Inhibitory Effect of Oat Bran Ethanol Extract on Survival and Gemcitabine Resistance of Pancreatic Cancer Cells

Ultrasonic extraction and antioxidant evaluation of oat saponins

The aim of this study is to optimize the extraction process of oat saponins (Os) and to evaluate their antioxidant potential. Single factor experiment, response surface optimization design, and orthogonal test were employed to optimize the process of ultrasonic-assisted extraction of Os, and the optimal extraction conditions were as followed: ethanol volume fraction of 80 %, material-solvent ratio of 1:14, ultrasonic power of 400 W, ultrasonic time of 25 min, extraction temperature of 60℃, extraction time of 180 min, and the extraction rate of Os was 0.317 %±0.105 %. Using the method, the crude extract of Os was prepared and its abilities of scavenging radicals in vitro and inhibiting protein oxidation in pork were determined, with ascorbic acid (Vc) as the control. Results revealed that the scavenging ability of Os against DPPH radical, hydroxyl radical (·OH) and superoxide anion (O2-) increased with the concentration of Os. Interestingly, the scavenging abilities of Os against DPPH and O2- were far lower than that of Vc, but its scavenging ability against ·OH was very close to that of Vc, reaching 84.59 % and 96.33 %, respectively. Furthermore, the experiments of pork storage and Fenton oxidation system showed that Os with 0.09-0.72 mg/mL could reduce the production of carbonyl (8.49 %-50.05 %) and the oxidation of total sulfhydryl (1.29 %-25.86 %), and effectively inhibit the oxidation of protein in pork by 7.82 %-22.53 %. The results of this study will provide a theoretical basis for the application of oat saponins as a natural anti-protein oxidant in meat processing and storage.

Natural products as inhibitors against pancreatic cancer cell proliferation and invasion: possible mechanisms

Pancreatic cancer is one of the gastrointestinal tumors with the lowest survival rate and the worst prognosis. At the time of diagnosis, the majority of patients have missed the opportunity for radical surgical resection and opt for chemotherapy as their primary treatment choice. And drug resistance emerges during the application of the most widely used chemotherapeutic regimens such as modified FOLFIRINOX regimen, gemcitabine monotherapy or 5-Fluorouracil combination therapy, which further reduces the therapeutic efficacy. Therefore, it is urgent to explore better treatment strategies for pancreatic cancer. In recent years, more and more studies have found that natural products have significant anti-pancreatic cancer properties. In this paper, we reviewed the possible mechanisms by which natural products inhibit the proliferation and invasion of pancreatic cancer cells, including the possible mechanisms of targeting the inhibition of the growth and proliferation regulatory pathways of pancreatic cancer cells, inducing apoptosis and autophagy of pancreatic cancer cells, inhibiting the EMT process of pancreatic cancer cells, and inhibiting the angiogenesis of pancreatic cancer. Meanwhile, natural products have also hindered the progress of their basic and clinical research due to the complexity of their composition and the limitation of biological extraction technology. Further exploration of the specific molecular mechanisms of natural products to inhibit the proliferation and invasion of pancreatic cancer cells, optimization of purification and preparation techniques, and enrichment of basic and clinical trials to verify their efficacy and safety may be the future direction of natural products in the field of anti-pancreatic cancer research.

The Potential Functions and Mechanisms of Oat on Cancer Prevention: A Review

Oat is classified as a whole grain and contains high contents of protein, lipids, carbohydrates, vitamins, minerals, and phytochemicals (such as polyphenols, flavonoids, and saponins). In recent years, studies have focused on the effects of oat consumption on reducing the risk of a variety of diseases. Reports have indicated that an oat diet exerts certain biological functions, such as preventing cardiovascular diseases, reducing blood glucose, and promoting intestinal health, along with antiallergy, antioxidation, and cancer preventive effects. At present, cancer is the second leading cause of death worldwide. The natural products of oat are an important breakthrough for developing new strategies of cancer prevention, and their ability to interact with multiple cellular targets helps to combat the complexity of cancer pathogenesis. In addition, the comprehensive study of the cancer prevention activity and potential mechanism of oat nutrients and phytochemicals has become a research hotspot. In this Review, we focused on the potential functions of peptides, dietary fiber, and phytochemicals in oats on cancer prevention and further revealed novel mechanisms and prospects for clinical application. These findings might provide a novel approach to deeply understand the functions and mechanisms for cancer prevention of oat consumption.

A pharmacognostic approach for mitigating pancreatic cancer: emphasis on herbal extracts and phytoconstituents

Background

Pancreatic cancer is studied as one of the most lethal cancers with currently no control of its lethality, mainly due to its late diagnosis and lack of foolproof treatment processes. Despite continuous efforts being made in looking for therapies to deal with cancer, it keeps on being a labyrinth for the researchers. Efforts like discovering new treatment options, repurposing existing drugs, are continuously made to deal with this cancer.

Main body

With the urge to get answers and the fact that nature has all roots of therapeutics, efforts are made in the direction of finding those answers for providing ministrations for pancreatic cancer from plant products. Plant products are used as treatment options either directly in the form of extracts or an alternative to them is individual phytochemicals that are either isolated from the plants or are commercially synthesized for various purposes. In this review, we put forward such pharmacognostic initiatives made in combating pancreatic cancer, focusing mainly on plant extracts and various phytochemicals; along with the mechanisms which they triggered to fulfill the need for cytotoxicity to pancreatic cancer cells (in vitro and in vivo).

Conclusion

This study will thus provide insights into new combination therapy that can be used and also give a clue on which plant product and phytoconstituent can be used in dealing with pancreatic cancer.

Graphical abstract

Natural Products for Pancreatic Cancer Treatment: From Traditional Medicine to Modern Drug Discovery

Pancreatic cancer, the seventh most lethal cancer around the world, is considered complicated cancer due to poor prognosis and difficulty in treatment. Despite all the conventional treatments, including surgical therapy and chemotherapy, the mortality rate is still high. Therefore, the possibility of using natural products for pancreatic cancer is increasing. In this study, 68 natural products that have anti-pancreatic cancer effects reported within five years were reviewed. The mechanisms of anti-cancer effects were divided into four types: apoptosis, anti-metastasis, anti-angiogenesis, and anti-resistance. Most of the studies were conducted for natural products that induce apoptosis in pancreatic cancer. Among them, plant extracts such as Eucalyptus microcorys account for the major portion. Some natural products, including Moringa, Coix seed, etc., showed multi-functional properties. Natural products could be beneficial candidates for treating pancreatic cancer.

Inhibiting RRM2 to enhance the anticancer activity of chemotherapy

RRM2, the small subunit of ribonucleotide reductase, is identified as a tumor promotor and therapeutic target. It is common to see the overexpression of RRM2 in chemo-resistant cancer cells and patients. RRM2 mediates the resistance of many chemotherapeutic drugs and could become the predictor for chemosensitivity and prognosis. Therefore, inhibition of RRM2 may be an effective means to enhance the anticancer activity of chemotherapy. This review tries to discuss the mechanisms of RRM2 overexpression and the role of RRM2 in resistance to chemotherapy. Additionally, we compile the studies on small interfering RNA targets RRM2, RRM2 inhibitors, kinase inhibitors, and other ways that could overcome the resistance of chemotherapy or exert synergistic anticancer activity with chemotherapy through the expression inhibition or the enzyme inactivation of RRM2.