Calotropis procera (leaves) supplementation exerts curative effects on promoting functional recovery in a mouse model of peripheral nerve injury

MiR-21 regulates skeletal muscle atrophy and fibrosis by targeting TGF-beta/SMAD7-SMAD2/3 signaling pathway

Long-term denervation-induced atrophy and fibrosis of skeletal muscle due to denervation leads to poor recovery of muscle function. Studies have shown that the transforming growth factor-β1 (TGF-β1)-Smad signaling pathway plays a central role in muscle atrophy and fibrosis. Recent studies demonstrate the role of microRNAs (miRs) in various pathological conditions, including muscle regeneration. miR-21 has been shown to play a dynamic role in inflammatory responses and in accelerating injury responses to fibrosis. We used both RNA sequencing and quantitative RT-PCR strategies to examine the alternations of miRNAs during denervation-induced gastrocnemius muscle atrophy and fibrosis. Our data showed that MiR-21 was upregulated in denervated gastrocnemius muscle tissue, and TGF-β1treatment increased miR-21 expression. Inhibition of miR-21 reduced gastrocnemius muscle fibrosis and significantly downregulated the expression of p-SMAD2/3 and the fibrosis-associated markers TGF-β1, connective tissue growth factor, alpha smooth muscle actin. Masson's trichrome staining revealed that atrophy and fibrosis in gastrocnemius muscle tissue were reduced in the miR-21 inhibition group compared to the control group. We confirmed that SMAD7 is a direct target of miR-21 using a dual luciferase assay. Furthermore, Immunofluorescence and Western blot analyses revealed that miR-21 inhibition reduced SMAD2/3 phosphorylation and nuclear translocation. While SMAD7-siRNA abolished the effect. Consequently, the discovery that miR-21 regulates the atrophy and fibrosis of the gastrocnemius muscle offers a possible therapeutic approach for their management.

Mitigation of sciatica injury-induced neuropathic pain through active metabolites derived from medicinal plants

Sciatica characterized by irritation, inflammation, and compression of the lower back nerve, is considered one of the most common back ailments globally. Currently, the therapeutic regimens for sciatica are experiencing a paradigm shift from the conventional pharmacological approach toward exploring potent phytochemicals from medicinal plants. There is a dire need to identify novel phytochemicals with anti-neuropathic potential. This review aimed to identify the potent phytochemicals from diverse medicinal plants capable of alleviating neuropathic pain associated with sciatica. This review describes the pathophysiology of sciatic nerve pain, its cellular mechanisms, and the pharmacological potential of various plants and phytochemicals using animal-based models of sciatic nerve injury-induced pain. Extensive searches across databases such as Medline, PubMed, Web of Science, Scopus, ScienceDirect, and Google Scholar were conducted. The findings highlights 39 families including Lamiaceae, Asteraceae, Fabaceae, and Apocyanaceae and Cucurbitaceae, effectively treating sciatic nerve injury-induced pain. Flavonoids made up 53% constituents, phenols and terpenoids made up 15%, alkaloids made up 13%, and glycosides made up 6% to be used in neuorpathic pain. Phytochemicals derived from various medicinal plants can serve as potential therapeutic targets for both acute and chronic sciatic injury-induced neuropathic pain.

Comparative evaluation of ethyl acetate and n-Hexane extracts of Cannabis sativa L. leaves for muscle function restoration after peripheral nerve lesion

Peripheral nerve injuries are one of those complex medical conditions for which a highly effective first-line treatment is currently missing. The use of natural compound as medicines to treat various disorders has a long history. Our previous research explored that crude Cannabis sativa L. accelerated the recovery of sensorimotor functions following nerve injury. The purpose of the current study was to investigate the effects of n-Hexane and ethyl acetate extracts of C. sativa L. leaves on the muscle function restoration in a mouse model after sciatic nerve injury. For this purpose, albino mice (n = 18) were equally divided into control and two treatment groups. The control group was fed on a plain diet while treatment groups were given a diet having n-Hexane (treatment 1) and ethyl acetate (treatment 2) extracts of C. sativa L. (10 mg/kg body weight), respectively. The hot plate test (M = 15.61, SD = 2.61, p = .001), grip strength (M = 68.32, SD = 3.22, p < .001), and sciatic functional index (SFI) (M = 11.59, SD = 6.54, p = .012) assessment indicated significant amelioration in treatment 1 as compared to treatment 2 group. Furthermore, muscle fiber cross-sectional area revealed a noticeable improvement (M = 182,319, SD = 35.80, p = .013) in treatment 1 while muscle mass ratio of Gastrocnemius (M = 0.64, SD = 0.08, p = .427) and Tibialis anterior (M = 0.57, SD = 0.04, p = .209) indicated nonsignificant change. A prominent increase in total antioxidant capacity (TAC) (M = 3.76, SD = 0.38, p < .001) and momentous decrease in total oxidant status (TOS) (M = 11.28, SD = 5.71, p < .001) along with blood glucose level indicated significant difference (M = 105.5, SD = 9.12, p < 0.001) in treatment 1 group. These results suggest that treatment 1 has the ability to speed up functional recovery after a peripheral nerve lesion. Further research is necessary, nevertheless, to better understand the extract's actual curative properties and the mechanisms that improve functional restoration.

Axonal Regeneration: Underlying Molecular Mechanisms and Potential Therapeutic Targets

Axons in the peripheral nervous system have the ability to repair themselves after damage, whereas axons in the central nervous system are unable to do so. A common and important characteristic of damage to the spinal cord, brain, and peripheral nerves is the disruption of axonal regrowth. Interestingly, intrinsic growth factors play a significant role in the axonal regeneration of injured nerves. Various factors such as proteomic profile, microtubule stability, ribosomal location, and signalling pathways mark a line between the central and peripheral axons' capacity for self-renewal. Unfortunately, glial scar development, myelin-associated inhibitor molecules, lack of neurotrophic factors, and inflammatory reactions are among the factors that restrict axonal regeneration. Molecular pathways such as cAMP, MAPK, JAK/STAT, ATF3/CREB, BMP/SMAD, AKT/mTORC1/p70S6K, PI3K/AKT, GSK-3β/CLASP, BDNF/Trk, Ras/ERK, integrin/FAK, RhoA/ROCK/LIMK, and POSTN/integrin are activated after nerve injury and are considered significant players in axonal regeneration. In addition to the aforementioned pathways, growth factors, microRNAs, and astrocytes are also commendable participants in regeneration. In this review, we discuss the detailed mechanism of each pathway along with key players that can be potentially valuable targets to help achieve quick axonal healing. We also identify the prospective targets that could help close knowledge gaps in the molecular pathways underlying regeneration and shed light on the creation of more powerful strategies to encourage axonal regeneration after nervous system injury.