The results suggest that this fraction is a source of PTP1B inhibitory activity with a potential for treating diabetes.

Soluble epoxide hydrolase (sEH) is an enzyme involved in the metabolism of endogenous inflammatory and anti-apoptotic mediators. In the present study, we determined the effects of the inhibition of sEH on glucose homeostasis and islet damage in mice treated with streptozotocin (STZ), a model of chemical-induced diabetes. STZ increased daily water intake and decreased visceral (spleen and pancreas) weight in mice; sEH inhibition in STZ mice decreased water intake, but did not affect visceral weight. Hyperglycemia induced by STZ treatment in mice was attenuated by inhibiting sEH. The beneficial effects of sEH inhibition were accompanied, after 2 and 4 weeks of initial administration, by improving glucose tolerance. In contrast, sEH inhibition did not affect insulin tolerance. Using LC/MS analysis, neither STZ nor STZ plus sEH inhibition affected pancreatic and plasma ratios of epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids (DHETs), an index of EETs levels. Western blot analysis showed that mouse cytochrome P450 (CYP) 2C enzymes are the major epoxygenases in islets. On day 5 after initial STZ treatment, STZ induced islet cell apoptosis, while sEH inhibition in STZ mice significantly reduced islet cell apoptosis. These studies provide pharmacological evidence that inhibiting sEH activity provides significant protection against islet β-cell damage and improves glucose homeostasis in STZ-induced diabetes.

The aerial parts of the tarragon ( Artemisia dracunculus) were collected around Kukteppa village, Ziddi, Varzob region of Tajikistan. The essential oil of tarragon was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. Forty-five compounds representing 99.8% of total oil were identified. Sabinene (29.1%), estragole (24.6%), limonene (7.8%), ( Z)-artemidin (4.9%), myrcene (4.8%), and ( E)-β-ocimene (4.0%) were components with a representation higher than 4% of the essential oils of aerial parts of tarragon. Hierarchical cluster analysis of А. dracunculus essential oils on the global phytogeographic origin based on 30 essential oil components and 105 samples (globally) of this species, indicated the existence of its 7 major chemotypes: ocimene, α-terpinene, capillene, methyl eugenol, mixed chemotype, ( Z)-artemidin, and estragol chemotypes. The essential oils of А. dracunculus showed weak antioxidant and antibacterial activities. To our best knowledge, this is the first report concerning the chemical composition, chemotypic variation, antioxidant, and antimicrobial activities of the essential oils obtained from the aerial parts of А. dracunculus, growing wild in the Varzob region of Tajikistan.