Emerging trends in organ-on-a-chip systems for drug screening

New drug discovery is under growing pressure to satisfy the demand from a wide range of domains, especially from the pharmaceutical industry and healthcare services. Assessment of drug efficacy and safety prior to human clinical trials is a crucial part of drug development, which deserves greater emphasis to reduce the cost and time in drug discovery. Recent advances in microfabrication and tissue engineering have given rise to organ-on-a-chip, an in vitro model capable of recapitulating human organ functions in vivo and providing insight into disease pathophysiology, which offers a potential alternative to animal models for more efficient pre-clinical screening of drug candidates. In this review, we first give a snapshot of general considerations for organ-on-a-chip device design. Then, we comprehensively review the recent advances in organ-on-a-chip for drug screening. Finally, we summarize some key challenges of the progress in this field and discuss future prospects of organ-on-a-chip development. Overall, this review highlights the new avenue that organ-on-a-chip opens for drug development, therapeutic innovation, and precision medicine.

Acute and subacute oral toxicity characterization and safety assessment of COVID organics® (Madagascar's Anti­COVID Herbal Tea) in animal models

Introduction: Coronavirus disease 2019 (COVID 19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2. No drug has been generally approved as safe and effective for the treatment of COVID 19. Several therapeutic agents such as COVID Organics® (CVO) have been explored as treatment options. CVO is an herbal tea composed of 62% of Artemisia annua and 38% of other plants. There is presently no existing scientific report and data on the safety and efficacy of CVO herbal drug. Thus, acute and subacute toxicity studies were undertaken to evaluate the safety and toxicity of CVO on short and long term usage in animal models. Materials and Methods: Phytochemical and nutritional compositions of CVO were determined using standard methods. Acute oral toxicity was investigated using female Swiss albino mice (three per group). While subacute oral toxicity was done using female and male Swiss albino rats (five per group). The animals were administered 2000 mg/kg, 5000 mg/kg, therapeutic dose; 5500 mg/kg and supratherapeutic dose; 11,000 mg/kg of CVO herbal product. The control group received water ad libitum. The oral toxicity studies were done in accordance with Organization for Economic Corporation and Development guidelines. The experimental protocol was approved by the Institutional Animal Care and Use Committee, Nigerian Institute of Medical Research (Ethics No. IRB/17/043). Results: CVO is rich in antioxidants: flavonoids(10.3%), tannins(29.1%), and phenolics(434.4 mg). It contains proteins (33.8%), carbohydrates (34.5%), fat (6.8%), and fiber (0.5%). In the acute toxicity study, no mortality was recorded in all the treated and untreated groups. The lethal dose of CVO is >5000 mg/kg body weight. The hematological, biochemical, lipid profile, and histologic parameters were all normal at therapeutic doses when compared to the control group. Conclusion: The acute and subacute oral toxicity studies revealed that CVO is not toxic. The specific organ toxicity evaluations also indicated that CVO has no toxic effects on blood parameters and vital organs structure and function at therapeutic dose. Thus, CVO is safe for short and long term usage. We recommend that CVO should be subjected to efficacy studies to investigate whether it is effective for COVID 19 treatment as claimed by the manufacturer.

Analysis on clinical characteristics of 316 patients with hydrofluoric acid burns / 中华烧伤杂志

Objective@#To investigate the clinical characteristics of patients with hydrofluoric acid (HF) burns.@*Methods@#Clinical data of 316 patients with HF burns admitted to Zhejiang Quhua Hospital from January 2004 to December 2016 were retrospectively analyzed. Patients were divided into non and mild poisoning group (NMP, n=157), moderate poisoning group (MP, n=120), and severe and fatal poisoning group (SFP, n=39) based on the severity of poisoning. Occurrences of hypocalcemia, hypomagnesemia, hypokalemia, and hyperkalemia of patients within 24 hours after admission were recorded. Values of emergency urinary fluoride of patients on admission were recorded. Values of urinary fluoride of patients admitted to hospital in 4 hours post injury in groups MP and SFP at post injury hour 4, 12, and 24 and on post injury day 2, 3, 4, 5, 6, and 7 were also recorded. Electrocardiographic abnormalities of patients within 24 hours after admission were recorded. Data were processed with chi-square test, Kruskal-Wallis H test, and Mann-Whitney U test.@*Results@#(1) Hypocalcemia, hypomagnesemia, and hypokalemia occurred in some patients in each of the three groups, but no patient had hyperkalemia. Taking serum calcium namely total serum calcium as reference, the incidence rate of hypocalcemia of patients in group NMP was close to that in group MP (χ2=0.05, P>0.05). The incidence rate of hypocalcemia of patients in group SFP was significantly higher than that in group NMP or group MP (χ2=10.53, 7.92, P<0.01). The incidence rates of hypokalemia in the three groups were close (χ2=0.63, P>0.05). Taking serum ionized calcium as reference, the incidence ratio of hypocalcemia of patients in group NMP was close to that in group MP (χ2=0.01, P>0.05), while there were statistically significant differences in incidence ratio of hypocalcemia of patients between group SFP and each of group NMP and group MP (χ2=4.66, 4.47, P<0.05). Taking serum calcium as reference, the incidence rate of hypocalcemia of patients was 7.3% (23/316). Taking serum ionized calcium as reference, the incidence rate of hypocalcemia of patients was 60.0% (42/70), which was significantly higher than that of taking serum calcium as reference (χ2=113.74, P<0.01). The incidence rates of hypomagnesemia of patients in groups MP and NMP were close (χ2=0.02, P>0.05). The incidence rate of hypomagnesemia of patients in group SFP was significantly higher than that in group NMP or group MP (χ2=14.69, 9.94, P<0.01). (2) The urinary fluoride levels were tested in 288 patients, with the value of emergency urinary fluoride of patients on admission 0.2-590.0 mg/L. The values of urinary fluoride of 202 patients were above the normal value. The values of emergency urinary fluoride of patients in groups NMP, MP, and SFP were 2.15 (1.11, 4.30), 5.89 (1.72, 14.25), and 36.0 (13.2, 103.2) mg/L, respectively. The values of emergency urinary fluoride of patients in groups MP and SFP were significantly higher than the value in group NMP (χ2=23.28, 66.03, P<0.01). The value of emergency urinary fluoride of patients in group SFP was significantly higher than that in group MP (χ2=39.23, P<0.01). The value of urinary fluoride of 33 patients admitted to hospital within 4 hours post injury in groups MP and SFP reached the top at 4 hours post injury and then gradually declined, which returned to normal on about 5 days post injury. The values of urinary fluoride of patients in group SFP at 4, 12, and 24 hours post injury and on 2, 3, 4, 5, 6, and 7 days post injury were significantly higher than those in group MP (Z=-4.28, -4.15, -3.81, -4.21, -2.48, -2.06, -2.31, -2.68, -3.03, P<0.05 or P<0.01). (3) Twenty-seven patients had electrocardiographic abnormality. There were 12 patients with T wave changes (the most common), 8 patients with ST-T changes, 6 patients with ventricular arrhythmias, 6 patients with conduction block, and 1 patient with broadened QRS waveform. There was no patient with prolonged Q-T interval. The ratios of patients with the above electrocardiographic abnormalities in group SFP were higher than those in group NMP and group MP.@*Conclusions@#Clinical manifestations of patients with HF burn are hypocalcemia, hypomagnesemia, hypokalemia, and electrocardiographic abnormality. In addition to routine serum electrolyte and electrocardiogram monitoring, the levels of serum ionized calcium and urinary fluoride can be helpful to evaluate the severity of illness of the patients.

Development of drug toxicity and novel strategy for toxicity of Chinese materia medica based on zebrafish model / 中草药

With the advantages of high throughput activity screening and toxicity evaluation, zebrafish has become popular model organism in pharmaceutical research in recent years. Being integrated advantages both in vivo and in vitro, with high efficiency and low cost, evaluation using zebrafish has become an effective method in quick screening of early safety of compounds on abroad. In past years, studies on toxicity of traditional Chinese medicine (TCM) with zebrafish model have attracted more attention in China. The development in drug toxicity studies based on zebrafish model was reviewed, and novel strategy for toxicity of TCM using zebrafish was suggested in the paper.

Establishment of Immortalized Primary Human Foreskin Keratinocytes and Their Application to Toxicity Assessment and Three Dimensional Skin Culture Construction

In spite of frequent usage of primary human foreskin keratinocytes (HFKs) in the study of skin biology, senescence-induced blockage of in vitro proliferation has been a big hurdle for their effective utilization. In order to overcome this passage limitation, we first isolated ten HFK lines from circumcision patients and successfully immortalized four of them via a retroviral transduction of high-risk human papillomavirus (HPV) E6 and E7 oncogenes. We confirmed expression of a keratinocyte marker protein, keratin 14 and two viral oncoproteins in these immortalized HFKs. We also observed their robust responsiveness to various exogenous stimuli, which was evidenced by increased mRNA expression of epithelial differentiation markers and pro-inflammatory genes in response to three reactive chemicals. In addition, their applicability to cytotoxicity assessment turned out to be comparable to that of HaCaT cells. Finally, we confirmed their differentiation capacity by construction of well-stratified three dimensional skin cultures. These newly established immortalized HFKs will be valuable tools not only for generation of in vitro skin disease models but also for prediction of potential toxicities of various cosmetic chemicals.

"Omics" in pharmaceutical research: overview, applications, challenges, and future perspectives / 中国天然药物

In the post-genomic era, biological studies are characterized by the rapid development and wide application of a series of "omics" technologies, including genomics, proteomics, metabolomics, transcriptomics, lipidomics, cytomics, metallomics, ionomics, interactomics, and phenomics. These "omics" are often based on global analyses of biological samples using high through-put analytical approaches and bioinformatics and may provide new insights into biological phenomena. In this paper, the development and advances in these omics made in the past decades are reviewed, especially genomics, transcriptomics, proteomics and metabolomics; the applications of omics technologies in pharmaceutical research are then summarized in the fields of drug target discovery, toxicity evaluation, personalized medicine, and traditional Chinese medicine; and finally, the limitations of omics are discussed, along with the future challenges associated with the multi-omics data processing, dynamics omics analysis, and analytical approaches, as well as amenable solutions and future prospects.

Research Progress in Toxicity Assessment Using Zebrafish / 中国药师

Zebrafish toxicity assessment system is one of the important vertebrate model systems. Zebrafish is playing an increas-ingly important role in the field of toxicology studies because of its small size, short generation cycle, the transparent embryo and high reproductive rate. Now it is widely used in the embryonic derelopmental toxicology, pathological toxicology, environmental toxicology and other areas of toxicology studies with its unique advantages.

Protective role of Cassia auriculata leaf extract on hyperglycemia-induced oxidative stress and its safety evaluation.

Cassia auriculata L. (Caesalpiniaceae) is widely used from the ancient period to treat diabetes mellitus. In the present study, the antioxidant activity of C. auriculata aqueous leaf extract (CLEt) was evaluated in streptozotocin-induced mild diabetic (MD) and severe diabetic (SD) rats. A short-term toxicity assessment was also conducted in healthy rats to examine toxic effects of the extract. Oral administration of CLEt to MD and SD rats (100, 200 and 400 mg/kg body weight per day for a period of 21 days) produced significant fall in fasting blood glucose (FBG) in a dose-dependent manner. Treatment with the extract (400 mg/kg) showed significant reduction in serum levels of thiobarbituric acid reactive substances (TBARS) and oxidized low-density lipoprotein (OxLDL) in both MD and SD rats. The antioxidant defense system was also found to be improved in CLEt-treated (400 mg/kg) MD and SD rats, as revealed by significant increase in activities of erythrocyte’s antioxidant enzymes i.e. superoxide dismutase (SOD) and catalase (CAT) with a concomitant elevation in erythrocyte’s reduced glutathione (GSH) content. Moreover, there were no toxic signs in rats treated with high doses of the extract (1000 and 2000 mg/kg body weight per day for 21 days). Blood glucose, hepatic and renal function parameters in these rats were found within normal limits. Phytochemical screening of CLEt revealed the presence of alkaloids, flavonoids, saponins, tannins and cardiac glycosides with antihyperglycemic and antioxidant properties. This study suggests that CLEt possesses potent antioxidant activity along with antihyperglycemic potential, hence protective against diabetic complications.