Larvicidal Activity against Aedes aegypti and Chemical Characterization of the Inflorescences of Tagetes patula

Inula salicina L.: Insights into Its Polyphenolic Constituents and Biological Activity

In this study, UHPLC-HRMS analysis of the defatted methanol extract obtained from Inula salicina L. led to the identification of 58 compounds-hydroxycinnamic and hydroxybenzoic acids and their glycosides, acylquinic and caffeoylhexaric acids, and flavonoids and their glycosides. In addition, a new natural compound, N-(8-methylnepetin)-3-hydroxypiperidin-2-one was isolated and its structure was elucidated by NMR spectroscopy. The presence of a flavoalkaloid in genus Inula is described now for the first time. Chlorogenic acid was the main compound followed by 3,5-, 1,5- and 4,5-dicaffeoylquinic acids. The methanol extract was studied for its antioxidant potential by DPPH, ABTS, and FRAP assays and sun protective properties. In addition, a study was conducted to assess the effectiveness of the tested extract in inhibiting biofilm formation by Gram-positive and Gram-negative strains. Results from crystal violet tests revealed a notable decrease in biofilm mass due to the extract. The anti-biofilm efficacy was confirmed through the observation of the biofilm viability by live/dead staining. The obtained results showed that this plant extract could be used in the development of cosmetic products with antibacterial and sun protection properties.

Ethnomedicinal Importance of Patuletin in Medicine: Pharmacological Activities and Analytical Aspects

BACKGROUND

Plant-derived bioactive molecules have been a major source of therapeutic agents for human and veterinarian purposes. Different traditional medicine system across the globe had relied on natural resources to meet their demand of healthcare. Still in modern world, pharmaceutical industries look for phytochemicals to develop new drugs. The current review explores patuletin, a flavonoid for its diverse reported pharmacological activities along with its analytical techniques.

METHODS

Scientific data published on patuletin was collected from Scopus, Science Direct, Pubmed, Google, and Google Scholar. The collected data were analyzed and arranged as per specific pharmacological activities performed using in-vitro or in-vivo methods. Analytical methods of patuletin have been presented next to pharmacological activities Results: Available scientific literature indicates patuletin has anti-inflammatory, cytotoxic, genotoxic, hepatoprotective, antiproliferative, antiplatelet, antinociceptive, and antioxidant activity. In addition to these activities, its biological potential on breast cancer, rheumatoid arthritis, aldose reductase, and different types of microorganisms has been also presented in this work. Analytical data on patuletin signified the importance of patuletin for the standardization of herbal products and derived medicine.

CONCLUSION

It may be concluded that patuletin with its diverse biological activities and readily available analytical methods, holds the potential to be translated into a new drug entity.

Larvicidal Activity of Ethyl Acetate Extract of Derris elliptica Root against the Third-Instar Larvae of Cypermethrin-Resistant Aedes aegypti Offspring

Background:

Derris elliptica extracts have a high larvicidal potential against the laboratory strain of Aedes aegypti larvae, but the effect on offspring larvae of pyrethroid-resistant strains of the species is lack understood. This study aimed to determine the larvicidal activity of the ethyl acetate extract of tuba root against the third-instar larvae of the Cypermethrin-resistant Ae. aegypti offspring.

Methods:

The experimental study occupied four levels of ethyl acetate extract of D. elliptica namely 10, 25, 50, and 100 ppm, and each level was four times replicated. As many as twenty of healthy third-instar larvae, offspring of Cypermethrin-resistant Ae. aegypti were subjected to each experiment group. Larval mortality rate and lethal concentration 50% subject (LC₅₀) were calculated after 24 and 48 hours of exposure time.

Results:

Mortality of larvae increased directly proportional to the increase of extract concentration. Larval mortality rates after 24 and 48 hours of exposure were 40–67.5% and 62.5–97.5%, and LC₅₀ were 34.945 and 6.461ppm, respectively.

Conclusion:

The ethyl acetate extract of D. elliptica has the high effectiveness larvicidal potential against the third-instar larvae, offspring of the Cypermethrin-resistant Ae. aegypti. Isolation of the specific compound is necessarily done to obtain the active ingredient for larvicide formulation.

Chemical Constituents ofTagetes patulaand Their Neuroprotecting Action

Two novel flavonoids (1, 2) and 3 known compounds (3-5) were isolated from the flowers and whole plant of Tagetes patula L., and their structures were elucidated by means of ultra-high performance liquid chromatography with electrospray ionization, coupled to quadrupole-time-of-flight/mass spectrometry,1H and13C-nuclear magnetic resonance (NMR), as well as 2-dimensional-NMR (heteronuclear single quantum correlation and heteronuclear multiple bond correlation) and chemical methods. In addition, all the compounds were examined for their neuroprotective action on the injury of SH-SY5Y cells induced by glutamate, indicating that the protective effect of these compounds on glutamate-induced SH-SY5Y cell was marigold biflavone > patuletin > quercetin > kaempferol-3- O-β-d-glucoside > patuletin-3- O-α-l-arabinopyranoside. Thus, it could be concluded that flavonoids played a key role in the neuroprotective action of T. patula.

Larvicidal Compounds Extracted from Helicteres velutina K. Schum (Sterculiaceae) Evaluated against Aedes aegypti L

Helicteres velutina K. Schum (Sterculiaceae), a member of Malvaceae sensu lato, is a Brazilian endemic plant that has been used by the indigenous tribe Pankarare as an insect repellent. A previous study has reported the isolation of terpenoids, flavonoids and pheophytins, in addition to the larvicidal activity of crude H. velutina extracts derived from the aerial components (leaves, branches/twigs, and flowers). The present study reports the biomonitoring of the effects of fractions and isolated compounds derived from H. velutina against A. aegypti fourth instar larvae. A crude ethanol extract was submitted to liquid–liquid extraction with hexane, dichloromethane, ethyl acetate and n-butanol to obtain their respective fractions. Larvicidal evaluations of the fractions were performed, and the hexane and dichloromethane fractions exhibited greater activities than the other fractions, with LC₅₀ (50% lethal concentration) values of 3.88 and 5.80 mg/mL, respectively. The phytochemical study of these fractions resulted in the isolation and identification of 17 compounds. The molecules were subjected to a virtual screening protocol, and five molecules presented potential larvicidal activity after analyses of their applicability domains. When molecular docking was analysed, only three of these compounds showed an ability to bind with sterol carrier protein-2 (1PZ4), a protein found in the larval intestine. The compounds tiliroside and 7,4′-di-O-methyl-8-O-sulphate flavone showed in vitro larvicidal activity, with LC₅₀ values of 0.275 mg/mL after 72 h and 0.182 mg/mL after 24 h of exposure, respectively. This is the first study to demonstrate the larvicidal activity of sulphated flavonoids against A. aegypti. Our results showed that the presence of the OSO₃H group attached to C-8 of the flavonoid was crucial to the larvicidal activity. This research supports the traditional use of H. velutina as an alternative insecticide for the control of A. aegypti, which is a vector for severe arboviruses, such as dengue and chikungunya.