OBJECTIVES: This study evaluates the anti-inflammatory, cytotoxic and anti-cholinergic activities of Sida rhombifolia Linn. whole plant for the first time.
MATERIALS AND METHODS: S. rhombifolia whole plant was extracted by n-hexane, ethyl acetate and methanol using Soxhlet apparatus. The plant extracts were evaluated for their antioxidant (DPPH, FIC and FRAP), anti-inflammatory (NO and protein denaturation inhibitions), cytotoxic (MTT) and anti-cholinesterase (AChE) properties in a range of concentrations to obtain IC50 values. GC-MS analysis was carried out on the n-hexane extract.
RESULTS AND DISCUSSION: The ethyl acetate extract exhibited the most significant antioxidant activities by scavenging DPPH radicals and ferrous ions with EC50 of 380.5 and 263.4 μg/mL, respectively. In contrast, the n-hexane extract showed the strongest anti-inflammatory activity with IC50 of 52.16 and 146.03 μg/mL for NO and protein denaturation inhibition assays, respectively. The same extract also revealed the strongest effects in anti-cholinesterase and cytotoxic tests at the concentration of 100 μg/mL, AChE enzyme inhibition was 58.55% and human cancer cells, SNU-1 and Hep G2 inhibition was 68.52% and 47.82%, respectively. The phytochemicals present in the n-hexane extract are palmitic acid, linoleic acid and γ-sitosterol.
CONCLUSIONS: The present study revealed that the n-hexane extract possessed relatively high pharmacological activities in anti-inflammation, cytotoxicity and anti-cholinesterase assays. Thus, further work on the detail mechanism of the bioactive phytochemicals which contribute to the biological properties are strongly recommended.
METHODS: The title amides (4a-j) were obtained by simple nucleophilic substitution reaction of dexibuprofen acid chloride with substituted amines in good yield and chemical structures were confirmed by FTIR, 1H NMR, 13C NMR and mass spectral data.
RESULTS: The brine shrimp lethality assay results showed that all of the synthesized compounds are non-toxic to shrimp larvae. The inhibitory effects on tumor growth were evaluated and it was observed that N-(2,5-dichlorophenyl)-2-(4-isobutylphenyl) propionamide (4e) and N-(2-chlorophenyl)-2-(4-isobutylphenyl) propionamide (4g) exhibited excellent antitumor activity compared to all other derivatives. The compound 4e bearing 2,5-dichloro substituted phenyl ring and 4g possesses 2-chloro substituted phenyl ring exhibited 100% inhibition of the tumor growth. The anticancer activity was evaluated against breast carcinoma cell line (MCF-7) and it was observed that derivative 4e exhibited excellent growth inhibition of cancer cells with IC50 value of 0.01±0.002 µm, which is better than the standard drugs. The docking studies against breast cancer type 1 susceptibility protein BRCA1 (PDBID 3K0H) exhibited good binding affinities, which are in good agreement with the wet lab results. The compounds 4e and 4g showed the binding energy values of -6.39 and -6.34 Kcal/mol, respectively. The molecular dynamic (MD) simulation was also carried out to evaluate the residual flexibility of the best docking complexes of compounds 4e and 4g. The MD simulation analysis assured that the 4e formed a more stable complex with the target protein than the 4g. The synthesized amide derivatives exhibited were devoid of gastrointestinal side effects and no cytotoxic effects against human normal epithelial breast cell line (MCF-12A) were found.
CONCLUSION: Based upon our wet lab and dry lab findings we propose that dexibuprofen analogue 4e may serve as a lead structure for the design of more potent anticancer drugs.