Evaluation of in vitro and in vivo safety profile of the Indian traditional medicinal plant Grewia tiliaefolia

Synthesis of Pseudostellaria heterophylla polysaccharide-gold nanocomposites and their antitumor effect through immunomodulation

Polysaccharides from natural sources have an excellent immune function and low toxicity; however, their limitations such as short half-life and instability limit their sustained pharmacological activity. In this context, the combination of polysaccharides and nanotechnology have been developed to promote the stability and prolong the immune activities of polysaccharides. To synthesize and explore the antitumor effect and immunomodulatory activity of PHP-AuNPs. Polysaccharides extracted from Pseudostellaria heterophylla were used to synthesize gold nanocomposites (PHP-AuNPs), and their physicochemical properties and immunoregulatory effect in vitro and in vivo were analyzed. The PHP-AuNPs were green synthesized with high biosafety. PHP-AuNPs can activate macrophages in vitro and decrease the tumor weight and volume, whereas they increase the immune organ index in vivo. Besides, PHP-AuNPs showed a beneficial effect for maintaining the immune balance of CD4+/CD8+ T cells and modulating the release of cytokines such as TNF-α increase and IL-10 decrease in mice. All these results suggested that PHP-AuNPs exhibit a remarkable antitumor effect and stronger immunomodulatory activity than that of free PHP-1. RESEARCH HIGHLIGHTS: The P. heterophylla polysaccharide-gold nanocomposites (PHP-AuNPs) were synthesized and physicochemical properties were characterized. The cytotoxicity in vitro and immunomodulatory effects of PHP-AuNPs on macrophages were analyzed. The immune-antitumor effects in vivo of PHP-AuNPs have also been confirmed.

Phytochemical, Antioxidant Activity, and Toxicity of Wild Medicinal Plant of Melitotus albus Extracts, In Vitro and In Silico Approaches

Morocco is known for its high plant biodiversity, but many plants are poorly valorized. For this reason, this study aims to valorize the methanolic and aqueous extracts of Melitotus albus leaves by studying their antioxidant activity and toxicity. The extracts' antioxidant activity is assessed using the FRAP, DPPH, CAT, and ABTS methods. The chemical composition was determined using LC-MS analysis and evaluated using in silico studies. The results revealed that the total polyphenol content of the aqueous extract, 259.26 ± 7.79 (mg GAE/g), is higher than that of the methanolic extract, 131.41 ± 12.64 (mg GAE/g). The antioxidant activity by the methods of DPPH, ABTS, and phosphor molybdenum of aqueous extracts (0.087 ± 0.015, 0.014 ± 0.001 and 6.157 ± 1.050 mg eq vit C/g, respectively) is greater than that of methanolic extracts (0.107 ± 0.02, 0.167 ± 0.03, and 0.453 ± 0.014 mg eq vit C/g, respectively). The reducing power of iron (FRAP) shows that the methanolic extract has a greater reducing power than that of the aqueous extract with a low IC50 (0.011 ± 0.003 and 0.199 ± 0.016 mg/mL, respectively). The study of acute and subacute toxicity shows that the administration of the aqueous extract of M. albus at different doses increases the body weight of rats without modifying their general behavior. The M. albus extract had a 99.99% total phenolic content, as determined by LC-MS, consisting of 12 different components. The primary constituents of the extract are chlorogenic acid (43.68%), catechin/epicatechin (24.82%), quercetin-3-O-glucuronic acid (9.91%), naringin (7.64%), and p-hydroxybenzoic/salicylic acid (2.95%). The in-silico study showed that these compounds can passively permeate through the blood and have a beneficial effect on various organs of the body. Based on these results, M. albus can be used as a medicinal plant in phytotherapy, cosmetics, or as a dietary supplement. The bioactive compounds of these plants will require a lot of further effort in terms of isolation and characterization.

Anticonvulsant potential of Grewia tiliaefolia in pentylenetetrazole induced epilepsy: insights from in vivo and in silico studies

Epilepsy, a chronic neurological condition, impacts millions of individuals globally and remains a significant contributor to both illness and mortality. Available antiepileptic drugs have serious side effects which warrants to explore different medicinal plants used for the management of epilepsy reported in Traditional Indian Medicinal System (TIMS). Therefore, we explored the antiepileptic potential of the Grewia tiliaefolia (Tiliaeceae) which is known for its neuroprotective properties. Aerial parts of G. tiliaefolia were subjected to extraction with increasing order of polarity viz. hexane, chloroform and methanol. Antioxidant potential of hexane, chloroform and methanol extracts of G. tiliaefolia was evaluated by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assay, total antioxidant capacity (TAC) assay, reducing power assay (RPA) and DNA nicking assay. Additionally, quantitative antioxidant assays were also conducted to quantify total phenolic (TPC) and total flavonoid content (TFC). As revealed by in vitro assays, methanol extract was found to contain more phenolic content. Hence, the methanol extract was further explored for its anticonvulsant potential in pentylenetetrazole (PTZ) induced acute seizures in mice. The methanol extract (400 mg/kg) significantly increased the latency to occurrence of myoclonic jerks and generalized tonic clonic seizures (GTCS). Additionally, it also reduced duration and seizure severity score associated with GTCS. The Grewia tiliaefolia methanol extract was further screened by Ultra High-Performance Liquid Chromatography (UHPLC) for presence of polyphenolic compounds, among which gallic acid and kaempferol were present in higher amount and were further analysed by in silico study to predict their possible binding sites and type of interactions these compounds show with gamma amino butyric acid (GABA) receptor and glutamate α amino-3- hydroxyl-5-methyl-4-isoxazolepropionic acid (Glu-AMPA) receptor. It was revealed that gallic acid and kaempferol had shown agonistic interaction for GABA receptor and antagonistic interaction for Glu-AMPA receptor. We concluded that G. tiliaefolia showed anticonvulsant potential possibly because of gallic acid and kaempferol possibly mediated through GABA and Glu-AMPA receptor.

Acute and sub-acute toxicity study of ethanol extract from Nectandra leucantha Nees & Mart. (Lauraceae) barks

Nectandra leucantha has been used in traditional medicine. Several metabolites isolated from N. leucantha extracts displayed immunomodulatory, antileishmanial properties, but the determination of the toxicological profile in mammals has not previously been performed. In this study, the ethanol extract from N. leucantha barks (EENl) was characterized by HPLC/HRESIMS. To study acute toxicity, female mice received EENl in a single dose of 100, 300, 1000, or 2000 mg/kg bw. Later, sub-acute toxicity was introduced in female and male mice by oral gavage at 100, 500 or 1000 mg/kg bw for 28 consecutive days. Hematological and biochemical profiles from the blood as well as histological analysis from the liver and kidney were performed. The HPLC/HRESIMS analysis of the EENl revealed the presence of six neolignans chemically related to dehydrodieugenol B. In the oral acute and sub-chronic studies, EENl did not produce in all doses evaluated any alteration in behavior, biochemical, hematological, body weight gain and food intake or sudden death in Swiss mice. In addition, histopathological data did not reveal any disturbance in liver and kidney morphology after 28 days of EENl treatment. Our results indicate that EENl at dosage levels up to 2000 mg/kg bw is non-toxic and can be considered safe for mammals.

Safety assessment of Bauhinia cheilantha Bong. Steud leaves extract: acute, sub-acute toxicity, antioxidant, and antihemolytic evaluations

Bauhinia cheilantha (Fabaceae), known popularly as pata-de-vaca and mororó has been largely recommended treating several diseases in folk medicine. However, information on safe doses and use is still scarce. The goal was to evaluate in-vitro antioxidant and antihemolytic and also acute and sub-acute toxicity effects of hydroalcoholic extract from B. cheilantha leaves (HaEBcl). The identification of the compounds in the HaEBcl was performed by ultra-performance liquid chromatography coupled with a diode array detector and quadrupole time-of-flight mass spectrometry. Antioxidant and hemolytic activity of HaEBcl was evaluated in vitro. To study acute toxicity, female mice received HaEBcl in a single dose of 300 and 2.000 mg/kg. Later, sub-acute toxicity was introduced in both female and male mice by oral gavage at 300, 1000, or 2000 mg/kg for 28 consecutive days. Hematological and biochemical profiles were created from the blood as well as from histological analysis of the liver. HaEBcl is rich in flavonoids (quercitrin and afzelin), has no hemolytic effects and moderate antioxidant effects in vitro. Acute toxicity evaluation showed that lethal dose (LD₅₀) of HaEBcl was over 2000 mg/kg. Sub-acute toxicity testing elicited no clinical signs of toxicity, morbidity, or mortality. The hematological and biochemical parameters discounted any chance of hepatic or kidney toxicity. Furthermore, histopathological data did not reveal any disturbance in liver morphology in treated mice. Results indicate that HaEBcl has no hemolytic and moderate antioxidant effects in vitro. In addition, HaEBcl dosage levels up to 2000 mg/kg are nontoxic and can be considered safe for mammals.

Green synthesis of gold nanoparticles from Dendrobium officinale and its anticancer effect on liver cancer

A novel gold nanoparticle (Do-AuNP) was successfully synthesized from water extracts of traditional Chinese medicine Dendrobium officinale (DO) without using any extra chemicals regents. The physicochemical properties of Do-AuNPs were analyzed by transmission electron microscopy, dynamic light scattering, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and atomic force microscopy. The amount of DO extract on the AuNPs was about 13%. In order to evaluate the anti-tumor efficiency and biosafety, the inhibitory rate of HepG2 cells and survival rate of L02 cells were performed in vitro, and the immunohistochemical analysis of H&E, Ki-67, and TUNEL staining were conducted in vivo. Our results demonstrated that Do-AuNP had better anti-tumor efficiency compared with DO extraction alone without increasing toxicity in vivo and in vitro. The present study provides useful information for Do-AuNP as a new nanomedicine for liver cancer.

Acute toxicity studies of the South African medicinal plant Galenia africana

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G. africana LD₅₀ was over 2000 mg/kgbw for acute oral and dermal toxicity studies.

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G. africana was non-irritant on the reconstituted human epidermis models.

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Open application of extract at various concentrations did not result in a SI of ≥ 3.

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G. africana did not elicit a hypersensitivity response.

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G. africana can be used in the pharmaceutical and cosmetic industries.

Background

Medicinal plants are used by a large proportion of the global population as complementary and alternative medicines. However, little is known about their toxicity. G. africana has been used to treat wounds, coughs and skin diseases and is used in cosmetic formulations such as lotions and shampoos.

Methods

The acute oral and dermal toxicity potential of G. africana was analyzed after a single administration of 300 and 2000 mg/kgbw for acute oral toxicity and 2000 mg/kgbw for acute dermal toxicity. Female Sprague-Dawley rats were used for the acute oral toxicity study whereas both male and female Sprague-Dawley rats were used for the acute dermal toxicity study. In the Episkin skin irritation test, the irritation potential of G. africana (concentrate) and G. africana (in-use dilution) extracts were assessed using the Episkin reconstituted human epidermis. In the dermal sensitization study, female CBA/Ca mice were treated with G. africana concentrations of 50, 100 and 200 mg/ml respectively. The vehicle of choice was dimethylformamide which acted as a control.

Results

The results of the acute oral and dermal toxicity studies revealed that the median lethal dosage (LD₅₀) for G. africana extract in Sprague-Dawley rats was considered to exceed 2000 mg/kgbw. In the irritation test, the G. africana (concentrate) and G. africana (in-use dilution) extracts were non-irritant on the Episkin reconstituted human epidermis. In the dermal sensitization study, the stimulation index (SI) values for the mice treated with the G. africana extract at concentrations of 50, 100 and 200 mg/ml/kgbw, when compared to the control group, were 1.3, 0.9 and 1.3 respectively. The open application of the extract at the various concentrations did not result in a SI of ≥ 3 in any group. Hence, it did not elicit a hypersensitivity response.

Conclusion

These findings demonstrate that the acute toxicity profile for G. africana is acceptable and can subsequently be used for single use in the pharmaceutical and cosmetic industries.

Acute toxicity and antimicrobial activity of leaf tincture Baccharis trimera (Less)

Background

The present study aimed to evaluate the possible acute oral toxicity of Baccharistrimera leaf dye as well as its antimicrobial activity.

Method

Organization for Economic co-operation and development (OECD) 423 was used to assess acute oral toxicity and as per protocol a dose of 2000 mg/kg of tincture was administered to Wistar rats, male and female, and observed for 14 days. Biochemical and hematological analyzes were performed with sample collected of rat. The dye was evaluated for antimicrobial activity by agar diffusion and microdilution methods, which allow to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) and antibiofilm potential.

Results

The results showed that there was no loss of animals and no significant changes in hematological and biochemical parameters after oral administration of 2000 mg/kg of tincture and was considered safe by the OECD, classified as category 5. The dyeing also showed an important antimicrobial activity against gram positive and gram negative bacteria also significantly decreased the microbial biofilm.

Conclusion

The tincture of B.trimera leaf when given orally once can be considered safe and has a relevant antimicrobial potential that should be elucidated in subsequent research.

Safety assessment of methanolic extract of Terminalia chebula fruit, Terminalia arjuna bark and its bioactive constituent 7-methyl gallic acid: In vitro and in vivo studies

Terminalia chebula and Terminalia arjuna were widely used in traditional medicine for the treatment of memory impairment, inflammatory disorders and as an anti-aging agent. However, reports regarding their safety aspects are lacking. Hence, the present study was carried out to investigate the toxicity of methanolic extracts of Terminalia chebula fruit (TCF), Terminalia arjuna bark (TAB) and its bioactive constituent 7- Methyl gallic acid (7MG) under in vitro and in vivo conditions. In vitro toxicity profile of TCF, TAB and 7MG (250-2000 μg/ml) were assessed through cytotoxicity, hemolytic activity, mutagenicity and genotoxicity assays. Results of Ames test, comet assay, MTT and hemolytic assays illustrated that TCF, TAB and 7MG exhibited neither cytotoxic and genotoxic effect in PBMC nor hemolytic activity in RBC and no mutagenic effect in TA 98 and TA 100 up to a limited dose of 2000 μg/ml. Acute and subacute toxicity studies showed no significant change in body weight, behavior, hematology, biochemical parameters, organ weight and histopathology. Over all the results of acute and subacute toxicity studies conclude that oral administration of TCF, TAB and 7MG were observed to be relatively non-toxic and affords practical guidance for selecting safe dose for further clinical trials.

Beta sitosterol and Daucosterol (phytosterols identified in Grewia tiliaefolia) perturbs cell cycle and induces apoptotic cell death in A549 cells

Lung cancer is the leading cause of cancer related deaths both in developed and developing countries. Since majority of the existing therapeutic methods harms both normal and malignant cells, a viable alternative is to switch into safe and beneficial traditional medicinal plants. Hence the present study was framed to identify selective anti-lung cancer agents from the medicinal plant Grewia tiliaefolia (GT). Cell viability experiments showed that benzene extract of GT (BGT) leaf effectively inhibited the growth of A549 cells, while being non-toxic to normal human lung L132 and PBMC cells. Ames and comet assays demonstrated that BGT is of non-mutagenic and non-genotoxic nature in untransformed cells. The hematological and histopathological profiles of the in vivo acute and sub-acute toxicity studies demonstrated that BGT is safe and tolerable. Importantly, western blot analysis and Annexin V-FITC staining confirmed that BGT promotes mitochondrial dependent apoptotic cell death in A549 cells by arresting cell cycle at G2/M phase. Bio-assay guided fractionation revealed the presence of phytosteols (β-sitosterol and daucosterol) which significantly inhibited the growth of A549 cells both alone and in combination. This study warrants that these phytosterols in alone or in combination can be considered as safe and potential drug candidates for lung cancer treatment.

Phytochemical Screening and Antinociceptive and Antidiarrheal Activities of Hydromethanol and Petroleum Benzene Extract of Microcos paniculata Barks

Introduction. Microcos paniculata is traditionally used for treating diarrhea, wounds, cold, fever, hepatitis, dyspepsia, and heat stroke. Objective. To investigate the qualitative phytochemical constituents of hydromethanol (HMPB) and petroleum benzene extract of Microcos paniculata barks (PBMPB) and to evaluate their antinociceptive and antidiarrheal activities. Methods. Phytochemical constituents and antinociceptive and antidiarrheal activities were determined and evaluated by different tests such as Molisch's, Fehling's, Mayer's, Wagner's, Dragendorff's, frothing, FeCl₃, alkali, Pew's, and Salkowski's test, general test of glycosides, Baljet and NH₄OH test, formalin-induced paw licking, acetic acid-induced writhing, tail immersion, and hot plate tests, and castor oil and MgSO₄ induced diarrheal tests. Results. These extracts revealed the presence of saponins, flavonoids, and triterpenoids and significantly (^⁎P < 0.05, versus control) reduced paw licking and abdominal writhing of mice. At 30 min after their administration, PBMPB revealed significant increase in latency (^⁎P < 0.05, versus control) in tail immersion test. In hot plate test, HMPB and PBMPB 200 mg/kg showed significant increase in response latency (^⁎P < 0.05, versus control) at 30 min after their administration. Moreover, both extracts significantly (^⁎P < 0.05, versus control) inhibited percentage of diarrhea in antidiarrheal models. Conclusion. Study results indicate that M. paniculata may provide a source of plant compounds with antinociceptive and antidiarrheal activities.