Simultaneous Determination of Bergapten, Imperatorin, Notopterol, and Isoimperatorin in Rat Plasma by High Performance Liquid Chromatography with Fluorescence Detection and Its Application to Pharmacokinetic and Excretion Study after Oral Administration of Notopterygium incisum Extract

Assessing the efficacy and safety of Juan Bi Tang for dialysis-related myofascial pain in the fistula arm: Study protocol for a randomized cross-over trial

Background

Dialysis-related myofascial pain in hemodialysis (HD) patients is an important issue that is associated with many other psychosomatic problems. Effective interventions are required to alleviate pain in this group. Chinese herbal medicine (CHM) may be a potential therapeutic treatment for reducing pain. The aim of this study is to evaluate the effects of a classic CHM formula intervention on pain intensity, daily function, quality of life (QOL), and safety in patients receiving HD in a dialysis center within the context of southern Taiwan.

Methods

This will be a randomized, open label, cross-over trial with two parallel groups in a pre- and post-test study. Forty patients reporting myofascial pain related to the arteriovenous (AV) fistula in the arm during regular HD sessions will be recruited. Participants will receive 4 weeks of treatment with Juan Bi Tang (JBT) and 4 weeks of no treatment in a random order, separated by a washout period of 2 weeks. Treatment doses (3 g JBT) will be consumed thrice daily. The primary outcome measure will be the Kidney Disease Quality of Life 36-Item Short-Form Survey. Secondary outcomes will include the Fugl-Meyer Assessment-arm, Visual Analogue Scale (VAS) of pain, and grip strength. Outcomes will be collected before and after each intervention, for a total of four times per participant. The safety evaluation will focus on adverse events (AEs).

Discussion

This study will be the first to use CHM to treat patients receiving HD with dialysis-related myofascial pain in their fistula arm and to perform a complete assessment of the treatment, including records of QOL, arm function and muscle power, severity of pain, and safety. The results of the study will provide convincing evidence on the use of JBT as an adjuvant treatment for dialysis-related myofascial pain.

Trial registration

Clinicaltrials.gov registry (NCT04417101) registered 30 May 2020.

Pharmacological Properties of Bergapten: Mechanistic and Therapeutic Aspects

Bergapten (BP) or 5-methoxypsoralen (5-MOP) is a furocoumarin compound mainly found in bergamot essential oil but also in other citrus essential oils and grapefruit juice. This compound presents antibacterial, anti-inflammatory, hypolipemic, and anticancer effects and is successfully used as a photosensitizing agent. The present review focuses on the research evidence related to the therapeutic properties of bergapten collected in recent years. Many preclinical and in vitro studies have been evidenced the therapeutic action of BP; however, few clinical trials have been carried out to evaluate its efficacy. These clinical trials with BP are mainly focused on patients suffering from skin disorders such as psoriasis or vitiligo. In these trials, the administration of BP (oral or topical) combined with UV irradiation induces relevant lesion clearance rates. In addition, beneficial effects of bergamot extract were also observed in patients with altered serum lipid profiles and in people with nonalcoholic fatty liver. On the contrary, there are no clinical trials that investigate the possible effects on cancer. Although the bioavailability of BP is lower than that of its 8-methoxypsoralen (8-MOP) isomer, it has fewer side effects allowing higher concentrations to be administered. In conclusion, although the use of BP has therapeutic applications on skin disorders as a sensitizing agent and as components of bergamot extract as hypolipemic therapy, more trials are necessary to define the doses and treatment guidelines and its usefulness against other pathologies such as cancer or bacterial infections.

Bergapten: A review of its pharmacology, pharmacokinetics, and toxicity

Bergapten is a natural furocoumarin, also known as 5-methoxypsoralen, and its medicinal value has been paid more and more attention. By sorting out the pharmacological literature of bergapten, we found that bergapten has a wide range of pharmacological effects, including neuroprotection, organ protection, anticancer, antiinflammatory, antimicrobial, and antidiabetes effects. However，bergapten has complex impacts on the hepatic metabolic enzyme. Moreover, pharmacokinetic studies showed that bergapten has higher absolute bioavailability and can cross the blood-brain barrier and has a great potential for treating brain disease, but the mechanism needs further clarification to make greater use of its ability to treat brain diseases. Furthermore, the phototoxicity of bergapten combined with ultraviolet light has always been mentioned. In view of its wide range of pharmacological activities, bergapten is expected to be a potential drug candidate for the treatment of diabetes and diabetes-induced osteoporosis, epilepsy, Alzheimer's disease, depression, and cancer. However, further studies are needed to elucidate its molecular mechanisms and targets. The phototoxicity of bergapten as a side effect should be further avoided. On the other hand, the photoactivation of bergapten in the anticancer aspect can be better utilized.

Imperatorin: A review of its pharmacology, toxicity and pharmacokinetics

As a naturally occurring furanocoumarin, the medicinal value of imperatorin has been studied more and more. We hope to provide useful information for the further development of imperatorin by analyzing the literature of imperatorin in recent years. By collating the literature on the pharmacology of imperatorin, we found that the pharmacological activity of imperatorin is wide and imperatorin can be used for anti-cancer, neuroprotection, anti-inflammatory, anti-hypertension and antibacterial. In addition, we found that some researchers confirmed the toxicity of imperatorin. Pharmacokinetic studies demonstrated that oxidation metabolism is the main metabolic pathways of imperatorin. At present, the shortcomings of research on imperatorin mainly include: most pharmacological studies are concentrated in vitro, lacking enough in vivo experimental data; more and more studies showed that imperatorin has synergistic effect with other drugs in anticancer and other aspects, but lacking the detailed explanation of the mechanism of the synergistic effect; imperatorin has side effect, but it lacks enough experimental conclusions. Based on the above defects, we believe that more in vivo experiments of imperatorin should be carried out in the future; future research need to explore synergistic mechanisms of imperatorin with other drugs, especially in anticancer; the dose affects both the pharmacological activity and the side effect of imperatorin. The relationship between the dose and the two aspects need to be further studied in order to reduce the side effect. In addition, through structural modification of imperatorin, it is possible to improve the treatment effect and reduce side effect.

Mechanism-based inactivation of cytochrome P450 2D6 by Notopterol

Notopterol (NOT) is a major bioactive ingredient extracted from the rhizomes of either Notopterygium incisum Ting ex H. T. Chang or N. forbesii Boiss (Qianghuo in Chinese), a botanical drug that was adopted as a traditional Chinese medicine. NOT is suggested to show analgesic and anti-inflammatory effects in clinical practice. The inhibitory effects of NOT on human cytochrome P450 enzymes were investigated in the present study. Our results indicate that NOT inhibited the activity of CYP2D6 in a time-, concentration- and NADPH-dependent manner. The values of K_I and k_inact were 10.8 μM and 0.62 min^-1, respectively. The calculated k_obs at 10 μM was 0.29 min^-1, above the 0.02 min^-1 risk level. After incubation with NOT at 10 μM for 9 min, approximately 92% of CYP2D6 activity was inhibited. Such loss of enzyme activity was not restored through dialysis, which indicates that the observed enzyme inhibition was irreversible. Partition ratio of the inactivation was approximately 29. Quinidine, a competitive CYP2D6 inhibitor, demonstrated protection on enzymes against the NOT-induced inactivation, but such protection was not found in incubation systems fortified with glutathione or catalase/superoxide dismutase. Additionally, CYP3A4 was observed to function as an enzyme mainly involved in the biotransformation of NOT. Taken together, these findings indicate that NOT served as a mechanism-based inactivator of CYP2D6, meanwhile, those observed effects may induce the latent drug-drug interactions. The metabolic activation of NOT may be the key to trigger the inactivation of the enzyme.

Effect of Different Post-Harvest Processing Methods on the Chemical Constituents of Notopterygium franchetii by an UHPLC-QTOF-MS-MS Metabolomics Approach

Notopterygium franchetii is a herb used in traditional Chinese medicine, where it is known as qianghuo. Its bioactive qualities are influenced by the post-harvest processing methods used (such as drying). However, changes in chemical components according to the drying method are unknown. Fresh roots and rhizomes of N. franchetii were subjected to seven drying methods. Chromatography-mass spectrometry combined with targeted and untargeted analyses were used to investigate relationships between drying methods and chemical concentrations. According to targeted evaluations of the six main bioactive constituents, their total contents decreased significantly in all drying methods. Hierarchical clustering analysis of the drying methods and total metabolome detected 30 chemical constituents, for which heap maps were obtained. Hot air drying was the best processing method, producing the least chemical changes at the lowest cost, while shade drying caused the greatest chemical changes. In conclusion, the wide range of chemical changes in N. franchetii caused by drying was investigated. Such changes potentially affect the quality of herbal medicines.

A review of the ethnopharmacology, phytochemistry and pharmacology of Notopterygium incisum

ETHNOPHARMACOLOGICAL RELEVANCE

Notopterygium incisum Ting ex H.T. Chang, known in Chinese as 'Qianghuo' is a traditional Chinese medicinal herb with the rhizome and roots associated with meridians of the kidney and urinary bladder. It is pungent, bitter and warm in nature. It has been used over the years to disperse cold, prevent painful obstructions from wind, damp and warm pain. It has also been used with other herbs to treat wind-cold exterior syndrome and wind-cold-damp bi-syndromes and has been known to grow well in regions of high altitude such as Gansu, Tibet etc.

THE AIM OF THE REVIEW

This systematic review focuses on the ethnopharmacological uses of this herb, including recent advances on the phytochemical and pharmacological study of N. incisum. Recent analytical methods developed for the quantitative and qualitative determination of constituents in this herb have also been reviewed. Additionally, future trends and prospects in the study of this herb have been proposed.

MATERIALS AND METHOD

Various literature and electronic databases such as Pubmed, Science Direct, Springer, Wiley etc were searched and data obtained. Other online academic libraries such as Google Scholar and ethnopharmacological literature were searched systematically for more information on the herb.

RESULTS

This review focuses on the ethnopharmacological uses of N. incisum and also the various chemical constituents present in the herb and their various therapeutic effects such as analgesic, anti-inflammatory, anti-cancer and antioxidants effects. Analytical methods developed for the quantitative and qualitative determination of various compounds in this herb were further reviewed.

CONCLUSION

In this paper, we have reviewed various researches conducted on N. incisum especially in areas of its ethnopharmacological use, phytochemicals, pharmacology and developed analytical methods. This herb has been used over the years in treating headache, rheumatoid arthritis, cold, diaphoretic etc, prompting many types of research into identifying which compounds are responsible for these activities and their mechanism of action. More research is needed in the area of pharmacokinetics and toxicology to give further information on the clinical use and control the quality of the herb.