Neuroprotective Effect of Visnagin on Kainic Acid-induced Neuronal Cell Death in the Mice Hippocampus

Visnagin (4-methoxy-7-methyl-5H-furo[3,2-g][1]-benzopyran-5-one), which is an active principle extracted from the fruits of Ammi visnaga, has been used as a treatment for low blood-pressure and blocked blood vessel contraction by inhibition of calcium influx into blood cells. However, the neuroprotective effect of visnagin was not clearly known until now. Thus, we investigated whether visnagin has a neuroprotective effect against kainic acid (KA)-induced neuronal cell death. In the cresyl violet staining, pre-treatment or post-treatment visnagin (100 mg/kg, p.o. or i.p.) showed a neuroprotective effect on KA (0.1 microgram) toxicity. KA-induced gliosis and proinflammatory marker (IL-1beta, TNF-alpha, IL-6, and COX-2) inductions were also suppressed by visnagin administration. These results suggest that visnagin has a neuroprotective effect in terms of suppressing KA-induced pathogenesis in the brain, and that these neuroprotective effects are associated with its anti-inflammatory effects.

The Study on the Effects of Psoralen Derivatives on Epidermal Melanocytes in C57 BL Mice after Topical Photochemotherapy

BACKGROUND: Monofunctional psoralens plus UVA radiation are not severely phototoxic and have less mutagenic activity than bifunctional psoralens plus UVA radiation. OBJECTIVE: The purpose of this study was to evaluate pigment producing effect using various concentrations(0.02%, 0.1%, 0.5%) of monofunctional psoralens such as angelicin, khellin and comparing it's effect with TMP in topical photochemotherapy. METHOD: Ninty three C57BL mice were painted with either angelicin, khellin or TMP solution in concentrations of 0.02%, 0.1% and 0.5% each and were UVA irradiated. Skin biopsies were performed at 1,3,5 weeks after UVA irradiation. The pigment producing effects were measured by the number, area and perimeter of the melanocytes after topical PUVA. RESULTS: The comparison of melanocyte numbers between different psoralens after five weeks of photochemotherapy showed a significant difference in decreasing order of TMP, khellin and angelicin. The area and perimeter of melanocytes were larger in the TMP group after five weeks photochemotherapy than the other group. However in the khellin and angelicin group, the area and perimeter of melanocytes were not increased by increasing the frequency of the UVA irradiation. CONCLUSION: The number, area and perimeter of melanocytes after topical PUVA increased in the TMP group compared to angelicin or khellin group. We expect the clinical application of angelicin and khellin in vitiligo is possible considering the result of the study of pigment producing effect with a higher concentration and higher dose of UVA.

Interaction of xanthines with khellin

The potentiality of interaction of khellin with certain xanthine derivatives, viz, caffeine, theophylline, acepifylline and dyphelline was investigated. Differential ultraviolet spectrophotometry revealed a marked effect of xanthines on the exthinction coefficient of khellin. Applying continuous variation method on spectrophotometric measurements revealed the formation of 1: 1 complexes between khellin and caffeine or theophylline, 2: 1 khellin- acepifylline as well as 1: 2 khellin - dyphelline complexes. The results of determination of the stability constant of the complexes revealed that theophylline and caffeine exhibit the highest tendency to complex with khellin, while acepifylline and dyphelline show a more or less weak tendency. The dissolution of khellin as well as the investigated khellin complexes was found to follow first order kinetics during the first 30 min of the dissolution run. On the other hand, the solublizing power of the investigated xanthine derivatives was also calculated

A Study on the Effect of Various Dosage of Khellin on Epidermal Melanocytes and a Comparison with Trimethylpsoralen in Systemic Photochemotherapy / 대한피부과학회지

Ninety black C 57 BL mice were divided into control and photochemotherapy groups. Control group was subdivided into a UVA 1rradiation only subgroup and a khellin only administration subgroup, while the phototherapy group was subdivided into one TMP and two khellin administration subgroups with dosages of 1.5mg/kg, 5mg/kg and 20mg/kg, respectivly. UVA was administered three thimes a week in a dose of 4J/cm for 4 weeks. Skin biopsies were taken at 0, l, 2, 3 and 4 weeks and the split DOPA stain was employed to observe pigment production. The number, size and circumference of the melanocytes were assessed. In summary, our results inclicate that khellin, which is slightly less effective than TMP at the same effective dose, is quite effective for pigment production and the degree of the production is dose related.

reaction of alkyl phosphites with asymmetric p-quinones khellinquinone and psoralenequinone

The reaction of khellinquinone 1 with trialkyl phosphites under varying experimental conditions, has been investigated. In methylene chloride, the reaction of quinone 1 with trimethyl phosphite and triethyl phosphite afforded, mainly, the respective monoalkyl ethers [15 and 16] of khellinquinol 12. The behaviour of psoralenequinone 2 towards attack by dimethyl phosphite and trimethyl phosphite, was also studied. Possible reaction-mechanisms have been considered and structural reasonings were based upon analytical, chemical and spectroscopic grounds