Phytochemical screening and in vitro radical scavenging activities of “Gola” guava fruit and leaf extracts

Abstract

This study aimed to investigate the chemical and antioxidant characteristics of 50% and 70% hydroethanolic Gola guava fruit (GF) and guava leaf (GL) extracts by high‐performance liquid chromatography (HPLC) and Fourier‐transform infrared spectroscopy (FTIR). Total phenolic content (TPC) was determined by Folin–Ciocalteu reagent. The ability to scavenge free radicals was evaluated using DPPH (2,2‐diphenyl‐1‐picrylhydrazyl), H2O2 (hydrogen peroxide), and ABTS+ (2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid)) in vitro assay. Fours hydroethanolic Gola GF and GL extracts (GF50%, GF70%, GL50%, and GL70%): 50% hydroethanolic leaves extract showed the highest TPC (299.06 ± 2.69 mg GAE/g dry extract) and TFC (31.05 ± 1.67 mg CE/g). GL50% (299.06 ± 2.69 mg GAE/g dry extract) showed high TPC than GL70%. While GL50% and GL70%’s antioxidant potential was higher than GF extracts. TPC showed a highly positive correlation with DPPH, H2O2, and a moderately positive correlation with ABTS·+. HPLC analysis indicated the presence of flavonoid compounds including quercetin and kaempferol as well as phenolic acids like gallic, syringic, m‐coumaric, p‐coumaric, vanillic, ferulic, benzoic, caffeic, chlorogenic, cinnamic, sinapic, and ascorbic acids. A high number of phenolic compounds was identified in GL50% followed by GF50% through HPLC. The extraction of bioactive compounds was more efficient with 50% hydroethanolic solvent. The FTIR spectrograms showed changes in the chemical groups and determined the extracts' functional groups. In conclusion, findings support the use of phenolic compounds extracted from GF and GL, not only for their antioxidant activity, but also provide an important basis for potential use of phenolic compounds as crosslinking agents of sulfated and non‐sulfated glycosaminoglycan. Novelty impact statement This study manifests the best extraction solvent for optimized recovery of all antioxidant compounds of Gola GF and GL at maximum potential and provides an insight into the chemical profile of extracts. The chemical characterization by HPLC and FTIR pave the way for the possible natural antioxidant's formulation and development of functional food with a specific investigation to elucidate the action of mechanism at the cellular and organism level to evaluate the pharmacological potential of extracts.

Antioxidant and Anti-Cytotoxicity Effect of Phenolic Extracts from Psidium guajava Linn. Leaves by Novel Assisted Extraction Techniques

“…The prevention of cardiovascular disease; anticancer, anti-tumor, anti-ulcer, antiallergy, anti-viral, and anti-inflammatory activity; anti-diabetic and gastroprotective effects; and antihypertensive, immunomodulatory, and anti-infective effects are only a few of the benefits [ 33 ]. Shahid et al [ 34 ] used HPLC and FTIR analysis to examine the chemical and antioxidant properties of 50% and 70% hydroethanolic Gola guava fruit (GGF) and guava leaf (GGL) extracts. Their study suggests GGL shows higher phenolic compounds and AA than GGF.…”