PART 1: Screening of Thirty-one Medicinal Plant Species Against Herpes Simplex Virus, Acetone and Methanol Extracts from the Root Tissue of Kalanchoe pinnata Interferes with HSV Types 1 and 2 DNA replication and Early and Late Gene Expression Preventing the Spread of HSV in vitroPART 2: Professional Development Curriculum: Integrating Molecular Biology and Microbiology into the Existing Secondary Biology Curricula
PART 1: Thirty-one medicinal plant species from Hawaii, Morocco, and the Sonoran Desert, USA have been shown in past studies to be highly inhibitory to pathogenic bacteria, fungi, and certain cancer cell lines. However, none were tested for antiviral activity. Acetone and methanol extracts from these species were bio-assayed for antiviral activity against herpes simplex virus types 1 and 2 (HSV 1 and HSV 2) and for cytotoxicity to the Vero C1008 cell line. Extracts from these species were tested in vitro for antiviral activity using an immunoperoxidase mini-plaque reduction assay to detect viral structural protein synthesis. Sulforhodamine B and neutral red assays were used to qualitatively and quantitatively assess the cytotoxicity of extracts to C1008 cells, and to compute a 50% cytotoxic concentration (CC50) using a dose response curve. Eight of the 31 plant species assayed showed significant antiviral activity against herpes simplex virus types 1 and 2. The acetone extract of Kalanchoe pinnata Pers. (Crassulaceae) produced the most promising results with an IC50 of 0.025 mg/ml and a CC50 of 1.25 mg/ml yielding a therapeutic index of 50. Additionally, this extract reduced plaque numbers to zero or near zero at a concentration of 0.1 mg/ml when added 30 min before and up to 8 h post infection. Further tests were performed on the K. pinnata extract in pursuit of the mechanisms of observed antiviral properties. Quantitative PCR was used to determine HSV susceptibility to the acetone extract. Antiviral mechanisms were investigated by measuring the reduction of viral DNA at different time points post infection and by measuring the reduction of viral RNA transcripts for five specific genes: alpha gene UL54, beta genes UL23 and UL30, and gamma genes US4 and UL17. Examination of transcript number found a significant decrease in viral DNA replication and early and late gene transcription when infected cells were exposed to K. pinnata suggesting post entry events were blocked by extract.
PART 2: The professional development curriculum was written for the Alpine School District and will offer teachers the opportunity to develop and enhance skills for effective science teaching emphasizing molecular biology and microbiology disciplines. The course begins with four assumptions about the nature of secondary science in-service. First, the understandings and abilities required to be a masterful teacher of science are not static. Second, science content increases and changes, and a teacher's understanding in science must keep pace. Third, knowledge about the process of learning is continually developing, requiring teachers to stay informed. And fourth, we live in a changing society that deeply influences events in schools; social changes affect students as they come to school and affect what they need to carry away with them. While the main intent of this course is to improve the knowledge base for secondary life science teachers in the microbiology and molecular biology disciplines, it is expected that teachers will return to their own classroom and use the materials and ideas they have acquired from this course. Included in the concepts stressed are: 1) the historical routes of molecular biology, (2) biotechnology and its influence in society, (3) the relationship between viruses and evolution, order and organization, (4) the immune system and examples that stress structure and function, change and constancy, and (5) the personal and social impact of pathogens. Teachers are introduced to new information in virology, molecular biology and immunology using case studies, practicing scientific inquiry, and recognizing the unifying themes of biology in microbiology and molecular biology.