Therapeutic potential of hypnotic herbal medicines: A comprehensive review.

Insomnia affects millions of people worldwide, prompting considerable interest in herbal remedies for its treatment. This review aims to assess the therapeutic potential of such remedies for insomnia by analyzing current scientific evidence. The analysis identified several herbs, including Rosmarinus officinalis, Crocus sativus, Rosa damascena, Curcuma longa, Valeriana officinalis, Lactuca sativa, Portulaca oleracea, Citrus aurantium, Lippia citriodora, and Melissa officinalis, which show promise in improving overall sleep time, reducing sleep latency, and enhancing sleep quality. These plants act on the central nervous system, particularly the serotonergic and gamma-aminobutyric acid (GABA)ergic systems, promoting sedation and relaxation. However, further research is necessary to fully understand their mechanisms of action, optimal dosages, and treatment protocols. Combining herbal medicines with conventional treatments may offer an effective natural alternative for those seeking medication. Nevertheless, individuals should consult their healthcare provider before using herbal remedies for insomnia. While this review provides evidence supporting their use, additional high-quality studies are needed to firmly establish their clinical efficacy.

The Valorisation of Melissa officinalis Distillation By-Products for the Production of Polyphenol-Rich Formulations.

Lemon balm (Melissa officinalis) is an aromatic and medicinal plant, rich in bioactive ingredients and with superior antioxidant activity. The essential oil of this plant is an expensive product, so the use of the by-products of the essential oil industry is particularly useful. The aim of this research was to process Melissa officinalis distillation by-products to develop a series of polyphenol-rich formulations. In the present research, lemon balm was distilled in a laboratory-scale distiller, and the recovered by-product was used for further successive extractions with acetone and water, using a fixed-bed semi-batch extractor. Acetone extract exhibited relatively poor results as far as yield, phenolic composition and antiradical activity are concerned. However, the aqueous extract presented high yield in both total phenolic content (i.e., 111 mg gallic acid equivalents (GAE)/g, on a dry herb basis (dw)), and anti-radical capacity (205 mg trolox equivalents (TE)/g dw). On a dried extract basis, the results were also impressive, with total phenols reaching 322 mg GAE/g dry extract and antiradical capacity at 593 mg TE/g dry extract. The phenolic components of the extract were identified and quantified by HPLC-DAD. Rosmarinic acid was the major component and amounted to 73.5 mg/g dry extract, while the total identified compounds were quantified at 165.9 mg/g dry extract. Finally, formulations with two different wall materials (gum arabic-maltodextrin and maltodextrin) and two different drying methods (spray-drying and freeze-drying) were applied and evaluated to assess their performance, yield, efficiency and shelf-life of total phenolic content and rosmarinic acid concentration. From the present investigation, it is concluded that after one year of storage, rosmarinic acid does not decrease significantly, while total phenolic content shows a similar decrease for all powders. According to the yield and efficiency of microencapsulation, maltodextrin alone was chosen as the wall material and freeze-drying as the preferred drying method.

Antitumor activity and phenolic profile of Melissa officinalis extract against human gastric adenocarcinoma cells.

Gastric cancer remains a global health concern, driving the exploration of natural products with anticancer potential. This study investigated the antiproliferative activity and chemical composition of a 70% ethanolic extract from Melissa officinalis L. against human gastric cancer cells. The extract was prepared and evaluated for total phenolic content, antioxidant capacity and flavonoid content. The MTT test checked how well it stopped the growth of human gastric adenocarcinoma (AGS) and normal dermal fibroblast (HDF) cells. Data analysis (SPSS Statistics) determined viable cell percentages and performed regression analysis (p<0.05). The extract exhibited significant antiproliferative activity against AGS cells compared to normal cells (p<0.05), with decreasing IC50 values (564.3, 258.0 and 122.5 µg/ml) over 24, 48 and 72 hours. It also displayed antioxidant activity (IC50=16.8±1.41µg/ml) and contained substantial phenolics (225.76±4.1 mg GAE/g) and flavonoids (22.36±2.6 mg RUT/g). This study suggests the 70% ethanolic extract of M. officinalis effectively suppresses AGS cell growth and possesses promising antioxidant properties, highlighting its potential as a natural source of anticancer and antioxidant agents, deserving further investigation.

Melissa officinalis essential oil as an antimicrobial agent against Listeria monocytogenes in watermelon juice.

The burden of foodborne illness has a negative effect on public health, but also in countries' economy. Melissa officinalis is an aromatic plant known for its biological properties, including antioxidant and antimicrobial effects. This work highlighted M. officinalis essential oil's antioxidant potential and antimicrobial activity against L. monocytogenes, presenting a bactericidal action and being able to inhibit some virulence attributes, such as biofilm formation. The pre-exposure of the bacterium to subinhibitory levels of essential oil (0.125 µL/mL) did not induce high tolerance to stresses (such as high temperature, low pH, osmotic stress and desiccation) or cross-resistance with antibiotics, while not modifying the invasion ability to Caco-2 cells. When applied in food model media (lettuce, chicken and milk) and watermelon juice, the essential oil showed to have antimicrobial activity in a lettuce leaf model medium, further diminishing L. monocytogenes contamination and inhibiting the natural microbiota present in watermelon juice. M. officinalis essential oil shows potential to be used as control of L. monocytogenes in watermelon juice, while increasing the food's microbial shelf life.

Antioxidant Activity and Photosynthesis Efficiency in Melissa officinalis Subjected to Heavy Metals Stress.

The aim of this study was to assess influence of cadmium and zinc treatments on antioxidant activity combined with the photosynthesis efficiency in a popular herb lemon balm (Melissa officinalis L.). Plants were grown under greenhouse conditions by the pot method. The Mn, Cu, Cd, and Zn contents in soil and plants were measured by HR-CS FAAS. The activity of net photosynthesis, stomatal conductance, transpiration rate, intercellular CO2, and index of chlorophyll in leaves were determined for all investigated species. Reduction of the net photosynthesis was observed for cultivations subjected to either Zn or Cd treatments. Phenolic contents were determined by the chemical Folin-Ciocalteu method, while enhanced voltammetric analysis was applied to assess the antioxidant properties of plant extracts. Both of these approaches yielded similar results. Herbal extracts had exceptional antioxidant capacities and were good scavengers of free radicals and reactive oxygen species. Structural similarity of cadmium and zinc facilitated their mutual structural exchange and prompted substantial expansion of phenolics under the mixed Zn and Cd treatments.

Melissa officinalis L. nanoethosomal formulation: evaluation of antioxidant, enzyme inhibitory activities and in vitro toxicity.

This work aimed to create an extract of Melissa officinalis L. with strong antiradical efficacy, characterize it, and enhance its long-term efficacy by developing an ethosomal formulation. DPPH and ABTS assays were used to test the antiradical activity of extracts with different ethanol ratios obtained from the aerial part. Phytochemical characterization of the extract with the highest activity, ethyl acetate fraction of 60% ethanol extract, was analyzed by HPLC. The active ethyl acetate fraction was loaded into ethosomes, and characterization and release studies of the formulation were performed. The released extract from the formulation exhibited substantial antiradical action as well as inhibition of collagenase (71.5%) and elastase (75.5%) enzymes. The toxicity of the active extract and the formulation was determined in the mouse fibroblast cell line. This study successfully developed a long-term antioxidant and enzyme inhibitor formulation containing M. officinalis, which stands out for its medicinal properties.

Harvest Stage and Brewing Conditions Impact Mineral Content, Phenolic Compounds, and Antioxidant Capacity of Lemon Balm (Melissa officinalis L.) Herbal Tea.

Lemon balm (Melissa officinalis L.) is commonly consumed as an herbal tea for its antioxidant health benefits. Young seedlings known as microgreens are popular for their distinct flavors and can contain higher mineral content on a dry weight basis compared to their adult counterparts. However, the use of microgreens for herbal teas has not been previously investigated. In this study, lemon balm was grown to adult and microgreen harvest stages and prepared as herbal teas by brewing with boiled (100 °C) water for 5 minutes and room temperature water (22 °C) for 2 hours. The effects of harvest time and brewing method on the mineral content, phenolic compounds, and antioxidant capacity of lemon balm herbal teas were assessed. Results showed that adult lemon balm tea contained higher total phenolics, total flavonoids, rosmarinic acid, and antioxidant capacity than microgreen teas, with hot preparations containing the highest amounts (p ≤ 0.05). In contrast, microgreen lemon balm teas contained higher amounts of minerals (p ≤ 0.05), including calcium, potassium, magnesium, sodium, phosphorus, copper, and zinc. In general, brewing conditions did not impact the content of most minerals. Overall, the results support the potential of using dried microgreens as herbal teas. Microgreen lemon balm teas prepared hot and cold offer antioxidant compounds and are richer sources of minerals than adult teas. The ease of growth for microgreens offers consumers the opportunity for home preparation of a novel herbal tea beverage.

Memory and cognition enhancing effects of combination of Melissa officinalis and Panax ginseng.

Melissa officinalis and Panax ginseng extracts were investigated to determine combinatorial effects on cognitive behaviors' of albino-rats. The study was prospective-experimental; lasted from June-2022 to March-2023. Learning and memory measurements were done by animal-models. Data analyzed by 22nd version of SPSS. In Passive-avoidance-test both doses of Melissa officinalis and Panax ginseng (100/100mg/kg and 200/200mg/kg) showed significant differences in number of acquisition-trial between groups (p<0.001); drug treated groups showed longer latency-period compared to control and scopolamine (p<0.001). In time-spent-in-dark-chamber treated groups spent less-time in dark-chamber as compared to control and scopolamine (p<0.001). In Morris-water-maze-task treatment groups (100/100mg/kg and 200/200mg/kg) showed significant (p<0.001) decrease in escape-latency compared with control and scopolamine. Spatial-memory-probe showed significant interaction between drugs and days (p<0.001); time-spent in platform region is significantly increased (p<0.001) in both treatment groups compared with control and scopolamine. 8-arm-radial-maze-test showed the significant increase (p<0.05) in total number of correct responses in treatment groups (100/100mg/kg and 200/200mg/kg) compared to control and scopolamine. In-vitro studies revealed acetyl-choline-esterase inhibition by 36.40% from Melissa officinalis and Panax ginseng combination. Study concluded that combination of M. officinalis and P. ginseng extracts may significantly improve the effects on memory and cognition.

Molecular barcoding of Melissa officinalis L. (badranjboye) in Iran and identification of adulteration in its medicinal services.

Medicinal plants are an important source for treatment of diseases in many countries. Today, controlling the quality of the products of medicinal plants is an important task. Customer health may be in danger due to the fraud and misconduct by the sales associates in the sales centers. Melissa officinalis L. (Lamiaceae) is an important medicinal plant used for treatment of several diseases. In Iran, the species of Dracocephalum, Hymencrater, Nepeta and Stachys are mistakenly sold under the name of Badranjboye that have different pharmaceutical properties. For avoiding this mistake, this investigation was performed with the following aims: 1) Checking for the cheating and identifying the Badranjboye in the Iran's market of medicinal plants, 2) Providing the molecular barcode for the medicinal species of Melissa. For this purpose, Market-sold plant samples (leaves) and original reference plant species were compared by morphology, odor as well as Internal transcribed spacer (ITS) and chloroplast DNA ((psbA-trnH) and (trnL-trnF)) sequences. Various molecular analyses, such as sequencing, determination of genetic distance, and construction of phylogenetic tree were performed. These reports have shown that internal transcribed spacer (ITS) and chloroplast DNA (psbA-trnH) sequences are an efficient molecular marker to produce barcode gap and differentiating Melissa officinalis from other species.

Synergistic effects of Nepeta menthoides and Melissa officinalis aqueous extracts on reserpine-induced depressive-like behaviors in mice.

Nepeta menthoides Boiss. & Buhse and Melissa officinalis are extensively used in Persian medicine for the treatment of depression. Considering the active ingredients and main phenolic compounds of these plants and possible synergistic effects, this study examined the antidepressant and antioxidant activities of aqueous extract of N. menthoides (NM) and M. officinalis (MO) in reserpinized mice alone and combination. Mice were pretreated orally for 1-week with normal saline (10 ml/kg), fluoxetine (20 mg/kg), imipramine (10 mg/kg), NM (50-100-200-400 mg/kg), MO (150-350-550-750 mg/kg), and combination (NM 50 with MO 150 mg/kg). The behavioral changes were evaluated using forced swim, tail suspension, and open field tests, 24 hr after reserpine injection (4 mg/kg) on eighth day. The amounts of active components in the extracts and catalase (CAT) as a brain oxidative stress were measured with enzyme-linked immunosorbent assay. Data showed that this combination produced a synergistic action on behaviors and a significant increase in CAT activity. High-performance liquid chromatography results showed that rosmarinic acid contents in MO and NM were 6.42 ± 1.1 and 11.03 ± 2.16 mg/g of dried extract, respectively. Total flavonoid and phenolic contents of MO were higher than NM. The findings suggest that the present combination produces an antidepressant-like effect, which is possibly triggered by its antioxidant properties.

Melissa officinalis: Composition, Pharmacological Effects and Derived Release Systems-A Review.

Melissa officinalis is a medicinal plant rich in biologically active compounds which is used worldwide for its therapeutic effects. Chemical studies on its composition have shown that it contains mainly flavonoids, terpenoids, phenolic acids, tannins, and essential oil. The main active constituents of Melissa officinalis are volatile compounds (geranial, neral, citronellal and geraniol), triterpenes (ursolic acid and oleanolic acid), phenolic acids (rosmarinic acid, caffeic acid and chlorogenic acid), and flavonoids (quercetin, rhamnocitrin, and luteolin). According to the biological studies, the essential oil and extracts of Melissa officinalis have active compounds that determine many pharmacological effects with potential medical uses. A new field of research has led to the development of controlled release systems with active substances from plants. Therefore, the essential oil or extract of Melissa officinalis has become a major target to be incorporated into various controlled release systems which allow a sustained delivery.

Change in Secondary Metabolites and Expression Pattern of Key Rosmarinic Acid Related Genes in Iranian Lemon Balm (Melissa officinalis L.) Ecotypes Using Methyl Jasmonate Treatments.

The medicinal herb, lemon balm (Melissa officinalis L.), which is high in rosmarinic acid (RA), has well-known therapeutic value. The goals of this study were to investigate the effects of methyl jasmonate (MeJA) on RA content, total phenolic content (TPC), and total flavonoid content (TFC), as well as changes in expression of their biosynthesis-related key genes (MoPAL, Mo4CL, and MoRAS) in Iranian lemon balm ecotypes, as first reported. Our results revealed that MeJA doses significantly increase the RA content, TPC, and TFC in both ecotypes compared with the control samples. Additionally, the higher expression levels of MoPAL, Mo4CL, and MoRAS following treatment were linked to RA accumulation in all treatments for both Iranian lemon balm ecotypes. After 24 h of exposure to 150 µM MeJA concentration, HPLC analysis showed that MeJA significantly increased RA content in Esfahan and Ilam ecotypes, which was about 4.18- and 7.43-fold higher than untreated plants. Our findings suggested that MeJA has a considerable influence on RA, TPC, and TFC accumulation in MeJA-treated Iranian M. officinalis, which might be the result of gene activation from the phenylpropanoid pathway. As a result of our findings, we now have a better understanding of the molecular processes behind RA production in lemon balm plants.

Quantitative Proteome Analysis Reveals Melissa officinalis Extract Targets Mitochondrial Respiration in Colon Cancer Cells.

Melissa officinalis (MO), known as lemon balm, is a popular ingredient blended in herbal tea. In recent decades, the bioactivities of MO have been studied in sub-health and pathological status, highlighting MO possesses multiple pharmacological effects. We previously showed that hot water MO extract exhibited anticancer activity in colorectal cancer (CRC). However, the detailed mechanisms underlying MO-induced cell death remain elusive. To elucidate the anticancer regulation of MO extract in colon cancer, a data-driven analysis by proteomics approaches and bioinformatics analysis was applied. An isobaric tandem mass tags-based quantitative proteome analysis using liquid chromatography-coupled tandem mass spectrometry was performed to acquire proteome-wide expression data. The over-representation analysis and functional class scoring method were implemented to interpret the MO-induced biological regulations. In total, 3465 quantifiable proteoforms were identified from 24,348 peptides, with 67 upregulated and 54 downregulated proteins in the MO-treated group. Mechanistically, MO impeded mitochondrial respiratory electron transport by triggering a reactive oxygen species (ROS)-mediated oxidative stress response. MO hindered the mitochondrial membrane potential by reducing the protein expression in the electron transport chain, specifically the complex I and II, which could be restored by ROS scavenger. The findings comprehensively elucidate how MO hot water extract activates antitumor effects in colorectal cancer (CRC) cells.

The Impact of Soil pH on Heavy Metals Uptake and Photosynthesis Efficiency in Melissa officinalis, Taraxacum officinalis, Ocimum basilicum.

Herbs used in medicine should be grown under controlled and standardized conditions. Agricultural practices often induce changes to soil pH, which may affect migration of heavy metals in the environment, their accumulation in plant tissues and the concentration of medicinal ingredients. The aim of this work was to assess the influence of various soil pH on the biological parameters and uptake of manganese, copper and zinc by basil, dandelion and lemon balm. The soil analysis covered pH, organic matter content, bioavailable and total forms of investigated metals in soil. In plants cultivated in soil at pH covering the range 4.7-8.5 the concentrations of Mn, Cu and Zn were analyzed. Their mobility and availability were assessed by bioaccumulation factors, translocation factors and transfer coefficients. The seed germination and subsequent herbs growth were strongly dependent on soil pH for all investigated plant species. Photosynthetic efficiency at different pHs was positively correlated with uptake of Cu and Mn while Zn behaved in a more random way.

Different Types of Meatballs Enriched with Wild Thyme/Lemon Balm Aqueous Extract-Complex Characterization.

In the context of the increasing lactation problems among breastfeeding women, the development of a healthy lifestyle is needed. Different variants of pork, turkey, and beef meatballs, with added lemon balm (Melissa officinalis L.) and wild thyme (Thymus serpyllum L.) aqueous extract (6%), were obtained. These herbs were selected and used due to their antioxidant, antimicrobial, and lactogenic potential. Two thermal treatments, hot air convection (180 °C) and steam convection (94 °C), were applied for meatballs processing. The obtained meatballs were further subjected to a complex characterization. The functionality of the plant extracts was proved by the values of total content of polyphenols (2.69 ± 0.02 mg AG/g dw) and flavonoids (3.03 ± 0.24 mg EQ/g dw). FT-IR analysis confirmed the presence of trans-anethole and estragole at 1507-1508 cm-1 and 1635-1638 cm-1, respectively. Costumers' overall acceptance had a score above 5.5 for all samples, on a scale of 1 to 9. Further analysis and human trials should be considered regarding the use of lactogenic herbs, given their health benefits and availability.

Effect of graphene / metal nanocomposites on the key genes involved in rosmarinic acid biosynthesis pathway and its accumulation in Melissa officinalis.

BACKGROUND: Recently, numerous investigations have been done to study graphene and silver nanoparticle in the fields of agriculture and medicine. In the present study, the green synthesis of nanoparticles with two concentrations (0, 40, 60 mM) and their effect on the molecular and biochemical biosynthesis pathway of rosmarinic acid in a new method, low cost, and safe for the environment has been investigated. The transcript levels of key genes in the rosmarinic acid biosynthesis pathway (Tyrosine aminotransferase, rosmarinic acid synthase, and phenylalanine-ammonia lyase) were studied using real-time quantitative polymerase chain reaction. Then, the rosmarinic acid content was evaluated using HPLC. RESULTS: The results showed that a concentration-dependent manner was observed in treated plants. At the biochemical level, the use of nanocomposites at concentration of 40 mM showed higher soluble carbohydrate (37%), flavonoids (21%), total phenol (35%) as well as total protein (47%) compared to the control plants. HPLC results showed that rosmarinic acid content in the treated plants with a low concentration of nanocomposite (40 mM) was more affected than plants treated with a high concentration of nanocomposite (60 mM) (26%) and also compared to other treatments. At the molecular level, the result showed that Tyrosine aminotransferase and rosmarinic acid synthase gene expression was positively correlated with both silver nanoparticle concentrations and nanocomposite treatments, but phenylalanine-ammonia lyase gene expression was positively correlated only with nanocomposite at 40 mM concentration. CONCLUDE: It can conclude that the nanocomposite at low concentration is more likely to induce molecular and biochemical parameters. And also, in the rosmarinic acid biosynthesis pathway, the Tyrosine aminotransferase -derived pathway is more efficient than the phenylalanine-ammonia lyase -derived pathway by causing a nano-elicitor. Therefore, it was concluded that studied elicitor at low concentration, can create plants with higher production capacity.

Melissa officinalis tea favourably affects the frequency of premature ventricular beats and cardiometabolic profile among patients with premature ventricular contraction: A randomised open-label controlled trial.

BACKGROUND AND AIMS: Premature ventricular contraction (PVC) as one of the most common arrhythmias could worsen the morbidity of cardiovascular events, particularly concurrent with other risk factors. Considering the probable side effects of antiarrhythmic drugs chronic use, prescribing herbal medicines for such conditions is on the rise. Melissa officinalis (MO) is widely identified as an antiarrhythmic and cardioprotective agent but there is limited evidence for its clinical use. This research, thus, aimed to investigate the effects of MO tea among patients with PVCs. METHODS: The present 12-week randomised controlled trial enrolled 60 patients with confirmed diagnosis of moderate to low-grade PVCs. The patients in intervention group received MO teabags (containing 2-g dried leaves/250 mL in hot water) two times/day in addition to lifestyle modification recommendations, while control group only received lifestyle modification recommendations. After collecting the data, blood samples were gathered to explore serum concentrations of glucose and lipid markers. The number of premature ventricular beats and heart rates was determined by 24-hour rhythm Holter monitoring. RESULTS: On average, the patients aged 47 years and approximately 67.8% (n = 40) were women. The ANCOVA adjusted for baseline values and confounders revealed that patients in the MO tea group had significantly lower concentrations of triglyceride (adjusted mean (AM) = 144.75 mg/dL), total cholesterol (AM = 155.35 mg/dL), and fasting blood sugar (AM = 90.85 mg/dL), compared with the controls (AM = 174.27, 171.99, 99.84 mg/dL, respectively (P-value ≤.042). However, the intervention failed to affect LDL-C and HDL-C levels significantly. Significantly reduced frequency of 24-hour premature ventricular beats in the MO tea group (AM = 2142.39) was also noted compared with the controls (AM = 3126.05); (P-value = .017). The 24-hour heartbeats showed only a significant decrease within the intervention group (P-value < .01). CONCLUSION: Together, these results seem to support the higher cardioprotective effects of MO as a medicinal plant than lifestyle modifications alone. Nevertheless, further exploration of this hypothesis is warranted using large-scaled clinical trials.

Effect of Melissa officinalis on systolic and diastolic blood pressures in essential hypertension: A double-blind crossover clinical trial.

For a long time, Melissa officinalis (M. officinalis) has been used to treat cardiovascular diseases. Therefore, this study aimed at evaluating the effects of M. officinalis on systolic and diastolic blood pressures in hypertensive patients. We conducted a double-blind, controlled, randomized crossover clinical trial on 49 patients who received either M. officinalis capsules (400 mg/d; n = 23) or the placebo (n = 26) three times per day for a 4-week period. After a 2-week washout period, the M. officinalis group received placebo and the other group received M. officinalis for another 4-week period. The systolic and diastolic blood pressures were measured once at baseline and then every 2 weeks for 10 weeks. The statistical analysis of the obtained data revealed that the chronology of the consumption of M. officinalis and placebo had no effect on the systolic and diastolic blood pressures in these two studied groups. Moreover, it was found that systolic and diastolic blood pressures significantly decreased after the consumption of M. officinalis, compared to placebo. Systolic and diastolic blood pressures in group A at the beginning of the study were 152.30 ± 5.312 mmHg and 95.52 ± 1.988 mmHg, respectively, and, after the first phase (drug use), reached 129.88 ± 9.009 mmHg and 80.13 ± 5.488 mmHg, respectively. Systolic and diastolic blood pressures in group B at the beginning of the study was 152.26 ± 5.640 mmHg and 94.44 ± 2.607 mmHg, respectively, and after the second phase (drug use), reached 131.77 ± 8.091 mmHg and 81.46 ± 7.426 mmHg, (p = .005), respectively. Also, no significant side effects were observed during the study. According to the results, M. officinalis can reduce systolic and diastolic blood pressures of the patients with essential hypertension.

The effects of lemon balm (Melissa officinalis L.) on depression and anxiety in clinical trials: A systematic review and meta-analysis.

A systematic review and a meta-analytic approach were considered to investigate the effects of lemon balm as a medicinal herb on anxiety and depression in clinical trials and its side effects. All randomized clinical trials published up to October 30, 2020 that examined lemon balm in patients with symptoms of depression or anxiety, with acute or chronic manifestations, were searched in 12 online databases. Statistical analysis was performed using RevMan software. Continuous data were analyzed using standardized mean differences. Statistical heterogeneity was assessed using Chi2 , I2 , and p value tests. Based on meta-analysis results, lemon balm significantly improved mean anxiety and depression scores compared with the placebo (SMD: -0.98; 95% CI: -1.63 to -0.33; p = 0.003), (SMD: -0.47; 95% CI: -0.73 to -0.21; p = 0.0005) respectively, without serious side effects. Current evidence suggests that lemon balm may be effective in improving anxiety and depressive symptoms, particularly in the acute setting. Due to the high level of heterogeneity between studies, results should be interpreted with caution. The small number of clinical trials and differences between their methods were the limitations of the present study. Further high-quality studies are needed to firmly establish the clinical efficacy of the lemon balm.

NaCl-Induced Elicitation Alters Physiology and Increases Accumulation of Phenolic Compounds in Melissa officinalis L.

In nature, plants usually produce secondary metabolites as a defense mechanism against environmental stresses. Different stresses determine the chemical diversity of plant-specialized metabolism products. In this study, we applied an abiotic elicitor, i.e., NaCl, to enhance the biosynthesis and accumulation of phenolic secondary metabolites in Melissa officinalis L. Plants were subjected to salt stress treatment by application of NaCl solutions (0, 50, or 100 mM) to the pots. Generally, the NaCl treatments were found to inhibit the growth of plants, simultaneously enhancing the accumulation of phenolic compounds (total phenolics, soluble flavonols, anthocyanins, phenolic acids), especially at 100 mM NaCl. However, the salt stress did not disturb the accumulation of photosynthetic pigments and proper functioning of the PS II photosystem. Therefore, the proposed method of elicitation represents a convenient alternative to cell suspension or hydroponic techniques as it is easier and cheaper with simple application in lemon balm pot cultivation. The improvement of lemon balm quality by NaCl elicitation can potentially increase the level of health-promoting phytochemicals and the bioactivity of low-processed herbal products.