Sphingosine-1-phosphate selectively activates vagal afferent C-fiber subtype in guinea pig esophagus.

BACKGROUND: Activation and sensitization of visceral afferent nerves by inflammatory mediators play important roles in visceral nociception. Sphingosine-1-phosphate (S1P) is a lipid with intracellular and extracellular functions. Extracellularly, it can act as an autacoid via interactions with S1P receptors. The present study aims to determine the effect of S1P on esophageal vagal afferent nerve functions. METHODS: Extracellular single-unit recordings were performed in ex vivo guinea pig esophageal-vagal preparations. The action potentials (APs) evoked by mechanical distension and chemical perfusions applied to the vagal afferent nerve endings in the esophagus were recorded at their intact neuronal cell bodies in either nodose or jugular ganglia. The effects of S1P and its receptor subtype agonists on vagal afferents were recorded and compared. The expression of S1P receptors (S1PR1-3) in esophageal-labeled vagal nodose and jugular neurons was studied by single-cell RT-PCR. KEY RESULTS: Sphingosine-1-phosphate evoked AP discharges in almost all esophageal jugular but not nodose C-fibers without changing their responses to esophageal distension. Esophageal-labeled vagal nodose and jugular neurons highly expressed transcripts of S1PR1 and S1PR3. Agonists of S1PR1 and S1PR3 each partially mimicked S1P-induced effect in jugular C-fibers, suggesting that these receptors may contribute partially to S1P-induced activation effect on esophageal jugular C-fiber subtype. CONCLUSIONS & INFERENCES: These data, for the first time, demonstrated a selective activation effect of S1P on vagal afferent nerve subtype in the gastrointestinal tract. This may help to better understand its role in visceral inflammatory nociception.

Sex-dependent roles of prolactin and prolactin receptor in postoperative pain and hyperalgesia in mice.

Although surgical trauma activates the anterior pituitary gland and elicits an increase in prolactin (PRL) serum levels that can modulate nociceptive responses, the role of PRL and the PRL-receptor (PRL-R) in thermal and mechanical hyperalgesia in postoperative pain is unknown. Acute postoperative pain condition was generated with the use of the hindpaw plantar incision model. Results showed endogenous PRL levels were significantly increased in serum, operated hindpaw and spinal cords of male and female rats 24h after incision. These alterations were especially pronounced in females. We then examined the role of the PRL system in thermal and mechanical hyperalgesia in male and female mice 3-168 h after plantar incision with the use of knock-out (KO) mice with PRL or PRL-R gene ablations and in wild-type (WT) mice. WT mice showed postoperative cold hyperalgesia in a sex-dependent manner (only in females), but with no effect on heat hyperalgesia or mechanical allodynia in either sex. Studies in KO mice showed no effect of PRL and PRL-R gene ablation on heat and cold hyperalgesia in male mice, while heat hyperlgesia were reduced 3-72 h post-surgery in female PRL and PRL-R KO mice. In contrast, PRL and PRL-R ablations significantly attenuated mechanical allodynia 3-72 h post-surgery in both male and female mice. Overall, we found elevated PRL levels in serum, hindpaws and spinal cords after incision, and identify a contributory role for the PRL system in postoperative pain responses to thermal stimuli in females and to mechanical stimuli in both males and females.

RP-HPLC method for the simultaneous quantitation of boeravinone E and boeravinone B in Boerhaavia diffusa extract and its formulation.

A high-performance liquid chromatography method was developed and validated for the simultaneous quantitation of two major rotenoids, boeravinone E and boeravinone B, in Boerhaavia diffusa extract and its formulation. Chromatographic separation was carried out on an Inertsil ODS-3 column by using gradient mobile phase containing 0.1% v/v orthophosphoric acid in water and acetonitrile. The detection was carried out at 276 nm. The method was validated for specificity, precision, accuracy and robustness. The linearity (r(2) = 0.9989 and 0.9991) was found to be in the range of 7.26-35.75 µg mL(-1) and 2.20-11.00 µg mL(-1) for boeravinone E and B, respectively. The percent recovery observed from the extract sample was 95.22-95.83.

Protective effect of Luffa acutangula extracts on gastric ulceration in NIDDM rats: role of gastric mucosal glycoproteins and antioxidants.

OBJECTIVE: To study the comparative gastroprotective effect of Luffa acutangula methanolic extract (LAM) and aqueous extract (LAW) on type II diabetes rats. METHODS: Streptozotocin (65 mg/kg, i.p.) along with nicotinamide (120 mg/kg, i.p.) was used to induce non insulin dependent diabetes mellitus (NIDDM) in rats. A daily oral dose of aspirin (200 mg/kg, i.p.) was administered for initial seven days to induce gastric ulcerations in the diabetic rats. LAM and LAW were administered orally in the doses of 100, 200 and 400 mg/kg once daily for 21 days. Glibenclamide and ranitidine were used as standards for comparing the antidiabetic and antiulcer effect respectively. RESULTS: LAM significantly (P<0.01) increased mucosal glycoprotein and antioxidant enzyme level in gastric mucosa of diabetic rats than LAW (P <0.05). LAM was efficient in reversing the delayed healing of gastric ulcer in diabetic rats close to the normal level. LAM exhibited better ulcer healing effect than glibenclamide and LAW, because of its both antihyperglycemic and mucosal defensive actions. CONCLUSIONS: Thus, LAM is proved to be a better alternative for treating gastric ulcers co-occurring with diabetes.

Validated TLC method for simultaneous quantitation of kutkoside and picroside-I from Kutki extract.

INTRODUCTION: The two iridoid glycosides kutkoside and picroside-I are the active hepatoprotective principles of Picrorhiza kurroa Royle ex Benth (Scrophulariaceae), commonly known as Kutki. Quantitation of these phytoconstituents is important for the routine quality control of Kutki extract. OBJECTIVE: To develop and validate a simple, precise and rapid thin-layer chromatography (TLC) method for the simultaneous quantitation of kutkoside and picroside-I in Kutki extract. METHODOLOGY: The analysis was performed on a TLC precoated silica gel 60 F(254) plate with ethyl acetate:methanol:glacial acetic acid:formic acid (25:5:1:1, v/v/v/v) as mobile phase. Densitometric evaluation of kutkoside and picroside-I was carried out at 265 nm and the mobile phase showed good resolution with R(f) values 0.42 ± 0.03 and 0.61 ± 0.03 for kutkoside and picroside-I, respectively. The method was validated in terms of specificity, linearity, accuracy and precision. RESULTS: The content of kutkoside and picroside-I was found to be 2.18 and 1.90%, respectively, and was comparable with those obtained by HPLC. The linearity was found to be in the range of 80-480 ng/spot for both kutkoside and picroside-I. The average recovery values were found to be 96.5 and 96.0% for kutkoside and picroside-I, respectively. CONCLUSION: The developed method was found to be relatively simple, precise and reproducible for the simultaneous quantitation of kutkoside and picroside-I. The method does not employ any derivatisation procedure and can be used as a quality control tool for the routine analysis of commercial Kutki extracts.

Structure elucidation of a flavonoid glycoside from the roots of Clerodendrum serratum (L.) Moon, Lamiaceae

Apigenin-7-glucoside, C21H20O10 (7-(β-D-glucopyranosyloxy)-5-hydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one), was first time isolated from the roots of Clerodendrum serratum (L.) Moon, Lamiaceae. Structure elucidation of the compound was carried out by ¹H NMR and FAB-MS studies.

Apigenin-7-glucosídeo, C21H20O10 (7-(β-D-glucopiranosiloxi)-5-hidroxi-2-(4-hidroxifenil)-4H-1-benzopiran-4-ona), foi isolado pela primeira vez das raízes de Clerodendrum serratum (L.) Moon, Lamiaceae. A elucidação estrutural da susbtância foi feita através de estudos de ¹H NMR e FAB-MS.

Development and validation of a method for densitometric analysis of berberine in herbal extract and polyherbal formulation.

OBJECTIVE: To develop a new high-performance thin-layer chromatography (HPTLC) method for the quantification of berberine in herbal extract and pharmaceutical dosage form. MATERIALS AND METHODS: The HPTLC was performed on aluminium foil plates coated with 200 µm silica gel 60F(254). Linear ascending development with toluene:ethyl acetate:formic acid:methanol 9:9:3:1 (v/v/v/v) was performed at room temperature (25 ± 2°C) in a twin-trough glass chamber saturated with mobile-phase vapour. Compact bands (R(F) 0.58 ± 0.02) were obtained for berberine. Spectrodensitometric scanning was performed in fluorescence mode at 350 nm. The method was validated for precision, recovery, robustness, specificity, and detection and quantification limits, in accordance with International Conference on Harmonization guidelines. RESULTS: Linear regression analysis of the calibration plots showed a good linear relationship (r(2) = 0.9996 ± 0.0001) between peak area and concentration in the range 10-100 ng/band, respectively. The limits of detection and quantification were 2.8 and 9.3 ng/band. The recovery of the method was 98.5-100.6%. CONCLUSION: The above method was a rapid and cost-effective quality-control tool for routine analysis of berberine in herbal extracts and in pharmaceutical dosage form.

Transient receptor potential V1 regulates activation and modulation of transient receptor potential A1 by Ca2+.

The transient receptor potential A1 (TRPA1) channel contributes to nociceptive signaling in certain pain models. It has been suggested that Ca(2+), which activates and modulates TRPA1, could play a critical regulatory role in this process. Since TRPA1 and transient receptor potential V1 (TRPV1) channels are co-expressed and interact in neurons, we investigated whether activation and modulation of TRPA1 by Ca(2+) is regulated by TRPV1. Cell-attached recordings showed that TRPA1 is activated by extracellular Ca(2+) ([Ca(2+)](e)) in concentration-response fashion. This activation, especially by 2 mM [Ca(2+)](e) was substantially suppressed by co-expression with TRPV1. Inside-out recordings demonstrated that intracellular Ca(2+) ([Ca(2+)](i))-triggered activation of TRPA1 was attenuated by the presence of TRPV1 only at 2 mM [Ca(2+)](e), but not in Ca(2+)-free conditions. Further, depletion of internal Ca(2+) stores by thapsigargin generated TRPA1-mediated currents, which is affected by TRPV1 in both Chinese hamster ovary cells and sensory neurons. Since mustard oil current (I(MO)) is modulated by [Ca(2+)](e), we next examined whether alterations in the Ca(2+)-permeability of TRPV1 by mutating Y671 effect I(MO) properties. First it was demonstrated that the mutations in TRPV1 did not affect association of the TRPA1 and TRPV1 channels. However, these TRPV1 mutations, particularly Y671K, altered the following characteristics of TRPA1: magnitude of I(MO) in presence and absence of [Ca(2+)](e); the influence of [Ca(2+)](e) on the voltage-dependency of I(MO), and open probability of single-channel I(MO). In summary, activation of TRPA1 by [Ca(2+)](e) and [Ca(2+)](i) is controlled by the TRPV1 channel, and characteristics of I(MO) depend on Ca(2+) permeability of the TRPV1 channel.

Evaluation of Antiasthmatic Activity of Curculigo orchioides Gaertn. Rhizomes.

The ethanol extract of Curculigo orchioides was evaluated for antiasthmatic activity by using various in vitro and in vivo animal models. In vitro models like isolated goat tracheal chain preparation and isolated guinea pig ileum preparation were studied to know basic mechanism by which extract shows relaxant activity. The study showed that extract is effective against histamine-induced contraction. In isolated goat tracheal chain preparation and isolated guinea pig ileum preparation extract exhibits maximum relaxant effect (p< 0.01) against histamine at concentrations 100mug/ml and 25mug/ml respectively. Animal studies involved use of histamine induced bronchoconstriction in guinea pigs, egg albumin induced passive paw anaphylaxis in rats and haloperidol-induced catalepsy in mice. These studies showed significant (p< 0.01) protection at lower doses while further increase in the dose level showed reduced activity. Biochemical estimations in milk-induced total leukocytes count and milk-induced differential leukocyte count were also studied. In this study there was maximum increase in leucocytes and lymphocytes (99%) and maximum decrease in eosinophils up to 0% at dose 375mg/kg p.o. body weight was observed. The results of these studies indicated usefulness of ethanol extract of Curculigo orchioides in asthma.

Design, synthesis and antihistaminic (H1)activity of some condensed 2-(substituted)arylaminoethylpyrimidin-4(3H)-ones.

The synthesis and potential H1 receptor antagonistic activity of two novel series of condensed 2-arylaminoethylpyrimidin-4(3H)-ones (4, 5) and 4-amino-2-arylaminoethyl pyrimidines (6) have been reported. All the novel compounds were found to antagonize histamine in a competitive and reversible manner. When tested on guinea-pig ileum, compounds exhibited H1-antagonistic activity, (pA2 values) in the range of 8.6 to 9.7. Some of the lead compounds were evaluated by an in vivo method and were found to protect the guinea pigs against the histamine induced asphyxic shock at the doses comparable to or lower than those of the standard drugs, cetirizine (CAS 83881-51-0) and terfenadine (CAS 50679-08-8). The pA2 acetylcholine values of some of the lead compounds reflect about 1000-fold selectivity for histamine (H1) receptors. The 4-aminopyrimidines (6) were found to be more selective than their 4-one analogs (4, 5). In the radioligand binding study, one of the lead compounds, 6e, was found to bind reversibly at the histamine H1 receptor with the K1 value of 1.3 mumol/l and IC50 of 3.8 mumol/l. The lead compounds were found to have negligible sedative potential when tested in vivo. An indirect type of molecular modeling approach, using temelastine (CAS 86181-42-2) as the standard ligand, indicates that the potent activity of 4, 5 and 6 may be due to the increased spacer chain length between the pyrimidine nucleus and the side-chain aromatic ring.