Watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai) juice modulates oxidative damage induced by low dose X-ray in mice

Invasive alien plants and weeds in South Africa: A review of their applications in traditional medicine and potential pharmaceutical properties

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional pharmacopoeias are constantly evolving and adapting, hence the assimilation of alien plants and weeds into traditional systems of healing. Invasive plants are detrimental to the ecosystem, however they are also potential sources of secondary metabolites with useful biological activities.

AIM OF THE REVIEW

The aim of this review was to investigate published reports of traditional use and biological activity of declared invasive alien plants and other weeds in South Africa.

MATERIALS AND METHODS

Information was retrieved from scientific databases including Scopus, Web of Science, ScienceDirect, Google Scholar, PubMed, Chemical Abstracts Services and books, theses, dissertations and technical reports. Keywords used for the search engines were "South Africa" or "southern Africa" in conjunction with "(native weeds OR alien invasive)" AND "medicinal". Separate searches were conducted on the individual invasive plant species recorded as having been used in ethnobotanical surveys to determine their known biological activities and chemical components.

RESULTS

A total of 89 plant species regarded as invasive species or weeds in South Africa were identified as being used in traditional medicine. The most commonly mentioned plant family was the Asteraceae with a total of 15 species followed by the Fabaceae and Solanaceae with 6 species each. Of the 89 species recorded, 68% were reported to have traditional usage with both phytochemical and biological data available. A history of traditional usage coupled with biological data was available for 12% of species. Records of traditional usage alone were linked to 11% of species. Invasive alien species comprised 61% of recorded species, while native and non-invasive alien weeds formed the remaining 39%.

CONCLUSIONS

The exploration of alternative uses for weeds and particularly invasive plants, whether native or alien, as medicines for possible commercialisation may lead to innovative mechanisms for putting such species to good use.

Watermelon rind ethanol extract exhibits hepato-renal protection against lead induced-impaired antioxidant defenses in male Wistar rats

Lead acetate associated tissue injury has been linked to altered antioxidant defenses, hyperuricemia and inflammation. We hypothesized that watermelon rind extract, would ameliorate lead acetate-induced hepato-renal injury. Thirty Male Wistar rats received distilled water, lead acetate (Pb; 5 mg/kg) with or without watermelon rind extract (WM; 400 mg/kg; WM + Pb; 15 days of WM pretreatment); Pb + WM (15 days of WM post treatment) and simultaneous treatment (WM-Pb) for 30 days. Lead toxicity led to elevated serum malondialdehyde, creatinine, urea, uric acid, lactate dehydrogenase, liver injury enzymes, as well as decreased body weight. Decreased serum levels of reduced glutathione, nitric oxide, total protein and glutathione peroxidase activity was also observed. However, these alterations were ameliorated by watermelon rind extract in lead acetate-treated rats. Watermelon rind ethanol extract protects against lead acetate-induced hepato-renal injury through improved antioxidant defenses at least in part, via uric acid/nitric oxide-dependent pathway signifying the health benefits of this agricultural waste and a potential for waste recycling while limiting environmental pollution.

Effects of radiation and role of plants in radioprotection: A critical review

Radiation can be lethal at high doses, whereas controlled doses are useful in medical applications. Other applications include power generation, agriculture sterilization, nuclear weapons, and archeology. Radiation damages genetic material, which is reflected in genotoxicity and can cause hereditary damage. In the medical field, it is essential to avoid the harmful effects of radiation. Radiation countermeasures and the need for radioprotective agents have been explored in recent years. Considering plants that evolve in radiative conditions, their ability to protect organisms against radiation has been studied and demonstrated. Crude extracts, fractioned extracts, isolated phytocompounds, and plant polysaccharides from various plants have been used in radioprotection studies, and their efficiency has been proven in various in vitro and in vivo experimental models. It is important to identify the mechanism of action to develop a potent plant-based radioprotective agent. To identify this protective mechanism, it is necessary to understand the damage caused by radiation in biological systems. This review intends to discuss the effects of ionizing radiation on biological systems and evaluate plant-based radioprotectants that have tested thus far as well as their mechanism of action in protecting against the toxic effects of radiation. From the review, the mechanism of radioprotection exhibited by the plant-based products could be understood. Meanwhile, we strongly suggest that the potential products identified so far should undergo clinical trials for critically evaluating their effects and for developing an ideal and compatible radioprotectant with no side-effects.

Intake of Watermelon or Its Byproducts Alters Glucose Metabolism, the Microbiome, and Hepatic Proinflammatory Metabolites in High-Fat-Fed Male C57BL/6 J Mice

BACKGROUND

Watermelon intake has demonstrated effects on blood pressure regulation along with other health benefits.

OBJECTIVE

We hypothesized that intake of whole watermelon and products made from watermelon rind (WR) and watermelon skin (WS) would remediate metabolic complications in C57BL/6 J male mice fed a diet modeling a Western-style diet.

METHODS

Ten-week-old male C57BL/6 J mice were provided either a low-fat (LF) diet [10% fat (by energy), 8% sucrose (by energy) and no added cholesterol], a high-fat (HF) diet [45% fat (by energy), 20% kcal sucrose (by energy), and 1% (w/w) cholesterol], or an HF diet plus WS, WR, or watermelon flesh (WF) for 10 wk. Dried WF was provided at 8% of total energy (equivalent to 2 servings/d) and watermelon skin and rind were added at 2.25% (w/w, dry weight of additives) of diet. Animals were provided experimental diets ad libitum. Body weights, food intake, and glucose tolerance were determined. Serum insulin, inflammatory markers, microbiome, and the relative hepatic concentrations of 709 biochemicals were measured postmortem.

RESULTS

The final body weight of the LF control group was significantly lower than that of the HF-fed control group (32.8 ± 0.9 g compared with 43.0 ± 1.7 g, P ≤ 0.05). Mice in treatment groups fed HF supplemented with watermelon products had final body weights similar to those of the HF-fed control mice. Serum insulin concentrations were reduced by ∼40% in mice fed an HF diet with WR supplementation compared with mice fed an HF diet alone (P ≤ 0.05). Depending on the individual species or group, microbiome populations changed significantly. Supplementation with WF resulted in a return to the basal hepatic concentrations of monohydroxy fatty acids and eicosanoids observed in LF-fed mice (P ≤ 0.05).

CONCLUSIONS

In obese male mice, supplementation with each of the watermelon products to an HF diet improved fasting blood glucose, circulating serum insulin concentrations, and changes in hepatic metabolite accumulation. At a modest level of supplementation to an HF diet, fiber-rich additives made from WR and WS further improved glucose metabolism and energy efficiency and shifted the microbiome composition.

The roles of radio-functional natural chemicals for the development of cancer radiation therapy

Ionizing radiation (IR) targeted at killing cancer cells also damages normal human cells and tissues through oxidative stress. Thus, the practical treatment of cancer using radiation therapy (RT) is sometimes limited because of the acute side effects in individual patients. In addition, some radioresistant cancers are difficult to treat with limited doses of IR, which leads to treatment failure. Natural chemicals that have unique physiological functions and low toxicity offer significant advantages for the development of new radiation therapies. Natural chemicals can counteract the oxidative damage caused by IR during RT because of their strong antioxidant ability. Certain natural chemicals can also serve as radiosensitizers that can enhance the cancer-killing effects. This review article discusses the main roles of radio-functional natural chemicals in the development of cancer RT.

Supplementation of 100% Flesh Watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] Juice Improves Swimming Performance in Rats

Nutritional intervention of fruit juice supplementation is able to maximize exercise performance. Watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] contains high L-citrulline content and consumption of watermelon juice may promote ergogenic effects. The aim of the present study was to investigate the role of 100% flesh watermelon juice and 100% rind watermelon juice supplementation for 14 days on swimming performance in rats. Twenty four male Sprague-Dawley rats were randomly divided into four groups: Cx group of rats supplemented with filtered tap water (negative control), L-cit group of rats supplemented with L-citrulline (positive control), FR group of rats supplemented with 100% flesh watermelon juice, and RR group of rats supplemented with 100% rind watermelon juice. Each group was supplemented for 14 days ad libitum prior to swimming exercise protocol. The rats were performed swimming exercise for 3 days and swimming time until exhaustion was measured. Plasma samples were collected to measure lactate concentration, ammonia concentration, and nitric oxide production. Rats supplemented with 100% flesh watermelon juice demonstrated significantly prolonged of swimming time until exhaustion, reduction of lactate and ammonia concentrations, and increased of nitric oxide production compared to Cx and L-cit groups (P<0.05). These findings postulate that supplementation with 100% flesh watermelon juice improves endurance in swimming performance.

Watermelon and l-arginine consumption improve serum lipid profile and reduce inflammation and oxidative stress by altering gene expression in rats fed an atherogenic diet

Watermelon (Citrullus lanatus) is rich in l-citrulline, an l-arginine precursor that may reduce cardiovascular disease risk. The purpose of this study was to compare the effects of watermelon powder and l-arginine on lipid profiles, antioxidant capacity, and inflammation in rats fed an atherogenic diet. We hypothesized that watermelon and l-arginine would increase antioxidant capacity and reduce blood lipids and inflammation by modulating hepatic gene expression. Male Sprague-Dawley rats aged 21 days (N = 32) were assigned to 3 groups and fed diets containing watermelon powder (0.5% wt/wt), l-arginine (0.3% as 0.36% l-arginine HCl wt/wt), or a control diet for 9 weeks. Watermelon and l-arginine supplementation improved lipid profiles by lowering serum concentrations of triglycerides, total cholesterol, and low-density lipoprotein cholesterol (P < .050). Serum concentrations of C-reactive protein were significantly lower (P < .050) in the watermelon and l-arginine groups. Rats in the watermelon and l-arginine groups showed reduced oxidative stress, increased total antioxidant capacity, and higher concentrations of superoxide dismutase and glutathione S-transferase (P < .050). Concentrations of aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase were lower (P < .050) in the watermelon and l-arginine groups. Watermelon and l-arginine consumption upregulated hepatic gene expression of endothelial nitric oxide synthase and downregulated expression of fatty acid synthase, 3-hydroxy-3-methylglutaryl-CoA reductase, sterol regulatory element-binding protein 1, sterol regulatory element-binding protein 2, cyclooxygenase-2, and nuclear factor-κB p65 (P < .050). The results support the hypothesis that watermelon and arginine improve cardiovascular disease risk factors including lipid profile, antioxidant capacity, and inflammation by altering relevant gene expression.

Development of Isocratic RP-HPLC Method for Separation and Quantification of L-Citrulline and L-Arginine in Watermelons

Watermelons (Citrullus lanatus) are known to have sufficient amino acid content. In this study, watermelons grown and consumed in Malaysia were investigated for their amino acid content, L-citrulline and L-arginine, by the isocratic RP-HPLC method. Flesh and rind watermelons were juiced, and freeze-dried samples were used for separation and quantification of L-citrulline and L-arginine. Three different mobile phases, 0.7% H₃P0₄, 0.1% H₃P0₄, and 0.7% H₃P0₄ : ACN (90 : 10), were tested on two different columns using Zorbax Eclipse XDB-C₁₈ and Gemini C₁₈ with a flow rate of 0.5 mL/min and a detection wavelength at 195 nm. Efficient separation with reproducible resolution of L-citrulline and L-arginine was achieved using 0.1% H₃P0₄ on the Gemini C₁₈ column. The method was validated and good linearity of L-citrulline and L-arginine was obtained with R² = 0.9956, y = 0.1664x + 2.4142 and R² = 0.9912, y = 0.4100x + 3.4850, respectively. L-citrulline content showed the highest concentration in red watermelon of flesh and rind juice extract (43.81 mg/g and 45.02 mg/g), whereas L-arginine concentration was lower than L-citrulline, ranging from 3.39 to 11.14 mg/g. The isocratic RP-HPLC method with 0.1% H₃P0₄ on the Gemini C₁₈ column proved to be efficient for separation and quantification of L-citrulline and L-arginine in watermelons.

Phytochemical Ginkgolide B Attenuates Amyloid-β1-42 Induced Oxidative Damage and Altered Cellular Responses in Human Neuroblastoma SH-SY5Y Cells

Oxidative stress is an upsurge in reactive oxygen/nitrogen species (ROS/RNS), which aggravates damage to cellular components viz. lipids, proteins, and nucleic acids resulting in impaired cellular functions and neurological pathologies including Alzheimer's disease (AD). In the present study, we have examined amyloid-β (Aβ)-induced oxidative stress responses, a major cause for AD, in the undifferentiated and differentiated human neuroblastoma SH-SY5Y cells. Aβ1-42-induced oxidative damage was evaluated on lipids by lipid peroxidation; proteins by protein carbonyls; antioxidant status by SOD and GSH enzyme activities; and DNA and RNA damage levels by evaluating the number of AP sites and 8-OHG base damages produced. In addition, the neuro-protective role of the phytochemical ginkgolide B (GB) in countering Aβ1-42-induced oxidative stress was assessed. We report that the differentiated cells are highly vulnerable to Aβ1-42-induced oxidative stress events as exerted by the deposition of Aβ in AD. Results of the current study suggest that the pre-treatment of GB, followed by Aβ1-42 treatment for 24 h, displayed neuro-protective potential, which countered Aβ1-42-induced oxidative stress responses in both undifferentiated and differentiated SH-SY5Y neuronal cells by: 1) hampering production of ROS and RNS; 2) reducing lipid peroxidation; 3) decreasing protein carbonyl content; 4) restoring antioxidant activities of SOD and GSH enzymes; and 5) maintaining genome integrity by reducing the oxidative DNA and RNA base damages. In conclusion, Aβ1-42 induces oxidative damage to the cellular biomolecules, which are associated with AD pathology, and are protected by the pre-treatment of GB against Aβ-toxicity. Taken together, this study advocates for phytochemical-based therapeutic interventions against AD.

Risk management of free radicals involved in air travel syndromes by antioxidants

Frequent air travelers and airplane pilots may develop various types of illnesses. The environmental risk factors associated with air travel syndromes (ATS) or air travel-related adverse health outcomes raised concerns and need to be assessed in the context of risk management and public health. Accordingly, the aim of the present review was to determine ATS, risk factors, and mechanisms underlying ATS using scientific data and information obtained from Medline, Toxline, and regulatory agencies. Additional information was also extracted from websites of organizations, such as the International Air Transport Association (IATA), International Association for Medical Assistance to Travelers (IAMAT), and International Civil Aviation Organization (ICAO). Air travelers are known to be exposed to environmental risk factors, including circadian rhythm disruption, poor cabin air quality, mental stress, high altitude conditions, hormonal dysregulation, physical inactivity, fatigue, biological infections, and alcoholic beverage consumption. Consequences of ATS attributed to air travel include sleep disturbances (e.g., insomnia), mental/physical stress, gastrointestinal disorders, respiratory diseases, circulatory-related dysfunction, such as cardiac arrest and thrombosis and, at worst, mechanical and terrorism-related airplane crashes. Thus safety measures in the cabin before or after takeoff are undertaken to prevent illnesses or accidents related to flight. In addition, airport quarantine systems are strongly recommended to prepare for any ultimate adverse circumstances. Routine monitoring of environmental risk factors also needs to be considered. Frequently, the mechanisms underlying these adverse manifestations involve free radical generation. Therefore, antioxidant supplementation may help to reduce or prevent adverse outcomes by mitigating health risk factors associated with free radical generation.

Radioprotective agents to prevent cellular damage due to ionizing radiation

Medical imaging has become a central component of patient care to ensure early and accurate diagnosis. Unfortunately, many imaging modalities use ionizing radiation to generate images. Ionizing radiation even in low doses can cause direct DNA damage and generate reactive oxygen species and free radicals, leading to DNA, protein, and lipid membrane damage. This cell damage can lead to apoptosis, necrosis, teratogenesis, or carcinogenesis. As many as 2% of cancers (and an associated 15,000 deaths annually) can be linked to computed tomography exposure alone. Radioprotective agents have been investigated using various models including cells, animals, and recently humans. The data suggest that radioprotective agents working through a variety of mechanisms have the potential to decrease free radical damage produced by ionizing radiation. Radioprotective agents may be useful as an adjunct to medical imaging to reduced patient morbidity and mortality due to ionizing radiation exposure. Some radioprotective agents can be found in high quantities in antioxidant rich foods, suggesting that a specific diet recommendation could be beneficial in radioprotection.

Nanotoxic profiling of novel iron oxide nanoparticles functionalized with perchloric acid and SiPEG as a radiographic contrast medium

Emerging syntheses and findings of new metallic nanoparticles (MNPs) have become an important aspect in various fields including diagnostic imaging. To date, iodine has been utilized as a radiographic contrast medium. However, the raise concern of iodine threats on iodine-intolerance patient has led to search of new contrast media with lower toxic level. In this animal modeling study, 14 nm iron oxide nanoparticles (IONPs) with silane-polyethylene glycol (SiPEG) and perchloric acid have been assessed for toxicity level as compared to conventional iodine. The nanotoxicity of IONPs was evaluated in liver biochemistry, reactive oxygen species production (ROS), lipid peroxidation mechanism, and ultrastructural evaluation using transmission electron microscope (TEM). The hematological analysis and liver function test (LFT) revealed that most of the liver enzymes were significantly higher in iodine-administered group as compared to those in normal and IONPs groups (P < 0.05). ROS production assay and lipid peroxidation indicator, malondialdehyde (MDA), also showed significant reductions in comparison with iodine group (P < 0.05). TEM evaluation yielded the aberration of nucleus structure of iodine-administered group as compared to those in control and IONPs groups. This study has demonstrated the less toxic properties of IONPs and it may postulate that IONPs are safe to be applied as radiographic contrast medium.

Watermelon consumption improves inflammation and antioxidant capacity in rats fed an atherogenic diet

Cardiovascular disease (CVD) is the leading cause of death in the United States. Watermelon, rich in antioxidants and other bioactive components, may be a viable method to improve CVD risk factors through reduced oxidative stress. The purpose of the study was to determine the effects of watermelon powder consumption on lipid profiles, antioxidant capacity, and inflammation in dextran sodium sulfate (DSS)-treated rats fed an atherogenic diet. We hypothesized that watermelon would increase antioxidant capacity and reduce blood lipids and inflammation through modulation of related gene expression. Forty male-weanling (21 days old) Sprague-Dawley rats were divided into 4 groups (10 per group, total N = 40) in a 2 diets (control or 0.33% watermelon) × 2 treatments (with or without DSS) factorial design using an atherogenic diet. Watermelon-fed groups exhibited significantly lower serum triglycerides, total cholesterol, and low-density lipoprotein cholesterol (P< .05). C-reactive protein levels were significantly lower in watermelon-fed rats than the control (P= .001). In addition, oxidative stress as measured by thiobarbituric acid reactive substances was significantly lower in watermelon groups (P= .001). Total antioxidant capacity, superoxide dismutase, and catalase activities were greater in watermelon groups (P< .05). Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase were significantly lower in DSS-treated rats when watermelon was consumed (P< .05). Fatty acid synthase, 3-hydroxy-3methyl-glutaryl-CoA reductase, sterol regulatory element-binding protein 1, sterol regulatory element-binding protein 2, and cyclooxygenase-2 gene expression was significantly downregulated in the watermelon group without DSS (P< .05). These findings indicate that watermelon improves risk factors for CVD in rats through better lipid profiles, lower inflammation, and greater antioxidant capacity by altering gene expression for lipid metabolism.