Sauropus androgynus L. Merr.-A phytochemical, pharmacological and toxicological review

Exploring unconventional food plants used by local communities in a rural area of West Java, Indonesia: ethnobotanical assessment, use trends, and potential for improved nutrition

BACKGROUND

As one of the world's biodiversity hotspots, Indonesia contains over 25,000 plant species, including unconventional food plants (UFPs). These plants are integral to the dietary practices of rural communities, providing essential nutrients often overlooked in modern diets. However, the use of UFP is declining, with both their dietary and cultural values being undermined. In rural West Java, this decline in UFP biodiversity coincides with public health challenges related to malnutrition. This study aims to document the diversity of UFPs used by local communities in rural West Java, assess their nutritional value, and explore their consumption practices.

METHODS

Data were collected using mixed methods, including interviews with 20 key informants and food frequency questionnaire administered to 107 women in three villages in the area. The nutritional compositions of documented UFPs were obtained from literature and analysis. Bivariate correlation was used to analyze the relationships between UFP consumption frequency and potential correlates.

RESULTS

The study documented 52 species of UFPs from 29 families, many of which are rich in nutritional value. About half of respondents (56%) consumed UFPs moderately (2-3 times a week). UFP consumption frequency had a strong correlation (r = 0.70) with associated knowledge (r = 0.70, p < 0.01) and a weak correlation with age (r = 0.240, p = 0.015), livestock possession (r = 0.260, p = 0.008), and family size (r = - 0.220, p = 0.02). Motivations for UFP consumption included availability as free food (33%), medicinal value (26%), nostalgic value (23%), and preferred taste (18%). Most respondents (92%) agreed that consumption has declined compared to the past, with perceived reduced availability and lack of knowledge cited as the primary reasons for the declining trend.

CONCLUSIONS

UFP use is common in the study area, where local communities value these plants for their critical roles in diet, medicine, and culture. Given their significant potential to meet dietary needs, educating and raising awareness about UFPs can enhance their consumption and contribute to food and nutrition security.

Drugs targeting structural and nonstructural proteins of the chikungunya virus: A review

Chikungunya virus (CHIKV) is a single positive-stranded RNA virus of the Togaviridae family and Alphavirus genus, with a typical lipid bilayer envelope structure, and is the causative agent of human chikungunya fever (CHIKF). The U.S. Food and Drug Administration has recently approved the first chikungunya vaccine, Ixchiq; however, vaccination rates are low, and CHIKF is prevalent owing to its periodic outbreaks. Thus, developing effective anti-CHIKV drugs in clinical settings is imperative. Viral proteins encoded by the CHIKV genome play vital roles in all stages of infection, and developing therapeutic agents that target these CHIKV proteins is an effective strategy to improve CHIKF treatment efficacy and reduce mortality rates. Therefore, in the present review article, we aimed to investigate the basic structure, function, and replication cycle of CHIKV and comprehensively outline the current status and future advancements in anti-CHIKV drug development, specifically targeting nonstructural (ns) proteins, including nsP1, nsP2, nsP3, and nsP4 and structural proteins such as capsid (C), E3, E2, 6K, and E1.

Polyploid Genome Assembly Provides Insights into Morphological Development and Ascorbic Acid Accumulation of Sauropus androgynus

Sauropus androgynus (S. androgynus) (2n = 4x = 52) is one of the most popular functional leafy vegetables in South and Southeast Asia. With its rich nutritional and pharmaceutical values, it has traditionally had widespread use for dietary and herbal purposes. Here, the genome of S. androgynus was sequenced and assembled, revealing a genome size of 1.55 Gb with 26 pseudo-chromosomes. Phylogenetic analysis traced back the divergence of Sauropus from Phyllanthus to approximately 29.67 million years ago (Mya). Genome analysis revealed that S. androgynus polyploidized around 20.51 Mya and shared a γ event about 132.95 Mya. Gene function analysis suggested that the expansion of pathways related to phloem development, lignin biosynthesis, and photosynthesis tended to result in the morphological differences among species within the Phyllanthaceae family, characterized by varying ploidy levels. The high accumulation of ascorbic acid in S. androgynus was attributed to the high expression of genes associated with the L-galactose pathway and recycling pathway. Moreover, the expanded gene families of S. androgynus exhibited multiple biochemical pathways associated with its comprehensive pharmacological activity, geographic adaptation and distinctive pleasurable flavor. Altogether, our findings represent a crucial genomic asset for S. androgynus, casting light on the intricate ploidy within the Phyllanthaceae family.

Alkaline humic acid fertilizer alters the distribution, availability, and translocation of cadmium and zinc in the acidic soil-Sauropus androgynus system

Humic acids (HA) are a popular soil additive to reduce metal availability, but they have the drawbacks of reduced effectiveness over time and a significant reduction in soil pH. An alkaline humic acid fertilizer (AHAF) combining alkaline additives with HA was developed to overcome such drawbacks. A field experiment was conducted to investigate the effects of different AHAF application rates on the physicochemical properties, bioavailability, accumulation, and translocation of Cd and Zn heavy metals in Sauropus androgynus grown in acidic soil. Based on our results, the 100AF (100% AHAF) treatment significantly increased soil pH, cation exchange capacity (CEC), and organic matter content (OM) after one year of application. Compared with the control treatment (CK), the application of different rates of AHAF resulted in a 37.1-40.3% decrease in soil exchangeable Cd fractions (Exc-Cd) and an increase in the humic acid-bound Cd fractions (HA-Cd) Fe- and Mn-oxide-bound Cd fractions (OX-Cd), and organic matter-bound Cd fractions (OM-Cd) by 9.5-64.6%, 24.8-45.1%, and 158.8-191.2%, respectively (P < 0.05). The different AHAF treatments decreased the Res-Zn, Exc-Zn, and OM-Zn fractions by 69.6-73.0%, 7.4-23.9%, and 18.1-23.2%, respectively (P < 0.05), and increased the HA-Zn fraction by 8.4-28.1%. In the control treatment, the bioconcentration factors (BCFs) for Cd and Zn in different S. androgynus plant organs were in the following order: (Cd) Leaves > Stems > Branches > Roots > Edible branches; (Zn) Roots > Stems > Leaves > Branches > Edible branches. The transfer factors (TFs) of Cd and Zn in S. androgynus were classified as follows: TF2 > TF1 > TF3 > TF4. Thus, S. androgynus stems, and roots had a strong ability to transport Cd and Zn to the leaves. Compared with CK, the 100AF treatment significantly increased the BCFs for Zn in all plant parts (except BCFedible branches). In contrast, it significantly decreased all BCFs and TFs for Cd and the TF4 for Zn, effectively reducing Cd and Zn accumulation in the edible branches of S. androgynus. Soil pH, CEC, OM, and HA-M fraction were highly and significantly negatively correlated with Cd and Zn content in edible branches (P < 0.001). Stepwise multiple linear regression analysis revealed that the soil HA-M fraction was the key contributing factor for Zn accumulation and translocation in S. androgynus. Moreover, based on our findings, the absorption, uptake, and translocation of Cd and Zn were mainly determined by metal speciation and the pH in the soil. Moreover, the competitive antagonistic mechanisms between Zn and Cd absorption also affected their accumulation in S. androgynus. Thus, AHAF can be used as a soil amendment to sustainably improve acidic soils and effectively reduce Cd and Zn accumulation in edible branches of S. androgynus.

Ethyl palmitate, an anti-chikungunya virus principle from Sauropus androgynus, a medicinal plant used to alleviate fever in ethnomedicine

ETHNOPHARMACOLOGICAL RELEVANCE

Sauropus androgynus is a medicinal shrub used for the treatment of fever in ethnomedical traditions in various Southeast Asian countries.

AIM OF THE STUDY

This study was aimed to identify antiviral principles from S. androgynus against Chikungunya virus (CHIKV), a major mosquito-borne pathogen that re-emerged in the last decade, and to unravel their mechanism of action.

MATERIALS AND METHODS

Hydroalcoholic extract of S. androgynus leaves was screened for anti-CHIKV activity using cytopathic effect (CPE) reduction assay. The extract was subjected to activity guided isolation and the resultant pure molecule was characterized by GC-MS, Co-GC and Co-HPTLC. The isolated molecule was further evaluated for its effect by plaque reduction assay, Western blot and immunofluorescence assays. In silico docking with CHIKV envelope proteins and molecular dynamics simulation (MD) analyses were used to elucidate its possible mechanism of action.

RESULTS

S. androgynus hydroalcoholic extract showed promising anti-CHIKV activity and its active component, obtained by activity guided isolation, was identified as ethyl palmitate (EP), a fatty acid ester. At 1 μg/mL, EP led to 100% inhibition of CPE and a significant 3 log₁₀ reduction in CHIKV replication in Vero cells at 48 h post-infection. EP was highly potent with an EC₅₀ of 0.0019 μg/mL (0.0068 μM) and a very high selectivity index. EP treatment significantly reduced viral protein expression, and time of addition studies revealed that it acts at the stage of viral entry. A strong binding to the viral envelope protein E1 homotrimer during entry, thus preventing viral fusion, was identified as a possible mechanism by which EP imparts its antiviral effect.

CONCLUSIONS

S. androgynus contains EP as a potent antiviral principle against CHIKV. This justifies the use of the plant against febrile infections, possibly caused by viruses, in various ethnomedical systems. Our results also prompt more studies on fatty acids and their derivatives against viral diseases.

Effect of Sauropus androgynus L. Merr. on dengue virus-2: An in vitro and in silico study

ETHNOPHARMACOLOGICAL RELEVANCE

Sauropus androgynus L. Merr. (Euphorbiaceae) commonly known as "multigreen" and "multivitamin" is consumed as a vegetable and used in traditional medicine to relieve fever.

AIM OF THE STUDY

This in vitro study is aimed to explore the activities of the lipophilic fraction of the leaves of S. androgynus (LFSA) against dengue (DENV), chikungunya (CHIKV) viruses and malaria (P. falciparum strain 3D7) parasite.

MATERIALS AND METHODS

The LFSA was analyzed by using GC-FID and GC-MS. The antiviral activity of LFSA was studied using the Vero CCL-81 cell line. The cytotoxicity assay was performed using 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). Focus forming unit (FFU), cell-based immunofluorescence (IFA) assays, and quantitative RT-PCR, were used to determine and confirm antiviral activity against DENV and CHIKV. The antiparasitic activity of LFSA was carried out against P. falciparum strain 3D7 grown in fresh O+ human erythrocytes culture.

RESULTS

Twelve compounds were identified in LFSA using GC/MS. The most abundant compound was squalene (36.9%), followed by vitamin E (12.5%) and linolenic acid (10.2%). Significant reduction in DENV titre was observed under pre- and post-infection treatment conditions at a concentration of 31.25 μg/ml, but no anti-malarial and anti-CHIKV activity was observed. The Autodock-Vina-based in-silico docking study revealed that β-sitosterol could form a strong interaction with the DENV E glycoprotein.

CONCLUSION

Our findings suggest that LFSA can inhibit DENV infection and might act as a potent prophylactic/therapeutic agent against DENV-2. In-silico results suggested that β-sitosterol may block the viral entry by inhibiting the fusion process.

Anti-Dengue Activity of Lipophilic Fraction of Ocimum basilicum L. Stem

Ocimum basilicum L. is used to cure many types of fever in traditional medicine. This study aims to explore the antiviral activity of the lipophilic fraction of the stem of O. basilicum (LFOB) against dengue virus (DENV) and chikungunya virus (CHIKV). The LFOB was analyzed using GC-FID and GC-MS. The antiviral activity of LFOB was studied using the Vero CCL-81 cell line. The cytotoxicity assay was performed using 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). In vitro antiviral activity and FFU assay were used to determine and confirm antiviral activity against DENV and CHIKV. Twenty-six compounds were identified in LFOB using GC/MS. The most abundant compounds were β-sitosterol (22.9%), stigmasterol (18.7%), and campesterol (12.9%). Significant reduction in DENV titre was observed under pre- and post-infection treatment conditions at a concentration of 3.125 µg/mL, but no anti-CHIKV activity was observed. Our earlier and the present AutoDock-Vina-based in silico docking study revealed that β-sitosterol and stigmasterol could form strong interactions with the DENV E glycoprotein and DENV RdRp domain, respectively. Our findings suggest that LFOB can inhibit DENV infection and might act as a potent prophylactic/therapeutic agent against DENV-2. In silico results suggested that β-sitosterol and stigmasterol may block the viral entry by inhibiting the fusion process and viral replication respectively.

Exploring the Phytochemical Profiles and Antioxidant, Antidiabetic, and Antihemolytic Properties of Sauropus androgynus Dried Leaf Extracts for Ruminant Health and Production

Sauropus androgynus has become an essential plant in pharmaceutical formulations due to its beneficial antioxidant phytochemical components, participating in the antioxidant defense system and playing an important role in protecting human health. However, no research has been conducted on ruminant animals. This study aimed to evaluate the phytochemical profiles and biological potential of S. androgynus leaf extracts for ruminant health. Methanolic and hexanoic extracts from each commercially and noncommercially cultivated site were prepared over the course of five consecutive months. By means of HPLC-DAD, vitamins (ascorbic acid), essential oils (eugenol), tannins (gallic acid), cinnamic acids (caffeic acid, syringic acid, p-coumaric acid, sinapic acid and ferulic acid), and flavonoids (catechin, rutin, myricetin, quercetin, apigenin, and kaempferol) were detected. Variations in phytochemical composition were depending on solvent type but not on cultivation site or sample period. Methanolic extracts contained more phytochemicals than hexanoic extracts. Ascorbic acid and rutin were discovered to be the two most abundant phytochemicals in the methanolic extract of S. androgynus leaf, followed by essential oils, cinnamic acids, and tannins. In comparison to hexanoic extract, methanolic extract of S. androgynus demonstrated to be more efficient against oxidation scavenging: 1,1-diphenyl-2-picrylhydrazyl (IC₅₀ = 13.14 ± 0.055 (mg/mL)), nitric oxide (IC₅₀ = 55.02 ± 1.338 (mg/mL)) and superoxide (IC₅₀ = 25.31 ± 0.886 (mg/mL)), as well as α-glucosidase inhibitory activity (IC₅₀ = 9.83 ± 0.032 (mg/mL)). Similarly, methanolic was found to be more protective than hexanoic against oxidative damage in ruminant erythrocytes, with IC₅₀ values (mg/mL) for hemoglobin oxidation, lipid peroxidation, and hemolysis of 11.96 ± 0.011, 13.54 ± 0.012, and 5.940 ± 0.005, respectively. These findings suggested that the leaves of S. androgynus are a prospective source of phytochemical substances with health-promoting qualities for ruminant production.

Cultivation and conservation of underutilized medicinal and agricultural plants in India

In the current era, the increased demand of healthy food rich in antioxidants, vitamins and minerals and those having therapeutic value has led to over-exploitation of major agricultural and medicinal plants. This overburden can be reduced by an efficient utilization of underutilized plants with nutritional and medicinal importance. These underutilized plants are neglected or undervalued ‘minor’ crops having low production and sale. These less documented and less studied group of underutilized plants are considered as a rich source of various phytochemicals and secondary metabolites having bioactive compounds. These underutilized wild herbs that have not gained much attention from commercial as well as scientific community were selected for the present study. The present review elucidates the significance of these plants and recent biotechnological methods to conserve them. The present study on such food and medically important herbs would contribute in a wide recognition of their benefits for our society.

Sauropus androgynus (L.) Merr.: a multipurpose plant with multiple uses in traditional ethnic culinary and ethnomedicinal preparations

Various plants form the basis of multiple traditional ethnic cuisines and ethnomedicinal practices across the globe. The ethnic cuisines cater to the nutritional, dietary and medicinal requirements of the tribal and rural communities even today. Using literature from various scholarly databases, this study was conducted to consolidate a comprehensive review on the use of Sauropus androgynus (L.) Merr. in various traditional ethnic cuisines and ethnomedicinal preparations across the globe. The survey shows that it is used in multiple ethnic cuisines and is variously known in different countries and among the communities. Further, it possesses multiple nutritional and ethnomedicinal properties. Considering its importance in ethnic foods and ethnomedicinal preparations, it is important to investigate the nutritional composition, phytochemical constitution and pharmacological basis of ethnomedicinal uses. Therefore, we further compiled this information and found that it is a rich source of both micro- and macronutrients and packed with several bioactive compounds. Survey of pharmacological studies on its traditional medicinal uses supports its ethnomedicinal properties. Despite its importance in traditional food and ethnomedicinal systems, it remains underexplored. Limited information on the toxicity of its various extracts shows that further studies should be conducted to understand its safety aspects. Further clinical studies to prospect possible drug candidates from it should be attempted.

Sauropus brevipes ethanol extract negatively regulates inflammatory responses in vivo and in vitro by targeting Src, Syk and IRAK1

CONTEXT

Sauropus brevipes Müll. Arg. (Phyllanthaceae) has been used as an effective ingredient in a decoction for the treatment of diarrhoea. However, there was no report on its modulatory role in inflammation.

OBJECTIVE

This study investigates anti-inflammatory effect of S. brevipes in various inflammation models.

MATERIALS AND METHODS

The aerial part of S. brevipes was extracted with 95% ethanol to produce Sb-EE. RAW264.7 cells pre-treated with Sb-EE were stimulated by lipopolysaccharide (LPS), and Griess assay and PCR were performed. High-performance liquid chromatography (HPLC) analysis, luciferase assay, Western blotting and kinase assay were employed. C57BL/6 mice (10 mice/group) were orally administered with Sb-EE (200 mg/kg) once a day for five days, and peritonitis was induced by an intraperitoneal injection of LPS (10 mg/kg). ICR mice (four mice/group) were orally administered with Sb-EE (20 or 200 mg/kg) or ranitidine (positive control) twice a day for two days, and EtOH/HCl was orally injected to induce gastritis.

RESULTS

Sb-EE suppressed nitric oxide (NO) release (IC₅₀=34 µg/mL) without cytotoxicity and contained flavonoids (quercetin, luteolin and kaempferol). Sb-EE (200 µg/mL) reduced the mRNA expression of inducible NO synthase (iNOS). Sb-EE blocked the activities of Syk and Src, while inhibiting interleukin-1 receptor associated kinases (IRAK1) by 68%. Similarly, orally administered Sb-EE (200 mg/kg) suppressed NO production by 78% and phosphorylation of Src and Syk in peritonitis mice. Sb-EE also decreased inflammatory lesions in gastritis mice.

DISCUSSION AND CONCLUSIONS

This study demonstrates the inhibitory effect of Sb-EE on the inflammatory response, suggesting that Sb-EE can be developed as a potential anti-inflammatory agent.

Clinical Study on Plant Galactagogue Worldwide in Promoting Women's Lactation: a Scoping Review

Human milk is recommended by the World Health Organization (WHO) for the general well-being of infants. However, many mothers face an insufficient milk supply to breastfeed their children. Galactagogue, in particular, plant galactagogue, serves as a method to promote lactation. This in-depth review examines the evidence supporting different plants' galactagogic activity through clinical studies around the globe. A scoping review approach was adopted to establish the research questions, and define the findings, selection and analysis of the study. This scoping review highlights and compiles the clinical research performed globally involving plant galactagogue to better inform the medical practitioners, lactation consultants, nursing mothers, communities and relevant personnel on practicing, guidelines, policymaking and research. In general, a total of 1041 research publications were retrieved from different global bibliographic databases, of which only 13 articles were retained for analysis after applying the exclusion criteria. A total of 14 types of plants have undergone clinical studies in the past decade to verify their galactagogic activity. All but two showed a positive effect on promoting milk production. There were 42 articles categorised as excluded studies. The category includes review articles, surveys, case reports, introductory articles of regional plant galactagogue and preclinical studies, which involves animal testing and the studies exploring other issues related to plant galactagogue. The findings demonstrate that there is a significant research gap on the plant galactagogue using clinical studies. More clinical research is necessary to identify and verify the efficacy of various types of plant galactagogue for the benefit of humankind.

Polyherbal formula (ASILACT®) induces Milk production in lactating rats through Upregulation of α-Lactalbumin and aquaporin expression

Background

Polyherbal formula (PHF) contains extract of Sauropus androgynous (L.) Merr., Trigonella foenum-graceum L., and Moringa oleifera Lam. considered to induce galactagogue activity. This research aimed to evaluate the galactagogue activity of PHF and its effects on α-lactalbumin (LALBA) as well as aquaporin (AQP) gene expression at messenger ribonucleic acid (mRNA) levels in mammary glands of lactating rats.

Methods

Thirty lactating Wistar rats were randomly divided into five groups (n = 6), each has 7 pups. Group I was treated orally with distilled water as negative control. Groups II, III, and IV were orally administered with PHF at 26.25, 52.5 and 105 mg/kg/day, respectively. Group V was treated with domperidone 2.7 mg/kg/day, orally as positive control. The treatment was performed at third day until fifteenth day of parturition. The observed parameters include the galactagogue activity indicating by milk yield of lactating rats, the pup weight changes and lactating rats body weight changes during lactating period, mRNA expression of LALBA and AQP using quantitative Real Time Polymerase Chain Reaction (qRT-PCR) and histopathological analysis of mammary glands at the end of treatment period.

Result

The result showed that the PHF groups (52.5 and 105 mg/kg/day) and domperidone were significantly increased milk production of lactating rats (p < 0.05). The levels of mRNA expression of LALBA and AQPs were significantly upregulated by 105 mg/kg/day of PHF or 2.7 mg/kg of domperidone administration (p < 0.0001). Histopathological analysis of mammary glands shows that alveoli diameter was increase 14.59 and 19.33% at 105 mg/kg of PHF and 2.7 mg/kg of domperidone treatment, respectively.

Conclusion

The study suggested that PHF has potentially to induce galactagogue activity on lactating period through upregulation of LALBA and AQP genes at the mRNA level.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12906-020-03152-7.