In-vitro free radical scavenging effect and cytotoxic analysis of Black Cummins and Honey formulation

Phytochemical Analysis and Anti-Biofilm Potential That Cause Dental Caries from Black Cumin Seeds (Nigella sativa Linn.)

The oral cavity is an excellent place for various microorganisms to grow. Spectrococcus mutans and Spectrococcus sanguinis are Gram-negative bacteria found in the oral cavity as pioneer biofilm formers on the tooth surface that cause caries. Caries treatment has been done with antibiotics and therapeutics, but the resistance level of S. mutans and S. sanguinis bacteria necessitates the exploration of new drug compounds. Black cumin (Nigella sativa Linn.) is known to contain secondary metabolites that have antioxidant, antibacterial, anti-biofilm, anti-inflammatory and antifungal activities. The purpose of this review article is to present data on the potential of Nigella sativa Linn seeds as anti-biofilm. This article will discuss biofilm-forming bacteria, the resistance mechanism of antibiotics, the bioactivity of N. sativa extracts and seed isolates together with the Structure Activity Relationship (SAR) review of N. sativa compound isolates. We collected data from reliable references that will illustrate the potential of N. sativa seeds as anti-biofilm drug.

Thymoquinone enhances the antioxidant and anticancer activity of Lebanese propolis

BACKGROUND

Reactive oxygen species (ROS) are produced by multiple cellular processes and are maintained at optimal levels in normal cells by endogenous antioxidants. In recent years, the search for potential exogenous antioxidants from dietary sources has gained considerable attention to eliminate excess ROS that is associated with oxidative stress related diseases including cancer. Propolis, a resinous honeybee product, has been shown to have protective effects against oxidative stress and anticancer effects against several types of neoplasms.

AIM

To investigate the antioxidant and anticancer potential of Lebanese propolis when applied alone or in combination with the promising anticancer compound Thymoquinone (TQ) the main constituent of Nigella sativa essential oil.

METHODS

Crude extracts of Lebanese propolis collected from two locations, Rashaya and Akkar-Danniyeh, were prepared in methanol and the total phenolic content was determined by Folin-Ciocalteu method. The antioxidant activity was assessed by the ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and to inhibit H2O2-induced oxidative hemolysis of human erythrocytes. The anticancer activity was evaluated by [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide] MTT assay against HCT-116 human colorectal cancer cells and MDA-MB-231 human breast cancer cells.

RESULTS

The total phenolic content of propolis extract from Rashaya and Akkar-Danniyeh were 56.81 µg and 83.503 µg of gallic acid equivalent /mg of propolis, respectively. Both natural agents exhibited strong antioxidant activities as evidenced by their ability to scavenge DPPH free radical and to protect erythrocytes against H2O2-induced hemolysis. They also dose-dependently decreased the viability of both cancer cell lines. The IC50 value of each of propolis extract from Rashaya and Akkar-Danniyeh or TQ was 22.3, 61.7, 40.44 µg/mL for breast cancer cells at 72 h and 33.3, 50.9, 33.5 µg/mL for colorectal cancer cells at the same time point, respectively. Importantly, the inhibitory effects of propolis on DPPH radicals and cancer cell viability were achieved at half its concentration when combined with TQ.

CONCLUSION

Our results indicate that Lebanese propolis extract has antioxidant and anticancer potential and its combination with TQ could possibly prevent ROS- mediated diseases.

UPLC‒ESI‒MS/MS profiling of active polyphenolics in Morinda coreia leaf extract and in vitro antioxidant and antibacterial activity

In this study, aqueous and methanol extracts of Morinda coreia (MC) leaves were tested for antioxidant and antibacterial activity under in vitro conditions. Phytochemical analysis using UPLC-ESI-MS revealed the presence of phenolics, flavonoids, alkaloids, glycosides, amino acids, proteins, saponins, and tannins. Under in vitro conditions, antioxidant test using DPPH, ABTS, and reducing power demonstrated that the plant leaves play a crucial role in antioxidant activity compared to the commercial antioxidant butylated hydroxytoluene (BHT). The ABTS and DPPH free radical scavenging activities showed that the IC₅₀ values of the M. coreia methanol extract were 26.35 μg/mL and 200.23 μg/mL, respectively. The methanol extract of M. coreia contained higher levels of total phenols and flavonoids and higher free radical scavenging capacity than the aqueous extract. FTIR analysis of the methanol extract showed a substantial number of phenols in the functional groups of M. coreia leaves. The well diffusion assay using the methanolic extract of M. coreia (200 μg/mL) leaves showed antibacterial activity against Pseudomonas aeruginosa (19 ± 0.85 mm), Proteus sp. (20 ± 0.97 mm), Streptococcus sp. (21 ± 1.29 mm), and Enterobacter sp. (17 ± 0.2 mm). Thus, the present study revealed that the antibacterial and antioxidant activity of M. coreia leaf extract was due to the presence of 18 unknown and 15 primary known polyphenols.

Nigella sativa L. Phytochemistry and Pharmacological Activities: A Review (2019-2021)

Medicinal and aromatic plants are mainly characterized by the presence of different bioactive compounds which exhibit various therapeutic activities. In order to investigate the different pharmacological properties of different Nigella sativa extracts, a multitude of research articles published in the period between 2019 and 2021 were obtained from different databases (Scopus, Science Direct, PubMed, and Web of Science), and then explored and analyzed. The analysis of the collected articles allows us to classify the phytochemicals and the pharmacological activities through their underlying molecular mechanisms, as well as to explore the pharmacological activities exhibited by several identified compounds in Nigella sativa which allow a better understanding, and better elucidation, of the bioactive compounds responsible for the pharmacological effects. Also shown are the existence of other bioactive compounds that are still unexplored and could be of great interest. This review could be taken as a guide for future studies in the field.