Antioxidant Activity, Polyphenolic Profiles and Antibacterial Properties of Leaf Extract of Various Paulownia spp. Clones

Abstract

Paulownia spp. are widely distributed ornamental trees with leaves abundant in secondary metabolites of high medicinal potential. Eighteen breeding clones of Paulownia spp. were tested in terms of their antioxidant activity and total polyphenolic contents. The 50% ethanolic extracts (2 g/30 mL) of leaves and petioles were compared in the screening step. Eight paulownia clones were selected for detailed analyses including HPTLC polyphenolic profile, verbascoside content and antibacterial activity against five bacteria species (S. aureus, B. cereus, E. coli, Y. enterocolitica, S. enterica). The species-specific differences in terms of antioxidant activity correlated with phenolic compounds were found mainly in the case of leaf blade extracts, the highest for P. tomentosa × P. fortunei and the lowest for P. elongata × P. fortunei clones. The P. tomentosa clones varied greatly in this regard. In the HPTLC polyphenolic profile, the occurrence of some polyphenols was proved and the specific verbascoside content was quantified (70 to 225 mg/g DW). The P. tomentosa × P. fortunei hybrids had the highest inhibitory activity, mainly against Gram-positive bacteria, whereas only slight inhibition of S. aureus growth was observed for P. elongata × P. fortunei clones. The obtained results indicate diverse suitability of paulownia clones as a source of active ingredients.

The Impact of Paulownia Leaves Extract on Performance, Blood Biochemical, Antioxidant, Immunological Indices, and Related Gene Expression of Broilers

“…Paulownia is one of the traditional Chinese medical ( 13 ), which contains a variety of active ingredients such as flavonoids, phenolic acids, saponins, phenylethanoid glycosides, lignans, and triterpenoids in its leaf, fruit, and flower ( 12 , 19 , 35 ), with multiple pharmacological and economical values ( 18 ). Our GC mass analysis demonstrated that the methanolic extract of P. tomentosa included large amounts of thymol, phytol, flavonoids, and other bioactive compounds, which indicates the great efficacy of methanol as an organic solvent in extracting the primary bioactive molecules found within leaves.…”

“…Our GC mass analysis demonstrated that the methanolic extract of P. tomentosa included large amounts of thymol, phytol, flavonoids, and other bioactive compounds, which indicates the great efficacy of methanol as an organic solvent in extracting the primary bioactive molecules found within leaves. In addition, methanol is highly effective in extracting essential oils from plant material, particularly, the leaves ( 16 , 19 ). Thus, this research studied the incorporation of P. tomentosa leaf extract into broiler diets and has shown that it is a viable strategy for improving performance and general health status.…”

“…The main bioactive compounds found in paulownia (such as phenolic compounds, glycosides, flavonoids, lignans, saponins, syringin, and triterpenoids) exhibited several health benefits to consumers and animals ( 16 , 18 ). In addition, paulownia and its extract showed several therapeutic properties as antibacterial, anti-inflammatory, thirst-quenching, diuretic, antihypertensive, hemostatic, and insecticidal agents ( 13 , 19 , 20 ). Furthermore, it could be considered a growth promoter and immunostimulant agent at various concentrations in animal diets ( 12 , 21 ).…”

Paulownia Organs as Interesting New Sources of Bioactive Compounds

“…It is native to southeastern Asia (especially China), where it has been cultivated for decorative, cultural, and medicinal purposes for over 2000 years [ 1 , 2 ]. It is also known as the princess tree, royal tree, Kiri tree, empress tree, and phoenix tree [ 3 , 4 ], while its Chinese name is 泡桐 (pāo tóng) [ 5 ]. The genus Paulownia is believed to comprise 6 to 17 species depending on taxonomic classification [ 6 ].…”

“…The genus Paulownia is believed to comprise 6 to 17 species depending on taxonomic classification [ 6 ]. Of these, P. tomentosa , P. elongata , P. fortunei, and P. catalpifolia are considered the most popular [ 4 ].…”