Gamma-oryzanol (OR), a phytosteryl ferulate mixture extracted from rice bran oil, has a wide spectrum of biological activities in particular, it has antioxidant properties.

Nigella sativa or Black seed (N. sativa L.) is traditionally used for several ailments in many Middle Eastern countries. It is an annual herbaceous plant that belongs to the Ranuculacea family with many beneficial properties as antitumor, antidiabetic, antihypertensive, antioxidative and antibacterial. This work attempted to study the effect of N. sativa seeds powder and oil on atherosclerosis in diet‐induced hypercholesterolemic (HC) rabbits in comparison with simvastatin (ST). Twenty‐five adult New Zealand male white rabbits, weighing 1.5–2.5 kg, were divided into five groups; normal group (NC, n = 5) and four hypercholesterolemic groups (n = 20): a positive control (PC) and three HC groups force fed diet supplemented with 1000 mg Kg⁻¹ body weight of N. sativa powder (NSP), 500 mg Kg⁻¹ body N. sativa oil (NSO) and 10 mg Kg⁻¹ ST for 8 weeks. Feeding HC rabbits with N. sativa either in powder or oil forms was shown to significantly reduce (P < .05) total cholesterol (TC) and low‐density lipoprotein cholesterol (LDLC) levels and enhance high‐density lipoprotein cholesterol (HDL) levels after treatment for 2, 4, 6 and 8 weeks compared to the PC group. Plaque formation was significantly inhibited while the intima: media ratio was significantly reduced in the NSP and NSO supplemented groups compared to the PC group. In conclusion, treatment of HC rabbits with N. sativa seeds powder or oil showed hypocholesterolemic and antiatherogenic cardioprotective properties.

Prickly pear (Opuntia ficus-indica L.) is a member of the Cactaceae family originally grown in South America, and the plant is now distributed to many parts of the world, including the Middle East. The chemical composition and biological activities of different parts of prickly pear, including cladodes, flowers, fruit, seeds and seed oil, were previously investigated. Oil from the seeds has been known for its nutritive value and can be potentially used for health promotion. This review is an effort to cover what is actually known to date about the prickly pear seeds oil extraction, characteristics, chemical composition and potential health benefits to provide inspiration for the need of further investigation and future research. Prickly pear seeds oil has been extracted using different extraction techniques from conventional to advanced. Chemical characterization of the oil has been sufficiently studied, and it is sufficiently understood that the oil is a high linoleic oil. Its composition is influenced by the variety and environment and also by the method of extraction. The health benefits of the prickly pear seed oil were reported by many researchers. For future research, additional studies are warranted on mechanisms of action of the reported biological activities to develop nutraceutical products for the prevention of various chronic human diseases.

Background and Aim: Nigella sativa and its active constituent thymoquinone (TQ) have been exploited for their various health benefits. This work was aimed to investigate the regulatory effects of TQ-rich fraction (TQRF) and commercial TQ on the low-density lipoprotein receptor (LDLR) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) genes in HepG2 cells. Methods and Results: TQRF was extracted from N. sativa seeds using supercritical fluid extraction. The regulatory effects of TQRF at 80 μg/ml and TQ at 2 μg/ml on LDLR and HMGCR gene expression were investigated in HepG2 cells using quantitative real-time PCR. The TQ content in TQRF was 2.77% (w/w) and was obtained at a temperature of 40°C and a pressure of 600 bar. Treatment of cells with TQRF and TQ resulted in a 7- and 2-fold upregulation of LDLR mRNA level, respectively, compared with untreated cells. The mRNA level of HMGCR was downregulated by 71 and 12%, respectively, compared with untreated cells. Conclusion: TQRF and TQ regulated genes involved in cholesterol metabolism by two mechanisms, the uptake of low-density lipoprotein cholesterol via the upregulation of the LDLR gene and inhibition of cholesterol synthesis via the suppression of the HMGCR gene.

Many medicinal plant extracts have been proven to have significant health benefits. In contrast, research has shown that some medicinal plant extracts can be toxic, genotoxic, mutagenic, or carcinogenic. Therefore, evaluation of the genotoxicity effects of plant extracts that are used as traditional medicine is essential to ensure they are safe for use and in the search for new medication. This review summarizes 52 published studies on the genotoxicity of 28 plant extracts used in traditional medicine. A brief overview of the selected plant extracts, including, for example, their medicinal uses, pharmacological effects, and primary identified compounds, as well as plant parts used, the extraction method, genotoxic assay, and phytochemicals responsible for genotoxicity effect were provided. The genotoxicity effect of selected plant extracts in most of the reviewed articles was based on the experimental conditions. Among different reviewed studies, A total of 6 plant extracts showed no genotoxic effect, other 14 plant extracts showed either genotoxic or mutagenic effect and 14 plant extracts showed anti-genotoxic effect against different genotoxic induced agents. In addition, 4 plant extracts showed both genotoxic and non-genotoxic effects and 6 plant extracts showed both genotoxic and antigenotoxic effects. While some suggestions on the responsible compounds of the genotoxicity effects were proposed, the proposed responsible phytochemicals were not individually tested for the genotoxicity potential to confirm the findings. In addition, the mechanisms by which most plant extracts exert their genotoxicity effect remain unidentified. Therefore, more research on the genotoxicity of medicinal plant extracts and their genotoxicity mechanisms is required.