David H. Kinder

The hallucinogen derived from Salvia divinorum, salvinorin A, has κ-opioid agonist discriminative stimulus effects in rats

Data from clinical and preclinical studies converge implicating the plant-derived hallucinogen salvinorin A as an important pharmacologic tool; this psychoactive compound may expand scientific understandings on mammalian kappa-opioid receptor systems. Human salvinorin A effects, consistent with kappa-opioid receptor agonism, include antinociception, sedation, dysphoria and distorted perceptions. The experiments reported here measured salvinorin A (1-3mg/kg, i.p.) discriminative stimulus properties in male Sprague-Dawley rats conditioned to recognize the discriminative stimulus cue generated by the well characterized kappa-opioid agonist U-69593 (0.56 mg/kg, i.p.). At three distinct active doses, salvinorin A fully substituted for U-69593 without altering response rates. The lever choice pattern in U-69593 trained animals reverted to vehicle lever responding when a kappa selective antagonist compound, nor-BNI (4.5 nM, i.c.v.) was administered 1h prior to salvinorin A, yet nor-BNI alone failed to impact the rate or pattern of subject responses. These findings confirm and extend results published after similar drug discrimination tests were performed in rhesus monkeys. The discussion section of this article highlights public concern over salvinorin A misuse and emphasizes several potential pharmacotherapeutic applications for salvinorin A or analogue compounds.

Bromophenol blue staining of tumors in a rat glioma model.

OBJECTIVE:For patients with gliomas, decreasing the tumor burden with macroscopic surgical resection may affect quality of life, time to tumor progression, and survival. Injection of bromophenol blue (BPB) may enhance intraoperative visualization of an infiltrating tumor and its margins and improve the extent of resection. In this study, we investigated the uptake of BPB in experimental rat brain tumors. METHODS:We first conducted a toxicity study with bolus intravenous injections of 5, 60, and 360 mg/kg doses of BPB in nontumor-bearing Fischer 344 rats. No adverse effects were observed in any of the animals during the 60 day observation period. We then injected 9L tumor cells intracerebrally into Fischer 344 rats and approximately 2 weeks later, administered a bolus intravenous injection of 5 to 360 mg/kg BPB. Fifteen minutes after BPB injection, we sacrificed the animals and removed their brains. In a subsequent study, we injected 180 mg/kg BPB and sacrificed animals at several time points to monitor tumor staining over time. RESULTS:The stain was clearly visible and localized to the tumor for all BPB concentrations 60 mg/kg or greater, and in an additional experiment, we found that tumor staining persisted for at least 8 hours after BPB injection. CONCLUSION:We conclude that BPB helped visualize experimental tumors at time points from a few minutes to several hours after injection. Because BPB also proved to be nontoxic to the animals at effective concentrations, we believe the compound may be potentially useful in helping neurosurgeons visualize brain tumors in humans.

Effects of Extracts of Lupine Seed on Blood Glucose Levels in Glucose Resistant Mice: Antihyperglycemic Effects of Lupinus albus (White Lupine, Egypt) and Lupinus caudatus (Tailcup Lupine, Mesa Verde National Park)

Lupine is a medicinal food plant with potential value in the management of diabetes. In white mice, extracts of seeds of the white lupine [Lupinus albus (L. termis L.)] were associated with increased tolerance to an oral glucose bolus. Antihyperglycemic activity was present in extracts of the whole seed but not extracts of the seed coat, and was not detected when glucose was administered intraperitoneally rather than orally. However, in contrast to results seen with the prescription drug, acarbose, lupine extract did not appear to increase the bulk or carbohydrate content of the feces. Antihyperglycemic activity was also seen in extracts of the tailcup lupine (L. caudatus) found in the Four Corners Region of the United States.

A Comprehensive Ligand Based Mapping of the σ 2 Receptor Binding Pocket

The sigma (σ) receptor system consists of at least two major receptor subtypes: σ₁ and σ₂. Several potential therapeutic applications would benefit from structural knowledge of the σ₂ receptor but gaining this knowledge has been hampered by the difficulties associated with its isolation and, thus, characterization. Here, a ligand based approach has been adopted using the program PHASE® and a group of 41 potent and structurally diverse σ₂ ligands to develop several pharmacophore models for different families of σ₂ ligands. These pharmacophores were analyzed to identify the different binding modes to the receptor and were combined together to construct a comprehensive pharmacophore that was used to develop a structural model for the σ₂ binding pocket. A total of six binding modes were identified and could be classified as neutral or charged modes. The results presented here also indicate the significance of hydrophobic interactions to σ₂ binding and the requirement of hydrogen bonding interactions to increase the affinity for this receptor subtype. This work adds breadth to our knowledge of this receptors binding site, and should contribute significantly to the development of novel selective σ₂ ligands.

The effectiveness of jewelweed, Impatiens capensis, the related cultivar I. balsamina and the component, lawsone in preventing post poison ivy exposure contact dermatitis.

ETHNOPHARMACOLOGICAL RELEVANCE Impatiens capensis (jewelweed) is native to the Eastern and Midwestern US and Canada. Many Native American tribes used I. capensis and its close relatives to treat/prevent rash from plant sources particularly Toxicodendron radicans and Urtica dioica. I. balsamina (garden balsam) a native of China was used by the indigenous people of Asia for similar purposes. AIM OF STUDY This study aims to validate ethnopharmacological use of jewelweed in poison ivy (PI) dermatitis prevention and to refute scientific papers denying this efficacy. Additionally, the content of lawsone, the purported effective agent in jewelweed preparations, was measured to see if its concentration correlated with jewelweed preparation efficacy. MATERIAL AND METHODS Poison ivy was brushed onto forearms of volunteers in 6 locations and exposed areas were treated with jewelweed extracts, fresh plant mashes, soaps made of plant extracts, water and Dawn® dish soap. Rash development was scored on a scale of 0-14. RESULTS Jewelweed mash was effective in reducing poison ivy dermatitis, supporting ethnobotanical use. However, jewelweed extracts were not effective; and soaps made of these extracts were effective but no more so than jewelweed-free soaps. Lawsone content varied with harvest season and did not appear to affect rash development. CONCLUSION Jewelweed is an efficacious plant for preventing development of dermatitis following poison ivy contact, but soap is more effective. Lawsone content does not correlate with PI rash prevention. Perhaps saponins, the soapy component of jewelweed are the effective agents.

Efficacy of the saponin component of Impatiens capensis Meerb.in preventing urushiol-induced contact dermatitis.

ETHNOPHARMACOLOGICAL RELEVANCE Many different tribes of American Indians used jewelweed, Impatiens capensis Meerb, as a plant mash to reduce development of poison ivy dermatitis. Saponins are a natural soapy constituent found within plants. A 2012 study suggested that saponins may be present in jewelweed which could be responsible for its efficacy in preventing rash development following contact with Toxicodendron radicans (L.) Kuntze (poison ivy). This study validated this hypothesis and demonstrated additional biological activity of the jewelweed saponin containing extract. MATERIALS AND METHODS Fresh I. capensis leaves were extracted with methanol and further partitioned between ethyl acetate and water, with a final separation between water and n-butanol, to obtain a saponin containing extract. The presence of saponins in the extract was demonstrated by the observation of foaming and using a vanillin colorimetric assay for total saponins. Efficacy of the saponin containing extracts in rash reduction was tested by brushing poison ivy (PI) onto the forearms of volunteers (N=23) in six locations and treating these PI exposed areas with distilled water (control), saponin containing extracts, fresh plant mashes, and soaps made with and without plant extracts. Saponin containing extracts were further tested for biological activity against both gram negative and gram positive bacteria and against cancer cell lines A-375, HT-29, and MCF-7. Additionally, because saponins have been shown to have a stimulatory effect in cardiac muscle 2 µl saponin extract was applied superficially to black worms, Lumbriculus variegatus (N=5). RESULTS, AND CONCLUSIONS Both saponin containing extracts and all soaps tested were effective in reducing poison ivy dermatitis; thus, saponin content correlates with PI rash prevention. No apparent antibiosis was observed against any bacteria tested; however, dose response cytotoxicity was documented against MCF-7 breast cancer cells and cytostatic activity was seen against the HT-29 colon cancer cell lines. Lumbriculus variegatus exhibited a 138% increase in heart rate over baseline rate five minutes post treatment implying a possible positive chronotropic effect.

Lupine ( Lupinus caudatus L., Lupinus albus L.) Seeds: History of Use, Use as an Antihyperglycemic Medicinal, and Use as a Food

Publisher Summary This chapter highlights the medicinal properties of lupine seeds. In the case of the lupine, the plant also provides a source of nourishment that might not otherwise be available. It is also one of the several plant materials that have been shown to control diabetes in the lupine. The primary alkaloids found in most lupine species are lupinine and sparteine, which are part of the quinolizidine alkaloid class. This class of alkaloid can be hepatotoxic in large quantities. Most work related to the hypoglycemic effects of lupine has been conducted in animals. Recent work on streptozoticin-induced diabetic rats has shown that extracts of the seed can lower blood glucose levels in these rats to normal levels and can blunt the glucose spike following a meal. A major protein component of the seed is conglutins, which, in addition to their food value, have potentially therapeutic effects on cholesterol and blood glucose. Lupine, like other legumes, contains fiber as well as protein. Quinolizidine and pyrolizidine alkaloids are present in the lupine seeds and must be removed before consumption to avoid toxicity. Sweet lupines have been cultivated for their use as a feed in countries where arid conditions preclude or hamper the production of soybean.

Solid-phase synthesis of hydroxyethylamine angiotensin analogues.

Three hydroxyethylamine analogues of angiotensins II, III, and IV were prepared by solid-phase methods. The resin-bound peptide was alkylated with the iodomethylketone derivative of the N-terminal amino acid, followed by reduction to the alcohol using sodium borohydride. The iodomethylketones can be made in good yields from commercially available N-protected amino acids. The compounds were evaluated for their ability to displace labeled angiotensins from bovine adrenal membranes, and their metabolic stability tested in kidney homogenates and aminopeptidase M preparations. The hydroxyethylamine amide bond replacement reduced the affinity of the analogues; however, they were substantially more stable to enzymatic degradation.

Abstract 4297: Morphology of MCF-7 colonies formed in agarose cell culture

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Previously, we demonstrated that the MCF-7 cell line grows in a permissive 3-D agarose culture (Kinder and Aulthouse, Cancer Letters., 2004, 205(1), 49-53). Single cells form colonies over time; thus, mitotic activity can be monitored in response to various agents. We studied the morphology of the colonies that formed following growth from single cells at 3 time points: 1.5, 2, 2.5 weeks. The MCF-7 cells grew into clusters (solid) and hollow tube-like structures. These structures were confirmed by H&E stained serial sections of paraffin embedded cultures. H&E staining also revealed abundant mitotic figures. Because calcium foci are common in breast cancers, we also evaluated the cultures for calcium expression using the von Kossa reaction. Placenta was used as a control. At all time points, calcium was detected, but no particular pattern was noted in the calcium distribution between the clusters and the hollow tube-like structures. With morphology and calcium expression described, we further examined cell growth inhibition and cytotoxicity of estradiol and tamoxifen on the MCF-7 cells. Added estradiol enhanced the growth of the cells, while tamoxifen was cytostatic at concentrations below 1.3 × 10-4 nM. At high tamoxifen concentrations (>2 × 10-4 nM) cytotoxicity was noted. This was likely due to sigma-2 receptor binding rather than estrogen receptor blocking. Combination of estradiol with tamoxifen had a more pronounced effect on the cytotoxicity caused by tamoxifen. These morphological and mechanistic findings support the use of this model for studying the MCF-7 cell line in agarose culture. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4297. doi:10.1158/1538-7445.AM2011-4297

Computational strategies for the development of novel small molecule rheumatoid arthritis therapies.

Rheumatoid arthritis is a chronic autoimmune disorder that causes joint disfigurement and destruction leading to reduced quality of life. Effective drug therapies include the Disease Modifying Anti-Rheumatic Drugs which can help impede the progression of the disease but are not always effective. It is, therefore important to identify novel and effective therapies to combat this debilitating disorder. Several bioinformatics tools and computational approaches can be utilized to identify novel and effective therapies for rheumatoid arthritis and these are presented here.