Cancer is still one of the most widespread diseases globally, it is considered a vital health challenge worldwide and one of the main barriers to long life expectancy. Due to the potential toxicity and lack of selectivity of conventional chemotherapeutic agents, discovering alternative treatments is a top priority. Plant-derived natural products have high potential in cancer treatment due to their multiple mechanisms of action, diversity in structure, availability in nature, and relatively low toxicity. In this review, the anticancer mechanisms of the most common phytochemicals were analyzed. Furthermore, a detailed discussion of the anticancer effect of combinations consisting of natural product or natural products with chemotherapeutic drugs was provided. This review should provide a strong platform for researchers and clinicians to improve basic and clinical research in the development of alternative anticancer medicines.

The release of reactive oxygen species (ROS) and oxidative stress is associated with the development of many ailments, including cardiovascular diseases, diabetes and cancer. The causal link between oxidative stress and cancer is well established and antioxidants are suggested as a protective mechanism against cancer development. Recently, an increase in the consumption of antioxidant supplements was observed globally. The main sources of these antioxidants include fruits, vegetables, and beverage. Herbal infusions are highly popular beverages consumed daily for different reasons. Studies showed the potent antioxidant effects of plants used in the preparation of some herbal infusions. Such herbal infusions represent an important source of antioxidants and can be used as a dietary protection against cancer. However, uncontrolled consumption of herbal infusions may cause toxicity and reduced antioxidant activity. In this review, eleven widely consumed herbal infusions were evaluated for their antioxidant capacities, anticancer potential and possible toxicity. These herbal infusions are highly popular and consumed as daily drinks in different countries. Studies discussed in this review will provide a solid ground for researchers to have better understanding of the use of herbal infusions to reduce oxidative stress and as protective supplements against cancer development.

Cancer is considered the second leading cause of death worldwide and in 2018 it was responsible for approximately 9.6 million deaths. Globally, about one in six deaths are caused by cancer. A strong correlation was found between diabetes mellitus and carcinogenesis with the most evident correlation was with type 2 diabetes mellitus (T2DM). Research has proven that elevated blood glucose levels take part in cell proliferation and cancer cell progression. However, limited studies were conducted to evaluate the efficiency of conventional therapies in diabetic cancer patients. In this review, the correlation between cancer and diabetes will be discussed and the mechanisms by which the two diseases interact with each other, as well as the therapeutics challenges in treating patients with diabetes and cancer with possible solutions to overcome these challenges. Natural products targeting both diseases were discussed with detailed mechanisms of action. This review will provide a solid base for researchers and physicians to test natural products as adjuvant alternative therapies to treat cancer in diabetic patients.

Emerging evidence supports the role of rice bran in cancer prevention. Studies were conducted on multiple rice cultivars. However, limited studies were conducted on rice cultivars in the Middle East. In this study, rice bran growing in Iraq (O. sativa ssp. Japonica, cultivars: Amber Barka) was evaluated for its effect on preventing cancer and stimulating the immune system. Rice bran was collected from local mills in Al-Najaf (south of Iraq). Several solvent extracts (ethanol, methanol, n-hexane, and water) were prepared by maceration. MTT assay was used to measure the antiproliferative effects of extracts against a panel of cancer cell lines. The ability of each extract to induce apoptosis and inhibit angiogenesis was measured using standard ELISA kits. The effect of extracts on the immune system was evaluated using a lymphocyte proliferation assay, a pinocytic activity assay, a phagocytic activity assay, and a Th1/Th2 cytokine detection kit. A microbroth dilution method was used to detect the antimicrobial activity of each extract against different microbial strains. LC–MS analysis was used to detect the phytochemical composition of extracts, while DPPH assay was used to determine the antioxidant activity. For the in vivo study, rice bran was added to mouse fodder at 10% and 20%. Mice were treated for two weeks using mouse fodder supplemented with rice bran. In the third week of the experiment, EMT6/P breast cancer cells (1 × 10⁶ cells/mL) were injected subcutaneously into the abdominal area of each mouse. The dimensions of the grown tumors were measured after 14 days of tumor inoculation. A microbroth dilution method was used to evaluate the antimicrobial activity of rice bran extracts against three bacterial strains. The highest antiproliferative activity was observed in ethanol and n-hexane extracts. Ethanol and methanol extract showed the highest activity to induce apoptosis and inhibit angiogenesis. Both extracts were also effective to enhance immunity by activating lymphocytes and phagocytes proliferation with modulations of cytokine levels. The incorporation of rice bran in mice food caused a 20% regression in tumor development and growth compared with the negative control. All extracts exhibited limited antimicrobial activity against tested microorganisms. Methanol extract showed antioxidant activity with an IC₅₀ value of 114 µg/mL. LC–MS analysis revealed the presence of multiple phytochemicals in rice bran including apiin, ferulic acid, and succinic acid. Rice bran is a rich source of active phytochemicals that may inhibit cancer and stimulate the immune system. Rice bran’s biological activities could be due to the presence of multiple synergistically active phytochemicals. Further studies are needed to understand the exact mechanisms of action of rice bran.

Cancer is one of the leading causes of death globally. Conventional treatments such as surgery, radiotherapy, and chemotherapy are associated with several side effects, including chemoresistance and cancer relapse. As a result, there is a critical demand for new therapeutic agents to support the current therapeutic options. Recently, research started to focus on the possible positive interaction(s) between melatonin and many phytochemicals as a combination therapy to target altered metabolism in cancer. Such a combination has many advantages, including low toxicity, the possibility of having multiple synergistic anticancer effects, and low cost. This review comprehensively examines the current literature regarding combining melatonin with phytochemicals as a potential strategy to target cancer metabolism. It aims to contribute to the evolving landscape of cancer therapeutics by highlighting the potential benefits and future directions of melatonin–phytochemical combinations as an area of active research.

Cancer is a widespread disease and a leading cause of death worldwide. This has increased interest in foods that contribute to lowering its incidence. Olive oil is a key component of the Mediterranean diet and contains numerous bioactive compounds, including oleuropein, hydroxytyrosol, oleocanthal, squalene, sterols, tyrosol, and oleacein, which possess various properties and benefits. This review examines the potential of these compounds as anticancer agents and their ability to manage various types of cancer. Chemical structure, mechanisms of action, and potential to work in combination with conventional treatments were discussed for each compound. Studies discussed in this review show promising anticancer effects of olive oil compounds with high potential to augment conventional treatments through the anticipated anticancer effect of the Mediterranean diet with olive oil. This review focused on in vitro and preclinical studies of using olive oil phytochemicals in cancer research. However, further clinical and experimental studies are needed to determine the optimal dosage of olive oil and better confirm its therapeutic efficacy.