Compendium of the most significant studies with reference to properties, intake, effects.

Batiha GE, Tene ST, Teibo JO, Shaheen HM, Oluwatoba OS, Teibo TKA, Al-Kuraishy HM, Al-Garbee AI, Alexiou A, Papadakis M. The phytochemical profiling, pharmacological activities, and safety of malva sylvestris: a review. Naunyn Schmiedebergs Arch Pharmacol. 2022 Nov 22. doi: 10.1007/s00210-022-02329-w.

Abstract. Malva sylvestris is a plant commonly found in Europe, Asia, and Africa. The leaves and flowers of this plant have been used for centuries in traditional medicine to treat various ailments such as cough, cold, diarrhoea, and constipation. Google Scholar, PubMed, Scopus, and Web of Science were used to search for relevant material on the phytochemical profiling and pharmacologic activities of Malva sylvestris. The techniques used in phytochemical profiling and the pharmacologic activity of each compound were extracted from the included studies, including in vitro, in vivo, and clinical studies. The phytochemical analysis of Malva sylvestris revealed that the leaves and flowers are the most commonly used parts of the plant and contain various bioactive compounds such as flavonoids, mucilages, terpenoids, phenol derivatives, coumarins, sterols, tannins, saponins, and alkaloids. These phytochemicals are responsible for the many pharmacological activities of Malva sylvestris, such as anti-inflammatory, antimicrobial, hepatoprotective, laxative, antiproliferative and antioxidant properties. This review has presented an overview of the antinociceptive and anti-inflammatory activities and the cytotoxic effects of Malva sylvestris on different types of cancer cells. It has also summarised the work on developing copper oxide nanoparticles using Malva sylvestris leaf extract and its potential use in food and medicine. This review aims to highlight the traditional uses, phytochemistry, pharmacological activities, and safety of Malva sylvestris.

Vahabi S, Hakemi-Vala M, Gholami S. In vitro Antibacterial Effect of Hydroalcoholic Extract of Lawsonia inermis, Malva sylvestris, and Boswellia serrata on Aggregatibacter actinomycetemcomitans. Adv Biomed Res. 2019 Mar 20;8:22. doi: 10.4103/abr.abr_205_18.

Abstract. Background: Considering the increased rate of microbial resistance to antibiotics and chemical side effects of antibiotics and antiseptics used for the treatment of periodontal disease, there is a need for an alternative antimicrobial agent with fewer complications. Medicinal herbs have recently become popular as novel antimicrobial agents. This study aimed to assess the antibacterial effects of hydroalcoholic extracts of Lawsonia inermis, Malva sylvestris, and Boswellia serrata on Aggregatibacter actinomycetemcomitans. Materials and methods: Hydroalcoholic extracts of the three medicinal plants were obtained by the maceration technique and A. actinomycetemcomitans was cultured. Antimicrobial efficacy of the three medicinal plants was compared with that of 0.2% chlorhexidine (CHX) according to the Clinical and Laboratory Standards Institute protocol using agar disc diffusion and broth microdilution techniques. All tests were repeated three times. Results: Hydroalcoholic extracts of all three plants had antimicrobial activity against A. actinomycetemcomitans. The minimum inhibitory concentration (MIC) of L. inermis, M. sylvestris, and B. serrata was 78.1, 156.2, and 1666 μg/mL with no significant difference between them. The MIC of CHX was 3.33 μg/mL, which was significantly higher than that of B. serrata extract. Conclusion: Given that further in vivo studies confirm other properties of these extracts and their safety in terms of cytotoxicity and mutagenicity, hydroalcoholic extracts of L. inermis and M. sylvestris may be used in mouthwashes or local delivery systems to affect periodontal biofilm.

Bimakr M, Ganjloo A, Zarringhalami S, Ansarian E. Ultrasound-assisted extraction of bioactive compounds from Malva sylvestris leaves and its comparison with agitated bed extraction technique. Food Sci Biotechnol. 2017 Nov 30;26(6):1481-1490. doi: 10.1007/s10068-017-0229-5. 

Abstract. The effects of ultrasound-assisted extraction (UAE) variables-namely extraction temperature (40-60 °C), ultrasonic power (50-150 W), and sonication time (40-60 min)-on the extractive value (EV) of bioactive phenolics from Malva sylvestris leaves were investigated and optimized using Response surface methodology. The effects of extraction solvents (ethanol, ethyl acetate, and n-hexane) on EV, free radical scavenging activity (FRSA), total phenolic content (TPC), and major bioactive phenolics were studied using agitated bed extraction (ABE), and the results were compared with the UAE findings. Under the optimal UAE conditions (48 °C, 110.00 W, and 48.77 min) the experimental EV was 279.89 ± 0.21 mg/g with 71.12 ± 0.15% DPPHsc, 73.35 ± 0.11% ABTSsc, and a TPC of 152.25 ± 0.14 mg GAE/g. Ethanolic ABE results in higher EV (320.16 ± 0.25 mg g-1) compared to UAE, while the FRSA and TPC values were reduced. HPLC analysis revealed that the concentration of bioactive phenolics increased significantly (p < 0.05) under the optimal UAE conditions.

Mahmoodi Esfanddarani H, Abbasi Kajani A, Bordbar AK. Green synthesis of silver nanoparticles using flower extract of Malva sylvestris and investigation of their antibacterial activity. IET Nanobiotechnol. 2018 Jun;12(4):412-416. doi: 10.1049/iet-nbt.2017.0166. 

Abstract. High-quality colloidal silver nanoparticles (AgNP) were synthesised via a green approach by using hydroalcoholic extracts of Malva sylvestris. Silver nitrate was used as a substrate ion while the plant extract successfully played the role of reducing and stabilising agents. The synthesised nanoparticles were carefully characterised by using transmission electron microscopy, atomic-force microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and UV-vis spectroscopy. The maximum absorption wavelengths of the colloidal solutions synthesised using 70 and 96% ethanol and 100% methanol, as extraction solvents, were 430, 485 and 504 nm, respectively. Interestingly, the size distribution of nanoparticles depended on the used solvent. The best particle size distribution belonged to the nanoparticles synthesised by 70% ethanol extract, which was 20-40 nm. The antibacterial activity of the synthesised nanoparticles was studied on Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes using disk diffusion, minimum inhibitory concentrations and minimum bactericidal concentrations assays. The best antibacterial activity obtained for the AgNPs produced by using 96% ethanolic extract.

Martins CAF, Campos ML, Irioda AC, Stremel DP, Trindade ACLB, Pontarolo R. Anti-Inflammatory Effect of Malva sylvestris, Sida cordifolia, and Pelargonium graveolens Is Related to Inhibition of Prostanoid Production. Molecules. 2017 Nov 3;22(11):1883. doi: 10.3390/molecules22111883. 

Abstract. The ability of plant extracts and preparations to reduce inflammation has been proven by different means in experimental models. Since inflammation enhances the release of specific mediators, inhibition of their production can be used to investigate the anti-inflammatory effect of plants widely used in folk medicine for this purpose. The study was performed for leaves and flowers of Malva sylvestris, and leaves of Sida cordifolia and Pelargonium graveolens. These are three plant species known in Brazil as Malva. The anti-inflammatory activity of extracts and fractions (hexane, chloroform, ethyl acetate, and residual) was evaluated by quantitation of prostaglandins (PG) PGE₂, PGD₂, PGF2α, and thromboxane B₂ (the stable nonenzymatic product of TXA₂) concentration in the supernatant of lipopolysaccharide (LPS)- induced RAW 264.7 cells. Inhibition of anti-inflammatory mediator release was observed for plants mainly in the crude extract, ethyl acetate fraction, and residual fraction. The results suggest superior activity of S. cordifolia, leading to significantly lower values of all mediators after treatment with its residual fraction, even at the lower concentration tested (10 μg/mL). M. sylvestris and P. graveolens showed similar results, such as the reduction of all mediators after treatment, with leaf crude extracts (50 μg/mL). These results suggest that the three species known as Malva have anti-inflammatory properties, S. cordifolia being the most potent.