EVALUATION OF THE ANTIRADICAL ACTIVITY OF Ocimum basilicum L. (Sada Rayhon)

ABSTRACT

This study investigates the antioxidant potential of Ocimum basilicum L. (Sada Rayhon) using the DPPH radical scavenging method through spectrophotometric analysis at 517 nm. The antiradical activity of the ethanolic extract increased proportionally with the extract concentration, confirming the presence of biologically active compounds capable of neutralizing free radicals. Therefore, the obtained results demonstrate that the basil extract exhibits high free-radical scavenging activity and can be regarded as a promising natural bioactive source with antioxidant properties. These findings highlight the potential application of Ocimum basilicum in medicine, pharmacology, and food technology as a promising natural antioxidant agent.

АННОТАЦИЯ

В данном исследовании изучен антиоксидантный потенциал Ocimum basilicum L. (Сада Райхон) с использованием метода улавливания радикалов DPPH посредством спектрофотометрического анализа при длине волны 517 нм. Антирадикальная активность этанольного экстракта увеличивалась пропорционально концентрации экстракта, что подтверждает наличие биологически активных соединений, способных нейтрализовать свободные радикалы. Таким образом, полученные результаты показывают, что экстракт базилика проявляет высокую активность по улавливанию свободных радикалов и может рассматриваться как перспективный природный источник биоактивных соединений с антиоксидантными свойствами. Эти данные подчеркивают потенциал применения Ocimum basilicum в медицине, фармакологии и пищевой технологии в качестве эффективного природного антиоксидантного агента.

Keywords: Ocimum basilicum L., DPPH method, antiradical activity, IC50 value, ethanolic extract, spectrophotometry, bioactive compounds.

Ключевые слова: Ocimum basilicum L., метод DPPH, антирадикальная активность, значение IC₅₀, этанольный экстракт, спектрофотометрия, биологически активные соединения.

Introduction. In recent years, the chemical analysis and biological evaluation of natural compounds isolated from medicinal plants have become important fields of research in pharmaceutical, bioorganic, and food chemistry. Flavonoids, terpenoids, and other compounds found in plant extracts possess the ability to neutralize free radicals, which help protect against oxidative stress [1]. Thus, the evaluation of the antiradical activity of plants is regarded as one of the main criteria in assessing their biological value [2].

The history of traditional medicine in Uzbekistan dates back several millennia. Ancient sources indicate that our ancestors widely used medicinal plants to treat various diseases [3]. There are thousands of such plant species, each having a unique chemical composition and bioactivity. One of the most notable is basil (Ocimum basilicum L.), characterized by its pleasant aroma, essential oils, and biologically active compounds. Around 150 species of basil have been identified worldwide, and among the countries of the Commonwealth of Independent States, three main types are predominantly cultivated — camphor-type basil, eugenol-type basil, and common basil [4].

Basil (Ocimum basilicum L.) is a plant belonging to the Lamiaceae family, which has long been used in traditional medicine for the treatment of various diseases, particularly to calm the nervous system, improve digestion, and reduce inflammation. The essential oils and alcoholic extracts of this plant contain phenolic and aromatic compounds such as linalool, eugenol, methyl chavicol, and rosmarinic acid, which are natural substances known to stimulate physiological processes [5]. Recent studies have shown that Ocimum basilicum extracts possess strong free radical scavenging, antibacterial, and anti-inflammatory properties [6]. Therefore, basil (Sada Rayhon) is being studied not only as a traditional medihacinal plant but also as a promising natural source for modern pharmaceutical and cosmetic applications.

The aim of this study was to determine the interaction of the alcoholic extract of Ocimum basilicum L. with the DPPH radical and to evaluate its antiradical activity by calculating the IC₅₀ value. The obtained results serve as an experimental basis for assessing the antioxidant efficiency of basil extracts and their potential application as natural bioactive agents in pharmaceutical and food formulations.

Evaluation of Antiradical Activity Using the DPPH Method. The antiradical activity of the sample was assessed using the standard DPPH assay. The discoloration process of the purple-colored 2,2-diphenyl-1-picrylhydrazyl (DPPH) solution indicates the presence of antioxidant compounds. These compounds are capable of donating a hydrogen atom or an electron. The stable DPPH• radical was used as the primary reagent for spectrophotometric analysis in this study [7]. The method developed by Blois [8] was applied with minor modifications to assess the degree of DPPH radical inhibition[9]. In a 100 mL volumetric flask, a 7.92 mM DPPH• solution was prepared by dissolving the reagent in ethanol. The solution was wrapped in aluminum foil to protect it from light and stored at room temperature for 30 minutes in the dark before use.

Preparation of the Plant Extract. The sample was prepared using the alcoholic extract of Ocimum basilicum L. (Sada Rayhon). The plant material was immersed in 25 mL of 96% ethanol and subjected to extraction using an ultrasonic bath for 20 minutes. The resulting extract was filtered through a 0.45 µm syringe filter and used for analysis [10].

The antiradical activity of the sample was determined as follows: 3 mL of the DPPH solution and 100 µL of ethanol (used as a blank sample) were added to a 4 mL quartz cuvette and analyzed with a K7000 spectrophotometer (YOKE, China). The absorbance of the sample (D₁) was measured at 517 nm every 5 minutes for 30 minutes. To evaluate the antiradical properties, 25, 50, 75, and 100 µL of the plant extract were mixed with 3 mL of the DPPH solution, and the absorbance (D₂) was recorded under the same conditions at 517 nm. The total volume in the cuvette was adjusted to 3.1 mL to obtain a uniform total volume by adding ethanol.

The antiradical activity (ARA%) of the sample was calculated using the following formula:

Measured Absorbance and Calculated Values for Antiradical Activity in the Control and Experimental Ethanolic Extracts of Ocimum basilicum L. (Sada Rayhon) in DPPH Solution.

Table 1.

Values for Antiradical Activity

Figure 1. Graph showing the measured absorbance of control and experimental ethanolic extracts of Ocimum basilicum in the DPPH solution

The IC₅₀ value of the samples, which represents the concentration required to inhibit 50% of the DPPH radicals, was calculated based on the ARA% values obtained after 30 minutes for different volumes of the ethanolic extract added in each experiment. A graph was plotted using these data, and the IC₅₀ value was determined from the trend line.

Figure 2. Plot of antiradical activity (ARA%) values determined after 10 minutes versus the volumes of the ethanolic extract of Ocimum basilicum L.

The trend line equation of the plotted graph was expressed as y = mx + b, and the volume corresponding to 50% antiradical activity (ARA%) — representing the IC₅₀ value — was calculated using the formula x = (y − b) / m.

Results and Discussion. The ethanolic extract of Ocimum basilicum L. (Sada Rayhon) was evaluated using the DPPH radical-scavenging assay to determine its antiradical activity (ARA%). The decrease in optical absorbance at 517 nm indicated that the extract’s free-radical neutralizing capacity increased in a concentration-dependent manner, reflecting an efficient hydrogen-donating ability of its bioactive compounds. The calculated IC₅₀ value (117.3 µL) confirmed that the extract exhibited significant antioxidant potential. The discoloration of the DPPH solution revealed the active contribution of phenolic compounds and flavonoids to the radical-scavenging process. Collectively, these findings demonstrate that the ethanolic extract of Ocimum basilicum L. is a promising natural antioxidant agent with potential applications in the biomedical, pharmaceutical, and food industry.

Conclusion. The high antiradical activity of the ethanolic extract of Ocimum basilicum L. (Sada Rayhon) indicates its potential as a valuable natural source of antioxidants with significant biomedical potential. The ability of the extract to neutralize free radicals plays a key role in reducing oxidative stress at the cellular level, thereby contributing to the prevention and mitigation of inflammatory, cardiovascular, neurological, and oncological disorders. The obtained results support the development of preventive and therapeutic formulations based on the extract.

References:

1. Brand-Williams W., Cuvelier M. E., Berset C. Use of a free radical method to evaluate antioxidant activity. LWT—Food Science and Technology. 1995;28(1):25–30.
2. Halliwell B., Gutteridge J. M. C. Free Radicals in Biology and Medicine. Oxford University Press, 2015.
3. Asqarov.I.R. Sirli tabobat// T: Fan va texnlogiyalar nashriyot-matbaa uyi. Toshkent. 2021-y.
4. Asqarov.I.R. // Tabobat qomusi// T.: Mumtoz so`z. Toshkent. 2019.
5. Simon J. E., Morales M. R., Phippen W. B., Vieira R. F., Hao Z. Basil: A source of aroma compounds and a popular culinary and ornamental herb. In: Perspectives on New Crops and New Uses. ASHS Press. Alexandria. VA. 1999. p. 499–505.
6. Kumar R., Mishra A. N. Phytochemical and pharmacological profile of Ocimum basilicum L.: An overview. Asian Journal of Pharmaceutical and Clinical Research. 2018;11(3):25–30.
7. Gulcin. I., Beydemir. S., Sat. I.G., Kufrevioglu. O.I. Evaluation of antioxidant activity of cornelian cherry (Cornus mas L,) Acta Aliment,. Hung. 2005. 34. 193–202.
8. Blois. M.S. Antioxidant determinations by the use of a stable free radical. Nature 1958,181. 1199–1200.
9. Askarov.I.R., Muminov.M., Yusupov. M.A. Study of antiradical properties of artichoke (cynara scolymus l.) and milk thistle (sylybum marianum l.) vegetable oils. NamDU Ilmiy Axborotnomasi. 2024. 11. P.173-177.
10. Askarov. I. R., Abdullaev. S. S., Mamatkulova. S. A., & Abdulloev .O. S. (2024). Antioxidant activity and elemental composition of mixtures of fig and common unabi fruits. Journal of Chemistry of Goods and Traditional Medicine. 3(3). 179–205. https://doi,org/10,55475/jcgtm/vol3,iss3,2024,320.