Forskolin is a complex labdane plant diterpenoid, which has been used in the treatment of a variety of diseases based on its activity as an activator of adenosine monophosphate(cAMP) cyclase. Natural forskolin exists only in the cork layer of the root of Coleus forskohlii. Due to the complexity of the extraction and chemical synthesis processes, the yield and purity of forskolin cannot meet commercial requirements. In recent years, with the rapid development of synthetic biology and the analysis and interpretation of many diterpene biosynthetic pathways, a new approach has been provided for the green production of forskolin. In this paper, the structure, activity, biosynthetic pathway and the heterologous biosynthesis of forskolin were reviewed. The problems and solutions in the heterologous biosynthesis of forskolin were also discussed and summarized, which will provide references for the construction of high-yielding forskolin engineering strains.
Biosynthetic Pathways ; Colforsin

Adipose tissue is the main energy reserve of the body. When energy is required, adipocyte triglycerides stored in lipid droplets (LDs) are broken down by lipase, and free fatty acids are released to supply the physiological need. Intracellular LDs are active metabolic organelles in mammalian cells, particularly in adipocytes. The present study was aimed to investigate the morphological changes of LDs and the alternation of LD-associated perilipin family proteins during long-term lipolysis stimulated by forskolin. Primary differentiated adipocytes derived from epididymal fat pads of Sprague-Dawley (SD) rats were incubated in the presence or absence of 1 μmol/L forskolin for 24 h. Content of glycerol released to the culture medium was determined by a colorimetric assay and served as an index of lipolysis. Morphological changes of LDs were observed by Nile red staining. The mRNA level of perilipin family genes was detected by quantitative real-time PCR. The protein level and subcellular localization were examined by immunoblotting and immunofluorescence staining, respectively. The results showed that forskolin induced sustained lipolysis in differentiated adipocytes. The morphology of LDs changed in a time-dependent manner. Large clustered LDs became gradually smaller in size and eventually disappeared; in contrast, peripheral micro-LDs increased gradually in number until the cytoplasm was filled with numerous micro-LDs. The protein level of the perilipin family proteins showed obvious alternation. Mature adipocytes physiologically expressed a very low level of Plin2 protein, whereas in adipocytes stimulated with lipolytic forskolin, the protein and mRNA levels of Plin2 were significantly increased, and the increased Plin2 was specifically bound to the surface of LDs. During chronic stimulation of forskolin, the mRNA level of Plin3 was unchanged, but the mRNA levels of Plin1, Plin4 and Plin5 were significantly decreased. These results suggest that the morphology of LDs and perilipin family proteins on the surface of LDs are significantly altered during long-term lipolysis stimulated by forskolin, representing a dynamic process of the remodeling of LDs.
Adipocytes ; drug effects ; Animals ; Cells, Cultured ; Colforsin ; pharmacology ; Lipid Droplets ; Lipolysis ; Perilipin-2 ; metabolism ; Perilipins ; metabolism ; Rats ; Rats, Sprague-Dawley

The aim of this study was to evaluate the in vitro anti-inflammatory and utero-relaxant effect of α-bisabolol on the pregnant human myometrium. Samples from the pregnant human myometrium were used in functional tests to evaluate the inhibitory effect of α-bisabolol (560, 860, 1,200 and 1,860 µM) on spontaneous myometrial contractions. The intracellular cyclic adenosine monophosphate (cAMP) levels generated in response to α-bisabolol in human myometrial homogenates were measured by ELISA. The anti-inflammatory effect of α-bisabolol was determined through the measurement of two pro-inflammatory cytokines, tumor necrosis factor-α (TNFα) and interleukin (IL)-1β, and the anti-inflammatory cytokine IL-10, in pregnant human myometrial explants stimulated with lipopolysaccharide (LPS). Forskolin was used as a positive control to evaluate the cAMP and cytokine levels. α-Bisabolol was found to induce a significant inhibition of spontaneous myometrial contractions at the highest concentration level (p < 0.05). α-Bisabolol caused a concentration-dependent decrease in myometrial cAMP levels (p < 0.05) and a concentration-dependent decrease in LPS-induced TNFα and IL-1β production, while IL-10 production did not increase significantly (p>0.05). The anti-inflammatory and utero-relaxant effects induced by α-bisabolol were not associated with an increase in cAMP levels in pregnant human myometrial samples. These properties place α-bisabolol as a potentially safe and effective adjuvant agent in cases of preterm birth, an area of pharmacological treatment that requires urgent improvement.
Adenosine Monophosphate ; Animals ; Colforsin ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans* ; Immunomodulation ; In Vitro Techniques ; Inflammation ; Interleukin-10 ; Interleukins ; Mice ; Myometrium ; Necrosis ; Obstetric Labor, Premature ; Pregnancy ; Premature Birth ; Uterine Contraction ; Uterus*

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are confirmed to be expressed in bladder interstitial Cajal-like cells (ICC-LCs), but little is known about their possible role in cystitis-associated bladder dysfunction. The present study aimed to determine the functional role of HCN channels in regulating bladder function under inflammatory conditions. Sixty female wild-type C57BL/6J mice and sixty female HCN1-knockout mice were randomly assigned to experimental and control groups, respectively. Cyclophosphamide (CYP)-induced cystitis models were successfully established in these mice. CYP treatment significantly enhanced HCN channel protein expression and I(h) density and significantly altered bladder HCN1 channel regulatory proteins. Carbachol (CCH) and forskolin (FSK) exerted significant effects on bladder ICC-LC [Ca²⁺]i in CYP-treated wild-type (WT) mice, and HCN1 channel ablation significantly decreased the effects of CCH and FSK on bladder ICC-LC [Ca²⁺]i in both naive and CYP-treated mice. CYP treatment significantly potentiated the spontaneous contractions and CCH (0.001-10 µM)-induced phasic contractions of detrusor strips, and HCN1 channel deletion significantly abated such effects. Finally, we demonstrated that the development of CYP-induced bladder overactivity was reversed in HCN1 -/- mice. Taken together, our results suggest that CYP-induced enhancements of HCN1 channel expression and function in bladder ICC-LCs are essential for cystitis-associated bladder hyperactivity development, indicating that the HCN1 channel may be a novel therapeutic target for managing bladder hyperactivity.
Animals ; Carbachol ; Colforsin ; Cyclophosphamide ; Cystitis ; Female ; Humans ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels* ; Mice* ; Telocytes* ; Up-Regulation* ; Urinary Bladder*

The aim of this study was to evaluate the relaxant and anti-inflammatory effects of two thalidomide analogs as phosphodiesterase-4 (PDE-4) inhibitors in pregnant rat uterus. Uteri from Wistar female rats were isolated at 19 day of pregnancy. Uterine samples were used in functional studies to evaluate the inhibitory effects of the thalidomide analogs, methyl 3-(4-nitrophthalimido)-3-(3,4-dimethoxyphenyl)-propanoate (4NO2PDPMe) and methyl 3-(4-aminophthalimido)-3-(3,4-dimethoxyphenyl)-propanoate (4APDPMe), on prostaglandin-F2α (PGF2α)-induced phasic, K⁺-induced tonic, and Ca²⁺-induced contractions. Accumulation of cAMP was quantified in uterine homogenates by ELISA. Anti-inflammatory effect was assessed by using ELISA for determination of the pro-inflammatory cytokines tumor necrosis factor-α (TNFα) and interleukin (IL)-1β, and anti-inflammatory IL-10, from uterine explants stimulated with lipopolysaccharide (LPS). Nifedipine, forskolin and rolipram were used as positive controls where required. Both thalidomide analogs induced a significant inhibition of the uterine contractions induced by the pharmaco- and electro-mechanic stimuli. Nifedipine and forskolin were more potent than the analogs to inhibit the uterine contractility, but these were more potent than rolipram, and 4APDPMe was equieffective to nifedipine. Thalidomide analogs increased uterine cAMP-levels in a concentration-dependent manner. The LPS-induced TNFα and IL-1β uterine secretion was diminished in a concentration-dependent fashion by both analogs, whereas IL-10 secretion was increased significantly. The thalidomide analogs induced utero-relaxant and anti-inflammatory effects, which were associated with the increased cAMP levels as PDE-4 inhibitors in the pregnant rat uterus. Such properties place these thalidomide analogs as potentially safe and effective tocolytic agents in a field that urgently needs improved pharmacological treatments, as in cases of preterm labor.
Animals ; Colforsin ; Cyclic Nucleotide Phosphodiesterases, Type 4 ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Interleukin-10 ; Interleukins ; Necrosis ; Nifedipine ; Obstetric Labor, Premature ; Phosphodiesterase 4 Inhibitors* ; Pregnancy ; Rats* ; Rolipram ; Thalidomide* ; Tocolytic Agents ; Uterine Contraction ; Uterus*

OBJECTIVETo observe the effect of Kanli Granule (KG) on myocardial mechanics in pressure overload induced diastolic heart failure (DHF) rats.

METHODSTotally 60 male Wistar rats were divided into the sham-operation group, the model group, the KG group, and the Valsartan group according to random digit table, 15 in each group. The pressure overload induced DHF model was established in all groups except the sham-operation group using abdominal aortic constriction surgery. Totally 7 rats died after modeling (with the mortality of 10. 67%) , and the rest 53 finished the following test. Rats in the KG group were administered with KG extract (calculated as 6. 75 g crude drug/kg) by gastrogavage. Rats in the Valsartan group were administered with Valsartan (7.2 µg/g) by gastrogavage. Equal volume of double distilled water was administered to rats in the model group and the sham-operation group by gastrogavage. All rats were intervened for 32 weeks. The response of isolated heart papillary muscle tonus to isoprenaline (ISO) and adenylate cyclase (Forskolin) was respectively observed. The enhancement phenomenon after resting development force (DF) of isolated heart papillary muscle tonus, and changes of DF in different Ca²⁺ concentrations were observed.

RESULTS(1) In the ISO response test: Compared with the sham-operation group, the amplifications of DF, ±df/dt, -df/dt were obviously elevated in the model group (P < 0.05). Compared with the model group, the amplifications of DF and ±df/dt were obviously lowered in the KG group (P < 0.01), and the amplification of ±df/dt was also reduced in the Valsartan group (P < 0.01). (2) In the Forskolin response test: Compared with the sham-operation group, the amplifications of DF and ±df/dt obviously increased in the model group (P < 0.05). Compared with the model group, the amplifications of DF and ±df/dt were obviously reduced in the KG group (P < 0.01), and the amplification of DF was also reduced in the Valsartan group (P < 0.05). (3) In post-resting DF enhancement test: Compared with the sham-operation group, the amplification of DF showed gradually decreasing tendency along with prolonged resting time in the model group, and they were obviously lowered at all time points (P < 0.05). Compared with the model group, the amplification of DF was gradually increasing along with prolonged resting time in the KG group. The amplification of DF at post-resting 240 s was obviously larger in the KG group than in the model group (P < 0.05). The amplification of post-resting DF still showed gradually decreasing tendency along with prolonged resting time in the Valsartan group, with increased amplifications of DF at post-resting 60 s and 120 s (P < 0. 05) (4) The amplifications of DF in different Ca²⁺ concentrations: Compared with the sham-operation group, the amplifications of DF were significantly elevated in different Ca²⁺ concentrations (1.75, 3.5, 7.0 mmol/L ) (P < 0.05, P < 0.01). Compared with the model group, there was no statistical difference in amplification of DF in different Ca²⁺ concentrations in the KG group (P > 0.05). The amplifications of DF in different Ca²⁺ concentrations were significantly reduced in the Valsartan group (P < 0.05).

CONCLUSIONSThe ISO response and the Forskolin response were enhanced in isolated heart papillary muscle tonus of pressure overload induced DHF rats; enhanced post-resting DF was reduced; DF in different supra-physiologic levels of Ca²⁺ was still enhanced. KG could significantly improve excessive enhancement of pressure overload induced DHF rats in ISO response and Forskolin response, and improve enhancement of post-resting myocardium.

Animals ; Colforsin ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Heart ; drug effects ; physiopathology ; Heart Failure, Diastolic ; drug therapy ; Isoproterenol ; pharmacology ; Male ; Random Allocation ; Rats ; Rats, Wistar

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the Na(+)-K(+)-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain (3.0 micromol/L) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 (3.0 micromol/L), an inhibitor for reverse mode of Na(+)-Ca(2+) exchangers (NCX), but did not by L-type Ca2+ channel blocker nifedipine (1.0 micromol/L) or protein kinase A (PKA) selective inhibitor H-89 (3.0 micromol/L). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline (100.0 micromol/L), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP (0.5 micromol/L) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 (30 micromol/L), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.
8-Bromo Cyclic Adenosine Monophosphate ; Adenosine ; Cardiomegaly ; Colforsin ; Cyclic AMP-Dependent Protein Kinases ; Endothelin-1* ; Heart Diseases ; Nifedipine ; Ouabain* ; Phosphotransferases ; Protein Kinases

OBJECTIVES: In mammals, cochlear hair cell loss is irreversible and may result in a permanent sensorineural hearing loss. Secondary to this hair cell loss, a progressive loss of spiral ganglion neurons (SGNs) is presented. In this study, we have investigated the effects of neural-induced human mesenchymal stem cells (NI-hMSCs) from human bone marrow on sensory neuronal regeneration from neomycin treated deafened guinea pig cochleae. METHODS: HMSCs were isolated from the bone marrow which was obtained from the mastoid process during mastoidectomy for ear surgery. Following neural induction with basic fibroblast growth factor and forskolin, we studied the several neural marker and performed electrophysiological analysis. NI-hMSCs were transplanted into the neomycin treated deafened guinea pig cochlea. Engraftment of NI-hMSCs was evaluated immunohistologically at 8 weeks after transplantation. RESULTS: Following neural differentiation, hMSCs expressed high levels of neural markers, ionic channel markers, which are important in neural function, and tetrodotoxin-sensitive voltage-dependent sodium currents. After transplantation into the scala tympani of damaged cochlea, NI-hMSCs-injected animals exhibited a significant increase in the number of SGNs compared to Hanks balanced salt solution-injected animals. Transplanted NI-hMSCs were found within the perilymphatic space, the organ of Corti, along the cochlear nerve fibers, and in the spiral ganglion. Furthermore, the grafted NI-hMSCs migrated into the spiral ganglion where they expressed the neuron-specific marker, NeuN. CONCLUSION: The results show the potential of NI-hMSCs to give rise to replace the lost cochlear cells in hearing loss mammals.
Animals ; Bone Marrow ; Cell Differentiation ; Cochlea ; Cochlear Nerve ; Colforsin ; Ear ; Fibroblast Growth Factor 2 ; Guinea Pigs* ; Hair ; Hearing Loss ; Hearing Loss, Sensorineural ; Humans ; Ion Channels ; Mammals ; Mastoid ; Mesenchymal Stromal Cells* ; Neomycin ; Neurons ; Organ of Corti ; Regeneration* ; Scala Tympani ; Sensory Receptor Cells ; Sodium ; Spiral Ganglion ; Transplantation ; Transplants

Cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-dependent chloride channel, plays key roles in fluid secretion in serous epithelial cells. Previously, we identified two polymethoxylated flavonoids, 3',4',5,5',6,7-hexamethoxyflavone (HMF) and 5-hydroxy-6,7,3',4'-tetramethoxyflavone (HTF) which could potentiate CFTR chloride channel activities. The present study was aimed to investigate the potentiation effects of HMF and HTF on CFTR Cl(-) channel activities by using a cell-based fluorescence assay and the short circuit Ussing chamber assay. The results of cell-based fluorescence assay showed that both HMF and HTF could dose-dependently potentiate CFTR Cl(-) channel activities in rapid and reversible ways, and the activations could be reversed by the CFTR blocker CFTRinh-172. Notably, HMF showed the highest affinity (EC50 = 2 μmol/L) to CFTR protein among the flavonoid CFTR activators identified so far. The activation of CFTR by HMF or HTF was forskolin (FSK) dependent. Both compounds showed additive effect with FSK and 3-Isobutyl-1-methylx (IBMX) in the activation of CFTR, while had no additive effect with genistein (GEN). In ex vivo studies, HMF and HTF could stimulate transepithelial Cl(-) secretion in rat colonic mucosa and enhance fluid secretion in mouse trachea submucosal glands. These results suggest that HMF and HTF may potentiate CFTR Cl(-) channel activities through both elevation of cAMP level and binding to CFTR protein pathways. The results provide new clues in elucidating structure and activity relationship of flavonoid CFTR activators. HMF might be developed as a new drug in the therapy of CFTR-related diseases such as bronchiectasis and habitual constipation.
Animals ; Colforsin ; Colon ; metabolism ; Cystic Fibrosis Transmembrane Conductance Regulator ; drug effects ; Flavones ; physiology ; Flavonoids ; pharmacology ; Genistein ; Intestinal Mucosa ; metabolism ; Mice ; Rats

This paper is to report the study of the metabolism of forscolin in plasma and liver microsomes for guiding clinical therapy. Forscolin was quantified by HPLC-MS/MS. The metabolic stability of forscolin in rat, Beagle dog, monkey and human plasma and liver microsomes, mediated enzymes of forscolin and its inhibition on cytochrome P450 isoforms in human liver microsomes were studied. Results showed that forscolin was not metabolized in plasma of the four species but metabolized in liver microsomes of the four species. The t1/2 of forscolin in rat, Beagle dog, monkey and human liver microsomes were (52.0 +/- 15.0), (51.2 +/- 5.9), (6.0 +/- 0.2) and (11.9 +/- 1.8) min; CL(int) were (75.6 +/- 18.7), (60.9 +/- 6.8), (513.8 +/- 14.3) and (176.2 +/- 25.6) mL x min(-1) x kg(-1); CL were (34.8 +/- 4.5), (23.3 +/- 1.0), (40.3 +/- 0.5) and (17.9 +/- 0.3) mL x min(-1) x kg(-1), respectively. Forscolin was metabolized by CYP3A4 in human liver microsomes. There was definite inhibition on CYP3A4 at the concentrations of forscolin between 0.1 ng x mL(-1) and 5 microg x mL(-1). Therefore, forscolin is rapidly excreted from liver microsomes. Attention should be paid to the drug interaction when forscolin was used along with other drugs metabolized by CYP3A4 in clinics.
Animals ; Chromatography, High Pressure Liquid ; Coleus ; chemistry ; Colforsin ; blood ; isolation & purification ; metabolism ; Cytochrome P-450 CYP3A ; metabolism ; Dogs ; Humans ; Macaca ; Metabolic Clearance Rate ; Microsomes, Liver ; metabolism ; Plants, Medicinal ; chemistry ; Rats ; Tandem Mass Spectrometry