Previous reports showed that the Steroidal Glycoalkaloid Solamargine inhibited proliferation of non-melanoma skin cancer cells. However, Solamargine was not tested systematically on different types of melanoma cells and was not simultaneously tested on normal cells either. In this study we aimed to investigate the effect of Solamargine and the mechanism involved in inhibiting the growth of different types of melanoma cells. Solamargine effect was tested on normal cells and on another three melanoma cell lines. Vertical growth phase metastatic and primary melanoma cell lines WM239 and WM115, respectively and the radial growth phase benign melanoma cells WM35 were used. The half inhibitory concentration IC50 of Solamargine was determined using Alamarblue assay. The cellular and subcellular changes were assessed using light and Transmission Electron Microscope, respectively. The percentage of cells undergoing apoptosis and necrosis were measured using Flow cytometry. The different protein expression was detected and measured using western blotting. The efficacy of Solamargine was determined by performing the clonogenic assay. The data collected was analyzed statistically on the means of the triplicate of at least three independent repeated experiments using one-way ANOVA test for parametric data and Kruskal–Wallis for non-parametric data. Differences were considered significant when the P values were less than 0.05. Hereby, we demonstrate that Solamargine rapidly, selectively and effectively inhibited the growth of metastatic and primary melanoma cells WM239 and WM115 respectively, with minimum effect on normal and benign WM35 cells. Solamargine caused cellular necrosis to the two malignant melanoma cell lines (WM115, WM239), by rapid induction of lysosomal membrane permeabilization as confirmed by cathepsin B upregulation which triggered the extrinsic mitochondrial death pathway represented by the release of cytochrome c and upregulation of TNFR1. Solamargine disrupted the intrinsic apoptosis pathway as revealed by the down regulation of hILP/XIAP, resulting in caspase-3 cleavage, upregulation of Bcl-xL, and Bcl2, and down regulation of Apaf-1 and Bax in WM115 and WM239 cells only. Solamargine showed high efficacy in vitro particularly against the vertical growth phase melanoma cells. Our findings suggest that Solamargine is a promising anti-malignant melanoma drug which warrants further attention.

Fifty-one samples of Omani honey were analyzed for their contents of glucose, fructose, maltose, and sucrose. The Fructose/glucose ratio and its role in honey crystallization were also studied, as well as the protein content of the honey samples. This study has shown that the mean percentage of reducing sugars lie within the limits set by local Omani legislation. Fructose and glucose represented the largest portion. Maltose and sucrose levels were low 3.62 kg/100 kg and 1.29 kg/100 kg, respectively. Most honey samples did not crystallize after 18 months of storage. Protein content in all samples was low with an average of 2 kg/100 kg. Fructose, glucose, and sucrose levels were higher in summer honey samples (69.7 kg/100 kg) than the winter ones (60.6 kg/100 kg).

Our results confirm the presence of the furanocoumarins psoralen, xanthotoxin, isopimpinellin, angelicin and bergapten as normal constituents of Pastinaca sativa roots. However, the amounts of these compounds were increased in induced roots. The amount of increase in the induced roots varied depending on the inducing agent and time of incubation. In addition the results show for the first time the presence of pimpinellin and isobergapten as constitutive antifungal compounds in P. sativa roots.

In addition to its traditional medicinal importance, Solanum incanum (thorn apple) is also a rich source of important cytotoxic glycoalkaloids such as solamargine and solasonine. The effect of salinity stress on solamargine and solasonine production by Solanum incanum plants grown in soil has been investigated. Salinity stress has been applied by adding NaCl to the soil, in concentrations: 0.0 (control), 75, 150, and 225 mM for 8 weeks. HPTLC method was used for analysis of solamargine and solasonine in leaves, stem and roots. A positive correlation was observed between 150 mM NaCl salinity and production of solamargine and solasonine in leaves. In roots, solamargine content was not affected by NaCl treatment, whereas solasonine content increased with a short-term salinity treatment. However, salinity seems to reduce the production of solamargine and solasonine in the roots of Solanum incanum. The possibility of using NaCl as an efficient and economical elicitor of glycoalkaloid production in Solanum incanum plants is rejected on the basis of the results obtained.

Objectives: Afzal is a common smokeless tobacco product (STP) available illegally in Oman. This study aimed to assess pH and moisture levels and determine cancer-enhancing factors in a randomly selected sample of Afzal. Methods: This study was carried out at the Sultan Qaboos University in Muscat, Oman, between April and December 2013. A package of Afzal was purchased from a single provider and divided into samples. The pH and moisture content of the samples were measured according to the protocols of the Centers for Disease Control and Prevention. Gas chromatography-mass spectrometry was used to analyse nicotine levels and ionexchange chromatography (IC) was used to determine concentrations of nitrate, nitrite, chloride, fluoride, bromide, sulphate and phosphate anions. Results: The samples had an alkaline pH of 10.46 with high levels of total (48,770.00 μg per g of STP [μg/g]) and unionised (48,590.00 μg/g) nicotine. The concentration of nitrate (8,792.20 μg/g) was alarmingly high. The chloride concentration (33,170.80 μg/g) showed a surge on IC chromatography. The moisture content percentage was 52.00%. Conclusion: The moisture content percentage and chloride concentration of Afzal was consistent with those of other STPs. In contrast, nitrite, sulphate and phosphate concentrations were below reported levels of other STPs. All anion concentrations were below the maximum daily limit set by international health organisations. However, the high concentrations of nitrite, nitrate and nicotine and the elevated alkaline pH observed in the analysed Afzal samples suggest that STP users will face health risks as a result of their use.