Phytochemical Characterization and In Vitro Anti-Inflammatory Evaluation of Geranium Oil (Pelargonium Graveolens)

Medicinal plants have been used for centuries as a natural source of therapeutic compounds. Essential oils obtained from aromatic plants are widely recognized for their antimicrobial, antioxidant, anti-inflammatory, and wound-healing properties (1). Among these, Geranium oil, obtained from Pelargonium graveolens, is an important essential oil used in pharmaceutical, cosmetic, and aromatherapy products because of its pleasant fragrance and medicinal value (2).

Geranium oil contains several bioactive constituents, including citronellol, geraniol, linalool, and caryophyllene, which contribute to its pharmacological activities (3). These compounds exhibit strong antioxidant and anti-inflammatory effects by reducing inflammatory mediators and protecting tissues from oxidative stress (4). Because of these properties, geranium oil has attracted attention as a natural alternative for the management of inflammatory disorders.

Characterization of herbal products is essential to ensure their quality, purity, and therapeutic consistency. Modern analytical techniques such as UV-visible spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Gas Chromatography–Mass Spectrometry (GC-MS), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA) are commonly employed for this purpose (5,6). These techniques provide valuable information regarding chemical composition, functional groups, and thermal stability.

The present study aimed to characterize geranium oil using physicochemical and instrumental analytical methods and to evaluate its in vitro anti-inflammatory activity using the protein denaturation assay. The findings may support the future development of herbal formulations containing geranium oil for the treatment of inflammatory conditions (7).

Material and Methods

Pure Geranium oil (Pelargonium graveolens) was procured from a certified supplier and used throughout the study. Initially, the oil was evaluated for miscibility in various organic solvents and its boiling point was determined (8). UV-visible spectroscopy was performed to determine the maximum absorption wavelength (λmax), and a calibration curve was prepared according to Beer–Lambert's law for quantitative estimation (9).

FTIR spectroscopy was carried out over the range of 4000–400 cm⁻¹ to identify characteristic functional groups present in the oil (10). The phytochemical constituents were further analyzed using Gas Chromatography–Mass Spectrometry (GC-MS) to identify the major volatile compounds. Thermal properties were investigated by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) to evaluate thermal stability (11).

The in vitro anti-inflammatory activity of geranium oil was assessed using the protein denaturation assay. The percentage inhibition of protein denaturation was calculated and compared with the standard anti-inflammatory drug. All experiments were carried out in triplicate, and the results were expressed as mean values (12).

Results and discussion:

Geranium Oil: -

For further analysis, the miscibility of pure geranium oil was established. Geranium oil contains different pharmaceutical ingredients which shows the distinct pharmacological activities. Geranium oil is miscible in methanol, ethanol, chloroform, acetone, butanol, toluene, acetic acid and immiscible in water, Ethyl acetate. Miscibility of geranium oil was shown in Fig 24. and Table.6. respectively.

Fig. 1. Miscibility of Geranium Oil in Different Solvent

Fig. 2 Boiling Point of Geranium Oil

Fig.3. λmax of Geranium Oil in Ethanol

Sr. No	Concentration	Absorbance
1	1µg/ml	0.16
2	2µg/ml	0.32
3	3µg/ml	0.474
4	4µg/ml	0.57
5	5µg/ml	0.865

 

Fig.4. Calibration curve of pure Geranium Oil and correlation coefficient

Fig.5.FT-IR spectra of Pure Geranium Oil

Fig.6.GC-MS of Geranium Oil

Fig.7. DSC graph of Geranium Oil

Fig.8.TGA graph of Geranium Oil

CONCLUSION

The present study successfully characterized Geranium oil (Pelargonium graveolens) using physicochemical and instrumental analytical techniques. UV spectroscopy, FTIR, GC-MS, DSC, and TGA confirmed the presence of important bioactive constituents, characteristic functional groups, and good thermal stability. GC-MS analysis revealed citronellol as the major component along with several other pharmacologically active compounds. The in vitro anti-inflammatory study demonstrated that geranium oil effectively inhibited protein denaturation, indicating significant anti-inflammatory potential. The findings support the traditional medicinal use of geranium oil and highlight its value as a natural therapeutic agent. Overall, the study suggests that geranium oil can serve as a promising ingredient for the development of herbal pharmaceutical and topical formulations. Further studies involving in vivo pharmacological evaluation, toxicity assessment, formulation development, and clinical investigations are recommended to establish its safety, efficacy, and therapeutic applications.

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