Phytochemicals and Cytotoxicity of Quercus infectoria Ethyl Acetate Extracts on Human Cancer Cells

Phytochemical Profiling and Biological Activities of Quercus sp. Galls (Oak Galls): A Systematic Review of Studies Published in the Last 5 Years

Quercus species have been widely used in traditional medicine, and recently, researchers' attention has focused on galls of the genus Quercus as a source of health-promoting phytochemicals. This review presents a summary of the most recent findings on the phytochemistry and bioactivity of oak galls, following the screening of scientific papers published in two relevant databases, PubMed and Embase, between January 2018 and June 2023. The oak galls are rich in active compounds, mostly gallotannins and phenolic acids. Due to these secondary metabolites, the reviewed studies have demonstrated a wide range of biological activities, including antioxidant and anti-inflammatory actions, antimicrobial properties, tissue-protective effects, and antitumor, anti-aging, and hypoglycemic potential. Thus, oak galls are a promising natural matrix, to be considered in obtaining pharmaceutical and cosmetic preparations used in anti-aging strategies and, together with medications, in the management of age-related diseases. In further evaluations, the valuable functional properties of oak galls, reported mostly in preclinical studies, should be confirmed with clinical studies that would also take into account the potential health risks of their use.

In vitro alpha-amylase and alpha-glucosidase inhibitory activity and in vivo antidiabetic activity of Quercus coccifera (Oak tree) leaves extracts

Quercus species are group of plants known as oak which represent important genus of Fagaceae family. These species are widely distributed in Mediterranean countries. Many of those species used in traditional medicine to treat and prevent various human disorders such as diabetes. Exhausted extraction for Quercus coccifera leaves were carried out using n-hexane, chloroform, methanol, boiled water and microwaved water. Extracts were subjected to phytochemical screening, acute toxicity study, and in vitro and in vivo animal model to evaluate antidiabetic activity of the produced extracts. The highest in vitro activity against α-amylase and α-glucosidase activity was obtained from methanolic extract with an IC₅₀ of 0.17 and 0.38 µg/ml respectively and better than the positive control acarbose. While the rest of the extract was either with moderate or low activity. Similarly, in the in vivo study, methanolic extract with a concentration of 200 mg/kg/day was able to reduce the blood glucose level for the diabetic mice to 146.8 mg/dL with normal bodyweight and biochemical signs when compared to the normal mice group. While the rest of the extracts were either with moderate or low ability to maintain blood glucose level for diabetic mice with few signs of hepatic and renal toxicity and weight loss. All data were statistically significantly different with p-value of less than 0.001 at confidence interval of 95% with high variance homogeneity. In conclusion, methanolic plant leaves extract of Q. coccifera can possibly be used alone to control the elevation of blood glucose level with a renal and hepatic protective property.

Efficacy of frankincense‐based herbal product in urinary incontinence: A randomized, double‐blind, placebo‐ and active‐controlled clinical trial

Urinary incontinence is a silent epidemic that has a serious impact on a person's quality of life (QOL). This study aimed to evaluate the efficacy of frankincense-based herbal product (FHP) in urinary incontinence compared with placebo and solifenacin. In this randomized, double-blind clinical trial, 120 postmenopausal women with mixed urinary incontinence were randomized to one of the three groups of FHP, placebo, and standard treatment (solifenacin). Frequency, amount of leakage, and score of urinary incontinence as well as the QOL were measured at the end of the second and fourth weeks and 2 weeks after the interruption of the treatment. The ICIQ-UI SF and I-QOL questionnaires were used for the measurements. Mean frequency of urinary incontinence and amount of leakage significantly decreased in the FHP and solifenacin groups in the fourth week compared to the placebo group. In addition, 2 weeks after treatment completion, the effects of the FHP were significant compared to the solifenacin group. Due to the effect of FHP on improving the QOL and also the prolonged effect of this drug, the use of FHP in urinary incontinence, as a complementary treatment could be suggested.

Gaz Alafi: A Traditional Dessert in the Middle East With Anticancer, Immunomodulatory, and Antimicrobial Activities

Background

From the earliest times, manna has been widely used as a tasty local sweet or folk medicine. The type of manna being investigated in the present study is called Gaz-alafi, a mixture of insect and Quercus brantii leaves secretions from oak forests in the north of Iraq and west of Iran.

Methods

Aqueous and ethanol extracts were prepared as decoction. Various phytochemical tests were conducted to analyze manna composition, including total phenolic contents using the Folin-Ciocalteu method and LC-MS. Gallic acid and catechin were detected in both extracts, in addition to tiliroside presence in ethanol extract, which added more value to the phenolic content of ethanol extract. Cytotoxic activities of Gaz alafi were evaluated against breast cancer cell lines and compared to normal cell lines and doxorubicin using the MTT assay. Antimicrobial properties were assessed against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, and Candida albicans using the dilution method of the micro-titer plate. Serum levels of IFN-γ, interleukin-2 (IL-2), interleukin-4 (IL-4), and interleukin-10 (IL-10) were measured using ELISA. The effect of extracts on splenocyte proliferation was evaluated using the lymphocytes proliferation assay. Macrophage function was evaluated using the nitro blue tetrazolium assay, whereas pinocytosis was evaluated using the neutral red uptake assay. Ten days after tumor inoculation, changes in tumor size, survival rates, levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine were measured.

Results

The growth of cancer cells was inhibited by Gaz alafi ethanol extract. An alteration in IFN- γ, IL-2, and IL-4 levels toward antiproliferation immune response were reported for both extracts. The aqueous extract efficiently stimulated lymphocyte proliferation, phagocytosis, and pinocytosis, followed by the ethanol extracts with moderate activity. After treating the mice with ethanol extracts, a significant reduction in tumor size and several undetected tumors were recorded.

Conclusions

Gaz alafi extracts (aqueous and ethanol) are promising sources for anticancer and immunostimulatory agents. Further studies are needed to fully identify the chemical composition of Gaz alafi extracts.

Impact of Quercus infectoria Galls Extract on Thyroid Gland and Testicular Functions in Diabetic Rats

Diabetes mellitus has been reported to be accompanied by thyroid and testicular dysfunctions. The objective of this study was to investigate the effect of Quercus infectoria galls (QIg) extract on the thyroid gland and testicular functions in diabetic rats. Sixteen rats were randomly divided into four equal groups, consisting of normal control, diabetic untreated control, diabetic treated with oral administration of 500 mg/kg BW and 1000 mg/kg BW, respectively for 15 days. Serum blood glucose, thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), testosterone (T), and luteinizing hormone (LH) were assessed. At the end of the experimental period, the rats were euthanized for histopathological analysis of thyroid gland and testis. Furthermore, immunohistochemistry was used to assess the expression of thyroid transcription factor-1 (TTF-1) in the thyroid gland of rats. The significant increase in serum blood glucose level in diabetic rats (DC) was markedly decreased by treatment with QIg extract (500 mg and 100 mg/kg BW) almost to the normal level. The reduced thyroid hormones, both the T3 and T4 were significantly recovered after 15 days of treatment with QIg extract (500 mg and 100 mg/kg BW). Whereas serum concentration of testosterone was significantly reduced in diabetic rats with QIg extract (500 mg and 100 mg/kg BW) treatment. Histopathological analysis of diabetic rats showed a wide range of morphological alterations in thyroid gland and testicular structures, which were almost completely, restored back to normal by treatment of rats with QIg extract. Furthermore, results showed overexpression of TTF-1 in the thyroid gland of diabetic rats, which was recovered back to normal expression after 15 days of treatment with QIg extract. These findings may provide new insights into the potential role of QIg extract as a promising therapeutic agent against diabetic complications in thyroid gland and testicular functions.