Profiling Bioactive Compounds in the Bark of Cinchona officinalis L. and Anti-arthritic Properties Thereof

Abstract

The bark samples of C. officinalis were collected from The Nilgiris district of Tamil Nadu. The collected samples were processed and extracted using methanol solvent. The extracts showed high yield of secondary metabolites especially alkaloids, phenols, flavonoids, steroids, terpenoids, sterols, quinones and tannins. Alkaloid content was very high in C.officinalis followed by phenol, flavonoid, steroid and Tannin. The secondary metabolites present in C. officinalis (Bark) were isolated, purified, identified and characterized using differential Chromatographic techniques such as TLC, HPLC and GC-MS/ MS. The compounds identified using High Performance Liquid Chromatography (HPLC) technique in bark of C. officinalis in the retention times of 1.750, 2.250, 4.016 and 7.266 minutes were quinine, isoquinidine and cinchonidine. The compounds were then characterized using GC- MS/ MS technique with reference to NIST library. The compounds were eluted from the bark of C. officinalis in the retention time of 9.569, 10.488, 11.814, 13.593, 14.282, 16.542, 16.967, 23.494, 24.954, 25.151, 25.988, 26.752, 26.982, 27.906, 28.277, 31.454, 33.604, and 35.744 minutes. By correlating the retention times with (NIST) mass spectral library the eluted compounds were confirmed as Phthalic acid, Hexadecanoic acid,1,2,3,5-Cyclohexanetetrol, Cinchonab-9-one, 9,12-Octadecadienoic acid (Z,Z)-, Heptadecanoic acid, Quinine, Cinchonine, Cinchonidine, Phenol, Quinine, and gamma.-Sitosterol. The phytochemicals present in the C. officinalis (Bark) samples were evaluated for their biological properties viz., anti-inflammatory activity and anti-arthritic activity in in-vitro conditions. Anti- inflammatory properties of plant samples were tested by protein denaturation method using diclofenac (75 mg/ ml concentration) as positive control. The methanol extract of C.officinalis (Bark) showed anti- inflammatory properties of range between 17.0 and 57.3%. Anti- arthritic activity of bark extract of C. officinalis (75 mg/ ml concentration) was evaluated by albumin denaturation method using diclofenac (75 mg/ ml concentration) as positive control. The methanol extract of C.officinalis (Bark) showed anti- arthritic properties of range between 18.4 and 58.5%. From the study it is understood that the alkaloids and polyphenols present in the methanolic extract of bark of C. officinalis were responsible for their biological properties. Hence, C. officinalis can serve as an alternative to synthetic drugs available in the market to treat arthritis subject to safety (toxicity) studies in humans. Based on the In vitro results, it was confirmed that the bark of C.officinalis possesses comparatively high biological values. Thus an herbal aerosol for arthritis may be formulated using the bark extract of C.officinalis as key ingredient and the therapeutic product will be of cost effective, easy to use and pocket friendly.