Protection of DNA and microsomal membranes in vitro by Glycyrrhiza glabra L. against gamma irradiation

Natural radioprotectors on current and future perspectives: A mini-review

Radiation therapy is used as the primary treatment for cancer. Eighty percent of cancer patients require radiation therapy during treatment or for medical purposes. During treatment, radiation causes various biological defects in the cells. The prevalence of cytotoxicity limits the dose used for effective treatment. This method is designed to strike a balance between removing cancer cells and protecting normal tissues. Unfortunately, effective radiation is unavailable once acute toxicity occurs during clinical radiation therapy. Therefore, a lot of research interest is needed in the discovery of radioprotective drugs to accelerate treatment to reduce this toxicity (i.e., normal tissue toxicity to cancer cell death). Radiation protectors may be chemicals or drugs that minimize the damage caused due to radiation therapy in living organisms. The determination of effective and nontoxic radiation protection is an essential goal for radiation oncologists and basic radiobiologists. However, despite the advantages, many radioprotectors were found to have disadvantages which include cost, less duration, toxicity, and effect on the central nervous system. Therefore in recent years, the focus has been diverted to finding out optimal natural products to act as radioprotectors. Natural radiation protectors are plant compounds that protect normal (noncancerous) cells from damage from radiation therapy. Natural herbal products are nontoxic with proven therapeutic benefits and have long been used to treat various diseases. In conclusion, we find that there are various radiation protectors with different purposes and mechanisms of action.

Medicinal Uses of Licorice (Glycyrrhiza glabra L.): A Comprehensive Review

Innumerable plants have been used widely as integral medicinal sources since the start of human civilization. The demand for herbal medicines is constantly increasing with time overtime. Licorice ( Glycyrrhiza glabra family Leguminosae) is one of the most used herbal plants in foods, in medicinal forms, and substantially researched on a worldwide scale. It was used as traditional and complementary medicine against innumerable ailments including allergies, liver toxicity, gastric ulcer, lung diseases, skin disorders, oral health problems including tooth decay, and inflammation. The constituents of licorice include various essential oils, sugars, inorganic salts, resins, amino acids, and nucleic acids. Biological activity has been observed to be portrayed by active compounds of licorice including triterpene, flavonoids, and saponins. In recent years, licorice has been widely researched to discover its benefits, constituents, and its mechanism of action. The review summarizes the therapeutic and pharmacological benefits of licorice and its uses in different health-related conditions along with its toxicity and maximum levels of licorice consumption.

Pterocarpus santalinus L. extract mitigates gamma radiation-inflicted derangements in BALB/c mice by Nrf2 upregulation

Plant-based natural extracts contain several nutrients and bioactive compounds, such as phenolics and flavonoids, that possess various health-promoting activities. This study investigated the effects of polyphenols from Pterocarpus santalinus hydroalcoholic extract (PSHE) against gamma radiation-induced derangements via the upregulation of Nrf2. Ultra High Performance Liquid Chromatography Coupled to High Resolution Mass Spectrometry (UHPLC-HRMS/MS) analysis was performed to identify the possible radioprotectors. In vivo and in vitro studies, namely Real-Time-PCR (RT-PCR) analysis, Reactive Oxygen Species (ROS) scavenging activity, lipid peroxidation and GSH levels, DNA damage and cell death studies, anti-inflammatory (Sandwich ELISA), immunomodulatory studies (antibody staining), and model free radical scavenging assays, were performed. Vanillic acid, protocatechuic acid, para-hydroxybenzoic acid, chlorogenic acid, TNF-α inhibitor (Eudesmin), isoflavone (Daidzein 7-o-glucoside), astragalin (Kaempferol 3-o-glycoside), and other polyphenols were identified in PSHE using UHPLC-HRMS/MS analysis. Prophylactic administration of PSHE (-1 h) rendered more than 33% survival in mice exposed to 8 Gy whole-body-irradiation with increased mice survival and recovery of bone marrow and spleen cellularity. Real-time RT-PCR analysis showed that PSHE treatment (50 µg/mL) upregulated Nrf2, HO-1, and GPX-1 in mice splenocytes. At 50 µg/mL, PSHE reduced ROSscavenging activity, mitochondrial and spleen membrane lipid peroxidation levels, DNA damage, and cell death, and increased GSH levels. At 10 µg/mL, PSHE treatment diminished the content of IL-6 and TNF-α. At 50 µg/mL, PSHE suppressed lymphocyte proliferation. These findings indicate that polyphenols of PSHE possess marked antioxidant, anti-inflammatory, and immunomodulatory capacities, which play important roles in the prevention of radiation damage.

Feeding Preference of Altica deserticola (Coleoptera: Chrysomelidae: Alticinae) for Leaves of Glycyrrhiza inflata and G. uralensis

A leaf-disc-test method was used under controlled laboratory conditions to determine the feeding preference of Altica deserticola Latreille (Coleoptera: Chrysomelidae) on leaves of two liquorice species, Glycyrrhiza inflata Batalin and G. uralensis Fisch. ex DC. Leaf hardness and thickness, cuticle thickness, and nitrogen and tannin contents were compared between the two liquorices to explore their feeding resistance to A. deserticola. The larvae ate only G. uralensis leaves, while the adults fed on the leaves of both species but preferred those of G. inflata. The leaf hardness and thickness and cuticle thickness, as well as the nitrogen, total tannins, tannin chemicals contents in leaves, were significantly greater in G. inflata than in G. uralensis. The larvae having smaller chewing mouthparts could not feed on hard leaves with thick cuticle on both sides. The thicker cuticle and harder texture of G. inflata blades may be important physical traits for effective defence against larval phytophagy, while the higher tannin content in its leaves may be an important chemical trait determining their feeding preference. The larger adults, having stronger mouthparts, could consume nitrogen-richer G. inflata leaves to obtain the energy needed for flight and reproduction.

Telomeres, DNA Damage and Ageing: Potential Leads from Ayurvedic Rasayana (Anti-Ageing) Drugs

Ageing, while a relentless, unidirectional and pleiotropic phenomenon of life, is a key trigger for several age-related disorders, such as cancer, cataract, osteoporosis, hypertension, cardiovascular (CV), metabolic and even neurodegenerative ailments, including Alzheimer's (AD) and Parkinson's (PD) disease [1] [...].

Economic Importance

The beneficial effects of liquorice in treating chills, colds, and coughs have been fully discussed in Ayurveda, as well as in the texts of ancient Egyptians, Greeks, and Romans. The plant has been prescribed for dropsy during the period of famous Hippocrates. The reason being that it was quite helpful as thirst-quenching drugs (Biondi et al. in J Nat Prod 68:1099–1102, 2005; Mamedov and Egamberdieva in Herbals and human health-phytochemistry. Springer Nature Publishers, 41 pp, 2017). No doubt, the clinical use of liquorice in modern medicine started around 1930; Pedanios Dioscorides of Anazarba (Adana), first century AD-Father of Pharmacists, mentions that it is highly effective in the treatment of stomach and intestinal ulcers. In Ayurveda, people in ancient Hindu culture have used it for improving sexual vigor.

Histopathological Evaluation of the Effectiveness of Glycyrrhizic Acid as a Radioprotector Against the Development of Radiation-Induced Lung Fibrosis

BACKGROUND

Radiotherapy of the thorax often causes lung inflammation leading to fibrosis.

OBJECTIVES

The aim of this study was to investigate whether the use of glycyrrhizic acid (GLA) could improve the development of lung fibrosis in irradiated animals.

MATERIALS AND METHODS

Wistar rats were divided into four groups. Group A rats received thoracic irradiation. Rats in group B received GLA and irradiation. Group C received GLA and no irradiation. Group D received no GLA and irradiation. GLA was administered at a dose of 4 mg/kg body weight using an intraperitoneal injection one hour before thoracic irradiation. Radiation therapy was delivered on a Cobalt-60 unit using a single fraction of 16 Gy. The animals were sacrificed at 32 weeks following thoracic irradiation. The lungs were dissected and blind histopathological evaluation was performed.

RESULTS

Histopathologically, a decrease (statistically not significant) in the thickening of alveolar or bronchial wall, formation of fibrous bands, and superimposed collagen were noted in the animals in group B as compared to the animals in group A.

CONCLUSION

In this experimental study, administration of GLA one hour before thoracic irradiation may be a protective agent against radiation-induced fibrosis in animals and this model could be used in future studies.

Glycyrrhiza glabra. Edible Medicinal and Non-Medicinal Plants. Dordrecht: Springer Netherlands; 2016. pp. 354-457. [DOI: 10.1007/978-94-017-7276-1_18]

Liquorice foliage

Modulation expression of tumor necrosis factor α in the radiation-induced lung injury by glycyrrhizic acid

To evaluate the ability of glycyrrhizic acid (GLA) to reduce the tumor necrosis factor α (TNF-α), release on messenger ribonucleic acid (mRNA) and protein production in the lungs using GLA in response to irradiation were studied. The animals were divided into four groups: No treatment (NT group), GLA treatment only (GLA group), irradiation only (XRT group), and GLA treatment plus irradiation (GLA/XRT group). Rats were killed at different time points. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) was used to evaluate the mRNA expression of TNF-α in the lungs (compared with non-irradiated lungs). An enzyme-linked immunosorbant assay (ELISA) assay was used to measure the TNF-α protein level. The TNF-α mRNA expression in the lungs of the XRT rats was clearly higher at all-time points compared to the NT rats. The TNF-α mRNA expression in the lungs of the GLA/XRT rats was lower at all-time points compared to the XRT rats. Release of the TNF-α on protein level in the lungs of the XRT rats increased at all-time points compared to the NT rats. In contrast to the XRT rats, the lungs of the GLA/XRT rats revealed a reduction on TNF-α protein level at 6 h after irradiation. This study has clearly showed the immediate down-regulation of the TNF-α mRNA and protein production in the lungs using GLA in response to irradiation.

Inhibition of Cell Growth and Cellular Protein, DNA and RNA Synthesis in Human Hepatoma (HepG2) Cells by Ethanol Extract of Abnormal Savda Munziq of Traditional Uighur Medicine

Abnormal Savda Munziq (ASMq) is a traditional Uighur medicinal herbal preparation, commonly used for the treatment and prevention of cancer. We tested the effects of ethanol extract of ASMq on cultured human hepatoma cells (HepG2) to explore the mechanism of its putative anticancer properties, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) bromide, neutral red and lactate dehydrogenase (LDH) leakage assays, testing the incorporation of (3)[H]-leucine and (3)[H]-nucleosides into protein, DNA and RNA, and quantifying the formation of malondialdehyde-thiobarbituric acid (MDA) adducts. ASMq ethanol extract significantly inhibited the growth of HepG2 and cell viability, increased the leakage of LDH after 48 hours or 72 hours treatment, in a concentration- and time-dependent manner (P < .05). Cellular protein, DNA and RNA synthesis were inhibited in a concentration- and time-dependent manner (P < .05). No significant MDA release in culture medium and no lipid peroxidation in cells were observed. The results suggest that the cytotoxic effects of ASMq ethanol extract might be related to inhibition of cancer cell growth, alteration of cell membrane integrity and inhibition of cellular protein, DNA and RNA synthesis.

Can the therapeutic gain of radiotherapy be increased by concurrent administration of Asian botanicals?

Therapeutic gain by radiotherapy can be achieved through improved targeting, selectively sensitizing malignant cells, or protecting normal tissue. The majority of synthetic chemical radiation sensitizers and normal tissue protectors have proved to be too toxic at effective clinical doses. However, Asian botanicals (from both Chinese and Ayurvedic medicine) are being evaluated for their ability to improve therapeutic gain through the modulation of reactive oxygen species. An increase in the efficacy of radiotherapy on tumor tissue allows a reduction in the dose applied to normal tissues. In addition, some botanicals may selectively protect normal tissue or increase its repair following radiation therapy. The results are promising enough to consider clinical trials.

Polysaccharides isolated from Ganoderma lucidum occurring in Southern parts of India, protects radiation induced damages both in vitro and in vivo

The in vivo and in vitro radioprotective property of the polysaccharides isolated from Ganoderma lucidum were determined by survival studies, induction of micronucleus in reticulocytes of mice, strand breaks in plasmid pBR322 DNA and inhibition of lipid peroxidation (TBARS assay). Polysaccharides were administered as a single dose after whole body exposure to 10Gy (60)Co γ-radiation to Swiss albino mice. At a dose of 500μg/kg body wt, the polysaccharides were most effective in protecting animals from radiation induced loss of lethality. Administration of 500μg/kg body wt to animal exposed to 10Gy gamma radiation resulted in more than 60% survival on the 30th day compared to the dose of 300mg/kg/body wt administration of amifostine, a clinically used radioprotective drug. The induction of micronuclei was reduced by the administration of polysaccharides. The decrease in micronuclei induction was dose dependent. Thus following 4Gy exposure the micronuclei in polychromatic erythrocytes (MNCE) was reduced from 28.16±3.049 to 16.0243±2.074 and 6.30±2.422 by polysaccharides at doses of 250μg/kg body wt and 500μg/kg body wt, respectively, and to 10.4±2.581 by amifostine at a dose of 300mg/kg body wt. The results indicate the significant protective effect of Ganoderma polysaccharides against radiation induced damages. The findings thus suggest the potential use of Ganoderma polysaccharides as novel radioprotective agent.

Hypocholesterolaemic and antioxidant effects ofGlycyrrhiza glabra (Linn) in rats

The hypocholesterolaemic and antioxidant effects of Glycyrrhiza glabra (GG) root powder were examined in hypercholesterolaemic male albino rats. A 4-week administration of GG root powder (5 and 10 gm% in diet) to hypercholesterolaemic rats resulted in significant reduction in plasma, hepatic total lipids, cholesterol, triglycerides and plasma low-density lipoprotein and VLDL-cholesterol accompanied by significant increases in HDL-cholesterol levels. Furthermore, significant increases in fecal cholesterol, neutral sterols and bile acid excretion along with an increase in hepatic HMG-CoA reductase activity and bile acid production were observed in these animals. The root powder administration to hypercholesterolaemic rats also decreased hepatic lipid peroxidation with a concomitant increase in superoxide dismutase (SOD) and catalase activities and total ascorbic acid content. Thus, the hypocholesterolaemic and antioxidant effects of GG root appeared to be mediated via (i) accelerated cholesterol, neutral sterol and bile acid elimination through fecal matter with an increased hepatic bile acid production and (ii) improving the activities of hepatic SOD, catalase and increasing the ascorbic acid content. The normo-cholesterolaemic animals when fed with GG root powder at 10 gm% level, registered a significant decline in plasma lipid profiles and an increase in HDL-cholesterol content. The antioxidant status of these animals also was improved upon treatment.

Cytotoxicity of abnormal Savda Munziq aqueous extract in human hepatoma (HepG2) cells

Abnormal Savda Munziq (ASMq) is a traditional Uighur medicinal herbal preparation commonly used to treat diseases such as diabetes, cardiovascular diseases, chronic asthma and especially digestive cancer. Earlier studies have shown that ASMq is a free radical scavenger and could prevent mitochondrial and DNA oxidative damage. In this study, we tested the effects of aqueous extract of ASMq on human hepatoma cells (HepG2) to explore the possible mechanism of its putative anticancer properties. Aqueous extract of ASMq was tested on HepG2 proliferation (MTT assay) at 72 h, cell viability at 48 h (neutral red assay), lactate dehydrogenase release over 48 or 72 h as a measure of cytoplasmic leakage, lipid peroxidation (malondialdehyde-thiobarbituric acid adducts) at 48 h, and incorporation of [3H]-leucine, [3H]-thymidine and [3H]-uridine into cellular protein, DNA and RNA, respectively, at 24 or 48 h to assess the inhibition effects to cellular macromolecule synthesis. Our results showed a significant (P < 0.05) time- and concentration-dependent inhibition of HepG2 proliferation and viability, with increased cytoplasmic leakage, and time- and concentration-dependent inhibition of protein, DNA and RNA synthesis. No lipid peroxidation was found at these concentrations. The results of the present study suggest that the putative anticancer mechanisms of ASMq may at least involve cytotoxicity.

Radioprotection by plant products: present status and future prospects

The development of radioprotective agents has been the subject of intense research in view of their potential for use within a radiation environment, such as space exploration, radiotherapy and even nuclear war. However, no ideal, safe synthetic radioprotectors are available to date, so the search for alternative sources, including plants, has been on going for several decades. In Ayurveda, the traditional Indian system of medicine, several plants have been used to treat free radical-mediated ailments and, therefore, it is logical to expect that such plants may also render some protection against radiation damage. A systematic screening approach can provide leads to identifying potential new candidate drugs from plant sources, for mitigation of radiation injury. This article reviews some of the most promising plants, and their bioactive principles, that are widely used in traditional systems of medicine, and which have rendered significant radioprotection in both in vitro and in vivo model systems. Plants and their constituents with pharmacological activities that may be relevant to amelioration of radiation-mediated damage, including antiemetic, antiinflammatory, antioxidant, cell proliferative, wound healing and haemopoietic stimulatories are also discussed.

Radioprotection of DNA by glycyrrhizic acid through scavenging free radicals

Gamma-radiation induced strand breaks in plasmid pBR322 DNA. Glycyrrhizic acid (GZA) protected plasmid DNA from radiation-induced strand breaks, as the disappearance of super-coiled (ccc) form was prevented by the compound with a dose-reduction factor of 2.04 at 2.5 mM concentration. Studies of comet assay on human peripheral blood leukocytes exposed to gamma radiation in the presence and absence of glycyrrhizic acid ex vivo revealed that this compound protected the cellular DNA from radiation-induced strand breaks in a concentration-dependent manner. An intraperitoneal administration of the GZA to mice one hour before exposure to gamma radiation protected cellular DNA from radiation-induced strand breaks in peripheral blood leucocytes and bone marrow cells, as revealed by comet assay. Pulse radiolysis studies indicated that glycyrrhizic acid offered radioprotection by scavenging free radicals. The rate constants for the reaction of glycyrrhizic acid with OH* and e(aq)- are 1.2 x 10(10 ) M(-1) s(-1) and 3.9 x 10(9 ) M(-1) s(-1), respectively.

Radioprotection of normal tissues in tumor-bearing mice by troxerutin

The flavanoid derivative troxerutin, used clinically for treating venous disorders, protected biomembranes and cellular DNA against the deleterious effects of gamma-radiation. The peroxidation of lipids (measured as thiobarbituric acid-reacting substances, or TBARS) in rat liver microsomal and mitochondrial membranes resulting from gamma-irradiation up to doses of 500 Gy in vitro was prevented by 0.2 mM troxerutin. The administration of troxerutin (175 mg/kg body weight) to tumor-bearing mice by ip one hour prior to 4 Gy whole-body gamma-irradiation significantly decreased the radiation-induced peroxidation of lipids in tissues such as liver and spleen, but there was no reduction of lipid peroxidation in tumor. The effect of troxerutin in gamma-radiation-induced DNA strand breaks in different tissues of tumor-bearing mice was studied by comet assay. The administration of troxerutin to tumor-bearing animals protected cellular DNA against radiation-induced strand breaks. This was evidenced from decreases in comet tail length, tail moment, and percent of DNA in the tails in cells of normal tissues such as blood leukocytes and bone marrow, and these parameters were not altered in cells of fibrosarcoma tumor. The results revealed that troxerutin could preferentially protect normal tissues against radiation-induced damages in tumor-bearing animals.