Current Bioactive Compounds - Volume 18, Issue 5, 2022

Currently, the research focus has been on finding new alternatives to synthetic mosquito repellents due to their toxicity. Natural products act as a suitable alternative since plant-based mosquito repellents have been used traditionally due to their low toxicity. Essential oils as mosquito repellent have gained importance due to various functional bioactive constituents. Different formulations of essential oils have been studied from time to time to enhance the stability and protection time. However, the underlying mechanism of repellent activity of the bioactive constituents against specific mosquito species remains unexplored. This review focuses on the various sources of essential oil with their bioactive components and their receptor-based mechanism of action for inducing mosquito repellency against different mosquito species. Furthermore, a comparison of the various formulations of essential oil-based mosquito repellents with synthetic repellents has been discussed.

This manuscript aims to describe the various pharmacological activities of Piper nigrum. Pepper is a common spice of the plant which is used as spice in preparation of various foods. Pepper production is centered in Kerela, followed by Karnataka and Maharashtra in India. Other big pepper-producing countries include Indonesia, Malaysia, Brazil, Vietnam, and Sri Lanka. It has various pharmacological activities which is why it is used in the treatment of different diseases. The manuscript mainly describes the antituberculosis, anticonvulsant, analgesic, antipyretic, anti- inflammatory, antimicrobial, antioxidant, gastrointestinal and anticancer activities of Piper nigrum. The manuscript also describes the various studies related to the pharmacological activities of Piper nigrum. It is concluded from the manuscript that Piper nigrum has great efficacy in the treatment of various diseases.

The use of herbal remedies for medicinal purposes is becoming more popular around the world. As a result, plants have become viable treatment options for a variety of diseases. Garcinia kola (bitter kola) is a perennially grown plant in the Guttiferae family that has been evaluated and reported to have numerous health-promoting properties. Kolaviron is a biflavanoid and major phytochemical found in Garcinia kola that includes Garcinia Biflavanoid-1 (GB-1), kolaflavanone, and Garcinia Biflavanoid-2 (GB-2). It is obtained as a fraction extracted from Garcinia kola. Kolaviron's pharmacological properties include anti-inflammatory, anti-spasmodic, ameliorative, anti-asthmatic, anti-cancer, anti-malarial, hepatoprotective, antioxidant, anti-atherogenic, neuroprotective, anti-diabetic, and anti-amnesic properties. Kolaviron is recommended for use in clinical settings because it has been shown to have a high therapeutic efficacy in clinical trials. The purpose of this review is to assess the therapeutic efficacy of kolaviron.

Background: Lantana camara L. belongs to the family Verbenaceae. It originated in Tropical America in Southern Georgia and the North of Texas, and was introduced in Calcutta, India, in the year 1809 as an ornamental hedge. The plant L. camara is also distributed in Southeast Asia, China, Australia, Brazil, West Indies, Kenya, Mexico, East Africa, and Tanzania. Many of its phytoconstituents possess medicinal properties which are used traditionally to treat fever, uterine hemorrhage, and excess menstrual discharge, chronic ulcers, rheumatism, gonorrhea, toothache, gastrointestinal pain, etc., and it has been used in Brazil for curing malaria, mange, headaches, colds, and fevers. Objective: The review elaborates traditional practices related to Lantana camara L., its phytochemistry, and its role in various types of cancers.. Methods: The data on L. camara were collected through different online databases, like Web of Science, PubMed, Science Direct, Springer, and Google Scholar. Results: Major phytoconstituents isolated from the plant shows anticancer activity, especially lantadene A-D, icterogenin, oleanolic acid, lantacamaric acid A, B, oleanonic acid, etc. In vitro and in vivo studies demonstrate the potential of the plant for various cancers. Certain extracts, isolated compounds, and their semi-synthetic derivatives have depicted a significant cytotoxic and anti-proliferative effect. Conclusion: Clinical studies related to the therapeutic efficacy of Lantana camara L. are not yet established, therefore, making it crucial to direct future researches in this area.

Iridoids are monoterpenoids classed with a cyclopentanopyran framework and detected in various plants and certain special animals. In plants, it exists as glycosides, generally bound to glucose. Around six hundred iridoid glycosides are available in fifty-seven families of plants. Iridoids are abundant in dicotyledonous plants belonging to the Diervillaceae, Loganiaceae, Apocynaceae, Scrophulariaceae, Lamiaceae, and Rubiaceae families. Analytical techniques like chromatography, NMR, UPLC, etc., are used for the identification, separation, and estimation of either herbal extracts or formulations of iridoids. Advanced analytical techniques are useful for precise and accurate quantification of active ingredients responsible for therapeutic effects. They can be achieved by a developed and validated robust analytical method. Iridoids have shown diverse pharmacological properties. Some of the important activities are immunomodulatory, neuroprotective, anti-inflammatory, hepatoprotective, and cardio-protective effects. The other important activities are antimicrobial, antioxidant, hypoglycemic, hypolipidemic, anticancer, choleretic, antispasmodic, and purgative activities attributed to iridoids. There were not many efforts made in the past to gather and review the literature on various aspects of iridoids. This review article has collected a myriad of literature on old and advanced analytical techniques, including method development and validation of methods for quantitative and qualitative analysis of iridoids. The review also emphasizes the role of iridoids in the prevention of various ailments.

Background: Pyranopyrazoles have a variety of biological activities and can be obtained by various starting materials and synthetic methods. Also, pyrazolopyrano[2,3-b]quinolins that contain pyranopyrazole moiety have some biological activities such as anti-acetylcholinesterase and anti-butyrylcholinesterase activity. In this research, our objective is to prepare pyranopyrazole compounds and pyrazolopyrano[2,3-b]quinolins in a simple way and then evaluate their antibacterial effect. Methods: In this study, pyrano[2,3-c]pyrazole derivatives have been synthesized by condensing malononitrile, aromatic aldehydes, and 3-methyl-1-phenyl-2-pyrazolin-5-one in the presence of magnesium perchlorate as a catalyst. Then we prepared pyrazolopyrano[2,3-b]quinolins via subsequent Friedlander reaction between cyclohexanone and the obtained pyrano[2,3-c]pyrazoles. Also, the antimicrobial activity of the synthesized pyrazolopyrano[2,3-b]quinolins against Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli was measured. Then we studied molecular docking of them to find the predicted compounds' interactions and binding energy with DNA-gyrase with the AutoDock 4.2 software. Results: Pyrazolopyrano[2,3-b]quinolins were synthesized in the optimized conditions. Evaluation of their antibacterial activities showed that these compounds have moderate to good antibacterial activities against four bacteria species. Also molecular docking tests of docked compounds showed a strong bonding interaction with DNA-Gyrase and had been docked into the intercalation place of DNA of DNA-gyrase complex. The molecule bonded to the DNA stabilized by the H bonds, hydrophobic interactions, and π-π interaction. Conclusion: We have developed an efficient and one-pot ecofriendly protocol for the synthesis of some novel pyrano[2,3-c]pyrazol derivatives and pyrazolopyrano[2,3-b]quinolins under simple conditions and then tested them for their antibacterial activities. Also, we studied molecular docking of them. These compounds showed moderate to good inhibitory action.

Background: Honey is a sweet and flavorful natural product that comes from a lot of nectar of medicinal plants. Objective: This study aimed to determine the botanical origin, physicochemical parameters, antioxidant contents, and antibacterial activities of Algerian honey. Methods: The physicochemical parameters of the honey analyzed were measured using the methods established by the European Honey Commission. The antioxidant contents were determined using colorimetric assays, and the antioxidant activities were estimated using reducing power, DPPH, ABTS, and FRAP assays. Antibacterial activities were measured using sensitivity testing and minimal inhibitory concentration. Results: The majority of the samples analyzed were monofloral honey (Fabaceae), and other medicinal plant pollens were identified as minor and very minor pollen (Asteraceae, Tiliaceae, Myrtaceae, and Apiaceae). The physicochemical parameters of the honey were in accordance with the legislation, and the analyses of proline and HMF confirmed their authenticity. The content of total phenolic compounds and total flavonoids ranged from 26 to 159 mg GAE/100 g and 10 to 43 mg EC/100 g, respectively. The analyzed samples of honey showed variable antioxidant activities that differed from one honey to another, and antibacterial activity tests showed that S. aureus and K. pneumoniae were the most sensitive strains with inhibition zones of 24 to 28 mm and 8 to 35 mm in diameter, respectively. Very high correlations were observed between color, antioxidants, and antioxidant activities. Conclusion: This study confirmed the powerful properties of honey to trap free radicals and inhibit bacterial growth, thus it could be used as a therapeutic agent.