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Yu Gan Long (YGL) is a Chinese traditional herbal medicine that has been used in the treatment of liver fibrosis for many years in clinical practice. However, its anti-hepatofibrotic mechanism has not been studied yet. In this study, the effect and mechanism of YGL in reducing liver fibrosis was demonstrated in vivo. Our results showed that liver fibrosis biomarkers collagen IV (Col IV), type III precollagen (PCIII), hyaluronuc acid (HA) and laminin (LN), were increased after CCl4 treatment and decreased by YGL. Among the liver fibrosis indicators, α-smooth muscle actin (α-SMA) was decreased by YGL in the CCl4-treated rats, while MMP2 and MMP9 was upregulated followed by TIMP1 downregulation. Proteins involved in liver fibrosis such as p-Smad2, p-Smad3 and Smad4 were down-regulated, while Smad7 protein was up-regulated by YGL after CCl4-induced liver damage. YGL also suppressed the increase of TGF-β1, TNF-α, IL-1β, IL-6, IL-4 and IL-17 A induced by CCl4 treatment, while promoted IFN-γ expression. Finally, the transcription factors ROR-γt and GATA3 were decreased, while T-bet was increased after YGL treatment. These results suggested that YGL attenuated CCl4-induced hepatic fibrosis by accelerating the extracellular matrix degradation, blocking the TGF-β1/Smad signaling pathway and modulating the balance among IL-4, IL-17 A and IFN-γ, demonstrating YGL protective effect and its potential mechanisms in treating liver fibrosis.

Asthma is characterized by airway inflammatory infiltration, which leads to airway remodeling and airway hyperreactivity. Coleus forskohlii (CFK) has been used to treat asthma, however, the mechanism involved is not clear. To explore the antiasthma mechanism of extracts of Coleus forskohlii (ECFK), guinea pigs were administered with a spray of phosphoric acid histamine, and rats were sensitized with ovalbumin (OVA). Hematoxylin and eosin staining (H&E) were used to evaluate pathological changes in lung tissue. Enzyme-linked immunosorbent assay (ELISA) was used to determine cytokine levels in serum and bronchoalveolar lavage fluid (BALF). Immunohistochemistry and Western blot analysis were used to assess the expression of intercellular cell adhesion molecule-1 (ICAM-1), phosphorylation of p65 (p-p65), matrix metallopeptidase 9 (MMP-9), and tissue inhibitor of metalloproteinase 1 (TIMP-1). After ECFK treatment, the asthma incubation period of guinea pigs was significantly prolonged. The H&E results showed that the number of eosinophils in the 12.8 g/kg ECFK group was significantly lower when compared with the control group. Moreover, ELISA results demonstrated that interleukin (IL)-4, IL-5, and IL-17 in serum and BALF were significantly decreased, and interferon-γ (IFN-γ) and IL-10 were increased after ECFK treatment. In addition, ECFK treatment resulted in downregulation of ICAM-1, p-p65, MMP-9, and TIMP-1 in lung tissue after being sensitized by OVA. In conclusion, our findings indicated that ECFK significantly alleviated OVA-induced inflammatory infiltration and airway remodeling in asthma. This study laid a theoretical foundation for the clinical use of ECFK.

Melatonin, its agonists/antagonists were administered intrathecally (i.t.) before/after intradermal injection of capsaicin. Capsaicin produced an increase in the paw withdrawal frequency (PWF) in the presumed area of secondary mechanical allodynia and hyperalgesia. Melatonin agonists in the absence of a capsaicin injection decreased the PWF significantly, whereas melatonin antagonists given intrathecally alone were ineffective in the absence of a capsaicin injection. Pre-treatment with a melatonin agonist i.t. caused a reduction in the PWF after capsaicin. In contrast, the PWF increased after capsaicin with pre-administration of a melatonin antagonist i.t. Combined pre-treatment with melatonin and a melatonin antagonist i.t. prevented the change in PWF induced by melatonin alone after capsaicin. Intrathecal post-treatment with a melatonin agonist reduced the enhanced PWF that followed an injection of capsaicin, but treatment with a combination of a melatonin agonist and its antagonist did not alter the responses. The PWF was unaffected when melatonin analogs were applied i.t. at the T6 level or were injected intramuscularly adjacent to the L4 vertebra. In spinal rats, the data showed comparable effects of melatonin analogs on capsaicin-induced secondary mechanical hyperalgesia. Animal motor function tested by 'activity box' showed that motion activity was not affected by i.t. melatonin or its antagonist. These results suggest that activation of the endogenous melatonin system in the spinal cord can reduce the generation, development and maintenance of central sensitization, with a resultant inhibition of capsaicin-induced secondary mechanical allodynia and hyperalgesia.

The effects of bath applications of the nitric oxide (NO) donors sodium nitroprusside (SNP), diethylamine sodium (DEA), 3-morpholinosydnonimine (SIN-1), and S-nitroso-N-acetyl-penicillamine (SNAP) on the resting activity (RA) of afferent crista fibers were studied in isolated statocysts of the cuttlefish Sepia officinalis. The NO donors had three different effects: inhibition, excitation, and excitation followed by an inhibition. The SNAP analog N-acetyl- dl -penicillamine (xSNAP; with no NO moiety) had no effect. When the preparation was pre-treated with the NO synthase inhibitor N G -nitric- l -arginine methyl ester HCl ( l -NAME), the NO donors were still effective. When the preparation was pre-treated with the guanylate cyclase inhibitors methylene blue (M-BLU) or cystamine (CYS), NO donors had only excitatory effects, whereas their effects were inhibitory only when pre-treatment was with the adenylate cyclase inhibitors nicotinic acid (NIC-A), 2′,3′-dideoxyadenosine (DDA), or MDL-12330A. When pre-treatment was with a guanylate and an adenylate cyclase inhibitor combined, NO donors had no effect; in that situation, the RA of the afferent fibers remained and the preparation still responded to bath applications of GABA. Selective experiments with statocysts from the squid Sepioteuthis lessoniana and the octopod Octopus vulgaris gave comparable results. These data indicate that in cephalopod statocysts an inhibitory NO–cGMP and an excitatory NO–cAMP signal transduction pathway exist, that these two pathways are the key pathways for the action of NO, and that they have only modulatory effects on, and are not essential for the generation of, the RA.

The effects of bath application of the nitric oxide (NO) precursor l -arginine ( l -ARG) on the resting activity (RA) of afferent crista fibers were studied in isolated statocysts of the cuttlefish Sepia officinalis under various experimental conditions. l -ARG (threshold 10 −7 M) had three different effects: inhibition, excitation, and excitation followed by an inhibition; only the inhibitory effect of l -ARG was dose-dependent. d -Arginine ( d -ARG) had no effect. When the preparation was pre-treated with NO synthase inhibitors ( N G -Nitric- l -arginine methyl ester HCl ( l -NAME), N G -Nitro- l -arginine ( l -NOARG)), both the inhibitory and the excitatory effects of l -ARG significantly decreased at higher concentrations (10 −5 to −4 M), or were completely blocked at lower concentrations (10 −7 to −6 M), of l -ARG. When the preparation was pre-treated with guanylate cyclase inhibitors (1 H -[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ), methylene blue (M-BLU), cystamine (CYS)), l -ARG had only excitatory effects, whereas its effects were only inhibitory when the preparation was pre-treated with adenylate cyclase inhibitors 2′,3′-dideoxyadenosine (DDA), MDL-12330A (MDL), nicotinic acid (NIC-A)). l -ARG had no effects when the pre-treatment was with a guanylate cyclase inhibitor and an adenylate cyclase inhibitor combined; in that situation, the RA of the afferent fibers remained. These data indicate that in cephalopod statocysts, a cGMP and a cAMP signal transduction pathway (presumably via the generation of NO) are responsible for the effects of l -ARG on the RA of crista afferent fibers. They also indicate that the l -ARG–cGMP pathway is the dominant pathway and is inhibitory, and that both pathways have only modulatory effects on, but are not essential for, the generation of the RA.

The effects of bath application of l -glutamate and of excitatory amino acid agonists and antagonists on the resting activity of afferent crista fibers were studied in isolated preparations of the statocyst of the cuttlefish, Sepia of ficinalis . l -Glutamate (threshold 10 −5 M) and its agonists quisqualate and kainate (thresholds 10 −6 M) increased the resting activity in a dose-dependent manner. Glutamine (threshold 10 −5 M) was also excitatory, while d -glutamate had no effect. Also, no obvious excitatory effects were seen for NMDA and l -aspartate, nor was any antagonistic effect seen for the selective NMDA-receptor antagonist d -2-amino-5-phosphonovaleric acid ( d -AP-5). The spider toxin Argiotoxin 636 (threshold 10 −11 M), 2-amino-4-phosphonobutyric acid (AP-4), glutamic acid diethyl ester (GDEE), γ- d -glutamylaminomethyl-sulfonic acid (GAMS), and kynurenic acid decreased the resting activity and effectively blocked or reversed the effect of l -glutamate and its non-NMDA agonists. Preliminary experiments with statocysts from the squid Sepioteuthis lessoniana and the octopod Octopus bimaculoides gave comparable results. All data show that in cephalopod statocysts l -glutamate, via non-NMDA receptors, has an excitatory effect on the activity of afferent fibers, an effect consistent with its possible function as a hair cell transmitter.