Response to "Radiation therapeutic gain and Asian botanicals," by Stephen Sagar

Pharmacological features, health benefits and clinical implications of honokiol

Honokiol (HNK) is a natural polyphenolic compound extracted from the bark and leaves of Magnolia grandiflora. It has been traditionally used as a medicinal compound to treat inflammatory diseases. HNK possesses numerous health benefits with a minimal level of toxicity. It can cross the blood-brain barrier and blood-cerebrospinal fluid, thus having significant bioavailability in the neurological tissues. HNK is a promising bioactive compound possesses neuroprotective, antimicrobial, anti-tumorigenic, anti-spasmodic, antidepressant, analgesic, and antithrombotic features . HNK can prevent the growth of several cancer types and haematological malignancies. Recent studies suggested its role in COVID-19 therapy. It binds effectively with several molecular targets, including apoptotic factors, chemokines, transcription factors, cell surface adhesion molecules, and kinases. HNK has excellent pharmacological features and a wide range of chemotherapeutic effects, and thus, researchers have increased interest in improving the therapeutic implications of HNK to the clinic as a novel agent. This review focused on the therapeutic implications of HNK, highlighting clinical and pharmacological features and the underlying mechanism of action.Communicated by Ramaswamy H. Sarma.

Analysis of radio-sensitization patents in China from 2006 to 2015

INTRODUCTION

Radiotherapy is by means of ionizing radiation to kill tumor cells, inhibit and control the growth, metastasis and diffusion of tumor cells. During the last few decades, application of radiotherapy combined with chemotherapy and surgery are clinical mainstream treatments. However, little is known what radio-sensitization agents have been patented in China and what the potential drug candidates for patents are in China. Areas covered: This reviews covers research and patent literature of the last 10 years dealing with the discovery and development of novel radio-sensitization patents in China. Expert opinion: The 94 radio-sensitization patents granted from 2006 to 2015 mainly focus on six types of products. They are: traditional Chinese medicines (TCM), synthetic compounds, combinations of synthetic compounds and TCM, biological products, medical apparatus and others. In the course of tumor treatment, radiotherapy occupies an irreplaceable position. Previously believed that due to the prevalence of hypoxic cells in solid tumors, most of the tumor exist a certain degree of radiation resistance. To find effective ways to improve the sensitivity of tumor cells to radiation therapy has become a focus in scientific research and clinical treatment. So radiation sensitivity has been proposed and widely studied.

The synergistic effects of traditional Chinese herbs and radiotherapy for cancer treatment

Traditional Chinese medicine (TCM) has been demonstrated to have potent cytotoxic activity against certain malignant tumors. Ionizing radiation (IR) is one of the most effective methods used in the clinical treatment of cancer. The drawback of a single formula is that it limits the treatment efficacy for cancer, while comprehensive strategies require additional theoretical support. However, a combination of different antitumor treatment modalities is advantageous in restricting the non-specific toxicity often observed with an extremely high dose of a single regimen. The induction of apoptotic cell death is a significant process in tumor cells following radiotherapy or chemotherapy, and resistance to these treatments has been linked to a low propensity for apoptosis. Autophagy is a response of cancer cells to IR or chemotherapy, and involves the prominent formation of autophagic vacuoles in the cytoplasm. In this review, the synergistic effects of TCM and radiotherapy are summarized and the underlying mechanisms are illustrated, providing new therapeutic strategies for cancer.

Inhibition of radiation-induced DNA damage by jamun, Syzygium cumini, in the cultured splenocytes of mice exposed to different doses of γ-radiation

The radioprotective property of 50 mg/kg body weight jamun (Syzygium cumini) extract was studied in the cultured splenocytes of mice exposed to 0, 0.5, 1, 2, 3, or 4 Gy of γ-radiation. The spleens of irradiated mice were removed aseptically and the splenocytes were extracted from the individual spleens and cultured. The micronuclei were prepared 72 hours after irradiation in binucleate splenocytes by blocking cytokinesis with cytochalasin-B. Irradiation of mice resulted in a dose-dependent elevation in the micronucleated splenocytes. The exposure of mice not only elevated splenocytes bearing one micronucleus but also cells bearing 2 and multiple (>2) micronuclei indicating induction of complex DNA damage after irradiation. Oral treatment of mice with 50 mg/kg body weight of jamun leaf extract protected against the radiation-induced micronuclei formation. Jamun extract also protected against the formation of 2 and multiple micronuclei indicating repair or inhibition of complex DNA damage. The assessment of lipid peroxidation in mice brain homogenate has indicated a concentration dependent inhibition of lipid peroxidation by jamun extract. Studies in a cell free system revealed that jamun extract inhibited the formation of OH, O(2)-, DPPH, and ABTS(+) free radicals in a concentration dependent manner. Our study demonstrates that jamun extract protected mice against the radiation-induced DNA damage and inhibition of radiation-induced free radical formation may be one of the mechanisms of radioprotection.