Inflammation is a natural protective mechanism that occurs when the body’s tissue homeostatic mechanisms are disrupted by biotic, physical, or chemical agents. The immune response generates pro-inflammatory mediators, but excessive output, such as chronic inflammation, contributes to many persistent diseases. Some phenolic compounds work in tandem with nonsteroidal anti-inflammatory drugs (NSAIDs) to inhibit pro-inflammatory mediators’ activity or gene expression, including cyclooxygenase (COX). Various phenolic compounds can also act on transcription factors, such as nuclear factor-κB (NF-κB) or nuclear factor-erythroid factor 2-related factor 2 (Nrf-2), to up-or downregulate elements within the antioxidant response pathways. Phenolic compounds can inhibit enzymes associated with the development of human diseases and have been used to treat various common human ailments, including hypertension, metabolic problems, incendiary infections, and neurodegenerative diseases. The inhibition of the angiotensin-converting enzyme (ACE) by phenolic compounds has been used to treat hypertension. The inhibition of carbohydrate hydrolyzing enzyme represents a type 2 diabetes mellitus therapy, and cholinesterase inhibition has been applied to treat Alzheimer’s disease (AD). Phenolic compounds have also demonstrated anti-inflammatory properties to treat skin diseases, rheumatoid arthritis, and inflammatory bowel disease. Plant extracts and phenolic compounds exert protective effects against oxidative stress and inflammation caused by airborne particulate matter, in addition to a range of anti-inflammatory, anticancer, anti-aging, antibacterial, and antiviral activities. Dietary polyphenols have been used to prevent and treat allergy-related diseases. The chemical and biological contributions of phenolic compounds to cardiovascular disease have also been described. This review summarizes the recent progress delineating the multifunctional roles of phenolic compounds, including their anti-inflammatory properties and the molecular pathways through which they exert anti-inflammatory effects on metabolic disorders. This study also discusses current issues and potential prospects for the therapeutic application of phenolic compounds to various human diseases.

A collection of chigger mites from three species of rodents in the ꞌAsir Region of Saudi Arabia resulted in the finding of 19 species. Four new species are described: Schoutedenichia asirensis sp. nov., Schoutedenichia saudi sp. nov., Microtrombicula microscuta sp. nov., and Microtrombicula muhaylensis sp. nov. Fifteen species – Gahrliepia lawrencei Jadin and Vercammen-Grandjean, 1952, Schoengastiella wansoni Wolfs and Vercammen-Grandjean, Walchia parvula Schluger, Ascoschoengastia browni Taufflieb, Mouchet and Courtois, Helenicula lukshumiae Nadchatram and Traub, Schoutedenichia thracica Kolebinova, Schoutedenichia zarudnyi Kudryashova, Ericotrombidium caucasicum (Schluger), Ericotrombidium galliardi (Vercammen-Grandjean and Taufflieb), Ericotrombidium kazeruni (Kudryashova), Microtrombicula centropi (Vercammen-Grandjean), Microtrombicula hoogstraali (Radford), Microtrombicula hyracis (Vercammen-Grandjean), Microtrombicula traubi (Muljarskaja and Verdieva), and Pentidionis agamae (André) – are for the first time recorded in Saudi Arabia and on new host species. Six of them are for the first time recorded outside their type localities and five were only known previously from the African continent.

We analyzed the blood from 400 one-humped camels, Camelus dromedarius (C. dromedarius), in Riyadh and Al-Qassim, Saudi Arabia to determine if they were infected with the parasite Trypanosoma spp. Polymerase chain reaction (PCR) targeting the internal transcribed spacer 1 (ITS1) gene was used to detect the prevalence of Trypanosoma spp. in the camels. Trypanosoma evansi (T. evansi) was detected in 79 of 200 camels in Riyadh, an infection rate of 39.5%, and in 92 of 200 camels in Al-Qassim, an infection rate of 46%. Sequence and phylogenetic analyses revealed that the isolated T. evansi was closely related to the T. evansi that was detected in C. dromedarius in Egypt and the T. evansi strain B15.1 18S ribosomal RNA gene identified from buffalo in Thailand. A BLAST search revealed that the sequences are also similar to those of T. evansi from beef cattle in Thailand and to T. brucei B8/18 18S ribosomal RNA from pigs in Nigeria.

Collections of chigger mites from murid rodents were performed in two bordering provinces of southwestern Saudi Arabia, Al Bahah and ‘Asir. A total of 561 chiggers belonging to 19 species were collected in 2020 and 2021 from 54 rodents of two species, Acomys dimidiatus (Cretzchmar) and Mus musculus L. One new species is described: Odontacarus thesigeri n. sp. Five species are recorded in Saudi Arabia for the first time: Microtrombicula abyssinica (Radford, 1947), Microtrombicula felis (Vercammen-Grandjean, 1965), Microtrombicula saperoi (Radford, 1954), Schoengastiella hypoderma Vercammen-Grandjean, 1956, and Schoutedenichia originalis Kudryashova, 1976. Among them, M. abyssinica and M. saperoi, are re-described based on type specimens and new materials.