Multidrug resistant bacteria have been a global health threat currently and frontline clinical treatments for these infections are very limited. To develop potent antibacterial agents with new bactericidal mechanisms is thus needed urgently to address this critical antibiotic resistance challenge. Natural products are a treasure of small molecules with high bioactive and low toxicity. In the present study, we demonstrated that a natural compound, honokiol, showed potent antibacterial activity against a number of Gram-positive bacteria including MRSA and VRE. Moreover, honokiol in combination with clinically used β-lactam antibiotics exhibits strong synergistic antimicrobial effects against drug-resistant S. aureus strains. Biochemical studies further reveal that honokiol may disrupt the GTPase activity, FtsZ polymerization, cell division. These biological impacts induced by honokiol may ultimately cause bacterial cell death. The in vivo antibacterial activity of honokiol against S. aureus infection was also verified with a biological model of G. mellonella larvae. The in vivo results support that honokiol is low toxic against the larvae and effectively increases the survival rate of the larvae infected with S. aureus. These findings demonstrate the potential of honokiol for further structural advancement as a new class of antibacterial agents with high potency against multidrug-resistant bacteria.

Trastuzumab resistance presents a significant challenge in the treatment of HER2+ breast cancer, necessitating the investigation of combination therapies to overcome this resistance. Honokiol, a compound with broad anticancer activity, has shown promise in this regard. This study aims to discover the effect of honokiol in increasing trastuzumab sensitivity in HER2+ trastuzumab-resistant breast cancer cells HCC1954 and the underline mechanisms behind. A bioinformatics study performed to explore the most potential target hub gene for honokiol in HER2+ breast cancer. Honokiol, trastuzumab and combined treatment cytotoxicity activity was then evaluated in both parental HCC1954 and trastuzumab resistance (TR-HCC1954) cells using MTT assay. The expression levels of these hub genes were then analyzed using qRT-PCR and those that could not be analyzed were subjected to molecular docking to determine their potential. Honokiol showed a potent cytotoxicity activity with an IC50 of 41.05 μM and 69.61 μM in parental HCC1954 and TR-HCC1954 cell line respectively. Furthermore, the combination of honokiol and trastuzumab resulted in significant differences in cytotoxicity in TR-HCC1954 cells at specific concentrations. Molecular docking and the qRT-PCR showed that the potential ERα identified from the bioinformatics analysis was affected by the treatment. Our results show that honokiol has the potential to increase the sensitivity of trastuzumab in HER2+ trastuzumab resistant breast cancer cell line HCC1954 by affecting regulating estrogen receptor signaling. Further research is necessary to validate these findings.

Aim: To investigate pharmacokinetics of honokiol after administration of honokiol liposome injection (HKLI) and support the clinical studies of HKLI; it is crucial to determine the concentration of honokiol in human biological samples. Experimental method & results: Human plasma samples were extracted by protein precipitation and analyzed by a new ultra-HPLC-MS/MS (UPLC-MS/MS) method with LLOQ of 0.5 ng/ml. The method was validated according to bioanalytical guidelines from the US FDA and EMA. Successful method validation proved that the method was sensitive and selective, and was suitable for determination of honokiol in clinical plasma samples. Conclusion: The method was successfully applied to evaluate the pharmacokinetics of honokiol after administration of HKLI to Chinese subjects with advanced non-small-cell lung cancer in a first in-human study.

BACKGROUND: Traumatic brain injury (TBI) leads to neuronal damage and neurological dysfunction. The aim of our study was to investigate the antioxidative effect of honokiol on TBI in rats with biochemical, histopathological and immunohistochemical methods.
METHODS: Sprague-Dawley rats were subjected to TBI with a weight-drop device using 300 g/1 m weight/height impact. Forty-five rats were divided into three groups as control group, TBI group and TBI + honokiol group (5 mg/kg/day, i.p.). Honokiol (5 mg/kg) dissolved in dimethyl sulfoxide (DMSO) was intraperitoneally administered to rats for 7 days after the trauma. At the end of experiment, blood samples were taken from the animals and analysed with various biochemical markers.
RESULTS: Histopathological examination of the trauma group revealed some degenerated pyramidal cells, dilatation and congestion in blood vessels, hyperplasia in endothelial cells, inflammatory cell infiltration around the vein and disruptions in glial extensions. In TBI + honokiol group, pyramidal neurons showed a decrease in degeneration, slight dilatation in blood vessels, improvement of endothelial cells towards the lumen, and reduction of inflammatory cells in the vessel. In TBI + honokiol group, vascular endothelial growth factor expression was positive in the endothelial and few inflammatory cells of the mildly dilated blood vessels. In the blood brain barrier deteriorated after trauma, it was observed that the glial foot processes were positive expression and extended to the endothelial cells in the TBI + honokiol group.
CONCLUSIONS: Glial fibrillary acidic protein expression showed a positive reaction in these processes. Considering the important role of antioxidants and inflammatory responses in cerebral damage induced by traumatic head injury, honokiol is thought to be important in decreasing lipid peroxidation, protecting the membrane structure of blood brain barrier, degeneration of neurons and glial cells.

Objective: To investigate the effect and intrinsic mechanism of Honokiol (HNK) enhanced tumor necrosis factor-related apoptosis inducing ligand (TRAIL) on hepatocellular carcinoma HepG2 cells. Methods: HepG2 cells were routinely cultured. Firstly, a concentration gradient of HNK was given to observe its effect on the vitality of tumor cells. Western blot were used to detect change in the expression levels of c-jun N-terminal kinase (JNK), death receptor 4 (DR4), and DR5.Secondly, we observed the effect of combined drugs (HNK and TRAIL) on the vitality of tumor cells. Apoptosis-related protein expression levels were detected to determine the apoptosis condition. Thirdly, JNK inhibitor SP600125 was used to block the JNK pathway, and it was evaluated whether JNK signaling pathway mediated the DR4 and DR5 levels and finally, the subcutaneous tumor model of nude mice was constructed, and enhancement effect of HNK on TRAIL was confirmed in vivo. Results: Cell vitality was decreased (P < 0.05) in a dose-dependent manner after treatment with gradient HNK. Combined effect of TRAIL and HNK was superior to that of single drug administration (P < 0.05). Western blot analysis showed that pJNK level increased after HNK treatment and TRAIL receptor DR4 and DR5 expression were up-regulated. Combined application of HNK and TRAIL, B lymphocyte tumor factor 2 (BCL2) decreased significantly while Bcl2 related X protein (Bax) increased significantly. Blocking JNK pathway by SP600125, the expression of DR4 and DR5 decreased (P < 0.05), Bax expression decreased and Bcl2 expression increased compared with HNK+TRAIL group. In vivo results showed that TRAIL inhibited the growth of subcutaneous tumors, and enhanced inhibition effect in combination with TRAIL and HNK. Conclusion: HNK may enhance the inhibitory effect of TRAIL on HepG2 cells by activating JNK pathway and then upregulating the expression of DR4 and DR5.
目的： 研究和厚朴酚（HNK）强化肿瘤坏死因子相关凋亡诱导配体（TRAIL）抗肝细胞癌HepG2细胞的作用及其机制。 方法： 常规培养HepG2细胞，首先给予梯度浓度HNK处理，观察其对肿瘤细胞活力的影响；Western blot法检测c-Jun氨基末端激酶（JNK）、死亡受体4（DR4）、DR5表达水平变化。进而联合应用HNK与TRAIL，观察联合用药对肿瘤细胞活力的影响；检测凋亡相关蛋白表达水平明确凋亡情况。然后采用JNK抑制剂SP600125阻断JNK通路，明确DR4、DR5水平变化是否由JNK信号通路介导。最后构建裸鼠皮下肿瘤模型，明确在体内水平下，HNK对TRAIL的强化效果。 结果： 梯度浓度HNK处理细胞后细胞活力剂量依赖性降低（P < 0.05）；联合应用TRAIL与HNK效果优于单纯用药（P < 0.05）；蛋白检测发现，HNK处理后pJNK水平上升，同时TRAIL受体DR4、DR5表达上调。联合应用HNK与TRAIL后，B淋巴细胞瘤因子2(bcl2)显著下降而Bcl2相关X蛋白（Bax）显著升高。SP600125阻断JNK通路后，与HNK + TRAIL组相比，DR4、DR5表达下降（P < 0.05），Bax表达下降而Bcl2表达升高。在体内结果显示，TRAIL抑制了皮下肿瘤的生长，联合应用TRAIL与HNK抑制作用增强。 结论： HNK可能通过激活JNK通路进而上调DR4、DR5表达来强化TRAIL对HepG2细胞的抑制作用。.

Counter-current chromatography (CCC) has been widely used as a preparative separation method to purify natural products from plant extracts and fermentation broths. Traditionally, throughput optimization in CCC has focused on sample concentration and sample volume. In this paper sample injection was considered as consisting of three variables: injection flow rate, post-injection flow rate and sample solvent. The effects of these parameters were studied using a honokiol purification from a Magnolia officinalis bark extract as a case study aiming to achieve the highest throughput/yield ratio for greater than 99% purity of this potential anti-cancer drug obtained for submission to the Chinese FDA. An injection method was established that increased the throughput of honokiol by 46.5% (from 3.05g/h to 4.47g/h), and decreased the solvent consumption of mobile phase and stationary phase per gram of honokiol by 40.0% (from 0.68L/g to 0.41L/g) and 48.4% (from 0.40L/g to 0.21L/g) respectively. These results show the importance of understanding the whole injection process when optimizing a given CCC separation.

OBJECTIVE: The purpose of this study was to investigate the protective effect of honokiol on experimental ischemia/reperfusion injury of rat ovary.
METHODS: A total of 40 female Wistar albino rats were used in this study. The rats were divided into five groups as follows: sham (Group I), torsion (Group II), torsion + detorsion (Group III), torsion + detorsion + saline (Group IV), and torsion + detorsion + honokiol (Group V). Bilateral adnexa in all the rats except for those in the sham group were exposed to torsion for 3 hours. The rats in Group IV were administered saline, whereas the rats in Group V were administered honokiol by intraperitoneal route 30 minutes before detorsion. Tissue and plasma concentrations of malondialdehyde and nitric oxide were determined. Ovarian tissue was histologically evaluated. Data analyses were performed by means of Kruskal-Wallis test and Mann-Whitney U-test (Bonferroni correction) in SPSS 15.0 (Statistical Package for Social Sciences; SPSS Inc., Chicago, IL, USA).
RESULTS: The torsion and detorsion groups had higher scores in vascular congestion, hemorrhage, and inflammatory cell infiltration compared with the sham group (P<0.005). In addition, total histopathological scores were significantly higher in the torsion and detorsion groups compared with the sham group (P<0.005). A significant reduction was observed in hemorrhage, inflammatory cell infiltration, and cellular degeneration scores, of all histopathological scores, in the honokiol group (P<0.005). Ovarian tissue concentrations of malondialdehyde were significantly higher in the torsion and detorsion groups compared with the sham and honokiol groups (P<0.005). Ovarian tissue concentrations of nitric oxide, on the other hand, were significantly higher in the torsion group compared with the sham, saline, and honokiol groups (P<0.005).
CONCLUSIONS: Honokiol has a beneficial effect on ovarian torsion-related ischemia/reperfusion injury.

BACKGROUND: Magnolia officinalis is one of the commonly used in traditional Chinese medicine for the treatment of fever, chronic bronchitis and stomach ailments. Magnolol and honokiol are isomers with hydroxylated biphenol compound in the extract of Magnolia officinalis. This study aims to determine the isomers in rat plasma and evaluate their pharmacokinetic pattern after administration emulsion.
METHODS: Sprague Dawley male rats received either an intravenous (i.v.25, mg/kg) or oral (50mg/kg) dose of the emulsion of the isomer. A sensitive and specific ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed for the investigation of the pharmacokinetics of magnolol and honokiol in rats. Kaempferol was employed as an internal standard.
RESULTS: The plasma samples were deproteinized with acetonitrile, the post-treatment samples were analyzed on an Agela C18 column interfaced with a triple quadrupole tandem mass spectrometer in negative electrospray ionization mode. Acetonitrile and 5 mmol/L ammonium acetate buffer solution (65: 35, v/v) was used as the mobile phase at a flow rate of 0.2 mL/min. Following oral administration of emulsion to rats, magnolol attained mean peak plasma concentrations of 426.4 ± 273.8 ng/mL at 1.20 h, whereas honokiol reached peak plasma concentrations of 40.3 ± 30.8 ng/mL at 0.45 h. The absolute bioavailability of magnolol and honokiol is 17.5 ± 9.7% and 5.3 ± 11.7%. By comparison, the AUC0-∞ of magnolol was 5.4 times higher than that of honokiol after intravenous administration, but AUC0-∞ of magnolol was about 18-fold higher than honokiol after oral administration.