Rauwolfia derivatives and breast cancer. A case/control study in Olmsted County, Minnesota

Genus Rauvolfia: A review of its ethnopharmacology, phytochemistry, quality control/quality assurance, pharmacological activities and clinical evidence

ETHNOPHARMACOLOGICAL RELEVANCE

The plants are from the genus Rauvolfia Plum. ex L. (Apocynaceae), which is represented by 74 species with many synonyms, and distributed worldwide, especially in the Asian, and African continents. Traditionally, some of them are used for the treatment of various disorders related to the central nervous system (CNS), cardiovascular diseases (CVD), and as an antidote due to the presence of monoterpene indole alkaloids (MIAs) such as ajmaline (144), ajmalicine (164) serpentine (182), yohimbine (190) and reserpine (214).

AIM

The present review provides comprehensive summarization and critical analysis of the traditional to modern applications of Rauvolfia species, and the major focus was to include traditional uses, phytochemistry, quality control, pharmacological properties, as well as clinical evidence that may be useful in the drug discovery process.

MATERIALS AND METHODS

Information related to traditional uses, chemical constituents, separation techniques/analytical methods, and pharmacological properties of the genus Rauvolfia were obtained using electronic databases such as Web of Science, Scopus, SciFinder, PubMed, PubChem, ChemSpider, and Google Scholar between the years 1949-2021. The scientific name of the species and its synonyms were checked with the information of The Plant List.

RESULTS

A total of seventeen Rauvolfia species have been traditionally explored for various therapeutic applications, out of which the roots of R. serpentina and R. vomitoria are used most commonly for the treatment of many diseases. About 287 alkaloids, seven terpenoids, nine flavonoids, and four phenolic acids have been reported in different parts of the forty-three species. Quality control (QC)/quality assurance (QA) of extracts/herbal formulations of Rauvolfia species was analyzed by qualitative and quantitative methods based on the major MIAs such as compounds 144, 164, 182, 190, and 214 using HPTLC, HPLC, and HPLC-MS. The various extracts of different plant parts of thirteen Rauvolfia species are explored for their pharmacological properties such as antimicrobial, antioxidant, antiprotozoal, antitrypanosomal, antipsychotic, cardioprotective, cholinesterase inhibitory, and hepatoprotective. Of which, clinical trials of herbal formulations/extracts of R. serpentina and MIAs have been reported for CVD, CNS, antihypertensive therapy, antidiabetic effects, and psoriasis therapy, while the extracts and phytoconstituents of remaining Rauvolfia species are predominantly significant, owning them to be additional attention for further investigation under clinical trials and QC/QA.

CONCLUSION

The present communication has provided a comprehensive, systematic, and critically analyzed vision into the traditional uses, phytochemistry, and modern therapeutic applications of the genus Rauvolfia are validated by scientific evidence. In addition, different plant parts from this genus, especially raw and finished herbal products of the roots of R. serpentina have been demonstrated for the QC/QA.

Antihypertensive drugs and the risk of cancer: a critical review of available evidence and perspective

: The issue of a potential danger of antihypertensive drugs related to cancer susceptibility is currently generating a major debate in the scientific community, concerns in the public and emphasized interest from the media. The present article is a thorough review of what is known on the various classes of antihypertensive drugs concerning the risk of developing different neoplasms and about the suggested pathophysiological mechanisms, whenever available. The main limitations of evidence derived from studies currently available in this setting are also discussed, high-lightening the need for newly developed approaches to generate more accurate recommendations and informed advice for physicians.

Historical vignette: Leonard T. Kurland, FACE (1921-2001), the rise of neuroepidemiology, and the Rochester Epidemiology Project

The creation of the field of neuroepidemiology was one of the two principal professional achievements of the American College of Epidemiology Fellow Leonard T. Kurland (1921-2001), the other being the establishment of the Rochester Project. In the former, Kurland established the role of the neuroepidemiologists in the development of the corpus of knowledge needed to control and prevent the occurrence of neurological conditions. Two examples of his endeavors in this regard were his work on the Guamanian focus of neurodegenerative diseases and his seminal investigations into the epidemiology of multiple sclerosis. He was also instrumental in the development of the Rochester, Minnesota community as a population laboratory within which epidemiologic investigations could be mounted. This pioneering achievement created a resource used by many generations of epidemiologists and clinicians to examine health and disease in the population.

Gallbladder disease in the general population: association with cardiovascular morbidity and therapy

PURPOSE

Both gallbladder (GB) and cardiovascular disease are very common diagnoses that carry substantial economic costs. Prior studies suggest that personal history of ischaemic heart disease (IHD) could determine the occurrence of GB disease. Additionally the use of thiazide diuretics may also be a risk factor for this condition. We aimed to evaluate different cardiovascular conditions and related drugs that could be associated with GB disease.

METHODS

We identified all incident cases of gallbladder disease occurring during 1996 among patients aged 20-79 years old registered in the General Practitioner Research Database. We performed a nested case control analysis using 2353 cases and 10,000 controls frequency matched to the cases by age and sex.

RESULTS

After adjusting for potential confounders IHD was associated with a small increased risk of GB disease (1.29, 95%CI:1.08-1.55). When only cases requiring cholecystectomy were considered in the analysis, the resulting estimate was 1.06 (95%CI:0.83-1.35). Users of thiazide diuretics presented an OR of 1.36 (95%CI:1.08-1.71). Other antihypertensive drugs were not associated with GB disease.

CONCLUSIONS

Our results confirm the small increased risk of GB disease associated with thiazide diuretics. On the other hand, our data do not support a major association between IHD and GB disease.

Hypertension and hormone-related neoplasms in women

The relation between hypertension and the risk of selected hormone-related neoplasms in women was investigated in a network of case-control studies conducted in Italy during 1983-1996. Cases were women younger than 75 years with histologically confirmed cancer of the breast (n=3406), endometrium (n=745), ovary (n=970), and thyroid (n=145). Controls were 3054 women admitted in the same geographic area for acute, nonneoplastic, non-hormone-related diseases. Odds ratios (ORs) of treated hypertension were computed after allowance for sociodemographic factors, smoking habits, alcohol consumption, parity, menopausal status, and body mass index (BMI) by means of unconditional logistic regression. The ORs were 1.2 (95% CI, 1.1 to 1.4) for breast cancer and 1.6 (95% CI, 1.3 to 1.9) for endometrial cancer, and the elevated ORs persisted after >/=5 years since diagnosis of hypertension. No significant association was observed for ovarian and thyroid cancer. For breast cancer, the association was apparently stronger at age 55 years or over and consequently after menopause. No appreciable effect modification was evident for endometrial cancer. Allowance for BMI did not explain the association of postmenopausal breast cancer and endometrial cancer with hypertension. The OR of postmenopausal breast cancer was 1.5 (95% CI, 1.1 to 2.0) in hypertensive women with BMI >/=30 kg/m(2) compared with normotensive women with BMI <25 kg/m(2). The corresponding figure for all endometrial cancers was 4.9 (95% CI, 3. 4 to 6.9). Even in the absence of a clear understanding of biological mechanisms, the definition of a role of hypertension on female hormone-related cancers can have relevant implications on individual risk assessment.

The occurrence of cancer in first admitted schizophrenic patients

The incidence of cancer was studied in a cohort of all first admitted 9156 patients in Denmark with a diagnosis of schizophrenia in the period 1970-1987. The overall incidence of cancer was reduced particularly in the males. Adjustment for the smoking habits of psychiatric patients enhanced this risk reduction. Fewer than expected had been diagnosed with cancer prior to the first schizophrenia admission. This tendency was limited to the female patients. The reduced cancer incidence was particularly marked for genital cancers, in particular testicular cancer, and skin cancers including malignant melanoma. Breast cancer risk was not increased, thus not substantiating concerns that neuroleptics would increase breast cancer risk through the elevation of serum prolactin levels. Some available evidence in the literature supports the hypothesis of an antineoplastic effect of neuroleptics as an explanation for the low occurrence of cancer in schizophrenic patients. Further large sample studies including an extension of the follow-up of this cohort are needed to establish the reduced risk of cancer in schizophrenic patients as well as exploring the causes for this reduction.

Drug-induced gallbladder disease. Incidence, aetiology and management

A great variety of drugs is reported to induce gallbladder disease by various pathogenetic mechanisms. Early epidemiological studies indicated a doubled risk of gallbladder disease in women taking oral contraceptives. More recent studies, however, have failed to confirm those findings; these conflicting results might be explained by the different methods used to define gallbladder disease. It was shown that the lithogenic index of the bile is increased during intake of oral contraceptives. Estrogens cause hypersecretion of cholesterol in bile, due to increase in lipoprotein uptake by the hepatocyte. Progesterone inhibits acyl coenzyme A-cholesterol acyl transferase (ACAT) activity, causing delayed conversion of cholesterol to cholesterol esters. Of the lipid lowering drugs, only clofibrate has been shown to increase the risk for gallstone formation. The other fibric acid derivatives have similar properties, but clinical experience is not as extensive. They seem to be inhibitors of the ACAT enzyme system, thereby rendering bile more lithogenic. Conflicting epidemiological data exist regarding the induction of acute cholecystitis by thiazide diuretics. Ceftriaxone, a third-generation cephalosporin, is reported to induce biliary sludge in 25 to 45% of patients, an effect which is reversible after discontinuing the drug. The sludge is occasionally a clinical problem. It was clearly demonstrated that this sludge is caused by precipitation of the calcium salt of ceftriaxone excreted in the bile. Long term use of octreotide is complicated by gallstone formation in approximately 50% of patients after 1 year of therapy, due to gallbladder stasis. Hepatic artery infusion chemotherapy by implanted pump is shown to be associated with a very high risk of chemically induced cholecystitis. Prophylactic cholecystectomy at the time of pump implantation is therefore advocated. Some drugs, such as erythromcyin or ampicillin, are reported to cause hypersensitivity-induced cholecystitis. Furthermore, there are reports on the influence of cyclosporin, dapsone, anticoagulant treatment, and narcotic and anticholinergic medication in causing gallbladder disease.

The autopsy and epidemiology--Olmsted County, Minnesota and Malmo, Sweden

The existence of high quality, population-based, medical data facilitates the practice of modern epidemiology with its concomitant benefits for clinical practice and public health policy. Two exceptional examples of such databases are provided by Malmo, Sweden, and Olmsted County, Minnesota. This paper outlines briefly the similarities between these two geographic entities, and focuses, in particular, on the central role of the autopsy in Olmsted County. Changing temporal and spatial patterns of autopsy are reviewed as well as two important related issues: the role of consent and the medico-legal autopsy. The paper concludes with a summary of some of the more noteworthy contributions of autopsy-based epidemiological research in Olmsted County, and offers several recommendations for the establishment of a select network of special population-based study areas. These epidemiological "laboratories", through the interchange of data and tissue specimens, could make significant contributions to the study of diseases both nationally and internationally. Their interactive efforts and high quality data bases would help to increase the efficiency of the expenditure of scarce societal resources in epidemiology and health care.

Mortality and causes of death in schizophrenic patients in Denmark

A cohort consisting of 6178 people that were psychiatric inpatients with a clinical schizophrenia diagnosis in 1957 were followed up from 1957 through 1986, and their cause-specific mortality was determined. Mortality from cardiovascular diseases, lung diseases, gastrointestinal and urogenital disorders, accidents and suicide was increased, whereas mortality from cerebrovascular disorders was reduced. In the male patients cancer mortality was reduced whereas cancer mortality in the female patients was increased. Mortality from a number of causes that theoretically could be associated with side effects from neuroleptics was increased. Mortality from some causes of death used as a measurement of the quality of medical care was found to be slightly increased. Further studies of the quality of the medical care provided to schizophrenic patients and of the association between neuroleptic medication and mortality are needed.

The incidence of cancer in schizophrenic patients

A cohort of 6168 schizophrenic patients was followed from 1957 to 1984 to determine the incidence of cancer in these patients. In the male schizophrenic patients the incidence of cancer was found to be significantly reduced in comparison with the general Danish population. This reduction was especially marked for cancer in the respiratory system, cancer of the prostate and cancer of the bladder. In the female patients the overall incidence of cancer did not differ from that of the general Danish population, but there was an increased risk of cancer of the digestive tract, especially cancer of the pancreas and a slight increase of the risk of breast cancer. In the female patients the risk of respiratory cancers and cancer of the female genital organs, especially cancer of the uterine cervix, was reduced. These alterations of the incidence of cancer in schizophrenic patients cannot be ascribed to differences in diagnostic accuracy. As a possible explanation of these findings a reduced exposure to well known carcinogens such as cigarette smoke may be relevant. We speculate that exposure to neuroleptics such as phenothiazines and reserpine may also be part of the explanation for the findings.

Neuroleptic treatment and other factors modifying cancer risk in schizophrenic patients

In a Danish cohort of schizophrenics consisting of 6,168 patients followed during 1957-1980, the incidence of certain types of cancer has been shown to be significantly decreased (5). From this cohort 30 males with lung cancer, 21 males with bladder cancer, 17 females with cancer of the uterine cervix and 40 females with breast cancer, were each matched to two "healthy" schizophrenic controls from the same cohort. A range of social, demographic and nosocomial factors were registered from the individual case files, and statistical analysis was carried out, using Cox's regression model. Neuroleptic treatment with various drugs other than reserpine reduced the risk of developing all four cancer types studied. In contrast reserpine treatment increased the risk of developing cancer of the breast and uterine cervix. Furthermore, cancer risk was found to be modified by other well-known risk factors.

Acute cholecystitis and thiazides

Drugs purchased by a random sample (17 000) of the population of Jämtland county, Sweden, are continuously monitored. Patients who had been admitted to the county's only hospital with acute cholecystitis and who were part of this sample were studied, and controls matched for age and sex were drawn from the sample. The purchase of thiazides and other drugs prescribed to the patients with acute cholecystitis was compared with that of the controls. The estimated relative risk of developing acute cholecystitis in patients who had purchased thiazides in the year before admission to hospital, as compared with those who had not, was 2.1 (95% confidence limit 1.1-3.9). As it has been reliably reported that the use of thiazides is not itself associated with cholelithiasis, the association found between thiazides and cholecystitis suggests that thiazides may increase the risk of acute cholecystitis developing in a patient with gall stones.

Prolactin receptors in human breast cancer

Prolactin receptors have been measured in 92 human breast carcinomas. Both free and total receptors (after desaturation by MgCl2) have been looked for. Free receptors have been found in 46% of the cases, total receptors in 72%. Specific binding ranges from 0.8 to 8.0%. No correlation could be found between prolactin receptors and age, weight, menopausal status and pathological features (differentiation, histoprognostic grading, cellular density). A highly significant correlation has been found between prolactin receptors on the one hand and estradiol and progesterone receptors on the other.

Reserpine and breast cancer in the Hypertension Detection and Follow-Up Program

Recent reports on the efficacy of pharmacological management in reducing mortality associated with mild hypertension have enhanced the importance of increasing our knowledge about drug toxicity. The Hypertension Detection and Follow-Up Program (HDFP) provides a convenient setting in which to examine the association reported between reserpine usage and breast cancer. In the intensively treated and followed group (Stepped Care [SC]), the relative breast cancer experience of those who did take reserpine and those who did not was examined. Of 2529 females in SC, 1036 received reserpine, with an average exposure of 1.97 years during 5 years of follow-up. Through extensive investigation, 21 cases of breast cancer were identified. using a life table regression method of analysis to adjust for actual time of reserpine exposure, race, sex, and medication status at entry, and comparing those who took reserpine with those who did not, the author's calculated a risk ratio of 1.28, with a confidence interval of 0.58 to 2.80. Adjustment for a number of other variables known to have relationships to breast cancer did not appreciably change the results. Thus, with certain precautions, the authors conclude that in this setting there is no indication of the recently postulated association of reserpine and the short-term enhancement of breast tumor growth.

Amenorrhea, galactorrhea, hyperprolactinemia syndrome and breast carcinoma in a young woman

A young female patient with amenorrhea, galactorrhea and hyperprolactinemia developed a carcinoma of the breast a few years later. Examination of the amenorrhea--galactorrhea syndrome did not reveal any prolactinoma so that hyperprolactinemia remains unexplained. Treatment with bromoergocryptine 5 mg daily was successful. The carcinoma was treated in the classic way by amputation of the breast, axillary curettage and adjuvant chemotherapy. However, the association of amenorrhea, galactorrhea and breast carcinoma via hyperprolactinemia raises the question of whether there is any etiologic--pathogenetic relationship. Convincing evidence of such a relationship has not been found in the literature.

Antihypertensive pharmacology

Although drug treatment of hypertension is associated with improved survival and decreased vascular complications, drug compliance is a major problem in the control of hypertension. All antihypertensive medications are associated with side effects; thus, it is a physician's responsibility to explain to each patient the side effects of the drugs he prescribes to treat hypertension, and to instill in the patient a sense of necessity for the treatment of hypertension. The choice of antihypertensive drug should be made based on each patient's lifestyle, overall health and ability to tolerate the drug. Ideally, the antihypertensive regimen should be simple, effective, convenient to take and have very few side effects.

Interaction of drugs, hormones, and nutrition in the causes of cancer

Hormones may act as promoters in the carcinogenic process, and occasionally their metabolites may act as antihormones or have new physiologic effects. Drugs can interact with the endocrine system in many ways. They can promote secretion of a hormone, alter its rate of removal from plasma, change plasma protein-binding characteristics, or modify routes of metabolism. Estrogens have a preparative effect on the uterine endometrium. There are biologic, clinical and epidemiologic reasons for believing that estrogen administration to postmenopausal women increases the risk for endometrial cancer. Although there are similar biologic reasons to associate prolonged estrogenic stimulation with breast cancerr, evidence for such an association is weak. Oral contraceptive use has been associated with a variety of hepatocellular tumors. Although estrogens, per se, can effect several hepatic functions, it seems likely that the 17 alpha-alkyl and 17 alpha-ethinyl functions of the progestins and estrogens are involved in this process. The role of estrogen use during pregnancy in the causation of vaginal cancer in female offspring and the role of androgens in prostate cancer have been discussed.

An experimental approach to the breast cancer, reserpine problem

Reserpine was administered intraperitoneally 3 times weekly to inbred female Syrian BIO hamsters of the 15.16 strain previously shown to be susceptible to methylcholanthrene (MC) induction of mammary cancer. Other groups of hamsters received non-carcinogenic doses of MC along with the reserpine administrations, and an additional group received a carcinogenic dose of MC alone. This last group demonstrated that BIO 15.6 females were indeed susceptible to MC mammary cancer induction, since 4 mg of MC administered by stomach tube (a total dose of 200 mg) caused mammary cancer in 52% of the animals. Mammary cancer was not observed in any of the animals given reserpine or reserpine in combination with the non-carcinogenic dose of MC.

Reserpine and breast cancer

After a series of studies on the linkage of reserpine with breast cancer, both evidence and interpretation appeared to be in conflict. Our case-control survey of long-term, comprehensive records from the Kaiser Foundation Medical Care Program, on 108 hypertensive breast cancer cases and 324 hypertensive controls, matched by year of birth and by race, produces a significant positive association between reserpine use and breast cancer. However, the association vanishes upon further matching with respect to the year of the first hypertension diagnosis and the subsequent length of follow-up. We thus fail to support suspicions of causality.

Effect of reserpine on cell proliferation in the developing rat bran: a biochemical study

Reserpine, a well-known CNS depressant which depletes central monoamine stores, was found to produce in the brains of 11-day-old rats a severe depression in cell proliferation in terms of the rate of [3H]thymidine incorporation into DNA. The effect was studied in detail 12 h after ther administration of the drug (2.5 mg/kg, s.c.) when the rate of in vivo DNA synthesis in the forebrain was about one-third of control: the decrease was less marked in the cerebellum (rate about two-thirds of control). It was possible to exclude side effects of the drug, such as restricted food intake, hypothermia and an elevation of the level of blood corticosteroids being responsible for the reduction of [3H]thymidine incorporation into DNA. Kinetic studies showed that reserpine had no marked effect on the entry of [3H]thymidine from blood to brain, but it caused some retardation in the rate of [3H]thymidine conversion into [3H]thymidine nucleotides. Nevertheless, the severe depression of DNA labelling was evident even after correcting the values on the basis of [3H]thymidine nucleotide concentrations. In contrast to these effects, thymidine kinase activity was normal in the brain of reserpine-treated animals.

Gallbladder disease as a side effect of drugs influencing lipid metabolism. Experience in the Coronary Drug Project

We analyzed data obtained during the Coronary Drug Project to discover the influence of the drugs used on the frequency of gallbladder disease. Of 2680 placebo-treated men who had had myocardial infarction, gallbladder disease developed in 69. Corresponding figures for those given 2.5 mg of estrogen, 5.0 mg of estrogen and 1.8 g of clofibrate per day were 46 of 1061, 47 of 1081 and 42 of 1051, respectively. Each treatment group differed from placebo by over twice the standard error of the difference, life-table analysis yielding P less than 0.05 for each drug-placebo comparison. Forty-five variables, including age, body weight, blood pressure, serum lipids and blood sugar, were evaluated as risk factors. Age significantly correlated with prevalence of known gallbladder disease at entry (r = 0.066, P less than 0.001). No variable yielded a strong and consistent correlation with the incidence of subsequent new gallbladder disease. Gallstone formation is a risk whenever clofibrate or estrogen is prescribed.