Bioactivity and Toxicity of Senna cana and Senna pendula Extracts

Flavonoids composition, antioxidant, anticholinesterase, and cytotoxic activities of flowers extract of Senna cearensis Afr. Fern

The Senna genus has a wide diversity of species, with an interesting chemical composition of secondary metabolites and applications as medicine. The folk medicine, mainly in developing countries, uses species of Senna to treat seizures, epilepsy and constipation. Though the recognized bioactivity, some Brazilian native species of Senna remain unexplored, such as Senna cearensis, a native species of Caatinga. This is the first report about the bioactivity of the flowers of S. cearensis Afr. Fern., a native species of northeast Brazil. In this communication, flavonoids and catechins are identified in S. cearensis flowers and the chemical composition is linked with its antioxidant, anticholinesterase, and cytotoxic activities. By UPLC-QTOF, some compounds that belong to the class of flavonoids were identified. They are: catechin, epigallocatechin, guibourtinidol-(4α-8)-catechin, and cassiaflavan-(Cat)-epicatechin. The cytotoxic activity is more noticeable for the HL60 (leukemia) cell line with a cell growth inhibition (GI%) of 81.65 ± 5.65.

A Review of Recent Studies on the Antioxidant and Anti-Infectious Properties of Senna Plants

The use of phytochemicals is gaining interest for the treatment of metabolic syndromes over the synthetic formulation of drugs. Senna is evolving as one of the important plants which have been vastly studied for its beneficial effects. Various parts of Senna species including the root, stem, leaves, and flower are found rich in numerous phytochemicals. In vitro, in vivo, and clinical experiments established that extracts from Senna plants have diverse beneficial effects by acting as a strong antioxidant and antimicrobial agent. In this review, Senna genus is comprehensively discussed in terms of its botanical characteristics, traditional use, geographic presence, and phytochemical profile. The bioactive compound richness contributes to the biological activity of Senna plant extracts. The review emphasizes on the in vivo and in vitro antioxidant and anti-infectious properties of the Senna plant. Preclinical studies confirmed the beneficial effects of the Senna plant extracts and its bioactive components in regard to the health-promoting activities. The safety, side effects, and therapeutic limitations of the Senna plant are also discussed in this review. Additional research is necessary to utilize the phenolic compounds towards its use as an alternative to pharmacological treatments and even as an ingredient in functional foods.

Anxiolytic-like effect of chrysophanol from Senna cana stem in adult zebrafish (Danio rerio)

The aim of this study was to evaluate the anxiolytic-like effect of chrysophanol (CHRY), isolated from hexane extract of Senna cana stem and its possible mechanism of action. CHRY was obtained through chromatographic treatments and its identity was confirmed by uni and bidimensional RMN¹H and RMN¹³C. Adult zebrafish (n = 6/group) were treated (with CHRY (4.0 or 12.0 or 40.0 mg/Kg; 20 µL; intraperitoneally) and submitted to acute toxicity and open field tests. Subsequently, other groups (n = 6/each) received CHRY for the analysis of its effect on the Light & Dark Test. The participation of the GABAergic system was also assessed using the diazepam (GABA_A receptor agonist) and flumazenil (GABA_A receptor antagonist). CHRY was considered non-toxic, it did not reduce the locomotor activity, and showed an anxiolytic-like effect. This effect was reduced by pre-treatment with flumazenil. The results suggest that CHRY is an anxiolytic-like agent mediated via the GABAergic system.

Anti-cholinesterase potential of diverse botanical families from Malaysia: Evaluation of crude extracts and fractions from liquid-liquid extraction and acid-base fractionation

ETHNOPHARMACOLOGICAL RELEVANCE

Enhancement of cholinergic functions in the brain via acetylcholinesterase inhibition is one of the main therapeutic strategies to improve symptoms associated with Alzheimer's or related cognitive deficits. There is a pathophysiological correlation between Alzheimer's and Diabetes Mellitus, as well as inflammation and oxidative stress that may cause cognitive decline.

AIM OF THE STUDY

The present study was intended to evaluate anti-cholinesterase potential of 177 Malaysian plant extracts from 148 species known to have related ethnomedicinal uses such as anti-inflammatory, anti-oxidant, anti-diabetic, epilepsy, headache, memory enhancement and anti-aging.

MATERIALS AND METHODS

Anti-cholinesterase screening against both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes was performed on the basis of in-vitro colorimetric 96-well microplate-based assay method. Potent active plant extracts were subjected to liquid-liquid extraction and acid-base fractionation for further analysis.

RESULTS

Fifty-seven plant extracts exhibited potent anti-cholinesterase activities (50-100% inhibition) at 200 μg/ml. Majority of the active plants originated from Fabaceae family. Coccoloba uvifera (L.) L. stem extract manifested the lowest IC₅₀ of 3.78 μg/ml for AChE and 5.94 μg/ml for BChE. A few native species including Tetracera indica (Christm. & Panz.) Merr., Cyrtostachys renda Blume and Ixora javanica (Blume) DC. showed cholinesterase inhibition despite limited local medical applications. Further anti-AChE evaluation (50 μg/ml) of 18 potent plant extracts harbored active polar components in butanol and water fractions, except Senna pendula (Willd.) H.S.Irwin & Barneby (leaves and stems), Acacia auriculiformis Benth. (leaves), Artocarpus altilis (Parkinson ex F.A.Zorn) Fosberg (leaves), and Macaranga tanarius (L.) Mull.Arg. (leaves) that showed inhibitory activity in less polar fractions. The acidic extraction of these four plant species improved their inhibition level against AChE.

CONCLUSION

This study rendered a preliminary overview of anti-cholinesterase activity from diverse Malaysian botanical families in which provided the medical relevance toward these native plant species, especially ones with limited ethnobotanical record or practice.