Effects of Myristicin in Association with Chemotherapies on the Reversal of the Multidrug Resistance (MDR) Mechanism in Cancer

Human Metabolism and Excretion of Kawakawa (Piper excelsum) Leaf Chemicals

SCOPE

Piper excelsum (kawakawa) has a history of therapeutic use by Māori in Aotearoa New Zealand. It is currently widely consumed as a beverage and included as an ingredient in "functional" food product. Leaves contain compounds that are also found in a wide range of other spices, foods, and medicinal plants. This study investigates the human metabolism and excretion of kawakawa leaf chemicals.

METHODS AND RESULTS

Six healthy male volunteers in one study (Bioavailability of Kawakawa Tea metabolites in human volunteers [BOKA-T]) and 30 volunteers (15 male and 15 female) in a second study (Impact of acute Kawakawa Tea ingestion on postprandial glucose metabolism in healthy human volunteers [TOAST]) consume a hot water infusion of dried kawakawa leaves (kawakawa tea [KT]). Untargeted Liquid Chromatography-Tandem Mass spectrometry (LC-MS/MS) analyses of urine samples from BOKA-T identified 26 urinary metabolites that are significantly associated with KT consumption, confirmed by the analysis of samples from the independent TOAST study. Seven of the 26 metabolites are also detected in plasma. Thirteen of the 26 urinary compounds are provisionally identified as metabolites of specific compounds in KT, eight metabolites are identified as being derived from specific compounds in KT but without resolution of chemical structure, and five are of unknown origin.

CONCLUSIONS

Several kawakawa compounds that are also widely found in other plants are bioavailable and are modified by phase 1 and 2 metabolism.

Borneol-modified docetaxel plus tetrandrine micelles for treatment of drug-resistant brain glioma

OBJECTIVE

Glioma is the most common and deadly primary malignant tumor in adults. Treatment outcomes are ungratified due to the presence of blood-brain barrier (BBB), glioma stem cells (GSCs) and multidrug resistance (MDR). Docetaxel (DTX) is considered as a potential drug for the treatment of brain tumor, but its effectiveness is limited by its low bioavailability and drug resistance. Tetrandrine (TET) reverses the resistance of tumor cells to chemotherapy drugs. Borneol (BO) modified in micelles has been shown to promote DTX plus TET to cross the BBB, allowing the drug to better act on tumors. Therefore, we constructed BO-modified DTX plus TET micelles to inhibit chemotherapeutic drug resistance.

SIGNIFICANCE

Provide a new treatment method for drug-resistant brain gliomas.

METHODS

In this study, BO-modified DTX plus TET micelles were prepared by thin film dispersion method, their physicochemical properties were characterized. Its targeting ability was investigated. The therapeutic effect on GSCs was investigated by in vivo and in vitro experiments.

RESULTS

The BO-modified DTX plus TET micelles were successfully constructed by thin film dispersion method, and the micelles showed good stability. The results showed that targeting micelles increased bEnd.3 uptake and helped drugs cross the BBB in vitro. And we also found that targeting micelles could inhibit cell proliferation, promote cell apoptosis and inhibit the expression of drug-resistant protein, thus provide a new treatment method for GSCs in vitro and in vivo.

CONCLUSIONS

BO-modified DTX plus TET micelles may provide a new treatment method for drug-resistant brain gliomas.

Triphenylphosphine Derivatives of Allylbenzenes Express Antitumor and Adjuvant Activity When Solubilized with Cyclodextrin-Based Formulations

Allylbenzenes (apiol, dillapiol, myristicin and allyltetramethoxybenzene) are individual components of plant essential oils that demonstrate antitumor activity and can enhance the antitumor activity of cytotoxic drugs, such as paclitaxel, doxorubicin, cisplatin, etc. Triphenylphosphine (PPh3) derivatives of allylbenzenes are two to three orders of magnitude more potent than original allylbenzenes in terms of IC50. The inhibition of efflux pumps has been reported for allylbenzenes, and the PPh3 moiety is deemed to be responsible for preferential mitochondrial accumulation and the depolarization of mitochondrial membranes. However, due to poor solubility, the practical use of these substances has never been an option. Here, we show that this problem can be solved by using a complex formation with cyclodextrin (CD-based molecular containers) and polyanionic heparin, stabilizing the positive charge of the PPh3 cation. Such containers can solubilize both allylbenzenes and their PPh3 derivatives up to 0.4 mM concentration. Furthermore, we have observed that solubilized PPh3 derivatives indeed work as adjuvants, increasing the antitumor activity of paclitaxel against adenocarcinomic human alveolar basal epithelial cells (A549) by an order of magnitude (in terms of IC50) in addition to being quite powerful cytostatics themselves (IC50 in the range 1-10 µM). Even more importantly, CD-solubilized PPh3 derivatives show pronounced selectivity, being highly toxic for the A549 tumor cell line and minimally toxic for HEK293T non-tumor cells, red blood cells and sea urchin embryos. Indeed, in many cancers, the mitochondrial membrane is more prone to depolarization compared to normal cells, which probably explains the observed selectivity of our compounds, since PPh3 derivatives are known to act as mitochondria-targeting agents. According to the MTT test, 100 µM solution of PPh3 derivatives of allylbenzenes causes the death of up to 85% of A549 cancer cells, while for HEK293T non-cancer cells, only 15-20% of the cells died. The hemolytic index of the studied substances did not exceed 1%, and the thrombogenicity index was < 1.5%. Thus, this study outlines the experimental foundation for developing combined cytostatic medications, where effectiveness and selectivity are achieved through decreased concentration of the primary ingredient and the inclusion of adjuvants, which are safe or practically harmless substances.