Potential in-vitro antioxidant and anti-inflammatory activity of Martynia annua extract mediated Phytosynthesis of MnO₂ nanoparticles

Abstract

The present research work describes the phyto-synthesis of Manganese dioxide nanoparticles (MnO₂NPs) from the reduction of potassium permanganate using Martynia annua (M.annua) plant extract. From the literature review, we clearly understood the M.annua plant has anti-inflammatory activity. Manganese dioxides are important materials due to their wide range of applications. Their increased surface area gives them distinct capabilities, as it increases their mechanical, magnetic, optical, and catalytic qualities, allowing them to be used in more pharmaceutical applications. A detailed review of literature highlighting the issues related to this present work and its knowledge gap that none of the inflammatory activities had been done by MnO₂ NPs synthesized from M.annua plant extract. So we selected this study. The product MnO₂ NPs showed the wavelength centre at 370 nm and was monitored by UV–Vis spectra. The wave number around 600 cm⁻¹ has to the occurrence of O–Mn–O bonds of pure MnO₂ confirmed by FTIR spectroscopy. Transmission electron microscopy images showed the morphology of MnO₂ NPs as spherical-shaped particles with average sizes at 7.5 nm. The selected area electron diffraction analysis exhibits the crystalline nature of MnO₂ NPs. The obtained MnO₂ NPs showed potential antioxidant and anti-inflammatory activity was compared to the plant extract. The synthesized MnO₂ NPs have a large number of potential applications in the field of pharmaceutical industries. In the future, we isolate the phytocompounds present in the M.annua plant extract and conduct a study against corona virus. MnO₂ produces manganese (III) oxide and oxygen, which increases fire hazard. But further research is required to understand their environmental behaviour and safety.

Graphical abstract

Highlights

• •MnO₂NPs synthesized using Martynia annua plant extracts phytochemicals (flavonoids, carbohydrates), act as a reducing agent.
• •UV–Vis spectra showed the wavelength absorption centre at 370 nm confirming the synthesis of MnO₂ NPs.
• •HRTEM analysis was used to identify the surface morphology of synthesized MnO₂ NPs, showing spherical shape particles with average sizes at 7.5 nm.
• •MnO₂ NPs exhibited good antioxidant and anti-inflammatory activity.

1. Introduction

1.1. Nanoparticles (NPs)

A nanoparticle (NPs) is a small particle that ranges between 1 and 100 nm in Size [1]. When the size of the NPs decreased the surface-to-volume ratio increased and it directed tominor changes in their physiochemical and biological properties. In the last few years, the NPs in medicine have had vast applications such as antimicrobial, antioxidant, anti-inflammatory, antiviral, anticancer, anti-HIV activities, and so on [1].When compared to traditional medications, anticancer medications produced using nanotechnology has demonstrated superior therapeutic benefits. Through a steady delivery of anticancer drugs to the intended cancer site, functionalized nanoparticles enhance their therapeutic efficacy. Metallic nanoparticles have drawn the attention of experts worldwide in nanotechnology for their potential use in biomedical applications. The native form of nanoparticles was found to be less harmful to tumor cells than those containing drugs. Since they are physically stable and have electrical conductivity, metallic nanoparticles have drawn attention. With their capacity to promote wound healing and prevent angiogenesis, among other uses, these nanoparticles (NPs) have several uses [2]. Particles ranging in size from 1 to 100 nm find extensive uses in fields such as medicine, cosmetics, biomedical sciences, electronics, chemical industries, single-electron transistors, light emitters, nonlinear optical devices, food packaging, animal husbandry, agriculture, and healthcare. The use of nanotechnology in targeted medicine delivery at the right dose to treat serious illnesses including HIV, cancer, and tumors are also gaining acceptance [3,4].

Nowadays, harmful diseases are controlled by the drugs prepared by the nano-biotechnology method. Usually, metal oxide receives more attention in nanotechnology due to the huge requirements in industries, pharmaceuticals such as disinfectants, catalysts, and antimicrobial drugs [5]. There are several methods available to prepare metal nanoparticles (MNPs) such as chemical reduction, ultraviolet, microwave radiation photochemical, and sonoelectrochemical methods. In recent years for synthesis of MNPs from metal ions using the reducing agents of organisms such as algae, fungi, yeast, bacteria, viruses, and plant extract has had the most powerful influence [6]. The green syntheses of MNPs are more stable, high yield, and have low toxicity. NPs have been employed as catalysts, chemical and biological sensors, antimicrobial agents, drug and gene delivery vehicles, cell labeling, and imaging agents [7]. The degradation of environmental pollutants, gas sensors, electrical, and optical devices, electrostatic dissipative coatings, solar cells, and external uses as antibacterial agents in lotions, mouthwashes, ointments, and surface coatings to prevent microbial growth are just a few of the many applications over NPs [8].

1.2. Manganese dioxide (MnO₂)

Various crystal structures of Manganese dioxides (MnO₂) have more attention because of their physical and chemical properties and its broad applications in catalysis, biosensors, water treatment, electrochemical supercapacitors, and others [9]. One of the most significant inorganic materials is MnO₂, and its electromagnetic properties and efficacy have been investigated carefully [10].

1.3. Manganese dioxide nanoparticles (MnO₂NPs)

MnO2NPs have great clinical translation potential. However, by contrast, the in vitro and in-vivo bio-safeties of MnO₂NPs have been deeply and thoroughly clarified for clinical translation, which hinders their clinical applications [11]. Because of the number of benefits, MnO₂NPs are one of the best options. Some of these benefits include their low cost in terms of workforce and environmental costs, as well as their high luminescence quantum yield. Their wide range of applications, enzymatic-like activity, excellent biocompatibility, advantageous therapeutic qualities, and extremely high theoretical specific capacitance are other appealing variables [12,13]. There are various physicochemical techniques to synthesize MnO₂NPs like hydrothermal process, Sol-gel process, Wet chemical and photochemical route, Co-precipitation technique, pyrolysis process, and low-temperature solution combustion method [14]. Compared to other distinct inorganic metal oxides, MnO₂NPs are relatively easy to obtain and non-toxic. Materials and medicines have undergone significant improvements as a result of recent developments, and these innovations all have enormous promise [15]. In several domains, including biomedical applications, energy storage, and catalysis, manganese oxide (MnO₂), a metal oxide nanoparticle, has demonstrated promising results. Recently, scientists have started investigating MnO₂NPs potential as a strong cancer therapeutic agent [16]. According to reports, MnO₂ NPs have uses in biosensors, supercapacitors, antibacterial, antimicrobial, and catalysis. Green synthesis has emerged as the most promising approach for producing environmentally safe and biocompatible nanomaterials, outperforming alternative approaches that need expensive and hazardous chemicals to achieve reduction [17]. Recently, whole plant, bacterial, and fungal extracts have been used in the green production of MnO₂NPs. This method is an environmentally eco-friendly, cost-effective large-scale synthesis for highly stable NPs. The reason is the presence of secondary metabolites such as steroids, terpenoids, flavonoids, saponins, tannins, glycosides, carbohydrates, and other phytochemical substances in plant, bacterial, and fungal extracts [[18], [19], [20]].

1.4. The use of plants in producing nanoparticles

Plants provide the best environment for the preparation of NPs. The MnO₂NPs prepared by chemical methods are not suitable for biological activities due to high toxicity [21]. An antioxidant is a substance that traps the free radicals produced during oxidation so that it controls the oxidation of other molecules. Natural antioxidant substances such as flavonoids, phenolic compounds, vitamins, and other plant pigments like anthocyanins are naturally available in plants [22]. Usually, free radicals and reactive oxygen species are the main sources of many disorders by prevent the reaction cycle in humans and cause diseases like cancer, heart disease, ageing, and diabetes [22]. Varieties of methods are available to measure the antioxidant and free radical scavenging activity such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, hydrogen peroxide scavenging assay, nitric acid scavenging activity, ferric reducing antioxidant power assay and reducing power method [22]. Recently, several medicinal plants extract such as Brassica oleraceae [14], Syzygiumaromaticum [23], Kalopanax pictus leaf extract [24], lemon extract, and turmeric curcumin extract [25], and Euphorbia heterophylla L. leaf extract [26] were used for the green synthesis of MnO₂NPs.

Martynia annua Linn belongs to the family Martyniaceae. This plant is used in Indian traditional medicine for epilepsy, inflammation, and tuberculosis [27] as antiepileptic and antiseptic tuberculosis glands of the neck, gargle for sore throat, etc [28]. Several phytocompounds such as steroids, terpenoids, alkaloids, glycosides, tannins, carbohydrates, phenols, flavonoids and anthocyanins, lipids, and phenolic acids were isolated in this plant [29]. The aim of the present work focused on green synthesis of MnO₂NPs from potassium permanganate solution using the reducing agents of M.annua plant extract and its antioxidant (DPPH assay) and anti-inflammatory activity.

2. Materials and methods

2.1. Collection of plant material and its extraction

All the chemicals, reagents, and other materials utilized in this work are purchased from Aldrich (Sigma-Aldrich), RANKEM, LOBA Chemie, Merck, SRL, (P) Ltd India. The fresh M.annua plants were collected from Tirunelveli district, Tamil Nadu, India. The plants were identified by Dr. M. Uthayakumar, Taxonomist and Assistant Professor, the Department of Plant Science, Manonmaniam Sundaranar University. M. annua plants were washed with running tap water followed by triple distilled water to remove dust. About 68 g of M. annua plants were taken in 1000 ml capacity Soxhlet extractor apparatus to extract with increasing order from non-polar to polar solvents like n-hexane (A1) (RANKH0310), chloroform (A2) (RANKC0580), ethyl acetate (00138 00500) (A3), acetonitrile (A4) (1-07031-2521) and triple distilled water (A5). Each extract was filtered and concentrated by distillation method. By using Soxhlet apparatus fresh M.annua whole plants were extracted with n-Hexane (400 ml) for 4 h at 50 °C. Then the mixture of solution was cooled and filtered. The supernatant n-hexane extract was collected and concentrated by distillation to get the n-hexane fraction and then the collected portions were stored for further usage. The remaining residue was used for the preparation of the following extract such as chloroform, ethyl acetate, acetonitrile, and water. The above-mentioned method was used for the preparation of the remaining extracts (chloroform, ethyl acetate, acetonitrile, and water). The obtained product was analyzed to standard method of phytochemicals analysis (Harborne 1998) [30] to find out the presence of various secondary metabolites in different solvents (Table 1). The active secondary metabolites of flavonoids, and carbohydrates presented in the A5 extract portion were used for the green synthesis of MnO₂ NPs.

Table 1.

Phytochemical analysis of M.annua plant extracts using different solvents.

S.No	Phytocompound	Experiment	Observation	Hexane (A1)	Chloroform (A2)	Ethyl acetate (A3)	Acetonitrile (A4)	Water (A5)
1	Steroids	Extract + Chloroform + Con. H2SO4	Red colour in H2SO4 layer	+	-	-	-	-
2	Terpenoids	Extract + Chloroform + Con. H2SO4	Reddish brown layer	+	-	-	-	-
3	Sterols	Extract + Con. H2SO4 shaken well and allow to stand	Red colour lower layer	+	-	-	-	-
4	Cardiac glycosides	Extract + glacial acetic acid+ 5%ferric chloride + Con.H2SO4	Reddish brown at the junction and bluish green upper layer	-	+	-	-	-
5	Glycosides	Extract + alcohol + dis.H2O + aqueous NaOH solution	Yellow colour	-	+	-	-	-
6	Quinones	Extract+ 1 ml of Con.H2SO4	Red colour	-	+	-	-	-
7	Saponins	Extract + distilled water + vigorous shaking	Froth foam formation	-	-	+	-	-
8	Coumarins	Extract + CHCl3+ NaOH	Yellow colour formation	-	-	-	+	-
9	Flavonoids	Extract + distilled water and warm. Filter and add 10%aq. NaOH	Yellow colouration	-	-	-	+	+
10	Carbohydrates	Extract + Benedict reagent	Brick red precipitate	-	-	+	+	+

Present (+) Absent (-).

2.2. Phyto-synthesis of MnO₂ NPs

In the phyto-synthesis of MnO₂ NPs, 0.1 ml of M. annua plant A5 extract was addedto 10 ml of 1 mM potassium permanganate (KMnO₄) (05410 00500) solution in a conical flask. The solution was kept aside in a dark place at room temperature overnight. After a few min, the pink colour solution was changed into a brown precipitated solution indicating the formation of MnO₂ NPs [31]. The M. annua plant A5 extract phytocompounds present in the solution act as a reducing and capping agent in the formation of MnO₂NPs from the KMnO₄ solution. The resulting brown-colored solution was centrifuged at 5000 rpm for 20 min in a high-speed centrifugation. The residual part of the NPs was washed with triple distilled water to remove the unreacted metal ions and phytochemicals. Finally, the obtained residue was placed in a microwave oven and heated to 200 °C for 6 h to remove the aqueous portion. The product of MnO₂ NPs was confirmed and analyzed by various spectral instrumentation techniques.

2.3. Characterization of MnO₂ NPs

The formation of MnO₂NPs was confirmed by UV–vis. spectra in the wavelength region at 200–800 nm using PerkinElmer Lambda 25 model spectrophotometer. The synthesized MnO₂NPs and M. annua plant extract A5 layer contained phyto-functional groups were determined by FTIR spectroscopy between the wave number from 4000 to 400 cm⁻¹ using Thermo Scientific Nicolet IS5. The particle size and surface morphology was determined using carbon-coated copper grid with a 200 mesh size JEOL JEM 2100 High resolution transmission electron microscope (HRTEM).Preparation of the samples for analysis by Energy-dispersive X-ray spectroscopy (EDX) is usually copper grid coated with carbon. This is because carbon has a low atomic number and the peak of the X-ray graph of carbon doesn't interfere with other peaks of other elements.

2.4. Determination of in-vitro antioxidant (DPPH radical scavenging) activity

DPPH free radical scavenging assay was determined by using M. annua plant A5 extract, synthesized MnO₂NPs, and standard Ascorbic acid (50-81-7). 100 ml of 0.1 mM DPPH (in methanol) was added to 300 μL of different concentrations of (500, 250, 100, 50, and 10 μg/mL) MnO₂NPs and plant extract. The reaction mixture was shaken vigorously by a shaker and allowed to stand for 30 min at room temperature. Then the absorbance was measured at 517 nm using UV–vis. spectrophotometer. Methanol has been used as blank and ascorbic acid used as standard. The capability of DPPH radical scavenging can be calculated by formula (1).

$$\%\text{Inhibition}=\left[(\text{Control}\text{OD}–\text{Sample}\text{OD})/\text{Control}\text{OD}\right]\times 100$$ (1)

where sample OD is the absorption of the DPPH solution with extract and MnO₂NPs, control OD is the absorption of the DPPH solution without extract and MnO₂ NPs.

2.5. Inhibition of protein denaturation

Protein denaturation is considered to be one of the reasons for inflammation. Bovineserum albumin (BSA) and Egg albumin (EA) methods were used to study in-vitro anti-inflammatoryactivity by protein denaturation. In the BSA method, the standard drug Diclofenac potassium [32] was mixed with 450 μL of 1 % BSA and added100 μL of this solution to 300 μL of plant extract and different volumes of (10, 25, 50, 75, and 100 μg/mL) MnO₂ NPs. The reaction mixtures were incubated at 37 °C and shaken by an orbital shaker REMI RS-12 PLUS for 30 min. Denaturation was induced by keeping the reaction mixture at 56 °C warm zone for 20 min. After cooling, the absorbance was measured at 580 nm using a UV–vis spectrophotometer. Diclofenac potassium was used as the reference.

In the EA method, standard drugs Diclofenac sodium were mixed with 450 μL of 1 % egg albumin (EA) and 100 μL of this solution, 300 μL of plant extract, and different volumes (10, 25, 50, 75, and 100 μg/ml) of MnO₂ NPs. The reaction mixtures were incubated at 37 °C with shaking for 30 min. The reaction mixture was kept at 56 °C warm zone for 20 min to cause denaturation.

After cooling, the absorbance was measured at 660 nm using a UV–vis spectrophotometer, and Diclofenac sodium was used as the reference sample [33]. The inhibition percentage of protein denaturation can be calculated using formula (2)

$$\left(\%\text{inhibition}\right)=\left[\left(\text{absorbance}\text{of}\text{control}-\text{absorbance}\text{of}\text{reaction}\text{mixture}\right)/\text{absorbance}\text{of}\text{control}\right]\mathrm{X}100$$ (2)

3. Results and discussion

3.1. Extraction and analysis of phytocompounds from Martynia annua plant extract

Freshly collected and thoroughly washed M. annua plant was loaded in the Soxhlet apparatus and extracted using the required amount of non-polar to polar solvents. The detailed extractions are shown in Flow chart 1. All the extracts were concentrated in the rotator evaporator to obtain the residue. The obtained residual part was used for qualitative preliminary phytochemical analysis revealed the presence of steroids, terpenoids, sterols, cardiac glycosides, glycosides, quinones, saponins, coumarins, flavonoids, and carbohydrates (Table 1). Initially, the n-hexane (A1) [34], chloroform (A2), ethyl acetate (A3), and acetonitrile (A4) extracts containing unwanted phytocompounds such as steroids, terpenoids, sterols, cardiac glycosides, quinones, saponins, and coumarins were discarded. Then the essential phytocompounds such as flavonoids and carbohydrates presented in the aqueous extract (A5)were concentrated and used for the green synthesis of MnO₂ NPs. The majorly present phytocompounds from the A5 fraction served as reducing/capping agents in the NP synthesis. Generally, the aqueous solvent is nontoxic. So we have used only the aqueous portion A5 fraction in the green synthesis of MnO₂ NPs and further processes [35].

Flow Chart 1.

Extraction, synthesis, characterization and application of MnO₂ NPs.

3.2. Phyto-synthesis of MnO2 NPs using Martynia annua plant A5 extract

M.annua plant A5 extract was added to 1 mM potassium permanganate solution in a conical flask and kept in a dark place at room temperature for overnight. The magenta-pink colour reaction mixture was changed into a brown to visually indicate the formation of MnO₂ NPs [31,36]. UV–vis spectra of MnO₂ NPs showed an intense absorption peak at 370 nm (Fig. 1.) confirmed the presence of MnO₂ NPs which is correlated with previous reports [37,38].

Fig. 1.

UV–vis absorption spectrum of the M.annua plant extract A5 fraction, KMnO₄ and MnO₂ NPs (insert images to change of colour in the synthesis of MnO₂ NPs).

3.3. FTIR analysis

The Phyto-functional group of MnO₂ NPs and A5 extract was determined by FTIR spectroscopy. Antioxidant phenolic acids and their analogues were detected by the FTIR peaks. The peaks in the green synthetic MnO₂ NPs verified the packing of organic compounds that are highly biodegradable and nontoxic phytoconstituents on the MnO₂ NPs surface. These chemicals may have contributed to the reduction and capping of the synthetic MnO₂ NPs. The M. annua plant A5 extracts wave numbers at 3310, 2926, 1600, 1376, and 1046 and MnO₂ NPs wave numbers at 3150, 1395, 1236, 850, and 600 cm⁻¹ shown in Fig. 2. The bands at 3310 and 3150 cm⁻¹ indicated the broad stretching vibration of O–H group [39]. The sharp peak at 2926 cm⁻¹ related to aliphatic C–H stretching vibrations [40]. The peak at 1395 cm⁻¹ described the bending vibration of the C–H bond [41]. The wave number at 1046 cm⁻¹ represented the C–O–C linkage of the polyphenolic group in plant extract [42]. The observed peak at1600 cm⁻¹ represents the C C stretching vibration groups and the peak at 1376 cm⁻¹ confirmed the O–H bending vibration of alcohols/phenols groups [43]. The surface –OH groups of Mn–OH for colloidal MnO₂ NPs showed a peak at 1236 cm⁻¹. Usually, mineral structures of Mn–O show decreased intensity of a peak in FTIR spectra due to the presence of stronger bondsand weak vibrations. So, the low intensity of peaks at 850 and 600 cm⁻¹ showed the presence of an O–Mn–O bond [24,44,45]. The FTIR spectral results showed that the flavonoids derivatives were present in the A5 extract and it is responsible for the synthesis of MnO₂ NPs [46].

Fig. 2.

FTIR spectrum of plant extract and MnO₂ NPs.

3.4. HRTEM analysis

The morphology and particle size of the MnO₂ NPs were determined by Transmission electron microscopy to obtain different magnification images, such as high magnification (Fig. 3a and b) and low magnification (Fig. 3c and d). The observed HRTEM images showed that the MnO₂ NPs exhibit spherical shape [47] with sizes from 10 to 23 nm [31]. The EDX analysis confirmed the presence of elements such as Mn and O in the synthesized MnO₂ NPs as shown in Fig. 3h. The metallic Mn exposed optical peak at 6 keV, which confirmed the reduction of manganese ion to zero valance [41]. Identical to this, in our study the appearance of optical peak value at 6 keV confirmed the formation of MnO₂ NPs. The SAED pattern revealed the crystalline nature of MnO₂ NPs (Fig. 3g) [44]. The image of lattice fringes (Fig. 3e and f) showed the configuration of the crystalline nature of MnO₂ NPs [45]. The histogram showed the average particle sizes around 7.5 nm (Fig. 3i).

Fig. 3.

HRTEM images of synthesized MnO₂ NPs with high magnificationsat 100 nm (a, b), low magnifications at 50 nm (c, d), lattice fringes at 10 nm (e) and at 5 nm(f); SAED pattern (g); Typical EDX spectrum (h); Histogram (i).

3.5. Biological applications

3.5.1. Antioxidant activity

The 2,2-diphenyl-1-picrylhydrazyl (DPPH) (Aldrich (Sigma-Aldrich) – D913-2)tests is a precise and cost-effective way to assess the antioxidant activity of meals and drinks as well as the capacity of various substances to function as hydrogen donors or free radical scavengers. Regardless of sample polarity, the DPPH approach is characterized as an easy, quick, and practical way to screen a large number of samples for radical scavenging activity and it doesn't require any special reaction variables. Antioxidants' capacity to scavenge free radicals is commonly measured using the DPPH technique [48]. Generally, plants have phytochemical compounds naturally having medicinal properties and antioxidant sources [49]. A stable free radical called DPPH is well known for its function in the reduction of absorbing hydrogen or electrons from donors [1]. Antioxidants can protect the human body from radicals and prevent the commencement of the degenerative diseases. MnO₂ NPs possess effective dose-dependent scavenging activity. When we increase the concentration of NPs, the activity of antioxidants also was increases [36,50]. DPPH-free radical scavenging activities of MnO₂ NPs at different concentrations are given in Fig. 4. The antioxidant effect corresponds to the disappearance of DPPH in the test samples. DPPH shows a strong absorption maximum at 517 nm (purple). The colour changes from purple to yellow followed by the formation of DPPH on absorption of hydrogen from an antioxidant [51]. From this, we decided, plants are a good source of natural antioxidants, and we can use this to treat diseases and disorders, especially those related to inflammation and oxidative stress. In comparison, the M.annua plant extract showed a lesser percentage inhibition, and MnO₂ NPs showed higher anti-oxidant activity, as shown in Fig. 4. The IC₅₀ value of plant extract is 339.59 μg/mL. Thus, MnO₂ NPs proved to be powerful at inhibiting the DPPH radical scavenging activity, with an IC₅₀ value of 309.93 μg/mL. The anti-oxidant activity of extract and MnO₂ NPs is higher% than previous literature reports even at 100 μg/mL with 56.18 % and 61.56 % inhibition [52].

Fig. 4.

DPPH free radical scavenging activity of M.annua plant extract and MnO₂ NPs at 10, 25, 50, 75, & 100 μg/mL.

3.5.2. In-vitro anti-inflammatory activity

Green-synthesized MnO₂ NPs were tested for their anti-inflammatory activity by Bovine Serum Albumin (BSA) method and Egg Albumin (EA) method. Inflammation is the tissue or organ injurious causes characteristic pain, swelling, temperature, and redness [53]. Inflammation and protein denaturation are closely related. Protein denaturation accelerates inflammation. It is an action in which protein drops its secondary and tertiary structures by applying pressure from outside, heat, or chemical compounds such as acid, base, inorganic salts. In the present work, different concentrations of aqueous plant extract and MnO₂ NPs were subjected to evaluation for anti-inflammatory activity. In the BSA method In Fig. 5a, the M. annua plant extract and MnO₂ NPs showed a percentage inhibition of denaturation at 100 μg/mL is 75.42 % and 77.49 %. In the EA method, Fig. 5 (b) showed 59.88 % and 71.73 % of inhibition denaturation. In Fig. 5 (a) and (b), the extract showed lesser inhibitory potential compared to MnO₂ NPs. In the BSA method of protein denaturation, the plant extract and MnO₂ NPs performed appropriate activity. Compared to previous studies, the green synthesized MnO₂ NPs showed better inhibition ability of denaturation in the BSA and EA methods with IC₅₀ values of 49.71 and 58.02 μg/mL [54]. According to our knowledge, this is the first one on the inflammatory activity by the MnO₂ NPs are synthesized from M. annua plant extract.

Fig. 5.

Anti-inflammatory activity of M.annua plant extract and MnO₂ NPs: (A) Egg albumin method; (B) Bovine serum albumin method.

4. Conclusion

MnO₂ NPs synthesized from M. annua extract, utilizing its secondary metabolites as reducing and capping agents, demonstrated promising antioxidant and anti-inflammatory activities, inhibiting reactive oxygen species and protein denaturation by 77.49 % at 100 μg/mL respectively obtained. These findings suggest their potential as safe and effective agents against various infections, with the need for further exploration regarding the isolation and evaluation of specific phytocompounds through column chromatography.

Data availability statement

Data will be made available on request.

CRediT authorship contribution statement

V. Thangapushbam: Writing – review & editing, Writing – original draft, Resources, Methodology, Investigation. P. Rama: Writing – review & editing. S. Sivakami: Writing – review & editing. M. Jothika: Writing – review & editing. K. Muthu: Validation, Supervision. Abdulrahman I. Almansour: Writing – review & editing, Funding acquisition. Natarajan Arumugam: Writing – review & editing. Karthikeyan Perumal: Writing – review & editing.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Appendix A. Supplementary data

The following is the Supplementary data to this article: