChI=1S/C17H14O6/c1-21-14-8-13-15(16(20)17(14)22-2)11(19)7-12(23-13)9-3-5-10(18)6-4-9/h3-8,18,20H,1-2H3

5-hydroxy-2-(4-hydroxyphenyl)-6,7-dimethoxychromen-4-one

Cirsimaritin; 6601-62-3; Scrophulein; Skrofulein; 4',5-Dihydroxy-6,7-dimethoxyflavone; 7-Methylcapillarisin; 6-Methoxygenkwanin; 6,7-Dimethoxyscutellarein;

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)

DMSO : ~22.73 mg/mL (~72.32 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (6.62 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 20.8 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.)