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PROSPECTS
OF SAFETY AND EFFICANCY OF SAGRA-4U IN MALIGNANT DISEASES & Di-SANCOR
IN AIDS Andrejs Liepins, Ph.D. Professor for Cell Sciences and Immunology Faculty of Medicine Memorial University of Newfoundland St. John's. Newfoundland Canada HISTORICAL PERSPECTIVE Plants that contain alkaloids as well as other chemicals, have been used in traditional medicine for many centuries, a practice that precedes the introduction of agriculture. Medicinal plants are still today the primary source of materia medica in many parts of the world, i.e. China, India, Amazon Region, etc. It is estimated, that even today about 75% of the world population still relies on plants, plant extracts ( phytopharmaceuticals) as their primary source of medicinals (Abelson, 1990). There are about 121 clinically useful prescription drugs worldwide that are derived from the higher plants. About 74% of them came to the attention of pharmaceutical industries because of their use in traditional medicine. Among the drugs derived from plants are the anticancer agents aspirin, vinblastine, vincristine, taxol, morphine, codeine; quinine, atropine, and digitalis also come from plants. While many chemicals of living thing are common to all, there are differences (toxic, edible, narcotic, etc.) that have been exploited by mankind. What is one creatures poison can be innocuous or helpful to another. What is toxic to one tissue or a neoplasm may not be toxic to the rest of an anima1. Hence, natural product or phytopharmaceutical research has been conducted, in one form or another, for many centuries. It is estimated that about 13,000 plant species have been used as drugs throughout the world and that about 25% of our current materia medica is derived from plants either as teas and extracts or as pure substances (Tyler, 1994). In recent years, there has been a resurgence in the screening of plant extracts for pharcological activities as part of governmental and industrial drug development programs. Although laboratory chemists have produced a variety of so called "designer drugs", which are mainly variants of existing phytochemicals, none of these theoretical designed compounds, have made a significant clinical impact in terms of clinical outcome of the disease. Plant phytochemicals, particularly alkaloids, have diverse pharmacologic activities that range from cytotoxins to antihypertensives and antimalarials. A well known use of plant extract is the muscle relaxant tubocurarine, which in its crude extract form serves as an arrow poison used by Amazon Indian tribes to incapacitate animals and undesirable guests. On the other hand, cocaine, derived by chewing of coca leaves is reported to ameliorate hunger and physical increase endurance. Coniine, the principal toxic alkaloid in hemlock (Comium maculatum), was responsible for the death of the Greek philosopher Socrates. Similarly, nicotine in tobacco, is thought to be the alkaloid responsible for addiction to smoking, whereas mescaline is reputed to produce vivid halucinations and a feeling of well being. Papaverine, is one of the principal alkaloids of opium, as is morphine and codeine. The latter alkaloids continue to be the principal analgesic in clinical practice. despite their addictive properties. Long before viagra, yohimbine, has been used as an aphrodisiac, whether in its pure alkaloid form or in its more traditional form: boiled yohimbe tree bark. The alkaloid colchicine has a long standing medical use in the treatment of gout and as scientific tool for the study of cell division (mitosis). MEDICAL USES OF SANGUINARIA Extracts from the bloodroot sanguinarina (Sanguninaria canadensis) consist of a mixture of benzophenantridine alkaloids. This mixture of alkaloids has a long history of use in pharmaceutical products and its composition is well defined (Harkrader, 1990). The medicinal use of plant extracts containing sanguinaria is already well documented since early history. The personal military doctor to Nero Claudius Caesar Gennanicus (54-64 AD), Pedanius Dioskorides wrote the medical handbook "De Materia Medica" (74-79 AD) which served as the main medical handbook up to the XVth century when the second edition was published in Frankfurt in 1536. Sanguinaria is a benzophenanthridine a1kaloid derived from herbaceous perennials of the Papaveraceae family, i.e. Sanguinaria canadensis. Alkaloids such as chelerythrine and sanguinarine that have been extracted from members of this plant family have a centuries' long history for their uses in herbal medicine and the treatment of many diseases in European countries (Columbo and Bosisio, 1996). Its use in the United States dates as far back as 1830, when sanguinaria was used in cough medications for its expectorant properties (Harkrader, 1990). One of its most notable features in recent years has been its antimicrobial properties, where it has been shown to reduce both gingival inflammation and supragingival plaque (Laster and Lobene, 1990: Godowski et aI., 1995; Kuftinec et a/., 1990). This has created an increasing interest in sanguinaria, ultimately leading to numerous studies into sanguinarine for its applications in the dentistry field, especially regarding its antimicrobial use in toothpastes and mouthwashes. In addition to its dental applications sanguinaria has also been shown to have antiviral and antitumor properties (Columbo and Bosisio, 1996; Fadeeva and Beliaeva, 1997). At the biochemical level sanguinaria has numerous diverse effects. It is an inhibitor of Na/K+ ATPase (Das and Khanna, 1997), tubulin assembly (Wolff and Knipling, 1993), and NFKB (Chaturvedi et al., 1997). Most interesting, it is also a DNA intercalator, which binds preferentia1ly to GC rich sequences (Nandi and Maiti, 1985; Saran et al., 1995). Our interest in sanguinarine was derived due to its relationship to Ukrain. Both sanguinarine and Ukrain are alkaloids derived from the Papaveraceae family, from such species as Chelidonium majus and sanguinaria canadiensis. Ukrain has been shown to be malignotoxic both in vitro (Nowicky eta/., 1992) and in vivo (Vyas and Jain, 1996; Kadan eta/., 1996). Interestingly, Ukrain and sanguinaria has also been shown to induce bimodal programmed cell death in malignant cells (Liepins et al., 1996). This bimodal cell death was described as apoptosis occurring at lower concentrations of these alkaloids whereas a blister cell death occurred at higher concentrations, interposed by a silent period where the cells appeared normal. The widely used, sanguinaria and celandine plants whose active ingredients are thought to be the alkaloids: sanguinarine, chelidorine chelerethryne, berberine, coptisine as well as flavomoids and phenolic acids. Extracts from these plants have been reported to have antiviral, antitumor and antimicrobial properties both in vitro and in vivo (Colombo and Bosio, 1996). About 25% of all written prescriptions written in the United States are for drugs that contain compounds originally identified from plants used in traditional or folk medicine (Holland, 1994). The alkaloid berberine has a variety of unique phannacological effects: antimicrobial, diuretic, smooth muscle relaxant and cardiac depressant activities. Plants containing berberine have been historically used to fight a number of infectious organisms, and the sulfate, hydrochloride and chloride forms are used in Western pharmaceutical medicine as antibacterial agents (Bruneton, 1995). More recently, berberine has been found to inhibit cell death (apoptosis) ofthymocytes which are critical immune effector cells. It is well known that the effectiveness of cancer chemotherapy is limited by toxicity to immune effector cells. Hence this alkaloid has become of interest for new therapeutic modalities for cancer. A developmental research program was initiated many years ago dedicated to the evaluation of benzophenanthridine alkaloids as potential cancer therapeuticals. TOXICOLOGY Reproductive and development toxicology with orally administered sanguinaria extract in rats and rabbits: Rabits & Rats: 10-60 mg/kg/day: no adverse effects on: estrous cycle; male or female capulatory activity; fertility; teratogenicity, gestation; lactation. Maternal oral toxicity thresholds were 60 mg/kg/day in rats. Maternal oral toxicity thresholds were 25 mg/kg/day in rabbits. Acute toxicity ( RTECS ) Rat-oral: LD50: 1656 mg/kg Rat-IV: LD50: 29 mg/kg Mus-Scu: LD50: 102 mg/kg Mus-iv: LD50: 15,9 mg/kg Subchronic Toxicity: sanguinarine chloride Rat diet ( 14 days ): 0;1.5S; 4.5; 15 mg/kg/day = No test article related toxity Rat oral gavage ( 30 days ): 0; 0.06; 0,30; 0.60 mg/kg/day = No test article related toxity
Documented properties of sanguinarine. 1. Antimicrobial against bacteria, fungi, and protozoa, and viruses. 2. Anti-inflammatory. 3. Local anesthetic effects. 4. Inhibits hepatic drug-metabolizing enzyme system. 5. Protein kinase C inhibitor. 6. Anticholinesterase inhibitor. 7. Inhibits microtubule assembly. 8. Cytotoxic to malignant tumor cells: selective induction of apoptosis. 9. Overcomes multidrug resistance (MDR) induced by other alkaloid chemotherapeuticals. 10. Antiviral: inhibits HIV -reverse transcriptase. DEVELOPMENT OF THERAPIES Sanguinaria has undergone extension clinical tests for safety and efficacy with licensing for its use in mouth rinses and toothpastes for the treatment of gingivitis and peridental disease (Frankos, 1990). The National Cancer Institute (USA) screened sanguinarine in the Development Therapeutics Program (NSC 59270 and NSC 35067) against 60 human cancer cell lines, their results showed: Total growth inhibition: TGI = 1 x 10 -5.98M 50% growth inhibition: GI-50 = 1 x l0-5.66M 50% Lysts inhibition: LC-50 = 1 X 10-4.58M Thus, these results show that sanguinaria was effective in inhibiting all major human cancer cell lines at concentrations of 1.02 uM to 4.48 uM. Since the NCI Developmental Therapeutic program does not include normal human cells as controls for their screens, it becomes imperative that these data be compared with that obtained by screening test compounds against normal human cells. SANGUINARINE TOXICITY TO NORMAL HUMAN CE LLS PMN = > 200 uM Lymphocytes = > 100 uM Fibroblasts = > 100 uM Thus, sanguinarine is selectively cytostatic and cytotoxic to human cancer cells but not to human lymphoid and/or somatic cells. Further since berberine protects the immune system, they mocytes from apoptosis, is antirnicrobical diuretic and smooth muscle relaxant it was chemically conjugated to sanguinarine to produce SAGRA-4U. |