James W. Rushing

Isolation, purification, and full NMR assignments of cyclopamine from Veratrum californicum

BackgroundThe Hedgehog signaling pathway is essential for embryogenesis and for tissue homeostasis in the adult. However, it may induce malignancies in a number of tissues when constitutively activated, and it may also have a role in other forms of normal and maladaptive growth. Cyclopamine, a naturally occurring steroidal alkaloid, specifically inhibits the Hedgehog pathway by binding directly to Smoothened, an important Hedgehog response element. To use cyclopamine as a tool to explore and/or inhibit the Hedgehog pathway in vivo, a substantial quantity is required, and as a practical matter cyclopamine has been effectively unavailable for usage in animals larger than mice.ResultsIn this paper, we report a rapid and efficient isolation and purification of large quantities of cyclopamine from the roots and rhizomes of Veratrum californicum Dur. (the Corn Lily or Western false hellebore). We also provide unambiguous assignments of the carbon and proton resonances by using the multinuclear spectra and the spin coupling networks.ConclusionThis method could meet a very real need within diverse scientific communities by allowing cyclopamine to become more readily available.

Bemisia argentifolii (Homoptera: Aleyrodidae) Attacking Species of Medicinal Herbal Plants

Abstract Research was conducted on the production potential of selected medicinal herbal plant species as new crops suitable for cultivation in South Carolina. Whiteflies (Bemisia argentifolii Bellows & Perring) were found in an experimental production field infesting five perennial species of medicinal herbal plants [feverfew, Tanacetum parthenium (L.) Schultz-Bipontinus; St. John’s wort, Hypericum perforatum L.; purple coneflower, Echinacea pallida (Nuttall) Nuttall and E. purpurea (L.) Moench; and common valerian, Valeriana officinalis L.]. This article reports on whiteflies attacking and developing on these plant species. Density of whitefly nymphs was highest (mean = 2.3/cm2) on the second fully expanded leaf on the apical meristem of E. purpurea as compared with the same leaf position on the other plant species where average whitefly density ranged from 0.1 to 0.6 nymphs per square centimeter from late November 1998 through January 1999. Similarly, adult capture on sticky cards was high (mean = 123 whiteflies per card) in plots of E. purpurea compared with plots of the other four species (mean = 8 to 20 whiteflies per card per species), and adult counts were elevated in the highest (440 kg N/ha) of three fertility rates in E. purpurea. Moreover, laboratory tests agreed with the observation of a higher population of B. argentifolii on E. purpurea compared with the other four plant species. The whitefly completed development on all five plant species, and whitefly-associated parasitoids emerged from field-leaf samples of each plant species.

Post-production stability of parthenolide in feverfew (Tanacetum parthenium)

ABSTRACT The influence of pH, temperature and light on parthenolide (PRT) content of feverfew was investigated. Feverfew powder and PRT standards mixed in citrate buffers at selected pH (2.4-7.2) were stored for four months. PRT declined in all treatments with greatest loss in solutions with pH below 5, and highest stability in solutions with pH 7.2. PRT in dry samples declined 30 percent after 320 days of storage. Degradation of PRT in feverfew solutions exposed to 40, 60, and 80°C for 24 h increased with increasing temperature. Dry samples exposed to various temperatures revealed stability of PRT at temperatures up to 130°C for short time periods.

Revival of Herbalism and Its Roots in Medicine

ABSTRACT The proper use of phytomedicines in human health care may add a dimension currently lacking in the United States in the treatment of certain diseases and syndromes. Sales of botanicals have been rising for the past few years and are expected to increase 12% to 16% annually for the next few years. As agriculturists, we are developing production techniques using good management practices to grow and process these new crops. However, a fundamental understanding of the genesis of this “new” industry is needed to appreciate the historic use of herbs and significance in society.

Dilemma of regulating dietary supplements.

ABSTRACT The manufacturing of herbal preparations or dietary supplements, has become a multibillion dollar industry in the United States. Presently, dietary supplements are not considered drugs by the government, but are classified as food supplements. The Dietary Supplement Health and Education Act of 1994 (DSHEA) has defined dietary supplements as a product intended to supplement the diet that contains one or more of a vitamin, mineral, an herb or other botanical, an amino acid or a dietary substance to supplement the diet by increasing the total dietary intake, or concentrates, metabolites, constituents, extracts or combinations of any ingredients described above. The main limitation of DSHEA is that it deals only with herbs as dietary supplements, i.e., as foods and not as drugs. A quandary still exists among: (1) the consumers who want to use these products safely; (2) the government that wishes to protect its citizens from potential hazards; and (3) the conventional medical community still questioning the safety and efficacy of these products. DSHEA does not appear to be the final verdict on herbal regulation, but just the first step in a long process of interpretation, evaluation, and decision-making required in the U.S. for regulation of any new class of such products. This paper reviews the current status facing the consumer, medical industry, and government in regards to herbal use.

Influence of Treatments with Heat, Chlorine Dioxide, or Ethylene Oxide on Microbiological Load and Parthenolide Content in Feverfew Leaves

Studies were conducted to determine the effects of heat treatments or fumigation with either chlorine dioxide (ClO2) or ethylene oxide (EO) gas on microbiological load and parthenolide content in feverfew (Tanacetum parthenium L. Schultz Bip) leaves. Treatments were applied postharvest in three separate studies. Heat treatments included dry heat (60°C for 48 h), steam heat (121°C for 20 min), or microwave heat (100%, 1200 W, 3 min). The ClO2 study included three concentrations: 2.2, 5, or 50 mg ClO2 L−1. The EO study included two concentrations: 4% or 12% v/v. Before and after each treatment, leaf powder was used to enumerate aerobic, coliform, and Escherichia coli counts using 3M Petrifilm count plates. Steam heat effectively eliminated microbiological contamination but reduced parthenolide content by 50%. Dry heat and microwave heat treatments both reduced microbiological load by 40%. Parthenolide content was reduced 10% by dry heat but was not affected by the microwave heat treatment. The ClO2 gas concentrations up to 5 mg ClO2 L−1 had no effect on microbial or parthenolide contents compared to the control. The 50 mg ClO2 L−1 concentration reduced the microbial content by 60% but also lowered the parthenolide content by 30%. Though 4% EO gas concentration had no effect on microbial load or parthenolide content, 12% gas concentration killed all the microbes present without affecting parthenolide content. These results suggest that fumigation with EO and microwave heat both have potential for use as sterilants for feverfew without affecting apparent medicinal quality.

An agromedicine initiative for first-year medical students, 1998-2004: biochemistry seminar proves feasible.

Abstract This report describes a 20 class-hour, 10-session seminar on agromedicine-oriented topics, delivered as part of a basic science course for medical students (biochemistry) at the Medical University of South Carolina. The course was initiated in 1998 and continued through 2004. The preceptors are family medicine and agricultural research professors. Concepts from primary care, epidemiology, entomology, toxicology, and food science appeal strongly to the first-year medical student group (limited to 10 students). The agromedicine/environmental medicine seminar series is one of 16 research seminars available for in-depth study. As part of the course in biochemistry, this seminar has earned positive evaluations from medical students who expect to widen their perspective on global health and the environment. Seminar topics include food safety, farm trauma, nutraceuticals, crop protection, insect-borne disease, occupational health and safety, diet and cancer, birth defects, and bioengineering. Seventy medical students have participated in the interdisciplinary seminar. They perceive environmental science as affecting the health of their patients and as an essential part of their preparation for curative and preventive medicine. Readers may find medical school curriculum committees more receptive to accepting and continuing an agromedicine offering if it can be incorporated in a basic science course such as biochemistry or pharmacology.