Phytochemical constituents, antioxidant and antibacterial activities of Plectocephalus varians (A. Rich.) C. Jeffrey ex Cufod root extracts

Abstract

Plants have been used to treat diverse types of diseases in different cultural groups around the globe. In this regard, the root of Plectocephalus varians (P. varians) is claimed to have a beneficiary effect in treating cancer and hemorrhoids in Ethiopia. Hence, this study aimed at the phytochemical investigation, antioxidant, and antibacterial activities of n-hexane, acetone, and methanolic extracts of P. varians root. The different crude extracts of P. varians were obtained through maceration technique. The total phenolic content (TPC) and total flavonoid contents (TFC) of the extracts were estimated using Folin-Ciocalteu Reagent (FCR) and aluminum chloride colorimetric assays, respectively. The antioxidant activities of the extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) assays. The antibacterial activities of the extracts were assessed by using disc diffusion method. The results echoed the presence of alkaloids, saponins, flavonoids, steroids, phenols, tannins, anthraquinones, terpenoids, polyphenols, and glycosides in the root of P. varians. The methanolic root extract (MRE) had the highest TPC (107.18 mg GAE/g) and TFC (120.194 mg QE/g) followed by acetone root extract (ARE) (TPC = 98.68 mg GAE/g; TFC = 64.038 mg QE/g) and n-hexane root extract (HRE) (TPC = 12.39 mg GAE/g; TFC = 9.917 mg QE/g). The DPPH radical scavenging and FRAP assays demonstrated the antioxidant effects of HRE (IC50 = 681.75 ppm; EC50 = 60.65 ppm), ARE (IC50 = 165.73 ppm; EC50 = 51.67 ppm) and MRE (IC50 = 132.06 ppm; EC50 = 30.97 ppm) of P. varians. Furthermore, the root fractions elicited pronounced dose-dependent growth inhibition against Staphylococcus aureus, Streptococci pyogenes, Escherichia coli, and Klebsiella pneumoniae with mean zone of inhibition (MZI) ranging from 11 ± 0.38 to 20 ± 0.04 mm at 800 ppm. Overall, the present study provides ethnopharmacological evidence suggesting the medicinal importance of P. varians. The results also call for further bioassay-guided phytochemical screening and in vitro and/or in vivo bioactivity testing.

Phytochemical characterization, antimicrobial and antioxidant activities of Terminalia catappa methanol and aqueous extracts

“…The findings of this study were in agreement with previous studies carried out by Poongulali et al [ 46 ] on the methanol extract of T. catappa extract, which demonstrated concentration dependent ferric reducing power. Phenolic compounds are responsible for the antioxidant activity due to the presence of one or more hydroxyl groups in their structure that are able to scavenge the free radicals [ 47 ]. Therefore the antioxidant activity of T. catappa L. extracts can be attributed to the presence of phenolics.…”

Immunomodulatory effects of epiphytic Loranthus micranthus leaf extracts collected from two host plants: Psidium guajava and Parkia biglobosa

“…Among the identified phytochemicals, saponins have cytotoxic, antiallergic, antiviral, molluscicidal, and immunomodulating activities [ 34 ]. Flavonoids and tannin compounds contain multiple hydroxyl groups required to neutralize free radicals, chelate metal ions, decompose peroxides, and quench singlet oxygen [ 35 ]. According to Yahfouf et al [ 36 ], polyphenols regulate the immune system through their regulatory actions on signaling pathways that are not limited to the mitogen-activated protein kinases (MAPk), Janus kinases-signal transducer and activator of transcription proteins (JAK/STAT), nuclear factor-κB (NF-κB), and arachidonic acid pathways.…”

Phytochemical Screening, Acute Toxicity Study, and Pharmacological Evaluation of Natsiatum herpeticum Buch.Ham. ex Arn.

“…The radical scavenging activity of EENH was determined using freshly prepared methanolic solution of 2,2-diphenyl-1-picrylhydrazyl (DPPH) reagent as described by Gashaye and Birhan 2023. 14 Ascorbic acid was used as the standard. 1M DPPH solution was added to samples of extract and standard.…”

“…Post incubation in the dark for about 30 min, absorbance of the solution was recorded at 517 nm. 14 The % DPPH radical scavenging activity (in triplicates) was calculated as mentioned below.…”