In vitro genotoxicity tests point to an unexpected and harmful effect of a Magnolia and Aristolochia association

Neuropharmacological potential of honokiol and its derivatives from Chinese herb Magnolia species: understandings from therapeutic viewpoint

Honokiol is a neolignan biphenol found in aerial parts of the Magnolia plant species. The Magnolia plant species traditionally belong to China and have been used for centuries to treat many pathological conditions. Honokiol mitigates the severity of several pathological conditions and has the potential to work as an anti-inflammatory, anti-angiogenic, anticancer, antioxidant, and neurotherapeutic agent. It has a long history of being employed in the healthcare practices of Southeast Asia, but in recent years, a greater scope of research has been conducted on it. Plenty of experimental evidence suggests it could be beneficial as a neuroprotective bioactive molecule. Honokiol has several pharmacological effects, leading to its exploration as a potential therapy for neurological diseases (NDs), including Alzheimer's disease (AD), Parkinson's disease (PD), cerebral ischemia, anxiety, depression, spinal cord injury, and so on. So, based on the previous experimentation reports, our goal is to discuss the neuroprotective properties of honokiol. Besides, honokiol derivatives have been highlighted recently as possible therapeutic options for NDs. So, this review focuses on honokiol's neurotherapeutic actions and toxicological profile to determine their safety and potential use in neurotherapeutics.

Assessment of the Cytotoxicity, Mutagenicity, and Genotoxicity of Two Traditional Chinese Herbs: Aristolochia baetica and Magnolia officinalis

Herbal remedies used in traditional medicine often contain several compounds combined in order to potentiate their own intrinsic properties. However, herbs can sometimes cause serious health troubles. In Belgium, patients who developed severe aristolochic acid nephropathy ingested slimming pills containing root extracts of an Aristolochia species, as well as the bark of Magnolia officinalis. The goal of the study was to evaluate, on a human renal cell line, Aristolochia and Magnolia extracts for their cytotoxicity by a resazurin cell viability assay, and their genotoxicity by immunodetection and quantification of the phosphorylated histone γ-H2AX. The present study also sought to assess the mutagenicity of these extracts, employing an OECD recognized test, the Ames test, using four Salmonella typhimurium strains with and without a microsomial fraction. Based on our results, it has been demonstrated that the Aristolochia-Magnolia combination (aqueous extracts) was more genotoxic to human kidney cells, and that this combination (aqueous and methanolic extracts) was more cytotoxic to human kidney cells after 24 and 48 h. Interestingly, it has also been shown that the Aristolochia-Magnolia combination (aqueous extracts) was mutagenic with a TA98 Salmonella typhimurium strain in the presence of a microsomial liver S9 fraction. This mutagenic effect appears to be dose-dependent.

Potentiation Effects of Ficus sycomorus Active Fraction Against Permethrin-Resistant Field-Population of Anopheles coluzzii (Diptera: Culicidae)

Insecticide resistance in mosquitoes is increasing amidst growing cases of global malaria, leading to high fatality in mostly Africa. To overcome the resistance as well as environmental effects of the synthetic insecticides, preliminary insecticidal and botanical potentiating effects of sub-lethal concentration (LC₂₅) Ficus sycomorus active fraction (AFFS) and its synergistic potential with standard insecticide permethrin were evaluated against malarial vector Anopheles coluzzii (Coetzee & Wilkerson) populations. The glutathione-S-transferase (GST) inhibitory activity of the AFFS was also investigated compared to standard GST inhibitor, diethyl meleate (DEM). The WHO standard protocol for adult bioassay was used to expose the adult mosquitoes with sub-lethal concentration (LD₂₅=0.49 mg/ml) of the plants' active fraction and permethrin (0.75%). The permethrin susceptibility screening result showed high level of resistance to permethrin in the field populations of A. coluzzii from Kano with 50.29 ± 2.14% average mortality after exposure to WHO diagnostic dose 0.75% permethrin. Post hoc Fisher's exact test showed that combination of sub-lethal concentration of AFFS with permethrin (mortality=73.02±12.10%; p=0.00352; RR=0.6923 and 95% CI = 0.5358-0.8946) was statistically significant, while the combination of sub-lethal concentration of AFFS with DEM showed no statistical difference (mortality=63.22±5.03; p=1; RR=0.6667 and 95% CI=0.4470-0.8438). This potentiation effect was signified to be additive effects with co-toxicity factor (CTF) of - 12.66. There was significant reduction of GST activities in the AFFS- and permethrin -exposed groups compared to unexposed populations of A. coluzzii (p < 0.05). The AFFS additively potentiate the permethrin activities by inhibiting GSTs, bio-transformational enzymes implicated in pyrethroids resistance. This study finding generally signifies the potential for bio-rational insecticide approach for malarial vector control.

An Overview on Analytical Methods for Quantitative Determination of Aristolochic Acids

Background:

Aristolochic acids are chemically linked to nitrophenanthrene carboxylic acids which are found in aristolochia plants. These compounds are intrinsically carcinogenic, while they have been used in traditional medicine from a long time ago. Despite the beneficial effects of herbals for treating some diseases, they possess some side effects.

Methods:

Therefore, the development of a sensitive and selective procedure for the determination of these harmful components in various complicated samples is an important task for health systems and drug authorities. In the past years, ultra-pressure liquid chromatography, high performance liquid chromatography and capillary electrophoresis with different detection systems were used for determination of aristolochic acids in various samples.

Results:

In this review, different analytical methods have been discussed in brief and applications of them in diverse samples have been summarized.

Conclusion:

Different approaches are compared from point of sensitivity, selectivity, and extraction efficiency.

Thin-layer chromatographic quantification of magnolol and honokiol in dietary supplements and selected biological properties of these preparations

Two isomeric biphenyl neolignans, magnolol and honokiol, are considered as constituents responsible for the healing effect of magnolia bark, a traditional Oriental medicine. To survey the increasing number of dietary supplements that contain magnolia bark or its extract, an affordable quantitative thin-layer chromatography (TLC) - densitometry method was developed. The methanol extracts were analyzed on the silica gel plates after manual sample application using n-hexane - ethyl acetate - ethanol (16:3:1, v/v/v) as a mobile phase. For quantitation, the chromatograms were scanned in the absorbance mode at the wavelength λ = 290 nm. The limits of detection and quantitation were 90 and 280 ng/zone for magnolol and 70 and 200 ng/zone for honokiol, respectively. None of the two targeted neolignans were detected in two of the six analyzed supplements. In the other four samples, the measured amounts were between 0.95-114.69 mg g^-1 for magnolol and 4.88-84.86 mg g^-1 for honokiol. Moreover, separations of these two neolignans on the TLC and high-performance TLC (HPTLC) layers were compared and HPTLC was combined with antioxidant (DPPH) and antibacterial (Bacillus subtilis and Aliivibrio fischeri) assays and mass spectrometry (MS), using the elution-based interface. Both magnolol and honokiol exhibited effects in all bioactivity assays. The HPTLC-MS tests confirmed purity of neolignan zones in the extracts of dietary supplements and supported tentative identification of the alkaloid piperine and the isoflavone daidzein as additional bioactive components of the investigated dietary supplements. Using the same mobile phase in the orthogonal directions 2D-HPTLC-MS experiments proved degradation, i.e., instability of magnolol and honokiol on the silica gel adsorbent.

A review of the phytochemistry and pharmacological activities of Magnoliae officinalis cortex

ETHNOPHARMACOLOGICAL RELEVANCE

Magnoliae Officinalis Cortex (the dried bark of Magnolia officinalis), a widely used traditional Chinese medicine, is also known as 'Houpo' (Chinese: ). Magnoliae Officinalis Cortex has a wide range of pharmacological effects and has been used to treat conditions such as abdominal distention, vomiting, diarrhea, food accumulation, Qi stagnation, constipation, phlegm and fluid retention and cough resulting from asthma.

AIMS OF THE REVIEW

The present paper reviews advances in research relating to the botany, ethnopharmacology, phytochemistry, pharmacology and toxicology of Magnoliae Officinalis Cortex. Prospects for future investigation and application of this herb are also discussed.

MATERIALS AND METHODS

Information on Magnoliae Officinalis Cortex was obtained from published materials, including ancient and modern books; PhD and MSc dissertations; monographs on medicinal plants; the pharmacopoeia of different countries and electronic databases, such as SCI finder, PubMed, Web of Science, ACS, Science Direct, Wiley, Springer, Taylor, AGRIS, Europe PMC, EBSCO host, CNKI, WanFang DATA, J-STAGE and Google Scholar.

RESULTS

More than 200 chemical compounds have been isolated from Magnoliae Officinalis Cortex, including lignans, phenylethanoid glycosides, phenolic glycosides, alkaloids, steroids and essential oils. The plant has been reported to have pharmacological effects on the digestive system, nervous system and cardiovascular and cerebrovascular systems, as well as antibacterial, anti-tumour, analgesic, anti-inflammatory and anti-oxidative effects.

CONCLUSIONS

Magnoliae Officinalis Cortex is an essential traditional Chinese medicine with pharmacological activities that mainly affect the digestive system, nervous system and cardiovascular and cerebrovascular systems. This review summarises its botany, ethnopharmacology, phytochemistry, pharmacology and toxicology. These information suggest that we should focus on the development of new drugs related to Magnoliae Officinalis Cortex, including specific constituents, so that Magnoliae Officinalis Cortex can exert greater therapeutic potential. Meanwhile, it is important to pay attention to the rational use of Magnolia resources, avoiding over-harvesting which could lead to lack of resources. We should also pursue research on Magnolia substitutes and develop resources such as Magnoliae Officinalis Flos and Magnolia Leaf.

Potentiation of Sodium Metabisulfite Toxicity by Propylene Glycol in Both in Vitro and in Vivo Systems

Many consumer products used in our daily lives result in inhalation exposure to a variety of chemicals, although the toxicities of the active ingredients are not well known; furthermore, simultaneous exposure to chemical mixtures occurs. Sodium metabisulfite (SM) and propylene glycol (PG) are used in a variety of products. Both the cytotoxicity and the sub-acute inhalation toxicity of each chemical and their mixtures were evaluated. Assays for cell viability, membrane damage, and lysosome damage demonstrated that SM over 100 μg/ml induced significant cytotoxicity; moreover, when PG, which was not cytotoxic, was mixed with SM, the cytotoxicity of the mixture was enhanced. Solutions of 1, 5, and 20% SM, each with 1% PG solution, were prepared, and the whole body of rats was exposed to aerosols of the mixture for 6 h/day, 5 days/week for 2 weeks. The rats were sacrificed 1 (exposure group) or 7 days (recovery group) after termination of the exposure. The actual concentration of SM in the low-, medium-, and high-exposure groups was 3.91 ± 1.26, 35.73 ± 6.01, and 80.98 ± 5.47 mg/m³, respectively, and the actual concentration of PG in each group was 6.47 ± 1.25, 8.68 ± 0.6, and 8.84 ± 1.77 mg/m³. The repeated exposure to SM and PG caused specific clinical signs including nasal sound, sneeze, and eye irritation which were not found in SM single exposure. In addition, the body weight of treatment group rats decreased compared to that of the control group rats in a time-dependent manner. The total protein concentration and lactate dehydrogenase activity in the bronchoalveolar lavage fluid (BALF) increased. Histopathological analysis of the lungs, liver, and nasal cavity was performed. Adverse effects were observed in the nasal cavity, with squamous cell metaplasia identified in the front of the nasal cavity in all high-exposure groups, which completely recovered 7 days after exposure was terminated. Whereas inhalation of SM for 2 weeks only reduced body weight in the high-dose group, inhalation of SM and PG mixtures for 2 weeks significantly decreased body weight and induced metaplasia of the respiratory epithelium into squamous cells in the medium- and high-dose groups. In conclusion, PG potentiated the toxicity of SM in human lung epithelial cells and the inhalation toxicity in rats.

Biological activity and toxicity of the Chinese herb Magnolia officinalis Rehder & E. Wilson (Houpo) and its constituents

Traditional Chinese herbal drugs have been used for thousands of years in Chinese pharmacopoeia. The bark of Magnolia officinalis Rehder & E. Wilson, known under the pinyin name "Houpo", has been traditionally used in Chinese and Japanese medicines for the treatment of anxiety, asthma, depression, gastrointestinal disorders, headache, and more. Moreover, Magnolia bark extract is a major constituent of currently marketed dietary supplements and cosmetic products. Much pharmacological activity has been reported for this herb and its major compounds, notably antioxidant, anti-inflammatory, antibiotic and antispasmodic effects. However, the mechanisms underlying this have not been elucidated and only a very few clinical trials have been published. In vitro and in vivo toxicity studies have also been published and indicate some intriguing features. The present review aims to summarize the literature on M. officinalis bark composition, utilisation, pharmacology, and safety.