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].

---

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.

---

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.

---

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

---

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 testing [1]
Salvigenin, rosmanol and Cirsimaritin in the dose range of 50-200 mg/kg did not produce any noticeable effects on grooming, sedation, respiratory arrest, convulsions or muscle activity. Furthermore, no case of lethality was found. Food and water consumption remained normal throughout the test period.

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

Cirsimaritin is a dimethoxyflavone that is flavone substituted by methoxy groups at positions 6 and 7 and hydroxy groups at positions 5 and 4' respectively. It is a dimethoxyflavone and a dihydroxyflavone. It is functionally related to a flavone.
Cirsimaritin has been reported in Achillea setacea, Artemisia xerophytica, and other organisms with data available.
See also: Tangerine peel (part of).

---

Purpose: Rosmarinus officinalis, traditionally known as rosemary, has been widely used in traditional medicines and has long been known as the herb of remembrance. However, few studies have investigated the effects of non-volatile components of rosemary on central nervous system function. Methods: Fractionation of R. officinalis led to the isolation of salvigenin, rosmanol and cirsimaritin, which were investigated in mouse models of acute toxicity, antinociception (tail immersion and hot plate tests), depression (tail suspension and forced swim tests) and anxiety (elevated plus maze and light/dark box paradigms). Results: Rosmanol, cirsimaritin and salvigenin were not found to exhibit any signs of acute toxicity (50-200 mg/kg), but elicited antinociceptive, antidepressant and anxiolytic activities. Conclusion: 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. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.[1]

---

Salvigenin, rosmanol and cirsimaritin have been previously shown to have biphasic modulation of 122L GABA receptors, and have demonstrated CNS activity in mouse models of antinociception, antidepressant and anxiolysis. We have shown that the anxiolytic activity is likely to be mediated via GABAA receptors. However, further studies are required to investigate possible mechanisms of action of these compounds in analgesia and depression and to investigate the effect of these compounds at GABAA receptor sub-types other than 122L 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.

---

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