The Herb Rhinacanthus nasutus (L.) Kurz, which is native to Thailand and Southeast Asia, has become known for its antioxidant properties. Neuronal loss in a number of diseases including Alzheimer’s disease is thought to result, in part, from oxidative stress. Glutamate causes cell death in the mouse hippocampal cell line, HT-22, by unbalancing redox homeostasis, brought about by a reduction in glutathione levels, and amyloid-β has been shown to induce reactive oxygen species (ROS) production. Here in, we show that ethanol extracts of R. nasutus leaf and root are capable of dose dependently attenuating the neuron cell death caused by both glutamate and amyloid-β treatment. We used free radical scavenging assays to measure the extracts antioxidant activities and as well as quantifying phenolic, flavonoid and sterol content. Molecules found in R. nasutus, lupeol, stigmasterol and β-sitosterol are protective against glutamate toxicity.

Gloriosa superba and Catharanthus roseus are useful in traditional medicine for treatment of various skin diseases and cancer. However, their molecular effect on psoriasis has not been investigated. In this study, the effect of ethanol extracts derived from G. superba leaves and C. roseus stems on the expression of psoriatic marker, keratin 17 (K17), was investigated in human keratinocytes using biochemical and molecular experimental approaches. Both extracts could reduce the expression of K17 in a dose-dependent manner through JAK/STAT pathway as demonstrated by an observation of reduced phosphorylation of STAT3 (p-STAT3). The inhibitory activity of G. superba extract was more potent than that of C. roseus. The Pearson's correlation between K17 and cell viability was shown positive. Taken together, the extracts of G. superba and C. roseus may be developed as alternative therapies for psoriasis.

Background: Neurite outgrowth is an important process in neural reorganization and repair after neuronal injury. Neurite outgrowth is one of the important mechanisms to maintain normal physiological neuronal function. Neurite stimulation may help to prevent or rehabilitate brain regions in neurodegenerative disease. Objectives: The aim of this study was to screen selected ethnopharmacological herbs for stimulatory effects on neurite outgrowth and to test for any cytotoxicity and phytochemical properties. Materials and methods: The herbal extracts derived from Acanthus ebracteatus Vahl. leaves, Carthamus tinctorius L. flower, and Streblus asper Lour. bark was tested for neurite outgrowth stimulation/potentiation and cytotoxic and phytochemical properties. Results: The extract of Carthamus tinctorius L. flowers at concentrations of 50 and 500 µg/mL could significantly stimulate potentiation of neurite outgrowth in Neuro-2a cells whereas other extracts could not. We found that treatment of the cells with a concentration up to 500 µg/mL of the Carthamus tinctorius L. extract showed no cytotoxicity. Conclusion: The neurite potentiation effect might be due to other chemical constituents rather than phytochemical properties, especially total flavonoid, and phenolic contents, and antioxidant activity of the Carthamus tinctorius L. extract. The result showed that Carthamus tinctorius L. flowers extract could be a good candidate for use as a drug protecting against neuronal damage and neurodegenerative disease since it provides low cytotoxicity and neurogenic enhancement.