Ginsenoside PPD's Antitumor Effect via Down-Regulation of mTOR Revealed by Super-Resolution Imaging

Therapeutic Potential of Natural Resources Against Endometriosis: Current Advances and Future Perspectives

Endometriosis (EMS) is defined as the appearance, growth, infiltration, and repeated bleeding of endometrioid tissue (glands and stroma) outside the uterus cavity, which can form nodules and masses. Endometriosis is a chronic inflammatory estrogen-dependent disease and occurs in women of reproductive age. This disorder may significantly affect the quality of life of patients. The pathogenic processes involved in the development and maintenance of endometriosis remain unclear. Current treatment options for endometriosis mainly include drug therapy and surgery. Drug therapy mainly ties to the use of non-steroidal anti-inflammatory drugs (NSAIDs) and hormonal drugs. However, these drugs may produce adverse effects when used for long-term treatment of endometriosis, such as nausea, vomiting gastrointestinal reactions, abnormal liver and kidney function, gastric ulcers, and thrombosis. Although endometriosis lesions can be surgically removed, the disease has a high recurrence rate after surgical resection, with a recurrence rate of 21.5% within 2 years and 40% to 50% within 5 years. Thus, there is an urgent need to develop alternative or additional therapies for the treatment of endometriosis. In this review, we give a systematic summary of therapeutic multiple component prescriptions (including traditional Chinese medicine and so on), bioactive crude extracts of plants/herbs and purified compounds and their newly found mechanisms reported in literature in recent years against endometriosis.

A composition of ursolic acid derivatives from Ludwigia hyssopifolia induces apoptosis in throat cancer cells via the Akt/mTOR and mitochondrial signaling pathways and by modulating endoplasmic reticulum stress

ETHNOPHARMACOLOGICAL RELEVANCE

Ludwigia hyssopifolia (LH), an ethnopharmacological herb used in Guangxi Zhuang medicine, is known for its extensive therapeutic use in treating throat disorders. The anti-laryngeal-cancer benefits of the ethyl acetate and petroleum ether fractions of the ethanolic extracts of LH have been shown in our prior cell-based research. Nevertheless, the specific impacts and underlying processes by which LH combats throat cancer effects have not been fully understood.

AIM OF THE STUDY

This study involved the extraction of a composition containing two derivatives of ursolic acid from LH (LH-CUAD). The present study aimed to assess the anti-throat-cancer effects of these derivatives and the underlying mechanisms through in vitro and in vivo experiments.

MATERIALS AND METHODS

Solvent extraction, fractionation, chromatography, and semipreparative high-performance liquid chromatography were used for the extraction, purification, and analysis of LH-CUAD. The in vitro and in vivo anti-throat-cancer effects of LH-CUAD were investigated using the throat cancer cell lines Hep-2 and FaDu as well as Hep-2 tumor-bearing nude mice.

RESULTS

LH-CUAD significantly inhibited the proliferation and migration of throat cancer cells without any prominent toxicity. The Hoechst 33258 staining, Annexin V-FITC/PI double-staining assays, and flow cytometry confirmed that LH-CUAD could induce throat cancer cell death from early to late apoptosis in vitro. LH-CUAD exhibited significant antitumor activity and low toxicity in a xenograft model, and induced throat cancer cells apoptosis in vivo. The apoptotic effects of LH-CUAD therapy were validated using Western blotting, which demonstrated the activation of a caspase cascade response triggered by an imbalance between the endoplasmic reticulum and mitochondria. In addition, it was observed that LH-CUAD exhibited inhibitory effects on Akt and mTOR phosphorylation, hence promoting apoptosis.

CONCLUSIONS

LH-CUAD induces apoptosis in both in vivo and in vitro models of throat cancer. This effect is achieved by activating the mitochondrial pathway, inhibiting the Akt/mTOR pathway and initiating endoplasmic reticulum stress. The findings of this study suggest that LH-CUAD has the potential to offer a novel approach to the clinical management of throat cancer.

Methylseleninic acid induces apoptosis of human bladder cancer cells through the ROS-mediated mitochondrial pathway

As the most common selenium derivative, methylseleninic acid (MSA) has attracted wide attention. Its apoptotic induction ability and the possible molecular mechanism in human bladder cancer (BC) J82 and T24 cells were investigated in the present study. We found that the survival of J82 and T24 cells were inhibited in a dose-dependent manner after MSA treatment. Propidium iodide (PI) staining and Annexin V-fluorescein isothiocyanate/PI double staining clarified that MSA stocked cells at G2 /M phase and caused apoptosis in J82 and T24 cells. Further, typical morphological features of apoptotic cells were also observed. Accumulation of reactive oxygen species (ROS) and loss of mitochondrial membrane potential were also detected by dichlorodihydrofluorescein diacetate and Rhodamin123 staining. Meanwhile, pretreatment with N-acetylcysteine, an ROS scavenging agent, found that the apoptosis of BC cells induced by MSA was related to the production of ROS. Western blot analysis results showed that MSA interrupted Bax/Bcl-2 balance, stimulated cytochrome c release into the cytoplasm, activated caspase-9 and caspase-3, and finally induced the apoptosis of the BC cells. These findings demonstrated that MSA was able to induce apoptosis in J82 and T24 cells through ROS-mediated mitochondrial apoptosis.

Dammarane-type leads panaxadiol and protopanaxadiol for drug discovery: Biological activity and structural modification

Based on the definite therapeutic benefits, such as neuroprotective, cardioprotective, anticancer, anti-diabetic and so on, the Panax genus which contains many valuable plants, including ginseng (Panax ginseng C.A. Meyer), notoginseng (Panax notoginseng) and American ginseng (Panax quinquefolius L.), attracts research focus. Actually, the biological and pharmacological effects of the Panax genus are mainly attributed to the abundant ginsenosides. However, the low membrane permeability and the gastrointestinal tract influence seriously limit the absorption and bioavailability of ginsenosides. The acid or base hydrolysates of ginsenosides, 20 (R,S)-panaxadiol and 20 (R,S)-protopanaxadiol showed improved bioavailability and diverse pharmacological activities. Moreover, relative stable skeletons and active hydroxyl group at C-3 position and other reactive sites are suitable for structural modification to improve biological activities. In this review, the pharmacological activities of panaxadiol, protopanaxadiol and their structurally modified derivatives are comprehensively summarized.

Harnessing the Power of Optical Microscopic and Macroscopic Imaging for Natural Products as Cancer Therapeutics

Natural products (NPs) are an important source for new drug discovery over the past decades, which have been demonstrated to be effectively used in cancer prevention, treatment, and adjuvant therapy. Many methods, such as the genomic and metabolomic approaches, immunochemistry, mass spectrometry, and chromatography, have been used to study the effects of NPs on cancer as well as themselves. Because of the advantages in specificity, sensitivity, high throughput, and cost-effectiveness, optical imaging (OI) approaches, including optical microscopic imaging and macroscopic imaging techniques have also been applied in the studies of NPs. Optical microscopic imaging can observe NPs as cancer therapeutics at the cellular level and analyze its cytotoxicity and mechanism of action. Optical macroscopic imaging observes the distribution, metabolic pathway, and target lesions of NPs in vivo, and evaluates NPs as cancer therapeutics at the whole-body level in small living animals. This review focuses on the recent advances in NPs as cancer therapeutics, with particular emphasis on the powerful use of optical microscopic and macroscopic imaging techniques, including the studies of observation of ingestion by cells, anticancer mechanism, and in vivo delivery. Finally, we prospect the wider application and future potential of OI approaches in NPs as cancer therapeutics.

Natural Product Triterpenoids and Their Semi-Synthetic Derivatives with Potential Anticancer Activity

Triterpenoids are distributed widely in higher plants and are of interest because of their structural diversity and broad range of bioactivities. In particular, there is a very large literature on the propensity of a variety of triterpenoids to act as potential anticancer agents. In the present review, the anticancer potential is summarized for naturally occurring triterpenoids and their semi-synthetic derivatives, including examples of lupane-, oleanane-, ursane-, and cucurbitane-type pentacyclic triterpenoids, along with dammarane-type tetracyclic triterpenes including ginsenosides and their sapogenins and dichapetalins, which have been characterized as antitumor leads from higher plants. Preliminary structure-activity relationships and reported mechanisms of the antineoplastic-related activity are included. Prior studies for triterpenoids of plant origin are supportive of additional work being conducted on the more detailed biological and mechanistic evaluation for the progression of this type of natural products as possible cancer chemotherapeutic agents.

20(s)-Protopanaxadiol (PPD) increases the radiotherapy sensitivity of laryngeal carcinoma

Laryngeal carcinoma (LC) is one of the most prevalent malignant tumors in the head and neck area. Due to its high morbidity and mortality, LC poses a serious threat to human life and health. Even with surgical removal, some patients were not sensitive to radiotherapy or experienced transfer or recurrence. 20(s)-Protopanaxadiol (PPD), a natural product from Panax ginseng, has been reported to have cytotoxic effects against several cancer cell lines. However, whether it can improve the radiation sensitivity and the underlying mechanism of PPD's sensitization effect is still unknown. Herein, from in vitro and in vivo experiments, we found that the combination of PPD and radiation not only significantly inhibited proliferation and induced apoptosis, but also suppressed the tumor growth in mouse models. These findings confirmed the role of PPD in enhancing the sensitivity of radiotherapy. Moreover, our work showed that the expression levels of mTOR and its downstream effectors decreased remarkably after PPD addition when compared to radiation only. This result suggested that PPD's excellent synergistic effects with radiation might be associated with the down-regulation of the mTOR signaling pathway in Hep-2 cells.

Polycaprolactone nanofibres loaded with 20(S)-protopanaxadiol for in vitro and in vivo anti-tumour activity study

In this work, 20(S)-protopanaxadiol (PPD)-loaded polycaprolactone (PCL) nanofibres were successfully fabricated by the electrospinning technique using Tween 80 as a solubilizer. Firstly, smooth and continuous nanofibres were collected using suitable solvents and appropriate spinning conditions. Secondly, nanofibre mats were characterized by scanning electron microscopy, thermogravimetric (TG) analysis, Fourier transform infrared spectroscopy and mechanical testing. Finally, nanofibrous membranes were evaluated using water contact angle, in vitro drug release, biodegradation test, in vitro and in vivo anti-tumour activity and cell apoptosis assay. Scanning electron microscopic observations indicated that the diameter of the drug-loaded nanofibres increased with the increase of drug concentration. TG analysis and mechanical test showed that nanofibres were equipped with great thermal and mechanical properties. Biodegradation test exhibited that the structure of fabricated nanofibres had a certain degree of change after 15 days. An in vitro release study showed that PPD from drug-loaded nanofibres could be released in a sustained and prolonged mode. The cytotoxic effect of drug-loaded nanofibre mats examined on human laryngeal carcinoma cells (Hep-2 cells) demonstrated that the prepared nanofibres had a remarkable anti-tumour effect. Meanwhile, the drug-loaded fibre mats showed a super anti-tumour effect in an in vivo anti-tumour study. All in all, PCL nanofibres could be a potential carrier of PPD for cancer treatment.

Polycaprolactone nanofibres loaded with 20(S)-protopanaxadiol for in vitro and in vivo anti-tumour activity study

In this work, 20(S)-protopanaxadiol (PPD)-loaded polycaprolactone (PCL) nanofibres were successfully fabricated by the electrospinning technique using Tween 80 as a solubilizer. Firstly, smooth and continuous nanofibres were collected using suitable solvents and appropriate spinning conditions. Secondly, nanofibre mats were characterized by scanning electron microscopy, thermogravimetric (TG) analysis, Fourier transform infrared spectroscopy and mechanical testing. Finally, nanofibrous membranes were evaluated using water contact angle, in vitro drug release, biodegradation test, in vitro and in vivo anti-tumour activity and cell apoptosis assay. Scanning electron microscopic observations indicated that the diameter of the drug-loaded nanofibres increased with the increase of drug concentration. TG analysis and mechanical test showed that nanofibres were equipped with great thermal and mechanical properties. Biodegradation test exhibited that the structure of fabricated nanofibres had a certain degree of change after 15 days. An in vitro release study showed that PPD from drug-loaded nanofibres could be released in a sustained and prolonged mode. The cytotoxic effect of drug-loaded nanofibre mats examined on human laryngeal carcinoma cells (Hep-2 cells) demonstrated that the prepared nanofibres had a remarkable anti-tumour effect. Meanwhile, the drug-loaded fibre mats showed a super anti-tumour effect in an in vivo anti-tumour study. All in all, PCL nanofibres could be a potential carrier of PPD for cancer treatment.

Cancer chemoprevention and therapy using chinese herbal medicine

Traditional Chinese medicine (TCM) plays an indispensable role in cancer prevention and treatment. Chinese herbal medicine (CHM) is a key component of TCM and has been practiced for thousands of years. A number of naturally occurring products from Chinese herbs extracts exhibit strong inhibitory properties against carcinogenesis, including CHM single-herb extracts, CHM-derived active components, and CHM formulas (the polyherbal combinations), which regulate JAK/STAT, MAPK, and NF-ҡB pathways. The present review aims to report the cancer-preventive effect of CHM with evidence from cell-line, animal, epidemiological, and clinical experiments. We also present several issues that have yet to be resolved. In the future, cancer prevention by CHM will face unprecedented opportunities and challenges.