Utilization of Physiologically Based Pharmacokinetic Modeling in Pharmacokinetic Study of Natural Medicine: An Overview.

Natural medicine has been widely used for clinical treatment and health care in many countries and regions. Additionally, extracting active ingredients from traditional Chinese medicine and other natural plants, defining their chemical structure and pharmacological effects, and screening potential druggable candidates are also uprising directions in new drug research and development. Physiologically based pharmacokinetic (PBPK) modeling is a mathematical modeling technique that simulates the absorption, distribution, metabolism, and elimination of drugs in various tissues and organs in vivo based on physiological and anatomical characteristics and physicochemical properties. PBPK modeling in drug research and development has gradually been recognized by regulatory authorities in recent years, including the U.S. Food and Drug Administration. This review summarizes the general situation and shortcomings of the current research on the pharmacokinetics of natural medicine and introduces the concept and the advantages of the PBPK model in the study of pharmacokinetics of natural medicine. Finally, the pharmacokinetic studies of natural medicine using the PBPK models are summed up, followed by discussions on the applications of PBPK modeling to the enzyme-mediated pharmacokinetic changes, special populations, new drug research and development, and new indication adding for natural medicine. This paper aims to provide a novel strategy for the preclinical research and clinical use of natural medicine.

Research and development of Chinese anti-COVID-19 drugs.

The outbreak and spread of coronavirus disease 2019 (COVID-19) highlighted the importance and urgency of the research and development of therapeutic drugs. Very early into the COVID-19 pandemic, China has begun developing drugs, with some notable progress. Herein, we summarizes the anti-COVID-19 drugs and promising drug candidates originally developed and researched in China. Furthermore, we discussed the developmental prospects, mechanisms of action, and advantages and disadvantages of the anti-COVID-19 drugs in development, with the aim to contribute to the rational use of drugs in COVID-19 treatment and more effective development of new drugs against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the variants. Neutralizing antibody is an effective approach to overcome COVID-19. However, drug resistance induced by rapid virus mutation will likely to challenge neutralizing antibodies. Taking into account current epidemic trends, small molecule drugs have a crucial role in fighting COVID-19 due to their significant advantage of convenient administration and affordable and broad-spectrum. Traditional Chinese medicines, including natural products and traditional Chinese medicine prescriptions, contribute to the treatment of COVID-19 due to their unique mechanism of action. Currently, the research and development of Chinese anti-COVID-19 drugs have led to some promising achievements, thus prompting us to expect even more rapidly available solutions.

The therapeutic effect of Taijiquan combined with acupoint pressing on the treatment of anxiety insomnia in college students: A study protocol for a randomized controlled trial.

Introduction: Sleep health is an important part of health and has become a common concern of society. For anxiety insomnia, the commonly used clinical therapies have limitations. Alternative and complementary therapy is gradually rising and showing remarkable effect in clinical practice. This is the first study to evaluate the therapeutic effect of Taijiquan combined with acupoint pressing in the treatment of anxiety insomnia in college students and to compare the difference in intervention before and after sleep, to choose the best treatment time. Methods and analysis: This is a multicenter, single-blind, randomized controlled trial. A total of 126 eligible subjects who have passed the psychological evaluation and met inclusion criteria by completing a psychometric scale will be randomly divided into treatment group A (treat before sleep), treatment group B (treat after sleep) and control group C (waiting list group) in a ratio of 1:1:1. All the three groups will receive regular psychological counseling during the trial, and the treatment groups will practice 24-style Taijiquan and do meridian acupuncture at Baihui (DU20), Shenting (DU24), Yintang (EX-HN3), Shenmen (HT7) and Sanyinjiao (SP6). This RCT includes a 2-week baseline period, a 12-week intervention period, and a 12-week follow-up period. The main results will be measured by changes in the Pittsburgh sleep quality index (PSQI) and Hamilton anxiety scale (HAMA). The secondary results will be measured by the generalized anxiety scale (GAD-7) and insomnia severity index (ISI). The safety of the intervention will be evaluated at each assessment. The statistical analysis of data will be carried out by SPSSV.26.0 software. Discussion: We expect this trial to explore the effectiveness of Taijiquan combined with acupoint pressing in the treatment of anxiety insomnia in college students and choose the best treatment time by comparison. Clinical trial registration: [www.ClinicalTrials.gov], identifier [ChiCTR2200057003].

Pine (Pinus sylvestris L.) bark proanthocyanidins affords prevention of peroxynitrite-induced l-tyrosine nitration, DNA damage and hydroxyl radical formation.

Peroxynitrite is known as a strong deleterious species that may readily trigger several geriatric diseases via injuring cellular constituents. Proanthocyanidins, a biological flavonoids constituent of Pinus sylvestris L. bark, has been attributed a large variety of pharmacological functions to its antioxidant potential. The results revealed that peroxynitrite could cause the generation of hydroxyl radical, the breakage of φX-174 plasmid DNA brand as well as the nitration of L-tyrosine. However, pine (Pinus sylvestris L.) bark proanthocyanidins extracts at low concentration range markedly inhibited the peroxynitrite -induced the formation of open circular DNA form (IC50 = 5.03±0.39 mg/mL). The 3-Nitro-L-tyrosine generated by the reaction of peroxynitrite with L-tyrosine was reduced by PBP (IC50 = 1.01±0.01 mg/mL). Besides, electron spin resonance spectroscopy data indicates that the intensive signal of dimethyl pyridine N-oxide hydroxyl radical adduct from peroxynitrite was reversed by pine bark proanthocyanidins extracts (IC50 =1.02±0.04 mg/mL). Moreover, the obtained data shows that PBP provides more efficient protection against peroxynitrite than that of ascorbic acid. Together, the present study suggests that pine bark proanthocyanidins could exert potent preventive activity against peroxynitrite -elicited cytotoxicity on the biomacromolecules, a study-worthy finding with pharmacological importance.

Hypolipidemic and antioxidant potential of bitter gourd (Momordica charantia L.) leaf in mice fed on a high-fat diet.

The purpose of this study was to investigate the antioxidant and hypolipidemic potential of bitter gourd (BG) leaf ethanol extract (LE) in mice fed a high-fat diet (HFD). Fifty mice were randomly separated into five groups with 10 animals of each group. The animals received normal diet (NC), HFD diet (HF), 200mg/kg/day LE with HFD (LLE), 400 mg/kg/day LE with HFD (MLE), 800mg/kg/day LE with HFD (HLE), respectively. After six weeks, HF group showed meaningfully (P<0.05) increased body weight, fat index, serum lipid and oxidant stress compared to NC group. However, serum TC, TG and LDL-c concentrations were lower in all LE treated groups compared with HF group (P<0.05). In addition to LLE group, HLD-c levels in LE treated groups were higher that that in HF group (P<0.05). Moreover, LE attenuated significantly (P<0.05) the MDA content and elevated the SOD activities of the liver tissues in a dose effect relationship. The histopathological examination confirmed the hepatoprotective effect of LE against liver damage induced by HFD. These findings illustrate that bitter gourd leaves may be valuable for preventing hyperlipidemia and oxidative stress induced by HFD.