Solamargine, a bioactive steroidal alkaloid isolated from Solanum aculeastrum induces non-selective cytotoxicity and Pglycoprotein inhibition

Abstract: Background: Solanum aculeastrum fruits are used by some cancer sufferers as a form of alternative treatment. Scientific literature is scarce concerning its anticancer activity, and thus the aim of the study was to assess the in vitro anticancer and P-glycoprotein inhibitory potential of extracts of S. aculeastrum fruits. Furthermore, assessment of the combinational effect with doxorubicin was also done. Methods: The crude extract was prepared by ultrasonic maceration. Liquid-liquid extraction yielded one aqueous and two organic fractions. Bioactive constituents were isolated from the aqueous fraction by means of column chromatography, solid phase extraction and preparative thin-layer chromatography. Confirmation of bioactive constituent identity was done by nuclear magnetic resonance and ultra-performance liquid chromatography mass spectrometry. The crude extract and fractions were assessed for cytotoxicity and P-glycoprotein inhibition in both cancerous and non-cancerous cell lines using the sulforhodamine B and rhodamine-123 assays, respectively. Results: Both the crude extract and aqueous fraction was cytotoxic to all cell lines, with the SH-SY5Y neuroblastoma cell line being most susceptible to exposure (IC50 = 10.72 μg/mL [crude], 17.21 μg/mL [aqueous]). Dose-dependent P-glycoprotein inhibition was observed for the crude extract (5.9 to 18.9-fold at 100 μg/mL) and aqueous fraction (2.9 to 21.2 at 100 μg/mL). The steroidal alkaloids solamargine and solanine were identified. While solanine was not bioactive, solamargine displayed an IC50 of 15.62 μg/mL, and 9.1-fold P-glycoprotein inhibition at 100 μg/mL against the SH-SY5Y cell line. Additive effects were noted for combinations of doxorubicin against the SH-SY5Y cell line. Conclusions: The crude extract and aqueous fraction displayed potent non-selective cytotoxicity and noteworthy P-glycoprotein inhibition. These effects were attributed to solamargine. P-glycoprotein inhibitory activity was only present at concentrations higher than those inducing cytotoxicity, and thus does not appear to be the likely mechanism for the enhancement of doxorubicin’s cytotoxicity. Preliminary results suggest that non-selective cytotoxicity may hinder drug development, however, further assessment of the mode of cell death is necessary to determine the route forward

Herbal remedies affecting coagulation : a review

CONTEXT: Herbal remedies are used to treat a large variety of diseases, including blood-related disorders. However, a number of herbal preparations have been reported to cause variations in clotting time, this is mainly by disruption of the coagulation cascade. OBJECTIVE: The compiling of plants investigated for effects on the coagulation cascade. METHODS: Information was withdrawn from Google Scholar and the journal databases Scopus and PubMed. RESULTS: Sixty-five herbal remedies ware identified with antiplatelet, anticoagulant or coagulating ability. Bioactive compounds included polyphenols, taxanes, coumarins, saponins, fucoidans, and polysaccharides. CONCLUSION: Although research has been conducted on the effect of herbal remedies on coagulation, most information relies on in vitro assays. Contradictory evidence is present on bleeding risks with herbal uses, though herb-drug interactions pose a threat. As the safety of many herbals has not been proven, nor their effect on blood parameters determined, the use of herbal preparations before undergoing any surgical procedure should rather be ceased.http://www.tandf.co.uk/journals/titles/13880209.as

Zinc oxide nanoparticles induce oxidative stress and histopathological toxicity in the thyroid gland and liver of rats

Zinc oxide nanoparticles are incorporated into cosmetics and sunscreens and are widely used in biomedical applications and the food industry. The increasing use of zinc oxide nanoparticles raises concerns about their safety. The aim of the study was to assess the effects of zinc oxide nanoparticles on oxidative and genotoxic parameters in the thyroid gland and liver of adult albino rats. Rats were divided into three groups; control, vehicle, and zinc oxide nanoparticles (200 mg/kg) and were subjected to treatment for 30 days. Oxidative stress parameters and genotoxicity were determined. Histopathological examination of both organs was undertaken. A significant reduction in triiodothyronine, thyroxine and thyroid-stimulating hormone was noted, whereas aspartate aminotransferase and alanine aminotransferase levels were significantly elevated. Increased malondialdehyde and decreased reduced glutathione levels were indicative of oxidative stress response in both organs. Additionally, elevated serum 8-hydroxydeoxyguanosine was noted which was supported by the results of the comet assay. Histopathological examination revealed alterations in the thyroid gland and liver. Sub-chronic exposure resulted in oxidative stress-mediated toxicity and genetic perturbations in both organs. Caution is warranted with repeated usage of products containing zinc oxide nanoparticles.https://www.tandfonline.com/loi/gtec202022-06-30hj2021Pharmacolog

Isolation of cycloeucalenol from Boophone disticha and evaluation of its cytotoxicity

Boophone disticha (Amaryllidaceae) is widely used in traditional medicine in southern Africa. Several alkaloids, volatile oils and fatty acids have been isolated from the plant. However, there has been no literature report of a triterpene from B. disticha. Cycloeucalenol, a cycloartane triterpene, together with its regio-isomer, was isolated from the ethyl acetate extract of the bulbs using column chromatography and preparative thin layer chromatography. Structural elucidation was carried out using 1D and 2D NMR and mass spectroscopy. The MTT and neutral red assays were used to assess the cytotoxicity of the compound in human neuroblastoma (SH-SY5Y) cells. The compound was obtained as a mixture of two regio-isomers, which were separated for the first time by chromatographic optimization. Integration of the 1H NMR spectrum showed that cycloeucalenol and its regio-isomer were present in a ratio of 1.04:1. A dose-dependent decrease in cell viability was observed using both cytotoxicity assays. IC51 values of 173.0 +/- 5.1 microM and 223.0 +/- 6.4 microM were obtained for the MTT and neutral red assays, respectively, indicative of the low toxicity of the compound. This work describes for the first time, the presence of triterpene compounds from the genus Boophone.http://www.naturalproduct.us/hb201

Drugged driving in South Africa: An urgent need for review and reform

Driving under the influence is a major threat to road safety in South Africa. Various psychoactive substances (both licit and illicit) have the potential to adversely affect driving performance and increase the probability of a road traffic accident. While it is common practice in South Africa to test drivers for alcohol levels, testing for additional impairing substances (including drugs of abuse) is rarely performed. In terms of current South African legislation, only driving under the influence of alcohol and a ‘drug having a “narcotic” effect’ is prohibited. This excludes several impairing psychoactive drugs which are not classified as narcotic substances. The aim of this article is to highlight issues and/or limitations surrounding drugged driving and to propose appropriate considerations for revision of the National Road Traffic Act. We also recommend revising existing legislation to include a comprehensive statutory definition and detailed provisions for drug testing to deter impaired driving

Application of a LC-MS/MS method developed for the determination of p-phenylenediamine, N-acetyl-p-phenylenediamine and N,N-diacetyl-p-phenylenediamine in human urine specimens

Cases of poisoning by p-phenylenediamine (PPD) are detected sporadically. Recently an article on the development and validation of a LC-MS/MS method for the detection of PPD and its metabolites, N-acetyl-p-phenylenediamine (MAPPD) and N,N-diacetyl-p-phenylenediamine (DAPPD) in blood was published. In the current study this method for detection of these compounds was validated and applied to urine samples. The analytes were extracted from urine samples with methylene chloride and ammonium hydroxide as alkaline medium. Detection was performed by LC-MS/MS using electrospray positive ionization under multiple reaction-monitoring mode. Calibration curves were linear in the range 5–2000 ng/mL for all analytes. Intra- and inter-assay imprecisions were within 1.58–9.52% and 5.43–9.45% respectively, for PPD, MAPPD and DAPPD. Inter-assay accuracies were within -7.43 and 7.36 for all compounds. Lower limit of quantification was 5 ng/mL for all analytes. The method, which complies with the validation criteria, was successfully applied to the analysis of PPD, MAPPD and DAPPD in human urine samples collected from clinical and postmortem cases.This work was made possible by an IFCC PSEP scholarship.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-08012017-12-31Pharmacolog

Prevalence and Profile of Drugs and Alcohol in Fatally Injured Drivers in Pretoria, South Africa

South Africa (SA) is faced with continuing challenges pertaining to drug and alcohol abuse. Currently, there is a paucity of information regarding the involvement of non-alcohol substances in road-traffic accidents, as drugged-driving cases are seldom identified or prosecuted. The aim of this study was to establish the prevalence and profile of drug and alcohol use among drivers involved in fatal road accidents in Pretoria, SA. A one-year prospective analytical study was conducted at the Pretoria Medico-Legal Laboratory. Biological samples were collected at autopsy and drug-screening was conducted using immunoassay techniques, followed by liquid chromatography-tandem mass spectrometry confirmation. Blood-alcohol concentrations were determined using headspace gas chromatography with flame ionization detection. The presence of one or more drugs of abuse was confirmed in 8% of fatally injured drivers (N = 112). The majority of drivers who tested positive for drugs or alcohol were males and younger than 40 years of age. Amphetamine-type stimulants were detected in 4.5% of cases, followed by opioids (3.6%) and cannabis (2.7%). Alcohol was detected in 57.5% of cases, and in combination with a drug(s) in 4.5% of cases. Drugs were detected in approximately one in twelve drivers who were fatally injured in motor-vehicle accidents in Pretoria. Current practices for detecting driving under the influence in SA need to be reviewed and further research is necessary to better establish the extent of drug- and alcohol-impaired driving, in order to develop appropriate prevention strategies

The use of methylphenidate as a cognitive enhancer by Health Sciences students at a South African university : a pilot study

BACKGROUND : The incremental off-label use of methylphenidate by students to enhance cognitive performance has been widely described in international studies. Recent local media reports have suggested a similar trend in spite of its strict prescription requirements. Although a few South African researchers have started reporting on this peculiarity, data regarding the bona fide extent of stimulant misuse among South African students remains unexplored. OBJECTIVES : To determine the incidence of methylphenidate use, methods of acquisition and perceived academic benefit among health sciences students at a South African university. METHODS : A quantitative cross sectional pilot study was conducted by administering a closed ended questionnaire to 160 students registered for various degrees in a Faculty of Health Sciences during August and September 2014. Student demographics, lifetime methylphenidate use, means and reasons of procurement, subjective assistance and experienced side effects were documented and analysed for trends and frequencies. RESULTS : Response rates varied considerably (1% - 40%) among students enrolled for different fields of study in the faculty of health sciences. Overall lifetime methylphenidate use was reported at 16.9%, with a noticeable 10% increase during examination periods. Enhancement in cognitive performance (81.5%) was the principle reason for use, although only 66.7% indicated a subjective academic benefit. The majority of respondents had a valid prescription (59.3%), of which 3.1% were justified by an attention deficit hyperactivity disorder diagnosis. Medical students accounted for 70% of methylphenidate users. Diversion of personal prescribed medication was expressed by 7.4% and the most frequently encountered side effects were anxiety (20%) and loss of appetite (17.8%). CONCLUSION : The unjustified medical use of methylphenidate in South African students correlates well with documented literature from international reports, confirming a global trend. Medical practitioners appear to prescribe this substance more frequently for off-label use, rather than for its registered indications. Methylphenidate use increases during times of high academic stress. Appropriate multidisciplinary student support and education relating to the misuse and long term adverse effects need to be implemented by the medical community and relevant university structures.This project was presented at the annual congress of the South African Society for Basic and Clinical Pharmacology, held at the University of the Witwatersrand in September 2015. A conference abstract was published in a supplementary edition of the South African Journal of Infectious Diseases.http://innovativejournal.in/ijnd/index.php/ijndam2018Pharmacolog

Pyrrolizidine alkaloids enhance alcohol-induced hepatocytotoxicity in vitro in normal human hepatocytes

OBJECTIVE : Herbal remedies containing pyrrilidozine alkaloids (PA)s can induce liver damage, including hepato-sinusoidal obstruction syndrome (HSOS) or veno-occlusive liver disease (VOD). Some individuals misusing alcohol consume also teas and/or herbal remedies containing PA. The interaction or additive toxicity of alcohol to PA toxicity needs to be addressed. The objectives of this study are 1) to review the scientific literature on the PA-induced liver toxicity; 2) identify possible mechanism(s) involved in PA-induced hepatocytotoxicity in the presence or absence of ethanol (EtOH) in vitro in normal human hepatocytes (NHH) in primary culture. To respond to the first objective, we systematically search all the literature engines (PubMed, Google Scholar) for liver induced damage due to PAs and summarize the results in an introductory systematic review. ORIGINAL ARTICLE EXPERIMENTAL DESIGN AND METHODS : Cells were exposed to one dose of 100 mmol/L EtOH for 24 hrs and to 2 doses of 100 mmol/L EtOH for consecutive 24 hrs periods, in the presence or absence of PAs (10 mg/mL), or the caspase-3 inhibitor IDN-1965 (50 μmol/L). Cells were analyzed for apoptosis by light microscopy, immuno-histochemistry, measuring cytokeratin-18 fragmentation, and transmission electron microscopy (TEM) (6000 cells/ treatment). Cytotoxicity was determined using succinate dehydrogenase (SDH) activity, an enzyme specific to the mitochondria. RESULTS : In NHH cells, a 100 mmol/L dose of Et-OH resulted in 22±2.5 apoptosis (p<0.001 vs. control). Two consecutive doses of 100 mmol/L Et-OH for 24 hrs each caused 36±3.0% apoptosis (p<0.001 vs. control and p<0.05 vs. one dose Et- OH). Pre-treatment with 50 μmol/L caspase inhibitor significantly reduced Et-OH-induced apoptosis [12±1.5% in 100 mmol/L (p<0.05) and 20±4.0% in 2×100 mmol/L (p<0.001)]. In addition, pre-treatment with 50 μmol caspase inhibitor in cells treated with PA + EtOH reduced apoptosis significantly (vs. non-exposed to caspase-inhibitor): Δ -22±3.0 % (p<0.05). HPC significantly decreased apoptosis compared to conditions lacking this supplementation in cells treated with EtOH-exposed cells present ballooning, Mallory bodies, changes in mitochondrial cristae and apoptosis by TEM. Pre-treatment with 50 μmol caspase inhibitor significantly reduced 100 mmol/L EtOH-induced (one dose) in NHH by 14±0.5% (p<0.05) compared to cells not exposed to the caspase-inhibitor. In cells treated concomitantly with PA and EtOH 100 mM Mallory-bodies and apo-necrotic cells have been observed. Pre-treatment with 50 μmol caspase inhibitor reduced the mitochondrial damage. A significant depletion in glutathione (GSH) was observed in Et-OH treated cells after 1 and 2 treatments (p<0.001 vs. control). Treatment with E t-OH enhanced PA-induced GSH-depletion and resulted in a significant increase in PA-induced cytotoxicity (p<0.001 vs. Et-untreated cells). Exposure to EtOH increased the cell culture media levels of the pro-inflammatory cytokine TNF. PA + EtOH-treated cells increased TNF-α levels in media compared to EtOH alone [86±8 vs. 53±5 pg/mL in cells exposed to 100 mmol/L EtOH (p<0.05) and 218±14 vs. 179±8 pg/mL in cells exposed to 2×100 mmol/L EtOH (p<0.05)]. CONCLUSIONS : PA up-regulates EtOH-induced hepatocytotoxicity by inducing the inflammatory cytokines and enhancing the apoptotic effects of ethanol. There is a need for monitoring herbal medicine in order to optimize traditional medicine use and maximize the clinical benefits. Additionally, there is necessary to communicate to physicians the possible negative results of herbal remedies use. Also, the interactions between herbal remedies and drugs of misuse should be communicated to consumers.The work was funded by In Vitro Drug Safety and Biotechnology. We are thankful for the financial contribution to Mahaffy -Gastroenterology Fund, Sunnybrook HSC, Toronto, ON, Canada.http://www.europeanreview.orgam2017Pharmacolog