Free radicals are one of the causes of chronic and degenerative diseases. Antioxidants can protect the progression of free radical mediated disorders. The aim of this study was to evaluate the antioxidant activity of Spirogyra neglecta (Hassall) Kützing in rats. The rats were divided into 5 groups. Group 1 served as control. Groups 2 and 3 were administered hot water extract of S. neglecta at 50 and 200 mg/kg bw, respectively, while groups 4 and 5 were fed 1% and 4% S. neglecta mixed diet, resp., for 13 weeks. Antioxidant enzymes were evaluated in livers of the rats. The activities of catalase and glutathione reductase were significantly increased in the group fed 50 mg/kg of the extract, compared with the control group. Glutathione peroxidase activity was also significantly higher in the group fed 50 and 200 mg/kg of the extract. The study suggests that S. neglecta may enhance antioxidant systems in the rat liver.

Spirogyra neglecta, a freshwater green alga, is a local food in the northern and northeastern parts of Thailand. This investigation explored the anticarcinogenicity of S neglecta and its possible cancer chemopreventive mechanisms in rats divided into 14 groups. Groups 1 and 10 served as positive and negative control groups, respectively. Groups 1-9 were intraperitoneally injected with diethylnitrosamine (DEN) once a week for 3 weeks. Groups 10-14 received normal saline instead. One week after the last DEN injection, groups 2-5 were administered for 9 consecutive weeks various doses of S neglecta extract (SNE) and dried S neglecta (SND), mixed with basal diet. Groups 6-9 and 11-14 similarly were administered various doses of SNE and SND starting from the first week of the experiment. Administration of SNE and SND was not associated with formation of glutathione-Stransferase placental form (GST-P) positive foci in rat liver. SNE and SND during initiation phase significantly reduced the number of GST-P positive foci in rats injected with DEN. The number of GST-P also diminished in groups treated with SNE and SND after injection with DEN, except for the low dose extract group. SNE showed stronger anticarcinogenic potency than SND. Furthermore, SNE also decreased the number of Ki-67 positive cells. However, the numbers of TUNEL-positive cells in the liver of the SNE-treated groups were not statistically different from the controls. The GST activity in 50 mg/kg bw of SNE and 1% of SND groups was significantly increased as compared to the positive control. In conclusion, Spirogyra neglecta (Hassall) Kützing showed cancer chemopreventive properties at the early stages of diethylnitrosamine-induced hepatocarcinogenesis in rats. Possible inhibitory mechanisms include enhancement of the activities of some detoxifying enzymes and/or suppression of precancerous cells.

Radon is the leading source of lung cancer mortality after smoking in Chiang Mai, Thailand. Finding a source of carcinogens is one of the important measures for preventing the cancer risk for this region. Specific sites at Pa Miang, Doi Saket have the highest incidences of lung cancer and have a combination of factors that influence indoor radon concentration. Our study identified the sources of indoor radon within several houses. The results indicate that geological and topographic characteristics, including active faults and mountain terraces, are the main sources of indoor radon, especially for wooden houses. Besides building materials, the design of the houses, ventilation conditions, and lifestyle choices are all factors influencing indoor radon concentrations and its associated risk. Although radon levels (29–101 Bq m−3) and total indoor annual effective doses (0.9–3.8 mSv year−1) received from all sources at these sites have shown no significant health risk due to radon exposure , this investigation will be useful as a starting point to guide strategies to respond and prevent the risk of lung cancer, especially in Chiang Mai.

Acute myeloblastic leukemia (AML) is a disease with a high rate of relapse and drug resistance due to the remaining leukemic stem cells (LSCs). Therefore, LSCs are specific targets for the treatment of leukemia. CD123 is specifically expressed on LSCs and performs as a specific marker. Curcumin is the main active compound of a natural product with low toxicity for humans. It has been reported to inhibit leukemic cell growth. However, curcumin is practically insoluble in water and has low bioavailability. In this study, we aimed to formulate curcumin nanoparticles and conjugate with the anti-CD123 to overcome the low water solubility and improve the targeting of LSCs. The cytotoxicity of both curcumin-loaded PLGA/poloxamer nanoparticles (Cur-NPs) and anti-CD123-curcumin-loaded PLGA/poloxamer nanoparticles (anti-CD123-Cur-NPs) were examined in KG-1a cells. The results showed that Cur-NPs and Cur-NPs-CD123 exhibited cytotoxic effects on KG-1a cells with the IC50 values of 74.20 ± 6.71 and 41.45 ± 5.49 µM, respectively. Moreover, anti-CD123-Cur-NPs induced higher apoptosis than Cur-NPs. The higher uptake of anti-CD123-Cur-NPs in KG-1a cells was confirmed by using flow cytometry. In conclusion, the anti-CD123-Cur-NPs formulation improved curcumin’s bioavailability and specific targeting of LSCs, suggesting that it is a promising drug delivery system for improving the therapeutic efficacy against AML.

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