Comparative assessment of antioxidant capacity and phytochemical profiles of Tilia, Mentha and Salvia herbal teas

Öz

Herbal teas prepared from Tilia (linden), Mentha (mint), and Salvia (sage) species are widely consumed due to their potential health benefits and their traditional use in the management of respiratory disorders and cold-related symptoms. These plants contain various bioactive compounds, including phenolics, flavonoids, and carotenoids, which may contribute to their antioxidant properties. The present study aimed to comparatively evaluate the antioxidant potential and phytochemical composition of methanol and water extracts obtained from Tilia, Mentha and Salvia sp. The antioxidant activities of the extracts were assessed using DPPH radical scavenging activity, reducing power, and metal chelating activity assays. In addition, the levels of important bioactive compounds, including total phenolics, total flavonoids, β-carotene, and lycopene, were determined to investigate their relationship with antioxidant activity. The results revealed notable differences among the tested plant species and extraction solvents. The water extract of Salvia sp. exhibited the strongest DPPH radical scavenging activity (IC50: 0.157 mg/ml), while Mentha sp. extracts demonstrated the highest reducing power (EC50: 0.305 mg/ml) and metal chelating activity (IC50: 0.756 mg/ml). Phytochemical analyses showed that the methanol extract of Mentha sp. contained the highest β-carotene and lycopene levels, whereas the highest total phenolic content was detected in the water extract of Mentha sp. In contrast, Salvia sp. extracts, particularly the methanol extract, displayed the highest flavonoid content. These findings suggest that phenolic and flavonoid compounds play a major role in the antioxidant activity of the extracts, while carotenoids may further enhance their antioxidant potential. Overall, the findings highlight the importance of Tilia, Mentha, and Salvia sp. as natural sources of antioxidant compounds. Among the tested plants, Mentha and Salvia extracts demonstrated comparatively stronger antioxidant properties, indicating their potential value as functional ingredients in nutraceuticals and herbal beverages.

Anahtar Kelimeler

• herbal tea
• antioxidant activity
• phenolic compounds
• traditional medicine

Ihlamur, Nane ve Adaçayının Antioksidan Kapasiteleri ve Fitokimyasal Profillerinin Karşılaştırmalı Değerlendirilmesi

Öz

Tilia (ıhlamur), Mentha (nane) ve Salvia (adaçayı) türlerinden hazırlanan bitki çayları, potansiyel sağlık yararları ve solunum yolu rahatsızlıkları ile soğuk algınlığına bağlı semptomların yönetimindeki geleneksel kullanımları nedeniyle yaygın olarak tüketilmektedir. Bu bitkiler, antioksidan özelliklerine katkıda bulunabilecek fenolikler, flavonoidler ve karotenoidler dâhil olmak üzere çeşitli biyoaktif bileşikler içermektedir. Bu çalışma, Tilia, Mentha ve Salvia türlerinden elde edilen metanol ve su ekstraktlarının antioksidan potansiyelini ve fitokimyasal bileşimini karşılaştırmalı olarak değerlendirmeyi amaçlamıştır. Ekstraktların antioksidan aktiviteleri DPPH radikal giderme aktivitesi, indirgeme gücü ve metal şelatlama aktivitesi testleri kullanılarak değerlendirilmiştir. Ayrıca, antioksidan aktivite ile ilişkilerini araştırmak amacıyla toplam fenolikler, toplam flavonoidler, β-karoten ve likopen olmak üzere önemli biyoaktif bileşiklerin düzeyleri belirlenmiştir. Sonuçlar, test edilen bitki türleri ve ekstraksiyon çözücüleri arasında dikkate değer farklılıklar olduğunu ortaya koymuştur. Salvia sp.’nin su ekstraktı en güçlü DPPH radikal giderme aktivitesini gösterirken (IC50: 0,157 mg/ml), Mentha sp. ekstraktları en yüksek indirgeme gücü (EC50: 0,305 mg/ml) ve metal şelatlama aktivitesini (IC50: 0.,756 mg/ml) göstermiştir. Fitokimyasal analizler, Mentha sp.’nin metanol ekstraktının en yüksek β-karoten ve likopen düzeylerini içerdiğini, buna karşılık en yüksek toplam fenolik içeriğin Mentha sp.’nin su ekstraktında tespit edildiğini göstermiştir. Buna karşın, özellikle metanol ekstraktı olmak üzere Salvia sp. ekstraktları en yüksek flavonoid içeriğini göstermiştir. Bu bulgular, fenolik ve flavonoid bileşiklerin ekstraktların antioksidan aktivitesinde önemli bir rol oynadığını, karotenoidlerin ise antioksidan potansiyellerini daha da artırabileceğini göstermektedir. Genel olarak, bulgular Tilia, Mentha ve Salvia türlerinin doğal antioksidan bileşik kaynakları olarak önemini vurgulamaktadır. Test edilen bitkiler arasında Mentha ve Salvia ekstraktları karşılaştırmalı olarak daha güçlü antioksidan özellikler göstermiş olup, bu durum bu bitklilerin nutrasötikler ve bitkisel içeceklerde fonksiyonel bileşenler olarak potansiyel değerlerini göstermektedir.

Anahtar Kelimeler

• bitki çayı
• antioksidan aktivite
• fenolik bileşikler
• geleneksel tıp

Kaynakça

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