Chemical Composition, Anti-Quorum Sensing, Enzyme Inhibitory, and Antioxidant Properties of Phenolic Extracts of Clinopodium nepeta L. Kuntze.

Phenolic extracts of Clinopodium nepeta were prepared and their preliminary phenolic profiles determined using HPLC-DAD with 26 phenolic standards. Apigenin (21.75 ± 0.41 µg/g), myricetin (72.58 ± 0.57 µg/g), and rosmarinic acid (88.51 ± 0.55 µg/g) were the most abundant compounds in DCM (dichloromethane), AcOEt (ethyl acetate), and BuOH (butanol) extracts, respectively. The DCM and AcOEt extracts inhibited quorum-sensing mediated violacein production by C. violaceum CV12472. Anti-quorum-sensing zones on C. violaceum CV026 at MIC (minimal inhibitory concentration) were 10.3 ± 0.8 mm for DCM extract and 12.0 ± 0.5 mm for AcOEt extract. Extracts showed concentration-dependent inhibition of swarming motility on flagellated P. aeruginosa PA01 and at the highest test concentration of 100 µg/mL, AcOEt (35.42 ± 1.00%) extract displayed the best activity. FRAP assay indicated that the BuOH extract (A0.50 = 17.42 ± 0.25 µg/mL) was more active than standard α-tocopherol (A0.50 = 34.93 ± 2.38 µg/mL). BuOH extract was more active than other extracts except in the ABTS●+, where the DCM extract was most active. This antioxidant activity could be attributed to the phenolic compounds detected. C. nepeta extracts showed moderate inhibition on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, and α-amylase. The results indicate that C. nepeta is a potent source of natural antioxidants that could be used in managing microbial resistance and Alzheimer's disease.

The Cosmetic Potential of The Medicinal Halophyte Tamarix Gallica L. (Tamaricaceae) Growing in The Eastern Part of Algeria: Photoprotective and Antioxidant Activities.

AIM AND OBJECTIVE: Currently, the use of ingredients from natural sources has gained great attention in the cosmetic field, especially for the development of new photoprotective formulations. Therefore, the present study aimed to evaluate the cosmetic potential of the crude methanol extract and the ethyl acetate fraction of the medicinal halophyte Tamarix gallica L. (Tg) growing in the area of Tebessa in the eastern part of Algeria, by assessing their phenolic and flavonoid contents, photoprotective and antioxidant activities. METHODS: The research approach consisted of determining phenolic and flavonoid contents of aerial parts via Folin-Ciocalteu and aluminum chloride methods, respectively. The antioxidant activity was measured through two in vitro methods, DPPH radical scavenging activity and total antioxidant capacity test (TAC). The in vitro photoprotective effect was evaluated according to the parameter SPF (Sun Protection Factor) by using the UV spectroscopic method in the UV-B region (290-320 nm). RESULTS: The methanol extract (Tg-MeOH) and ethyl acetate (Tg-EtOAc) fraction showed good antioxidant activity with IC50 values of 14.05±0.66, 27.58±1.98 µg/mL respectively in the DPPH test. Furthermore, both extracts displayed strong total antioxidant capacity (287.01±7.85, 246.7±1.12 mg AAE/g, respectively) in the TAC test. Both extracts exhibited high photoprotective activity, with sun protection factor (SPF) values 37.03±0.22 and 36.08±0.03. The antioxidant and photoprotective activities of these extracts were probably related to polyphenols content (190.27±0.74 mg AGE /g and 121.77±1.29 mg AGE /g, respectively) and flavonoids (78.75±0.06 mg QE /g and 58.67±1.19mg/g). CONCLUSION: Our findings show that extracts of Tamarix gallica L. could be a promising source to be mixed as a natural sunscreen and antioxidant agents into photoprotective cosmetic formulations.

In Vitro Assessment of Total Phenolic and Flavonoid Contents, Antioxidant and Photoprotective Activities of Crude Methanolic Extract of Aerial Parts of Capnophyllum peregrinum (L.) Lange (Apiaceae) Growing in Algeria.

Background:Capnophyllum peregrinum (L.) Lange (Apiaceae) is the unique taxon of capnophyllum genus in Algerian flora. It has never been investigated in regards to its total phenolic and flavonoid contents and antioxidant and photoprotective activities. Methods:C. peregrinum aerial parts extracted with absolute methanol. The total flavonoid and phenolic contents of the extract were evaluated to determine their correlation with the antioxidant and photoprotective activities of the extract. Results: The methanolic extract demonstrated a significant amount of phenolics and flavonoids (74.06 ± 1.23 mg GAE/g, 44.09 ± 2.13 mg QE/g, respectively) and exhibited good antioxidant activity in different systems, especially in 1,1-Diphenyl-2-picrylhydrazyl (DPPH), reducing power and total antioxidant capacity assays. Furthermore the extract showed high photoprotective activity with the sun protection factor (SPF) value = 35.21 ± 0.18. Conclusions: The results of the present study show, that the methanolic extract could be used as a natural sunscreen in pharmaceutics or cosmetic formulations and as a valuable source of natural antioxidants.