Green synthesis of silver nanoparticles using Indian Belladonna extract and their potential antioxidant, anti-inflammatory, anticancer and larvicidal activities

Atropa acuminata aqueous leaf extract biosynthesized silver nanoparticles showed strong antioxidant, anticancerous (HeLa cells) and anti-inflammatory activities. Besides, this bio syn-AgNP also proved effective against mosquito vectors causing malaria, dengue and filariasis. Present study highlights eco-friendly and sustainable approach for the synthesis of silver nanoparticles (AgNP) using aqueous leaf extract of A. acuminata, a critically endangered medicinal herb. The addition of 1 mM silver nitrate to aqueous leaf extract resulted in the synthesis of AgNP when solution was heated at 60 °C for 30 min at pH 7. Absorption band at 428 nm, as shown by UV-Vis spectroscopy confirmed the synthesis of AgNP. XRD patterns revealed the crystalline nature of AgNP and TEM analysis showed that most of the nanoparticles were spherical in shape. Zeta potential of AgNP was found to be - 33.5 mV which confirmed their high stability. FT-IR investigations confirmed the presence of different functional groups involved in the reduction and capping of AgNP. The synthesized AgNP showed effective DPPH (IC₅₀-16.08 µg/mL), H₂O₂ (IC₅₀-25.40 µg/mL), and superoxide (IC₅₀-21.12 µg/mL) radical scavenging activities. These plant-AgNP showed significant inhibition of albumin denaturation (IC₅₀-12.98 µg/mL) and antiproteinase activity (IC₅₀-18.401 µg/mL). Besides, biosynthesized AgNP were found to have strong inhibitory effect against a cervical cancer (HeLa) cell line (IC₅₀-5.418 µg/mL) as well as larvicidal activity against 3rd instar larvae of Anopheles stephensi (LC₅₀-18.9 ppm, LC₉₀-40.18 ppm), Aedes aegypti (LC₅₀-12.395 ppm, LC₉₀-36.34 ppm) and Culex quinquefasciatus (LC₅₀-17.76 ppm, LC₉₀-30.82 ppm) and were found to be non-toxic against normal cell line (HEK 293), and a non-target organism (Mesocyclops thermocyclopoides). This is the first report on the synthesis of AgNP using aqueous leaf extract of A. acuminata, validating their strong therapeutic potential.

Design, synthesis, in-vitro, in-vivo and in-silico studies of pyrrolidine-2,5-dione derivatives as multitarget anti-inflammatory agents

In recent years, drug discovery paradigm has been shifted from conventional single target inhibition toward multitarget design concept. In current research, we have reported synthesis, in-vitro, in-vivo and acute toxicity determination of N-substituted pyrrolidine-2,5-dione derivatives as multitarget anti-inflammatory agents. We synthesized cycloalkyl, alkyl and aryl carbonyl derivatives by the Michael addition of ketones to N-substituted maleimides using self-assembled three component system as an organocatalyst. Anti-inflammatory potential of the compounds was determined by using different in-vitro assays, like cyclooxygenase-1, cyclooxygenase-2 and 5-lipoxygenase, albumin denaturation and anti-protease assays. Amongst the synthesized compounds, 13a-e series of compounds showed inhibition in low micromolar to submicromolar ranges. These compounds also demonstrated COX-2 selectivity. Compound 13e with IC₅₀ value 0.98 μM and SI of 31.5 emerged as the most potent inhibitor of COX-2. Based on in-vitro results, in-vivo anti-inflammatory investigations were performed on compounds 3b and 13evia carrageenan induced paw edema test. The possible mode of action of compounds 3b and 13e were ascertained with various mediators like histamine, bradykinin, prostaglandin and leukotriene. In-vivo acute toxicity study showed the safety of synthesized compounds up to 1000 mg/kg dose. The selectivity of the compounds against cyclooxygenase isoforms was supported by docking simulations. Selective COX-2 inhibitors showed significant interactions with the amino acid residues present in additional secondary COX-2 enzyme pocket. Furthermore, in-silico pharmacokinetic predictions confer the drug-like characteristics.

Evaluation of anti-inflammatory potential of the leaves of Wendlandia heynei (Schult.) Santapau & Merchant in Sprague Dawley rat

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of W. heynei (family: Rubiaceae) are used by the folklore in swelling, wounds and body aches. In this study anti-inflammatory potential of W. heynei leaves has been evaluated during in vitro studies and in rat.

METHODS

Methanol extract of the leaves of W. heynei (WHLM) and its fractions; n-hexane (WHLH), chloroform (WHLC), ethyl acetate (WHLE), n-butanol (WHLB) and residual soluble aqueous (WHLA) were screened for phytochemical analysis and several active constituents (alkaloids, flavonoids, saponins, tannins, terpenoids, β-carotene and lycopene) were also quantified. Heat induced albumin denaturation assay and in vitro cell cultures was carried out for in vitro anti-inflammatory activity, while various in vivo assays like TPA induced ear edema, croton oil induced anus edema, formalin and carrageenan-induced hind paw edema was investigated in Sprague-Dawley rats. Alterations on levels of tumor necrosis factor (TNF-α), Interleukin-1β (IL-1β), IL-6 and prostaglandins (PGE₂) induced with WHLE was studied in serum after carrageenan induced paw edema in rat. Meanwhile, the dose dependent WHLE inhibition of NFκB pathway via regulation of the phosphorylation of IKKs, IκBα, and p65 subunit was studied in LPS-induced rat peritoneal macrophages. On account of marked anti-inflammatory activity of WHLE its bioactive components were analyzed by HPLC-DAD analysis.

RESULTS

The phytochemical analysis yielded alkaloids, saponins, tannins, coumarins, glycosides, quinones and vitamin C in WHLM and in all fractions. Fraction (WHLE) was enriched with alkaloids (20.20 ± 2.5%), flavonoids (25.26 ± 2.11%) and tannins (307.2 ± 2.03 mg of GAE/g of extract), while terpenoids (21.60 ± 1.65%) were the major constituents of WHLH. Ethyl acetate fraction convincingly protected heat induced albumin denaturation. WHLE exhibited highest edema inhibition in models of TPA-induced ear edema (74.51 ± 2.05) and croton oil-induced anal edema (75.38 ± 2.83). The pretreatment with WHLE significantly (p < 0.05) reduced the paw edema with formalin (78.99 ± 2.26%) assessed after 6 h and in carrageenan (75.71 ± 4.46%) was detected after 4 h. Level of anti-inflammatory markers; IL-1β, IL-6, TNF-α and PGE₂ in carrageenan induced paw edema in serum of rat was significantly (p < 0.001) decreased with WHLE pretreatment to rat. WHLE significantly inhibited the NFκB by reducing the phosphorylation of IKKs, IκBα, and p65 subunit in LPS-induced inflammation in rat peritoneal macrophages. HPLC-DAD analysis of WHLE indicated the presence of rutin, gallic acid, catechin, caffeic acid and myricetin.

CONCLUSIONS

It is concluded that WHLM fractions have marked anti-inflammatory activity and this study endorsed the folklore use of W. heynei leaves for swelling related disorders.

bark using albumin denaturation method

Introduction

In Ayurveda, many natural plant compounds are used to inhibit inflammatory pathways for centuries with less side effects. Different parts of Ficus racemosa L. (Udumber) plant are used in Ayurveda for many diseases. However, few studies have been conducted to evaluate pharmacological activities of F. racemosa.

Objective

The objective of the study was to in vitro analyze anti-inflammatory property of F. racemosa bark using albumin denaturation activity.

Methodology

F. racemosa bark extraction was performed using cold water and hot water. The concentration gradient of extracts was prepared using egg albumin and phosphate-buffered saline. The extract was incubated in a water bath at 37°C for 15 min and was heated at 70°C for 5 min. One nonsteroidal anti-inflammatory drug and one steroid were used as reference drugs. The percentage inhibition of protein denaturation was calculated.

Results

The inhibition rate of egg albumin denaturation for water extraction increased gradually with concentration. Significantly higher inhibition was showed in hot water extracts than cold water extracts at the concentration of 0.01 μg/ml and 0.1 μg/ml. In addition, the inhibition rate of water extraction was significantly higher than the reference drugs (P < 0.05).

Conclusion

Anti-inflammatory activity increases with the concentration of F. racemosa bark. Furthermore, the action of this plant is significantly higher than the reference drugs.