Investigating the efficacy of topical application of Ipomoea carnea herbal cream in preventing skin damage induced by UVB radiation in a rat model

Ultraviolet-B irradiation is a common environmental stressor that has detrimental effects on human skin. Natural sunscreens are well-known for their ability to benefit inflamed sunburn and dry skin. This study examined the effect of formulated Ipomoea carnea herbal cream on UVB-induced skin damage. We screened the bioactive compounds of I. carnea crude extract, showing significant antioxidant activity. Additionally, we evaluated the cytotoxicity, revealing that I. carnea extract has less toxicity to vero cells (IC50 98.45 μg/mL) than to A375 cells (IC50 48.95 μg/mL). Based on this, we formulated the I. carnea herbal cream (FIHC) at 50, 100 and 200 mg concentrations and evaluated its organoleptic characteristics. Then, the rats were exposed to UVB radiation (32,800 J/m2) four times/week (on alternate days) before the cream was applied topically to the dorsal skin surface. Under UVB stress without treatment, rats showed deep dermal damage. In contrast, rats treated with the FIHC exhibited significantly reduced sunburn. Moreover, the histopathological and biochemical assays were confirmed by the topical application of FIHC, which had potentially reduced the skin elasticity and maintained the imbalanced enzyme and non-enzymatic antioxidant activity. Our findings amply demonstrate that the FIHC significantly accelerated the recovery of UVB-induced lesions through antioxidant and down-regulation of skin photodamage.

Characterization of the complete chloroplast genome of Tabernaemontana divaricate (Apocynaceae), a valuable and endangered plant

Tabernaemontana divaricate is a vulnerable species of Apocynaceae with significant medicinal values. In this study, the complete chloroplast (cp) genome of T. divaricate was determined through the Illumina NovaSeq platform. The circular molecular genome was157,954 bp in length with two inverted repeats (IRa and IRb) regions of 25,769 bp, a large single-copy (LSC) region of 88,246 bp, and a small single-copy (SSC) region of 18,170 bp. It contained 131 genes, including 86 protein-coding, 37 tRNA, and eight rRNA genes. Phylogenetic analysis showed that T. divaricata exhibited the closest relationship with Catharanthus roseus and Rauvolfia serpentina.

Ethnopharmacology, phytochemistry, and biotechnological advances of family Apocynaceae: A review

The family Apocynaceae is one of the largest and important families in angiosperm. Several members of this family have medicinal properties and have been in the treatment of various ailments. Most of them are consumed as food by tribal people whereas a few plants are used as source of poison. Members of family Apocynaceae are rich in alkaloids, terpenoids, steroids, flavonoids, glycosides, simple phenols, lactones, and hydrocarbons. Other compounds such as sterols, lignans, sugars, lignans, and lactones have been isolated and systematically studied. Few studies have reported antioxidant, anti-inflammatory, antimicrobial, and cytotoxic activities of crude extracts as well as single compound(s) isolated from various members of the family Apocynaceae. Holarrhena antidysenterica, Rauvolfia serpentina, Carissa carandas, and Tabernaemontana divaricata are the extensively studied plants in this family. The present review provides a detailed outlook on ethnopharmacology, phytochemistry, and biological activities of selected members of this family. Moreover, it also covers the biotechnological advances used for large-scale production of bioactive compounds of therapeutic interest along with plant tissue culture-based approaches for conservation of this medicinally valuable family.

In vitro antioxidant and anticataractogenic potential of silver nanoparticles biosynthesized using an ethanolic extract of Tabernaemontana divaricata leaves

Silver nanoparticles (AgNPs) have been found useful in biological systems and in medicine since they possess a large surface area to volume ratio, which confers on them several unique properties. In the present study, AgNPs that had been biosynthesized using an ethanolic extract of Tabernaemontana divaricata leaf were evaluated for putative antioxidant potential and efficacy in preventing experimental in-vitro selenite-induced opacification of the ocular lens (cataractogenesis). The antioxidant potential of the AgNPs was evaluated in-vitro by looking for radical-scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide (H₂O₂) free radicals as well as by determining reducing power. The anticataractogenic potential of the AgNPs was evaluated in an in-vitro model of selenite-induced cataractogenesis in five groups of Wistar rat lenses cultured in Dulbecco's modified Eagle's medium (DMEM) for 24h: Group I lenses (negative control) were cultured in DMEM alone; Group II lenses were exposed to sodium selenite alone (100μM); Group III lenses were exposed simultaneously to sodium selenite and the T. divaricata extract (250μg/ml); Group IV lenses were exposed simultaneously to sodium selenite and the biosynthesized AgNPs (125μg/ml); and Group V lenses were exposed to the AgNPs alone. In these lenses, gross morphological changes, as well as activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), and levels of reduced glutathione (GSH) and malondialdehyde (MDA), were determined. In-vitro, the AgNPs (which were spherical in shape with an average diameter ranging from 15 to 50nm) showed potent and concentration-dependent radical-scavenging activity on DPPH and H₂O₂ free radicals as well as reducing power. The gross morphological changes seen in the cultured rat lenses were: all eight control (Group I) lenses remained transparent; dense opacification was noted in all eight selenite-challenged untreated (Group II) lenses; in selenite-challenged, simultaneously T. divaricata extract-treated (Group III) lenses, no opacification occurred in seven of eight (87.5%) lenses and only minimal opacification in one (12.5%) lens; all the eight Group IV (selenite-challenged, simultaneously AgNPs-treated) lenses did not show any opacification; and all the eight Group V lenses (exposed to AgNPs alone) remained as transparent as control lenses. The mean activities of CAT, SOD, GPx and GST, and the mean levels of GSH, were significantly (p<0.05) lower in Group II lenses than those in Groups I, III, IV and V lenses, while the mean MDA level was significantly (p<0.05) higher in Group II lenses than those in Groups I, III, IV and V lenses; oxidative damage possibly occurred in Group II lenses, whereas this appears to have been prevented in Groups III and IV lenses. These observations suggest that the T. divaricata leaf ethanolic extract, and also the AgNPs biosynthesized using the T. divaricata extract, possess effective in-vitro antioxidant activity and the potential to prevent experimental selenite-induced opacification in cultured Wistar rat lenses.