Discovery of chemical markers for improving the quality and safety control of Sinomenium acutum stem by the simultaneous determination of multiple alkaloids using UHPLC-QQQ-MS/MS.

Sinomenium acutum stem is a popular traditional Chinese medicine used to treat bone and joint diseases. Sinomenine is considered the only chemical marker for the quality control of S. acutum stem in mainstream pharmacopeias. However, higenamine in S. acutum stem is a novel stimulant that was banned by the World Anti-Doping Agency in 2017. Therefore, enhancing the quality and safety control of S. acutum stem to avoid potential safety risks is of utmost importance. In this study, a fast, sensitive, precise, and accurate method for the simultaneous determination of 11 alkaloids in S. acutum stem by ultrahigh-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-QQQ-MS/MS) was established. This method successfully analyzed thirty-five batches of S. acutum stem samples. The average contents of sinomenine, magnoflorine, coclaurine, acutumine, higenamine, sinoacutine, palmatine, magnocurarine, columbamine, 8-oxypalmatine, and jatrorrhizine were 24.9 mg/g, 6.35 mg/g, 435 µg/g, 435 µg/g, 288 µg/g, 44.4 µg/g, 22.5 µg/g, 21.1 µg/g, 15.8 µg/g, 9.30 µg/g, and 8.75 µg/g, respectively. Multivariate analysis, including principal component analysis (PCA), orthogonal partial least square method-discriminant analysis (OPLS-DA), and hierarchical cluster analysis (HCA), were performed to characterize the importance and differences among these alkaloids in S. acutum stem samples. As a result, sinomenine, magnoflorine, coclaurine, acutumine, and higenamine are proposed as chemical markers for quality control. Higenamine and coclaurine are also recommended as chemical markers for safety control. This report provides five alkaloids that can be used as chemical markers for improving the quality and safety control of S. acutum stem. It also alerts athletes to avoid the risks associated with consuming S. acutum stem.

Naloxegol, an opioid antagonist with reduced CNS penetration: Mode-of-action and human relevance for rat testicular tumours.

Naloxegol is an opioid antagonist which has been developed for the treatment of patients with opioid induced constipation. In the nonclinical safety program naloxegol was shown to have a very benign toxicity profile. In the rat, but not the mouse, 2-year carcinogenicity study a change in tumour pattern with an increase in testicular Leydig cell tumours (LCT) was observed after dosing at high (supra-pharmacological) concentrations. To establish the basis of the increase in LCT and to assess its potential relevance to humans, studies to exclude and potentially identify mode-of-action (MoA) were performed. A genotoxic mechanism was ruled out following negative results in the Ames, mouse lymphoma, and micronucleus assays. An effect on androgen metabolism was excluded since the treatment of rats with naloxegol for 14days did not result in any induction of CYP protein levels. It was demonstrated that administration of centrally restricted opioid antagonists naloxegol or methylnaltrexone at high doses induced an increase in LH release with no clear increase in testosterone, in contrast to the centrally acting opioid antagonist naloxone, which showed marked increases in both LH and testosterone. LCT due to increased LH stimulation is common in rats but not documented in humans. Collectively, the lack of genotoxicity signal, the lack of androgen effect, the increase in LH secretion in rats, which is no considered to be relevant for LCT formation in humans, and high margins to clinical exposures, the observed increase in LCT in the rat is not expected to be clinically relevant.

Development and evaluation of the Sinomenine transdermal patch.

Sinomenine transdermal patch was prepared and its properties were studied. The patches were produced by salivation method. The releasing rate in vitro of the patch was determined by HPLC. Peel test was used to evaluate the adhesion. Acute skin irritation test was performed in comparison with formalin (0.8%) by using mouse model. The Sinomenine TDDS Patch was prepared. The releasing rate in vitro followed the Higuchi equation (r>0.99), the releasing amount was beyond 90% in 24h. The peel adhesion to steel (N/25 mm) is 10 or above. The skin irritation tests showed negligible erythema and edema. The Sinomenine transdermal patch was prepared successfully and it may be beneficial for topical use.

[New study progress of sinomenine].

To further understand sinomenine, this paper has introduced the abstract technology, assaying, pharmaceutical chemistry, pharmacological action, pharmacotoxicology, pharmacokinetics and clinical application of sinomenine based on the important and significant contents of reference which have been consulted in the past ten years. Sinomenine is a kind of non-steroidal anti-inflammatory drugs with very effective and little side effect and expected it as a good new drug withdrawal medicine in the future.

Cytotoxic effects of sinococuline.

Three alkaloids, aknadinine, 1-nitroaknadinine and sinococuline, isolated from Stephania sutchuenensis were studied for their effects on a fibroblast cell line, eight tumor cell lines and a rat alveolar macrophage culture. Sinococuline is an effective tumor cell growth inhibitor whereas the toxicity of aknadinine and 1-nitroaknadinine towards all tested cells is low. A dose-dependent decrease in cell viability and in the uptake of tritiated-thymidine, -leucine and -uridine by these cells was observed when they were grown in the presence of sinococuline for 24 h. Exposure to sinococuline in vitro also altered the macrophage function by reducing the production of tumor necrosis factor and reactive nitrogen intermediates. Human leukaemic HL60 cells and mouse fibroblast L929 cells were used to study the underlying mechanism of cytotoxicity and apoptosis seem to be the mode of death induced by sinococuline

Xorphanol.

Xorphanol is a new mixed agonist-antagonist from the morphinan class of analgesics. On the basis of animal experiments, the physical dependence liability of xorphanol is predicted to be of a low order in man. Conceptually, xorphanol is of interest since in vitro experiments have revealed anti-naloxone properties and resistance to antagonism by opioid antagonists. At the practical level, xorphanol is a well tolerated, orally active analgesic that provides effective pain relief clinically.

Differentiation of multiple analgesic opiate receptors.

In order to analyse opiate receptors mediating anti-nociception, the activity pattern of different opiates was determined by using hot-plate (45 degrees C and 56 degrees C), tail-flick and algolytic tests on rats, and the acetic acid stretching test on mice, for evaluation of analgesic activity. Potentiation of barbiturate anaesthesia, measurement of pupillary diameter, and a modification of pentetrazol convulsion, were used for evaluation of non-analgesic activity. The efficacy and affinity constant (pA2) of the proposed opiate A receptor agonist and B receptor antagonist drug N-cyclopropylmethyl-norazido-dihydroisomorphine (CAM) were determined. CAM produced several opiate agonist (morphine-like) effects, often stronger than morphine, in three of the analgesic tests and two of the non-analgesic tests. On the other hand CAM proved to be a very strong narcotic antagonist, as potent as naloxone as evidenced by identical pA2 values, in the algolytic, 45 degrees C hot-plate and pentetrazol tests, but not in the 56 degrees C hot-plate, tail-flick and acetic acid tests. The potency differences for the actions of morphine and CAM in a heat test (56 degrees C hot-plate) compared with a non-heat test (acetic acid stretching) were found to be 8.6 and 540 respectively. It is concluded that opiate analgesia might be mediated by at least two receptors classified in terms of the antagonistic or agonistic activity of CAM.

Preclinical toxicity and teratogenicity studies with the narcotic antagonist analgesic drug TR5379M.

The narcotic antagonist TR5379M had po LD50 values of 365 and 750 mg/kg and iv LD50 values of 35.0 and 22.3 mg/kg in the mouse and rat, respectively. Subchronic (one month) po administration to rats at 40, 120, or 400 mg/kg/day and to cynomolgus monkeys at 20, 45, or 100 mg/kg/day showed the compound to be well tolerated at doses of 40 and 45 mg/kg, respectively. Deaths during the subchronic studies included one monkey following a single dose of 100 mg/kg and six rats following repeated doses of 400 mg/kg. Signs of toxicosis in rats included clonic convulsions (high-dose animals only) and mild dose-related salivation and hyperactivity. Signs of toxicosis in monkeys were limited to sporadic emesis and transiently decreased food consumption at all three dose levels. Emesis was not observed at doses of 20 or 45 mg/kg after the first week. Slightly increased weights (not significant at 40 mg/kg) for thyroid and adrenal glands occurred in male rats. Gross, microscopic, and clinical pathologic examinations revealed no treatment-related adverse effects at any dose level for either species. Administration of TR5379M to pregnant rats (20, 70, or 250 mg/kg/day on Days 6-15 of gestation) caused no teratogenicity or embryotoxicity and did not adversely affect any of the reproductive parameters examined. Dams given TR5379M at doses of 70 and 250 mg/kg salivated and had reduced weight gain. It was concluded from these studies that TR5379M has an adequate margin of safety to begin clinical investigations.

Reversible suppression of spermiogenesis in beagle dogs following overdosage with the narcotic analgesic cogazocine lactate.

Acute single overdosage (1.0 mg/kg, i.m.) with the novel benzmorphan narcotic analgesic agent Cogazocine lactate lowered serum LH and testosterone concentrations of Beagle dogs. The effect was rapidly reversible and persisted for less than 24 h after drug administration. Repeated administration (1.0 mg/kg, i.m.) induced reversible suppression of spermatid maturation with subsequent effects on semen characteristics. Examination of circulating LH and testosterone concentrations, together with pituitary and prostate morphology, suggested that the changes were due to inhibition of LH release. It is probable that the underlying mechanism is an exaggerated pharmacological response to repeated overdosage, common to many potent narcotic analgesic agents.

The pharmacology of 20681-S and 20682-S, 6-oxo-N-cyclopropylmethylmorphinans, as narcotic antagonist analgesics.

It has been demonstrated that L-3hydroxy-6-oxo-N-cyclopropylmethylmorphinan methansulfonate (20681-S) and L-3,14-dihydroxy-6-oxo-N-cyclopropylmethylmorphinan methansulfonate (20682-S), have antinociceptive and narcotic antagonistic properties. In the rodent antinociceptive test, the action of 20681-S was more potent and of longer duration than that of morphine and of cyclazocine after subcutaneous or oral administration. The antinociceptive effect of 20682-S ranked between that of morphine and that of pentazocine in the mouse acetic acid-writhing test. Both compounds possessed potent narcotic antagonistic activities, 20682-S being more active than naloxone and oxilorphan and 20681-S being equipotent with cyclazocine. The latent side effects (respiratory depression and fall in blood pressure) and the acute toxicity of 20681-S and 20682-S, were less than those of reference narcotic antagonists or of narcotic antagonist analgesics.

The animal pharmacology of buprenorphine, an oripavine analgesic agent.

1. The general pharmacology of buprenorphine, a potent analgesic agent derived from oripavine, is described. 2. After cute administration of buprenorphine, the spontaneous locomotor activity of mice was increased; rats displayed stereotyped licking and biting movements; behavioural depression was marked in guinea-pigs but mild in rhesus monkeys. The behaviour of cats was unchanged. 3. In general, buprenorphine reduced heart rate but had no significant effect on arterial blood pressure in conscious rats and dogs. 4. In anaesthetized, open-chest cats buprenorphine (0.10 and 1.0 mg/kg, i.v.) caused no major haemodynamic changes. 5. Buprenorphine (0.01-10 mg/kg i.a.) and morphine (0.30-30 mg/kg, i.a.) increased arterial PCO2 values and reduced PO2 values in conscious rats. With doses of buprenorphine greater than 0.10 mg/kg (a) the duration of respiratory depression became less, (b) ceiling effects occurred such that the maximum effects produced were less than those obtained with morphine. 6. Buprenorphine was a potent and long-lasting antagonist of citric acid-induced coughing in guinea-pigs. 7. At a dose level 20 times greater than the ED50 for antinociception (tail pressure), morphine suppressed urine output to a greater extent than the corresponding dose of buprenorphine in rats. 8. Over the range 0.01-1.0 mg/kg (s.c.), buprenorphine slowed the passage of a charcoal meal along the gastrointestinal tract in rats. After doses in excess of 1 mg/kg, the meal travelled increasingly further such that the distances measured at 10 and 30 mg/kg did not differ significantly from control values. In contrast, the morphine dose-response relationship was linear.

Partial agonist properties and toxicity of oral oxilorphan.

Alternative pharmacologic adjuncts are needed for the management of opiate abuse. Oxilorphan, a narcotic antagonist, was studied at 5 different dose levels (1, 2, 4, 6, and 8 mg) in 30 normal subjects to determine the relation of single oral doses and toxicity. The drug causes pupillary constriction and mild central nervous system side effects (nausea, dizziness) at all doses. Mean urine volume increased (P less than 0.05) during the 12 hours after 1 and 2 mg. Oxilorphan has partial agonist properties similar to dl-cyclazocine.

Antitussive activity and other related pharmacological properties of d-3-methyl-N-methylmorphinan (AT-17).

Antitussive activity and some other related pharmacological properties of d-3-methyl-N-methylmorphinan were studied. Toxic symptoms in mice and dogs were due to the CNS excitation. Acute toxicity of (AT-17) in mice was slightly (s.c.) or far (p.o.) weaker than that of codeine, but it was three times as toxic as codeine in dogs (i.v.). Antitussive efficacy was about 40% of that of codeine in dogs, whereas 77% as potent as codeine in cats. It showed no relaxing effect on the bronchial muscle of guinea pigs in either normal tone or histamine-induced spasms. It had analgesic effect 1/3 as potent as codeine in mice but it was not antagonized by levallorphan. The prolongation of hexobarbital sleeping time by AT-17 was similar extent to that by codeine. Anti-electroshock effect was half as potent as that of phenobarbital. The inhibitory effect on the transportation of intestinal contents in mice was far weaker than that of codeine. Effect on the respiratory and circulatory systems were also investigated.

Oxilorphan (l-N-cyclopropylmethyl-3,14-dihydroxymorphinan): a new synthetic narcotic antagonist.

Oxilorphan is a fully synthetic morphinan derivative containing the 14-hydroxy group characteristics of naloxone and naltrexone. As a narcotic antagonist, oxilorphan was 4 times more potent than dl-cyclazocine, equipotent to naloxone and about one-fourth as potent as naltrexone parenterally. Duration studies in rodents were inconclusive, but in antagonism of morphine analgesia and miosis in the dog, oxilorphan was longer acting than naloxone and equivalent to dl-cyclazocine. Oxilorphan was inactive in the conventional animal thermal analgesic tests. However, oxilone did exhibit relatively weak analgesic activity in preventing phenylquinone-induced abdominal contraction at doses about 700 times higher than those required for antagonist activity. The analgesic potency of oxilorphan was only 120 and 1/300 the potency of morphine and dl-cyclazocine, respectively, but was significantly greater than naltrexone and naloxone. Mice chronically treated with increasing doses of oxilorphan failed to exhibit withdrawal jumping after naloxone challenge. General central nervous system activity studies showed oxilorphan to be relatively free from central side effects at doses at which dl-cyclazocine produced pronounced effects.