The Effect of Leonurine on Multiterritory Perforator Flap Survival in Rats

Leonurine: a comprehensive review of pharmacokinetics, pharmacodynamics, and toxicology

Leonurine is an alkaloid unique to the Leonurus genus, which has many biological activities, such as uterine contraction, anti-inflammation, anti-oxidation, regulation of cell apoptosis, anti-tumor, angiogenesis, anti-platelet aggregation, and inhibition of vasoconstriction. This paper summarizes the extraction methods, synthetic pathways, biosynthetic mechanisms, pharmacokinetic properties, pharmacological effects in various diseases, toxicology, and clinical trials of leonurine. To facilitate a successful transition into clinical application, intensified efforts are required in several key areas: structural modifications of leonurine to optimize its properties, comprehensive pharmacokinetic assessments to understand its behavior within the body, thorough mechanistic studies to elucidate how it works at the molecular level, rigorous safety evaluations and toxicological investigations to ensure patient wellbeing, and meticulously conducted clinical trials to validate its efficacy and safety profile.

Assessment of the Effect of Leonurine Hydrochloride in a Mouse Model of PCOS by Gene Expression Profiling

Polycystic ovary syndrome (PCOS) is an endocrine disease commonly associated with metabolic disorders in females. Leonurine hydrochloride (Leo) plays an important role in regulating immunity, tumours, uterine smooth muscle, and ovarian function. However, the effect of Leo on PCOS has not been reported. Here, we used dehydroepiandrosterone to establish a mouse model of PCOS, and some mice were then treated with Leo by gavage. We found that Leo could improve the irregular oestros cycle of PCOS mice, reverse the significantly greater serum testosterone (T) and luteinising hormone (LH) levels, significantly reduce the follicle-stimulating hormone (FSH) level, and significantly increase the LH/FSH ratio of PCOS mice. Leo could also change the phenomenon of ovaries in PCOS mice presented with cystic follicular multiplication and a lacking corpus luteum. Transcriptome analysis identified 177 differentially expressed genes related to follicular development between the model and Leo groups. Notably, the cAMP signalling pathway, neuroactive ligand-receptor interactions, the calcium signalling pathway, the ovarian steroidogenesis pathway, and the Lhcgr, Star, Cyp11a, Hsd17b7, Camk2b, Calml4, and Phkg1 genes may be most related to improvements in hormone levels and the numbers of ovarian cystic follicles and corpora lutea in PCOS mice treated by Leo, which provides a reference for further study of the mechanism of Leo.

Tissue-Protective Mechanisms of Bioactive Phytochemicals in Flap Surgery

Despite careful preoperative planning, surgical flaps are prone to ischemic tissue damage and ischemia–reperfusion injury. The resulting wound breakdown and flap necrosis increase both treatment costs and patient morbidity. Hence, there is a need for strategies to promote flap survival and prevent ischemia-induced tissue damage. Phytochemicals, defined as non-essential, bioactive, and plant-derived molecules, are attractive candidates for perioperative treatment as they have little to no side effects and are well tolerated by most patients. Furthermore, they have been shown to exert beneficial combinations of pro-angiogenic, anti-inflammatory, anti-oxidant, and anti-apoptotic effects. This review provides an overview of bioactive phytochemicals that have been used to increase flap survival in preclinical animal models and discusses the underlying molecular and cellular mechanisms.

Upregulation of Nrf2 signaling and suppression of ferroptosis and NF-κB pathway by leonurine attenuate iron overload-induced hepatotoxicity

Hepatotoxicity is a major health concern that associates the iron overload diseases including hemochromatosis, sickle cell anemia, and thalassemia. Induction of ferroptosis, oxidative stress, and inflammation substantially mediates the iron-evoked hepatotoxicity. The current work investigated the potential protective effect of the natural alkaloid leonurine against the iron-induced hepatotoxicity and elucidated the underlining molecular mechanisms. Male Wistar rats were treated with iron only (30 mg/kg every other day over a ten-day period via intraperitoneal injection) or with iron and leonurine (leonurine: 100 mg/kg/day per oral via gastric gavage for 10 days) to establish the iron-overload model. Liver and blood specimens were then collected and subjected to molecular, biochemical, and histopathological investigations. The results revealed the ability of leonuirne to suppress the iron-induced ferroptosis as reflected by modulation of the ferroptotic biomarkers glutathione peroxidase 4, cyclooxygenase-2, liver iron content, lipid hydroperoxides, and the leakage of the liver intracellular enzymes. Leonurine alleviated the iron-induced oxidative damage and inflammatory response in the liver tissues as indicated by decreased levels of DNA oxidation, lipid peroxidation, and the pro-inflammatory cytokines. In the same context, it improved the antioxidant potential of the liver tissues and ameliorated the iorn-induced histopathological abnormalities. Mechanistically, leonurine enhanced nuclear translocation of the antioxidant transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and increased protein levels of its downstream targets NAD(P)H-quinone oxidoreductase 1 and heme oxygenase-1. Additionally, it suppressed the nuclear translocation of the inflammatory transcription factor nuclear factor kappa B (NF-κB) and downregulated its downstream pro-inflammatory cytokines tumor necrosis factor-alpha and interleukin-1 beta. The study highlights the hepatoprotective activity of leonurine against the iron-evoked hepatotoxicity that is potentially mediated through modulation of Nrf2 and NF-κB signaling.

Photoacoustic microscopy: a novel approach for studying perforator skin flap in a mouse model

Background

A comprehensive understanding of cutaneous microvessels is key to the design and use of the perforator skin flap. Compared with the various imaging technologies that have been applied in the clinical practice of the perforator skin flap, photoacoustic microscopy (PAM) is a very promising noninvasive imaging modality with high resolution and deep penetration in biological tissues.

Methods

PAM was employed to explore its multiple applications in a perforator skin flap. The following experiments were then conducted in 3 parts. In part 1, 7 mice were used to obtain the preoperative perforator mapping on the mouse back. In parts 2 and 3, 7 mice were used to design and harvest the multiterritory perforator flap. The status of the flap and the morphological changes of choke vessels were subsequently observed by PAM at several time points.

Results

The results showed that PAM could visualize and assess the vascular physiological and pathological conditions of the skin tissue in real time in vivo with high spatial and temporal resolution. It could also provide preoperative perforator mapping, including the total number of perforators, localization, vascular territories, and diameter. Furthermore, it could offer a quantitative, objective method to monitor the status of the perforator skin flap, and was capable of noninvasive characterization of the changes of choke vessels that play an important role in multiterritory perforator skin flap expansion and survival.

Conclusions

PAM has great potential to be an effective and precise quantitative imaging tool for perforator skin flap research, such in as flap design, monitoring, and choke vessel observation.

Butylphthalide Inhibits Autophagy and Promotes Multiterritory Perforator Flap Survival

Multiterritory perforator flap is an important plastic surgery technique, yet its efficacy can be limited by partial necrosis at the choke Ⅱ zone. Butylphthalide (NBP) has been used for many diseases but has not been studied in the multiterritory perforator flap. With the effect of NBP, we observed increasing in capillary density, inhibition of autophagy and oxidative stress, and a reduction in apoptosis of cells, all consistent with increased flap survival. However, the protective effect of NBP on multiterritory perforator flap was lost following administration of the autophagy agonist rapamycin (Rap). Through the above results, we assumed that NBP promotes flap survival by inhibiting autophagy. Thus, this study has found a new pharmacological effect of NBP on the multiterritory perforator by inhibiting autophagy to prevent distal postoperative necrosis and exert effects on angiogenesis, oxidative stress, and apoptosis within the flap.

Effects of oxidative stress and apoptosis on vascularity and viability of perforator flaps

We investigated lateral thoracic and posterior thigh perforator flaps for viability, vascularization, perfusion and apoptosis in a rat model. Wistar albino rats were divided into six groups: lateral thoracic artery perforator flap (LTPF) sham, 3 × 2 cm² LTPF, 3 × 6 cm² LTPF, posterior thigh perforator flap (PTPF) sham, 3 × 2 cm² PTPF, and 3 × 6 cm² PTPF. Flap viability was determined on postoperative days 1 and 7. On day 7, flaps were photographed and their viability was measured using two-dimensional planimeter paper. Tissue samples were harvested for examination by histology and immunohistochemistry. Viability differences were statistically significant. Epithelial thickness, vascularity and number of fibroblasts were reduced in the 3 × 6 cm² groups. Neovascularization and apoptosis based on molecular tests were not significantly different among groups. Flap size and location are important factors for closure of surgical or traumatic defects. We suggest that for clinical application, wound complications will occur less frequently with perforators that nourish large areas of flaps.